Branches Volume VI - Winter 2016

BRANCHES McGill Undergraduate Environment Journal Volume VI - Winter 2016

BRANCHES McGill Undergraduate Environment Journal

VOLUME 6 Winter 2016

McGill University Montreal, Canada BRANCHES acknowledges that McGill is situated on traditional Haudenosaunee Territory

Acknowledgements Copyright 2016 © Branches: The McGill Undergraduate Environment Journal, McGill University, Montreal, Canada.

Editorial selection, compilation and material © by the Editorial Board of Branches and its contributors.

Branches is an academic journal of McGill University with submissions by students.

Printed and bound in Canada by Solutions Rubiks Inc. All rights reserved. Except for brief passages quoted and cited from external authors, no part of this book may be reprinted or reproduced or utilized in any way of form without the permission in writing from the publisher.

Special thanks to the Arts Undergraduate Society of McGill University and the McGill Environment Students’ Society for enabling the publication of this journal.

Cover photo by Sophie Kronk

BRANCHES McGill Undergraduate Environment Journal

EDITORS IN CHIEF Elena Kennedy Nessa Ghassemi-Bakhtiari

UNDERGRADUATE EDITORS Dassyn Barris Reine Donnestad Lydia Kaprelian John Lindsay Sevrenne Sheppard Emma Sutherland Joseph Yang

DESIGN EDITOR Brayden Culligan

For more Branches, visit our website: mcgillbranches.tumblr.com

LETTER FROM THE EDITORS-IN-CHIEF

We’re very excited to share the sixth edition of Branches with you. As recent graduates of the MSE, we both wanted to ensure that students continued to have a space to share their work on environmental issues. Sharing knowledge and perspectives is essential to our post-MSE pursuits.

The underlying theme of this edition is ‘Where do we go from here?’ The multi-faceted reality of environmental change and degradation is uncontested. Setting the tone, the poem at the outset of this edition provides a beautifully morose illustration of the effects of overconsumption. We hope that this collection of work can provide some insights on how we, as members of the McGill community and beyond, can move forward. One author suggests improvements within the McGill School of Environment curriculum, which would expand students’ awareness of indigenous knowledge. Our second paper analyses the threats that climate change poses to turtle populations – knowledge that is essential to protecting this important species. Next, our editorial discusses the insights that Environment students can gain from an immersive field project, and offers advice to help them integrate that fresh perspective back home. Our fourth paper explores how recent innovations in solar cell technology will facilitate the transition to a more sustainable economy. Finally, a study of the Chilibre Chilibrillo Cave and its bats illustrates how baseline data can initiate local conservation measures to protect crucial ecosystems.

Knowledge can be expanded and shared in a diversity of ways, from empirical research to artistic research and interpretation. With this in mind, this year we sought to publish an equal number of what is conventionally considered to be academic and non-academic work. Going forward, we hope that Branches will expand this unique quality by accepting a wider variety of creative work. Throughout this edition, you will find photographic interpretations of the environment, which we hope will dazzle your aesthetic senses and ignite your imagination.

A special thanks goes out to each member of our editorial team. Their dedication and critical eyes created the driving forces behind the publication of this wonderful collection of quality work. We also wish to thank the contributors, who collaborated with us throughout the entire process.

On behalf of the Branches editorial board, Bonne lecture!

Elena Friederike Kennedy & Nessa Ghassemi-Bakhtiari Editors-in-Chief

TABLE OF CONTENTS Coughing Clouds

1

Decolonizing the Environment

5

Daniel Galef

Francesca Humi

It’s Getting Hot in Here: an essay on

12

Stories from the Edge of the Turtle’s Shell

19

Innovations in Photovoltaics and Solar Cells

29

Environmental Evaluation of the Chilibre Chilibrillo Cave

39

Moments in the Andean Highlands

49

About the Contributors

51

About the Editors

53

temperature dependent sex determination and development in sea turtles Jessica Ford

Sevrenne Sheppard

Benjamin Zank

Munib Khanyari & Alexandre Dallaire

Sophie Kronk

Coughing Clouds

The factory looms near and large, its gargantuan gantries a gunmetal gray.

Its snowy ash in the stratosphere has stolen the stars away.

1

When in the winter whiteness falls it descends as a blanket of ashen snow and the sea and the mountains are dishwater white — where did the constellations go?

- Daniel W. Galef

2

3

Flowers growing on the flanks of the Chimborazo Volcano Photo by Sophie Kronk

4

Decolonizing the Environment An Opinion Essay by Francesca Humi In recent years, acknowledgment of the need for inclusion of Indigenous voices and narratives in popular political, social, and economic discourse has gained momentum in Canada, particularly within post-secondary educational institutions.

This coincides with processes and events like the Truth and Reconciliation Commission, Prime Minister Harper’s apology in 2008, the Idle No More movement – an Indigenous grassroots movement mobilising to “help build sovereignty and resurgence of nationhood” (Idle No More, n.d.), and the overall better inclusion of historically marginalised voices in dominant academic and media discourse (Hanson 2009). The creation of the Minor Concentration in Indigenous Studies (MCIS) at McGill University in 2014 is an example of this phenomenon. This piece was written for INDG 200, the introduction course to Indigenous studies, taught

by Professor Allan Downey, the only tenured Indigenous professor at McGill. The purpose of the essay was to critically examine our own field of study. As a non-Indigenous female student of colour, I found it was important to reflect on my position as a settler in Montreal, and to question the way my academic concentration was being presented to me. Currently, questions are being asked on how to include Indigenous worldviews in the current system of education, how we can “Indigenise” it, how we can decolonise our institutions. The discussion focuses on the field of Environment, as taught at by the School of Environment at McGill Univer-

5

sity. Therefore, the aim of this exercise will be to look critically at the current program requirements and course material being taught in undergraduate classes. First, the colonial legacy of McGill as an institution, and ongoing colonial narratives in course material will be assessed. Second, methods to delegitimize colonial discourse, and decolonize narratives within the context of a post-secondary institution will be explored. Finally, outcomes from applied methods of decolonization will be reviewed.

Founded by James McGill, a Scottish settler and owner of enslaved Black and Indigenous bodies, McGill University has a significant colonial history. McGill’s downtown campus is located on the territory of the Kanien’kehá:ka, as marked by the Hochelaga Rock, which stands just West of Roddick Gates in memory of the original inhabitants of Tiohtiá:ke (Montreal), whose remains were discovered during the development of McGill’s campus in 1860 (SEDE, 2016). At the beginning of the Fall semester, the University was delivered a notice of seizure from the women titleholders of Kahnawake Mohawk community, stating that McGill is illegally occupying their land without permission, and is refusing to pay back its debt to the community (Mohawk Nation News, 2015). This legacy must be acknowledged in order to begin a process of decolonisation. It is also important to acknowledge that colonisation is an on-going process, imbedded in the institutional structures of

government and the public sector, which continue to reinforce systems of power that seek to assimilate and disempower indigenous peoples. Post-secondary students are uniquely situated in a position of privilege, which may be used to push for change to current educational structure and discourse in order to delegitimize oppressive systems of power.

Within the McGill School of Environment, the absence of indigenous narratives is concerning, given the geographic and political space McGill occupies, and the nature of environmental studies, which deal directly with environmental protection and management. For example, the course “Knowledge, Ethics and Environment”, a required course for all students in a School of Environment degree program, gives a history of environmental ethics and thought. Often, narratives of conservation in North America are portrayed as being developed by white male settlers. John Muir, for example, is credited as the founder of holism and the first advocate for the creation of wilderness parks. The park in question is Yosemite, which is described as the pristine and untouched wilderness. Muir encourages Americans to seek in wild nature rebirth, reflection, and spirituality. The presence of Indigenous people in such “wild” and “untouched” places is completely ignored both in the reading and the lectures. There is no acknowledgement that the current North American landscapes and ecosystems are the result of thousands of years of Indigenous interactions with the environment (Belanger 2014, 8, 31). Furthermore, this language surrounding preservation and conservation is chillingly similar to that of the “Terra Nullius” policy used by colonial forces to justify occupation of

the land. The method and language employed by these thinkers are filled with colonial heritage: this piece of land is beautiful and empty, and we must protect it from any human intervention. Underlying this type of view is also the assumption that all humans live in inherent disharmony with the environment because of enterprise and economic activity. All humans are necessarily abusive towards the environment, and progress and modernity are portrayed as an escape from the state of chaotic nature (Belanger 2014, 29). This is, of course, very Eurocentric: in the current Western system of capitalism, destruction of the environment seems inevitable. However, not all societies operate, or have operated, under a capitalist system: many records of (pre-contact) Indigenous societies say otherwise, e.g. the Haudenosaunee political economy, as described by Belanger (2014, 45-47), which encourages equal distribution of resources and minimisation of food wastage through trade.

In Indigenous culture, there is an overarching notion of holism, as illustrated in creation stories like the Seneca Creation Story (Swann 2004), where humans are an integral part of the Earth. Human life is owed to animal and plant life, and the animals serve a purpose to the people: “human beings were the last to emerge in the order of creation, and they are the most dependent of all creatures on the sacrifice of plant and animal life for their survival” (Collections Canada 2007). Other (oral) stories make parallels between human societies and animal societies, like in “The Boy and the Loon” (Normandin 1997), which contrasts the Western view of separation between humans and the rest of the world. Unfortunately, all of these stories and worldviews are silenced in the current teaching of environment. This alienates

6

Indigenous students, knowledge, and culture from the academia. This is also detrimental to environmental studies, as students will not challenge the mainstream capitalist notion of human destruction of nature in this way, meaning no radical change can be made.

Indigenous societies and perspectives are not always ignored: they are also romanticised with the trope of the “noble savage” (Belanger 2014, 8-9). This is a recurrent stereotype, presenting the “Indian Savage” as wise, sentimentally attached to land and primitive, as seen in mainstream media in films like “Pocahontas”, “The Lone Ranger” and “Dances with Wolves.” The issue with this trope is that it automatically puts Indigenous culture in the past, no longer relevant to today, when on the contrary, inclusion of Indigenous worldviews can be greatly beneficial to environmental studies. Indigenous knowledge and history have been systematically put in the past or dismissed as myths and legends by Euro-Canadians, as Louis Bird explains: “I always heard somebody say, ‘The legends are fantasies, they are fiction, they are fables, they are fairy tales.’

And this is where most of the Europeans or the Westernized people have classified them” (Bird 2003, 13). This is problematic, because these oral stories offer considerable knowledge on the environment, which each society interacts with (Hanson 2009). This knowledge is intricate and has the specificity of developing over thousands of years through direct experience.

To dismiss it is to ignore deep knowledge of North American ecosystems. It seems problematic for environmental studies not to better incorporate Indigenous knowledge within its curriculum, a key towards understanding ecosystems in colonised

7

North America. For instance, Indigenous knowledge would broaden the instructed concept of environmental management by offering the lived Indigenous experiences of the environment to compliment Western scientific knowledge (for a North American context) and changing the narrative from the environment as something to be managed, to the environment as something to live within.

So how do we equip post-secondary institutions and instructors to integrate indigenous knowledge and histories into their courses? One solution would be to require all undergraduate students in an Environment program to take a foundational indigenous studies course, or mandate that a dedicated section of core courses such as “Knowledge, Ethics, and Environment” must focus on indigenous narratives. The key is to include indigenous discourses as more than just an alternative view. This inclusion has the potential to give students the tools to frame and imagine environmental issues from different angles, and think radically in the most literal sense of the word – looing critically at the roots of our current predicaments in order to imagine possible solutions. This would not be contrary to environmental studies, as the conservation and/or preservation of the environment has radical implications: fundamentally changing the way we produce, consume, and interact to protect the environment. The inclusion of Indigenous narratives could also bridge into consideration of other “radical” perspectives through which to think about the field of Environment, such as feminist theory, queer or critical race theories. These tools for critique are not always centrally featured in environmental studies, but contribute to a more comprehensive under-

standing of environmental justice issues, especially when it comes to access to land and resources.

Accessibility of indigenous knowledge and narratives must also be challenged. The particularized format of academia limits the access and transmission of knowledge such as oral histories, which may offer important insights. Louis Bird, a Omushkego (Swampy Cree) storyteller and elder, is critical of the institution of academia, as he has faced issues with such regulations. Having never “attended the white man education properly” (Bird 2003, 12), Bird was unable to write down Cree oral histories prior to the oral history project – an Omushkego initative to create digital archive and recordings of Swampy Cree teachings in English and Cree (Our Voices, 2016). Legitimization of oral histories in academia makes sense: we are constantly taught that the environment and the Earth are dynamic systems sensitive to even minor changes, similar to Indigenous stories: “that is a good thing about the Indian legends. They were not written. They could not be written, because if you have to write it down, you restrict its flexibility” (Bird 2003, 5). These stories are very much alive, as is our natural environment. “[Another] important element in Aboriginal oral histories is the role the landscape plays by connecting oral histories to lived experiences,” writes Hanson, highlighting an important difference to written history, as it does not easily offer dialogue (Hanson 2009). We must also challenge the assumption that written history or knowledge is unbiased, which, of course, is false: any knowledge is necessarily influenced by the author’s background and life story, and offering Indigenous knowledge as another source can only create a more

comprehensive account of environmental knowledge and problems for a student.

Accessibility and legitimacy of this material in academia is an initial step towards Indigenisation.

Other symbolic ways of decolonizing education are compulsory land acknowledgements in-class, on course syllabi, or at official McGill ceremonies as a way of recognizing the traditional custodians of the land, acknowledging the continual process of colonisation, and stimulating conversations about colonisation and embedded racism at McGill and in university education systems.

Within environmental studies, it is also particularly relevant to recognize indigenous perspectives in consideration of the disproportionate effect environmental predicaments have on indigenous communities. If McGill is hoping to shape the future leaders of the world, this program is ineffective, in so far as it does not instil a systematic inclusion of the interests of the people being most affected by matters like fracking, oil spills, pipelines, global warming, Arctic exploration and exploitation.

There is a tendency to think that Arctic Canada is “for the taking” and that pipelines can go over empty land, not directly affecting Canadian or American population. Actual populations’ needs are being ignored, which is why classes like INDG 200 should be mandatory for all Environment students, even those outside of the MCIS program.

Indigenising and decolonising the field of environment would encourage students to think critically about the course material, their views on environmental issues, the context of their educations, and the capi-

8

talist, globalized system within which this is all occurring. Granting students access to Indigenous knowledge resources and appropriate language in discussing indigenous issues can only be beneficial. Working towards decolonisation in post-secondary education will hopefully create a space where all narratives are included, less biased, and inquisitive. Hopefully, it will foster meaningful conversations among students about their position and privilege at McGill. In environment, decolonisation is particularly relevant, because the field does not relate to phenomena that occur in a vacuum. It is has to do with the whole world’s future, and decisions made concerning the protection of the environment must be as inclusive as possible.

However, caution must be exercised: cultural appropriation and generalisation must be avoided, and a discourse of utilitarianism must not be employed. This is perhaps a critique that could be made against the present argument: including Indigenous knowledge necessarily removes it from the source and makes it a tool for discourse. This is why Indigenous knowledge must be taught and learnt on Indigenous terms, not the benefit of a particular cause, but as a means to achieve a specific end.

In conclusion, the study of environment at McGill carries the weight of Canada’s colonial past through the geographic space it occupies, and the material being taught. Indigenous knowledge tends to be either ignored, trivialised as “legends”, or stereotyped as a thing of the past. This could not be further from the truth, as Indigenous knowledge and culture is very much alive in reality. Initiatives as demonstrated by Louis Bird is still relevant to

9

the study of environment – knowledge of ecosystems accumulated over thousands of years gives depth to understanding of an environment that Western science cannot quite achieve. This is due to the Indigenous holistic worldview, where people are an integral part of the “natural world”, interconnected and interdependent on everything else. Incorporating Indigenous knowledge into the environmental studies will hopefully foster conversations about colonisation in the field of environment and at McGill, while promising a more radical examination of current environmental problems. This, of course, all has to happen on Indigenous terms, never letting this knowledge to be appropriated and transformed into something it is not meant to be.

References Belanger, Yale D. 2014. Ways of Knowing: An Introduction to Native Studies in Canada, 2nd Edition.

Toronto: Nelson Education.

Bird, Louis. “Traditional Education,” transcript from recording, 2003. Accessed online January 27, 2015. h t t p : / / w w w. o u r v o i c e s . c a / f i l e s t o r e / pdf/0/0/3/0/0030.pdf Hanson, Eric. 2009. “Oral Traditions.” First Nations Studies Program at UBC. Accessed online January 27, 2015. http://indigenousfoundations.arts.ubc.ca/home/ culture/oral-traditions.html Idle No More. N. d. “The Vision.” Idle No More Website. Accessed online February 21, 2016. http:// www.idlenomore.ca/vision Mohawk Nation News. September 12, 2015. “Mohawk Seizure Notice to McGill.” Mohawk Nation News Website. Accessed online February 22, 2016. http://mohawknationnews.com/ blog/2015/09/12/mohawk-seizure-notice-to-mcgill/

Normandin, Christine, editor. 1997. “The Boy and the Loon,” from Echoes of the Elders: The Stories and Paintings of Chief Lelooska. New York: DK Ink. Accessed online January 28, 2015. h t t p : / / w w w. c o l l e c t i o n s c a n a d a . g c . c a / stories/020020-119.01-e.php?&item_id_ nbr=19&page_sequence_nbr=1&&PHPSESSID=h 5463ih517q3phfmvvef2o6051 Our Voices. 2016. “About Our Voices.” Our Voices Website. Accessed online February 21, 2016. http://www.ourvoices.ca/index/about Royal Commission on Aboriginal Peoples. “Meeting on the Trickster’s Ground.” Volume 1, Part 3, Section 15, No. 4. Accessed online January 27, 2015. http://www.collectionscanada.gc.ca/webarchives/20071211051353/http://www.ainc-inac. gc.ca/ch/rcap/sg/sg53_e.html#153

Swann, Brian. 2004. “Seneca Creation Story,” from Voices from Four Directions: Contemporary Translations of the Native Literatures of North America. Lincoln: University of Nebraska Press, 2004. Accessed online at Collections Canada, January 28, 2015. http://www.collectionscanada. gc.ca/stories/020020-119.01-e.php?&item_id_ nbr=6&page_sequence_nbr=1&&page_id_nbr=34 &&&&&&&&&&PHPSESSID=h5463ih517q3phfm vvef2o6051 Social Equity and Diversity Education (SEDE) Office. 2016. “Hochelaga Rock.” SEDE Website.

Accessed online February 21, 2016. https://www.mcgill.ca/equity_diversity/students/ equity-projects-mcgill/hochelaga-rock

10

Waves in Malibu, California. Long Exposure. Photos by Julia Epstein

11

It’s Getting Hot in Here: an essay on temperature dependent sex determination and development in sea turtles

by Jessica Ford ABSTRACT: Sea turtles are valuable keystone species vital in maintaining a healthy ocean ecosystem. Sea turtles use temperature-dependent sex determination, which means that the temperature of the eggs in the nest during development determine the sex of the embryo. As sea turtles use type Ia temperature dependent sex determination, higher temperatures produce primarily female hatchlings. This trait could pose a problem, as rising temperatures could cause an increase in female hatchlings, which could skew sex ratios in the population to unsustainable levels. Sea turtles have a low population density, thus a reduction in the number of males could result in the majority of females being unable to breed. This would be extremely detrimental to the already declining population. To add to the ongoing stress on the species, hatchlings that develop in warmer temperatures are smaller, slower and weaker than hatchlings that develop in more optimal temperatures. As a result, attempts have been made to develop mitigation strategies. Here, the effectiveness of these strategies are examined, as well as what is currently known about the influence of temperature on the development and sex determination in sea turtles. This research is extremely important in order to understand how to protect sea turtles and their ocean ecosystem in new conditions brought about by climate change.

Introduction The life of a reptile is dictated heavily by temperature, influencing how quickly they can move, how efficiently they can digest their prey, and their ability to escape from predators. As all reptiles are poikilotherms, they regulate their internal temperature through adaptive behavior in relation to environmental factors. However, temperature plays a determinative role at certain points in the life history of some

reptile species, such as embryonic development and sex determination. For these reptiles, sex is determined not by genetics but rather by environmental factors experienced during development, particularly temperature. Three types of temperature dependent sex determination exist in reptiles: type Ia, type Ib and type II. For reptiles with type Ia temperature dependent sex determination, such as sea turtles, females are produced at high temperatures during development (Standora and Spo-

12

tila, 1985). For reptiles with Ib temperature dependent sex determination, such as tuataras, males are produced at high temperatures (Tomillo et al., 2015). Finally, for reptiles with type II temperature dependent sex determination, which includes some lizards, turtles and crocodiles, both the high and low extremes in temperature produce females (Valenzuela, 2004).

peratures associated with global warming have on this family, is important in order to better understand and protect sea turtle populations and their ecosystems in a changing climate.

In the case of sea turtles, their sex is determined by the temperature of the nest during the middle third of development (Standora and Spotila, 1985). Several aspects determine the temperature of the developing embryo, including the depth of the nest, the position of the egg within the nest, the temperature of the beach, the albedo of the beach, the amount of local precipitation, the distance of the nest from the intertidal zone, and the presence of vegetation shading the nest (Girondot and Kaska, 2014; Hill et al., 2015; Wyneken and Lolavar, 2015). Sex is not the only aspect of the embryo that is affected by the temperature of the nest: the size of the hatchling and the success of the clutch are also affected (Sim et al., 2015). However, unlike sex determination, these other characteristics of the embryo can be influenced by temperature at any time during incubation (Sim et al., 2015).

The mechanism underlying temperature dependent sex determination in sea turtles is not currently fully understood, nor is there one guiding theory upon which herpetologists – those who study reptiles and amphibians – agree (Wyneken and Lolavar, 2015). However, the hypothesis that currently has the most supporting evidence involves temperature sensitive enzymes that control the transcription of certain sections of DNA (Standora and Spotila, 1985). Though the temperatures at which the two sexes are produced varies amongst individual sea turtle species, males are generally produced between 24 ̊C and 26 ̊C, females between 28 ̊ C and 31 ̊C, and both males and females can be produced between 26 ̊C and 28 ̊C (Standora and Spolila, 1985). Thus, let us assume that there is a segment of DNA that codes for the development of testicles, and an enzyme that activates the transcription of this segment of DNA. Enzymes have an optimal temperature at which they function best, and beyond this temperature they begin to denature. Now, let us assume that the optimal temperature for this enzyme is between 24 ̊C and 26 ̊C. The enzyme then activates the transcription of the DNA encoding the genes for testicular development, resulting in male embryos.

At temperatures of 28 ̊C to 31 ̊C, the enzyme becomes denatured, and thus does not function properly. This would result in

We are already beginning to see indications that sea turtles are affected by a warming climate both in individual turtles (Ford and Kwong, 2016) and in population dynamics (Wyneken and Lolavar, 2015). Without understanding how these processes work, suitable mitigation strategies cannot be determined or developed.

Thereby, understanding the mechanics by which temperature influences sex in sea turtles, and the effects that rising tem-

13

A possible molecular mechanism for temperature dependent sex determination in sea turtles

the gene responsible for testicular development to remain inactivated, resulting in female embryos. At temperatures between 26 ̊C and 28 ̊C, some of the enzyme may have denatured in some embryos, but still be active in others, resulting in a mix of male and female embryos (Standora and Spotila, 1985). At temperatures below 24 ̊C and above 31 ̊C, most sea turtle embryos will not develop (Standora and Spotila, 1985). Alternatively, instead of using enzymes, sea turtle embryos could develop with an indifferent gonad, acted upon by temperature sensitive hormones following a similar mechanism (Standora and Spotila, 1985).

Possible evolutionary benefits of temperature dependent sex determination in sea turtles While the reasons behind the prevalence of temperature dependent sex determination in many species remains unclear, certain aspects could make temperature dependent sex determination evolutionarily advantageous (Shine, 1999). One possible advantage of temperature dependent sex determination is inbreeding avoidance: if a single clutch is effectively all the same sex, then that clutch cannot interbreed (Shine, 1999). Another possible evolutionary advantage pertains to species where high temperatures are not only associated with the production of females, but also the increased mortality in hatchlings (Tomillo, 2015). In the case of sea turtles nesting and developing at temperatures above 31 ̊C, the mortality of hatchlings increases dramatically, and the remaining hatchlings are all female (Standora and Spotila, 1985). The increase in the amount of females increases the fecundity (reproductive rate) of the popula-

tion, which is thought to counteract to loss of offspring due to increased temperature, and help the population recover (Tomillo, 2015). This adaption is thought to offer some resistance to rising temperatures in species with type Ia and type II temperature dependent sex determination, but may not be able to withstand the increased temperatures predicted in association with climate change if sex ratios within the population become unstable (Tomillo, 2015).

Climate change creating challenges for sea turtles Fluctuation in precipitation, rising sea levels and warming temperatures associated with climate change all threaten sea turtle nests and their nesting sites (Wyneken and Lolavar, 2015). If conditions are too dry, there is the possibility that the sea turtle eggs could dry out and the embryos perish (Hill et al., 2015). At the other extreme, too much rain or an increased high water mark due to tide increase could cause the developing embryos to drown (Hill et al., 2015). A sea level rise could eliminate a nesting beach entirely, leaving nowhere for the turtles to lay their eggs (Wyneken and Lolavar, 2015). Furthermore, if conditions are consistently too hot (typically above 34 ̊C), or too cold (below 24 ̊C), then the sea turtle eggs fail to hatch, and the embryos die (Blanck et al., 1981).

Even if the eggs do develop to completion, hot, dry conditions could lead to 100% female hatchlings in sea turtles (Wyneken and Lolavar, 2015). If sea turtle populations were composed entirely of females, then the potential evolutionary advantage provided by temperature dependent sex determination described above becomes

14

a hindrance. If there are no males in the population, then no matter how many females there are, the population will not recover because sea turtles are sexual organisms, requiring both females and males to reproduce.

Another issue arising due to increased temperatures in sea turtle nests extends beyond the sex of the hatchling. Temperature also plays a role in the morphological development of the hatchling, and their chances of survival as individuals (Sim et al., 2015). Temperature determines the incubation time of sea turtle nests, with warmer temperatures leading to shorter incubation times (Mrosovsky and Yntema, 1980). Sea turtles that have a shorter incubation time emerge as smaller hatchlings with a large residual yolk sac that is not fully absorbed and formed into muscle tissue (Reece et al., 2002; Sim et al., 2015).

These smaller hatchlings may be more susceptible to predation both on shore and in the sea (Gyuris, 1994; Gyuris, 2000; Burgess et al., 2006). Smaller hatchlings may be more likely to get eaten on their way to the sea, as they are both smaller in size, making them easier to eat by a larger range of predators, and move slower over the sand, producing less thrust with their front flippers (Gyuris, 2000; Sim et al., 2015). Once in the water, smaller sea turtles from shorter durations of incubation are less effective swimmers, producing less thrust in the water, and have less coordinated muscle movement compared to larger hatchlings which incubated for longer period of time (Sim et al., 2015). This could make the small hatchlings easy prey for a variety of predators, as they are both smaller and easier to catch (Burgess et. al., 2006; Gyuris, 1994). Thereby, sea turtles that developed at higher temperatures

15

have a lower hatchling success rate than those that develop at lower temperatures and incubate for longer (Sim et al., 2015).

Combined with the possibility of an all female population of sea turtles, slower, weaker, smaller hatchlings are a cause for concern for sea turtle populations in a warming climate.

Possible mitigation strategies Despite the aforementioned challenges presented to sea turtles due to climate change, certain studies suggest that sea turtles could have some resistance to increased temperatures, and that possible mitigation strategies could be effective in helping the population continue to produce both sexes. For instance, the sex of sea turtle hatchlings may be affected by environmental conditions other than temperature, such as moisture (Wyneken and Lolavar, 2015). Experiments have found that male hatchlings can develop even above the temperature threshold for all female development if the environment in which they develop is moist enough (Wyneken and Lolavar, 2015). For instance, the threshold temperature beyond which the hatchlings should all be female for loggerhead sea turtles (Caretta caretta) is 29 ĚŠC. However, when incubated in the lab at temperatures of 29.4 ĚŠC and 30.4 ĚŠC in moist conditions, the clutch produced both male and female hatchlings (Wyneken and Lolavar, 2015). As well, in samples of hatchlings in natural conditions taken over 10 years, all years were female biased, but the years that had especially high rainfall produced mixed sexes of sea turtle offspring, while years that were especially hot produced all female offspring (Wyneken and Lolavar, 2015). This is not just an artifact of rainfall creating cooler tempera-

tures; as when high moisture conditions were applied in the lab, the temperature was maintained above the threshold for producing all females, yet the clutch still produced hatchlings of both sexes. (Wyneken and Lolavar, 2015). This suggests that perhaps the threshold temperature for Caretta caretta is higher than previously assumed, or, perhaps more likely, that both temperature and moisture play a role in determining the sex of sea turtles (Wyneken and Lolavar, 2015).

Other studies argue that the potential resilience to rising temperatures conferred by increased precipitation rates, also associated with climate change, is not enough to counteract the predicted rise in temperature (Tomillo et al., 2015). Temperatures of 31.4 ĚŠC, even when combined with high moisture conditions, still produced all female hatchlings (Wyneken and Lolavar, 2015). Thus, if the temperature exceeds this threshold, then increased precipitation will not be effective in maintaining viable sex ratios. Further concerns arise in areas where sea turtle nests are not expected to receive higher levels of precipitation.

In fact, some are predicted to receive more droughts, increasing the potential for all female hatchlings, less successful hatchlings, and the threat of sea turtle extinction (Hill et al., 2015).

In lieu of this, several mitigation practices have been attempted to try and ameliorate the effect of warming temperatures on sea turtles. Nest watering was attempted at the Playa Grande hatchery in Costa Rica, with the hopes that the water could cool the sand and increase the moisture of the nest, leading to some male hatchlings (Hill et al., 2015). Results proved the process ineffective, as the effect of the water varied

with nest depth, with deeper nests being less effective, and within ten days after the end of the treatment, the nests returned to their original temperatures (Hill et al., 2015). It is important to note that the depth of the nest affects the level at which the eggs are effected by fluctuations in temperature. The deeper the nest, the less the nest temperature will fluctuate with air temperature, because depth has a buffering effect on temperature fluctuation (Hill et al., 2015). For instance, experiments have shown that although throughout the day air temperatures can vary widely, the nest temperature buried 45 cm in the sand fluctuated very little, and the temperature of a nest buried at 70 cm fluctuated even less (Hill et al., 2015). It has therefore been suggested that air temperature is not a good proxy for nest temperature when estimating nest temperatures in prior seasons from meteorological data (Girondot and Kaska, 2014). A more accurate proxy may be to use the temperature of the sea to estimate the temperature of the nest, as it has been found that sea temperature contributes more to nest temperature than air temperature (Girondot and Kaska, 2014). Dangers also exist associated with watering the sea turtle nests, such as accidently drowning the embryos (Hill et al., 2015). Thus, shading proved to be a better strategy for cooling the nests and producing male hatchlings, as it reduced the amount of solar radiation that hit the nest, and kept the sand cooler (Hill et al., 2015; Girondot and Kaska, 2014). Thus, increased vegetation on beaches may be an effective strategy to mitigate the effect of climate change on sea turtle nests, and may also serve beneficial to surrounding ecosystems by acting as habitat cover or a carbon sink, and even reducing beach erosion (Wood et al., 2014; Alves et al., 2009).

16

Conclusion The studies included in this paper agree that temperature has an effect on the sex of sea turtles, with very high temperatures producing solely female hatchlings. It is also agreed that temperature influences morphological changes that may threaten the viability of the embryo and the survival of the hatchlings. Some disagreement arises as to whether moisture offers resilience to rising temperatures, with some saying that moisture can produce male hatchlings even at high temperatures (Wyneken and Lolavar, 2015), and others arguing that this resistance fails at temperatures above 31oC (Tomillo et al., 2015).

However, the molecular mechanism of temperature dependent sex determination in sea turtles is currently unknown, making it a challenge to develop suitable mitigation strategies; creating a need for further research. The possible consequences of a skewed population of sea turtles with a female bias, and the effects of smaller sea turtles on the ecosystem, need to be studied as well in order to assess the need and use of successful mitigation strategies.

Sea turtles are important organisms that are necessary to maintain a healthy, balanced ecosystem (Wilson et al., n.d.).

Disturbingly, climate change and rising temperatures are not the only phenomena that threaten the survival of this species.

Human induced stresses such as fishing bycatch, habitat loss and poaching also contribute to the stress on sea turtle populations. Unfortunately, mitigation strategies surrounding climate change will not prove effective in increasing sea turtle numbers while these stresses are in place (Spotila 2011). Sea turtles are vital components of the ocean ecosystem and help keep jellyfish populations in check (Wilson

17

et al., n.d.) and keep our fisheries abundant (Jackson 2001). The more we know about this valuable keystone species, the better we can protect it.

References Alves F, Rowbeling P, Pinto P, Batista P. (2009). Valuing ecosystem service losses from coastal erosion using a benefits transfer approach: a case study for the central Portuguese coast. Journal of Coastal Research, 56, 1169-1173.

Blanck CE, Sawyer RH. (1981). Hatchery practices in relation to early embryology of the loggerhead sea turtle, Caretta caretta (Linne). J. Exp. Mar. Biol.

Ecol, 49, 163-177.

Burgess EA, Booth DT, Lanyon JM. (2006). Swimming performance of hatchling green sea turtles is affected by incubation temperature. Coral Reefs, 25, 341-349.

Ford J, Kwong K. (2016). Population sizes aren’t the only thing that’s shrinking: decreases in the size of the skulls of Caretta caretta and Chelonia mydas.

Behind the Roddick Gates (Redpath Museum Research Journal), 4, 40-47.

Girondot M, Kaska Y. (2014). Nest temperature in a loggerhead nesting beach in Turkey is more determined by sea surface than air temperature. Journal of thermal Biology, 47, 13-18.

Gyuris E. (1994). The rate of predation by fishes on hatchlings of the green sea turtle (Chelonia mydas).

Coral Reefs, 13, 137-144.

Gyuris E. (2000). The relationship between body size and predation rates on hatchling of the green turtle (Chelonia mydas): is bigger better? Sea Turtles of the Indo-Pacific: Research, Management and Conservation, 143-147.

Hill JE, Paladino FV, Spotila JR, Tomillo PS. (2015).

Shading and Watering as a Tool to Mitigate the Impacts of Climate Change in Sea Turtle Nests.

PLoS ONE,10(6), e0129528 doi:10.1371/journal. pone.0129528 Jackson J. (2001). What was natural in the coastal oceans? The National Academy of Sciences [Internet], 98(10), 5411–5418. Available from: http:// www.pnas.org/content/98/10/5411.full Mrosovsky N, Yntema CL. (1980). Temperature dependence of sexual differentiation in sea turtles: im-

plications for conservation practices. Biol. Conservation, 18, 217-280.

Reece SE, Broderick AC, Godley BJ, West SA. (2002). The effects of incubation environment, sex and pedigree on the hatchling phenotype in a natural population of loggerhead turtles. Evol. Ecol. Res, 4, 737-748.

Shine R. (1999). Why is sex determined by nest temperature in many reptiles? Tree, 14, 186–189.

Sim EL, Booth DT, Limpus CJ. (2015). Incubation temperature, morphology and preformace in loggerhead (Caretta caretta) turtle hatchlings from Mon Repos Queensland, Australia. The Company of Biologist, 4, 685-692. doi:10.1242/bio.20148995 Spotila JR. (2011). Saving Sea Turtles: Extraordinary Stories from the Battle Against Extinction. Baltimore (MD): Johns Hopkins University Press.

Standora EA, Spotila JR. (1985). Temperature Dependent Sex Determination in Sea Turtles. Copeia, 3, 711- 722.

Tomillo PS, Genovart M, Paladino FV, Spotila JR, Oro D. (2015). Climate change overruns resilience

conferred by temperature-dependent sex determination in sea turtles and threatens their survival. Global Change Biology, 21, 2980-2988.

Valenzuela N. (2004). Temperature-dependent sex determination. Reptilian Incubation. Environment, Evolution and Behaviour (ed. Deeming DC). 211227.

Wilson EG, Miller KL, Allison D, Magliocca M. n.d.

Why healthy oceans need sea turtles: the importance of sea turtles to marine ecosystems [Internet].

Oceana. Available from: http://oceana.org/sites/ default/files/reports/Why_Healthy_Oceans_Need_ Sea_Turtles.pdf Wood A, Booth DT, Limpus CJ. (2014). Sun exposure, nest temperature and loggerhead turtle hatchlings: Implications for beach shading management strategies at sea turtle rookeries. J. Expl. Mar. Biol, 451, 105-114.

Wyneken J, Lolavar A. (2015). Loggerhead sea turtle environmental sex determination: Implications of moisture and temperature for climate change based predictions for species survival. J. Exp. Zool. (Mol. Dev. Evol.), 323B, 295–314.

18

Stories from the Turtle’s Shell Sevrenne Sheppard Photos by Kate Hanly

19

Edge of the

20

Covered in temperate rainforest and surrounded by rich ocean ecosystems, Haida Gwaii is a remote archipelago off the Northwestern coast of British Columbia. Home to the Haida people for time immemorial, the islands are well situated for learning about natural resource management, sustainable economies, and reconciliation in the context of Haida Gwaii’s vibrant social and ecological systems. Each semester, a cohort of students from universities across Canada come to Haida Gwaii to learn about natural resource management, sustainable economies, and reconciliation. This semester program takes a place-based approach to learning, working in partnership with island communities to ground classroom learning with living case studies and local knowledge. Through learning together, we are re-imagining the role that postsecondary institutions have in local communities.

Haida Gwaii has long been characterized by an ever changing environment: rising sea levels, establishment of culturally significant cedar trees, fluxes in salmon stocks. For millennia, the Haida people have lived in an intimate and balanced relationship with the lands of Haida Gwaii, constantly adapting to changes in the natural environment.

21

This relationship has been challenged over the past two hundred years following colonial contact. In the late 1800’s, a devastating smallpox outbreak reduced the Haida population from 25000 to 600. As a result, survivors of the smallpox epidemic became concentrated in two (out of over a hundred) villages, Old Masset and Skidegate. The islands thereby became vulnerable to aggressive industrial development, resource extraction, and cultural oppression by settlers and the Canadian government.

Throughout the twentieth century, extractive industry on Haida Gwaii gathered momentum, leading to increasing concern for sustainability and environmental governance. In the 1970s, conflict over the logging of Athilii Gwaay (Lyell Island) culminated in the creation of Gwaii Haanas (meaning ‘Islands of Wonder’) National Park Reserve and Haida Heritage Site, and the signing of a co-management agreement between the Haida Nation and Government of Canada. Because the forestry industry on Haida Gwaii was unsustainable, the Haida Gwaii Land Use Plan was introduced to protect 50% of islands’ land base, followed by the initiation of a marine use planning process.

22

These developments in environmental governance represent a re-imagining of relationships between communities on Haida Gwaii, and a significant shift in power structures, institutions, and channels for decision-making. Today, Haida Gwaii remains a place unique in its ecological, spiritual and social characteristics, where people are committed to ensuring the long-term social and material sustainability of the islands’ environment and communities The motto of the Haida Gwaii semester program, “Sk’aadGa Gud ad is”, means “Learning Together”, or “Learning Balance”. This expression reflects the exchange of knowledge and experience that takes place between students, instructors, and the community. Learning balance also references a mandate to provide a broad and balanced perspective on the complex issues involved in resource management and reconciliation between Canadians and Indigenous peoples.

Woven through the semester program is the relationship between ‘Learning Together’ and building vibrant, resilient communities. Students in the program take part in five courses coordinated by the University of British Columbia. Each course contributes a unique dimension to a broader understanding of resource management and community development.

The History and Politics of Resource Management asks: what are the stories we tell about the land, particularly about forests? How are these stories told? Whose histories and perspectives are included or excluded?

A course in First Nations governance and reconciliation asks us which peoples’ narratives are upheld in the context of Canadian law and governance. Can changing these institutions contribute to reconciliation between Indigenous peoples and Canada?

The class on community development and rural economic planning questions the purpose for which economies exist, and how values intertwined in this purpose are shaped here on Haida Gwaii. How is Haida Gwaii, and its resource-dependent communities, diversifying their economies towards a more resilient and sustainable future? What is the role of informal economies and resistance to capitalism in rural communities?

23

24

25

26

Our final course in rainforest ecology brings us back to forestry on Haida Gwaii by exploring human cultural and economic impact on complex rainforest and riparian ecosystems. Throughout the semester, a community-based learning course has students engaging directly with island communities and local not-for-profit organizations while learning about cultural awareness. Many students are also involved in the community outside of class. I am finding valuable experience in connecting my interests in environment, storytelling, and youth engagement by teaching a weekend art class for preschoolers focusing on creative explorations of Haida Gwaii’s natural environment.

Our courses, instructors, and mentors ask that we pay attention, respect all stories, and consider that those with different perspectives also have different experiences. They encourage us to challenge our assumptions, and to listen and learn with open hearts. We are shown that we are all connected: to each other and to our environments.

What makes all that we are learning on Haida Gwaii so meaningful is what we will do with these ideas in our work that follows. We will hopefully share what we have learned with our home communities, and weave the values and understandings we have developed into the work we do as part of our unique callings.

27

As I write this I haven’t yet left Haida Gwaii, but I am beginning to think about what will stick with me the most from this experience and what is most important to remember.

When I think about this I am reminded of some parting advice from April Churchill, a Haida elder who presented to our class. She told us that, whatever you go on to do in your life, contribute to the Earth and honour your role as part of an interdependent and interconnected ecosystem. Try as hard as you can not to forget the way you are, right now, with hopes and dreams of contributing to your communities and to the environment in positive ways.

Learning together creates a community that fosters this hope of contributing to society and the environment. Recently, an instructor asked us to share with one another our dreams, the ones aside from academic aspirations and career goals. The stories I heard had to do with sharing, creating, loving, and living in a way that is light on the earth and supportive of each other. Being able to grow together as a group in such an extraordinary place filled with endless peer support and vibrant community is an important part of building a positive learning experience. Exploring together also creates informal opportunities to hear more about each other’s stories and perspectives.

Having grown up on Vancouver Island, 500 kilometers South of the archipelago, and having recently fallen in love with the North, my spirit is very happy here on Haida Gwaii. I know I will be back, someday (after all, I have been to St Mary’s Spring – all who drink the waters are destined to return to the islands). Until then, I plan to take all that I have learned, along with collective dreams of respect and love and interconnectedness and community, with me when I return to the work that I do in Montreal and elsewhere.

I want to share these lessons and values with as many others as possible, along with all the stories that are too long and wonderful to fit in just a few pages. And I hope, of course, to always remember the way I am right now, with an open heart and mind and a desire to keep learning wherever I can.

For more information on the Haida Gwaii Higher Education Society semester programs in Natural Resource Science (Fall), Natural Resource Studies (Winter), and Reconciliation Studies (Winter), visit www.hghes.ca

28

Innovations in Photovoltaics and Solar Cells

by Benjamin Zank ABSTRACT: The goal of this paper is to give the reader a brief overview of the world of photovoltaics, from its founding to the present day. The paper will also present the challenges and potential solutions of photovoltaics. It begins with a history of photovoltaics. It then describes the first and second-generation solar cells that are currently commercially available: crystal silicon photovoltaic cells and thin film and concentrator photovoltaic cells respectively. First generation solar cells have a high conversion rate efficiency for solar energy to chemical energy but use a lot of silicon in order to accomplish this. The challenge for the next generation of solar cells is to find a balance between making cells more sustainable while not totally compromising conversion efficiency. Some of the cells that could potentially become the third generation are dye sensitized solar cells, polymer solar cells, and quantum dot solar cells.

All of these are still very much in the development phase but are nevertheless very exciting. Another important aspect of solar power is the storage of excess energy. Solar-fuel plants need to be created to supplant the existing energy infrastructure, but advancements need to be made before that is plausible.

1. Introduction Humanity is currently facing a major challenge: the development of universally accessible renewable energy sources that are both physically and economically viable. The projected global energy demand by 2050 is somewhere around 28 terawatts (TW) (Mauzeroll 2015). Solar energy presents itself as possibly the best and safest renewable source to satisfy this demand.

Taking into account the amount of usable solar energy that reaches the ground, the global energy potential is approximately 600TW (Mauzeroll 2015).

Photovoltaics is defined as the direct con-

29

version, at an atomic level, of light to electricity (Xiao et al. 2004). Energy is converted through the photoelectric effect, in which a material absorbs photons of light and emits electrons. The emitted electrons can then be captured to create an electric current. The materials that are able to undergo the photoelectric effect are conductors (usually metals) and semiconductors.

As conductors do not have fully filled valence shells, electrons can easily be excited to become “free.� Semiconductors tend to have full valence shells, but much less energy is required to excite their electrons than those of insulators because they have smaller band gaps (Xiao et al. 2004).

2.0 History of Photovoltaics The first documentation of the photoelectric effect was in 1839 when a French physicist, Edmund Bequerel, was able to observe the production of an electric current while exposing certain materials to light (Knier 2011). In 1887, German physicist Heinrich Rudolph Hertz found that shining ultraviolet light onto two electrodes, while applying a voltage across them, changes the voltage at which sparking takes place (Xiao et al 2004). Further studies have shown that classical physicals could not explain the photoelectric effect, in which light is viewed as an electromagnetic wave. Theoretically, as the intensity of the light increases, the energy of the electrons should increase proportionally.

In fact, experiments have demonstrated that the current is directly proportional to the intensity, but the energy of the released electrons is proportional to the frequency and completely independent of the intensity (McQuarrie 2008).

In 1905, Albert Einstein published a paper that describes light as being made up of particles: photons. Photons contain a quantized amount of energy that is proportional to the frequency of the light.

Einstein assumed that photons would penetrate materials and transfer their kinetic energy to electrons upon collision. Below a certain frequency, no electrons are emitted, therefore a threshold frequency exists above which electrons are emitted from a material. The electron’s kinetic energy upon release from the material is directly related to the frequency of the photon (McQuarrie 2008).

Photovoltaic (PV) cells take advantage of the photoelectric effect in semiconductors.

A basic cell is made up of an anti-reflective coating, a front contact, back contact, and semi-conductive material. The semiconductor is manipulated by a process called doping: the purposeful introduction of impurities (other elements) into a pure semiconductor (How PV Cells Work 2007).

Depending on the impurity, the semiconductor (usually silicon for solar cells) then has spare electrons (N-type) or is missing electrons, which are known as “holes� (Ptype). The combination of N and P-type semiconductors creates a field when the spare electrons move to the holes, leaving the N-type positively charged and the P-type negatively charged. The semiconductor maintains the charges because of its insulator-like aspects. Standard Silicon PV cells have a very thin N-type layer (often phosphorous-doped) on top of a much thicker P-type layer (often boron-doped).

At the plane of contact between the two layers (the P-N junction) an electric field is generated. When sunlight hits the cell and creates free electrons, the electric field captures them, providing momentum and direction. From there, current is created when the cell is connected to an electrical load. Cells are arranged in modules that supply electricity at a certain voltage, with the current varying according to the amount of light. Modules are then arranged further into arrays (How PV Cells Work 2007).

Daryl Chapin, Calvin Fuller, and Gerald Pearson invented the first practical PV cell in Bell Telephone Laboratories in 1954.

The first practical uses of solar cells were powering satellites and other spacecrafts.

The space industry improved this technology by increasing the efficiency of the cells and by decreasing costs. Applications of solar cells in a non-space setting were

30

seriously considered for the first time with the energy crisis of the 1970s (Xiao et al.

2004).

2.1 Photovoltaics back on Earth In the context of space, the solar cells’ reliability was much more important than their cost efficiency, since mechanical issues cannot be resolved once the panels are released into space. When solar energy started to be considered for use on earth, the question of cost efficiency became more pressing. The solar industry came up with three potential ways of lowering the cost of panels: (1) Stick with and improve the efficiency of the single silicon crystal cell technology that had been used in space, thereby allowing production to take advantage of economies of scale; (2) Branch out beyond single crystal structure: the industry could expand the use of other materials such as a Gallium and Indium, as well as low cost optical lenses or mirrors to maximize efficiency; (3) Switch to non-crystalline thin film cells from materials such as amorphous Silicon, Cadmium Telluride (CdTe), and Copper Indium Gallium di-Selluride (CIS) (Aberle 2009).

The three types of solar cells mentioned above function in essentially the same way.

A photoactive semiconductor and a counter electrode, that can be another semiconductor or a metal, are immersed in an electrolyte with suitable redox couples.

When light hits the semiconductor-electrolyte interface (SEI), electrons are freed and the P and N-type layers are polarized.

31

The polarized charges are carried to the counter electrode, where an electrochemical reaction occurs with the redox electrolyte. The redox electrolyte is what regenerates the oxidized material.

The crystalline silicon (c-Si) cell is by far the most commonly used today. It has dominated the market due to its durability, stability and good electronic properties. The cell’s conversion efficiency only decreases by about 20% over the course of twenty years. The astronomical growth of the solar industries sector has allowed for manufacturing improvements and competition to occur. However, governmentsponsored programs have subsidized a lot of this growth. Unless the costs of photovoltaics can drop dramatically, they will not be able to compete with other energy sources or supplant the burning of fossil fuels.

The second option aims to minimize the need for the crystal by maximizing the light that hits the cell through the use of low cost mirrors, lenses, and multi junction cells. The multi junction system works by stacking several cells with decreasing work functions. When a photon does not have enough energy, it passes through the first cell and instead frees an electron in the second or third cell. This method is known as Concentrator PV (CPV) or high concentration PV (HCPV). In order for these cells to be used to their full potential, the lenses need to change direction throughout the day as the sun moves, and the panels should be deployed in very sunny locations. This increased complexity slowed the development of CPV cells - a cell that was designed in 1978 to have 40% conversion efficiency was not produced until 2012, at which point the con-

version percent was confirmed. In 2013, the best efficiency without the concentrator system was about 35%, while with the concentrator systems conversion percentages had gone past 44% (Aberle 2009).

These cells are more suited for large-scale operations to take full advantage of the systems and because of the added components. Yet these efficiencies have only been accomplished in optimized laboratory settings. Commercially, the best efficiency that has been achieved is around 15% for first generation photovoltiac cells (c-Si) (Kamat 2008).

The thin film technology, the second generation of solar cells, is seen as a low cost alternative that is becoming competitive with c-Si cells. Thin films use much less semiconductor material and have the potential to be fabricated on rigid (e.g. steel) or flexible (e.g. glass) materials and huge series-connected cells are possible. This technology has been around since the 1970s and 1980s with hydrogenated amphorous silicon (a-Si:H). Commercial a-Si models are not very popular because have only achieved a 6% power conversion efficiency (Aberle 2009). The efficiency is so low because of light-induced degradation.

The highest confirmed stable efficiency found by a lab in 2008 was 9.5% (Aberle 2009).

In the years since, there have been improvements in the use of silicon in thin film devices with Crystalline Silicon on Glass (CSG), as well as forays into other materials such as CdTe and CIS. Silicon has a natural advantage because of its widespread use across the microelectronics industry, such as in liquid crystal displays (LCDs), and therefore equipment used in these other fields can be easily

repurposed for solar cells (Aberle 2009).

Silicon’s abundance reduces the cost of silicon based cells in comparison with others. In 2004, the company Pacific Solar calculated the full manufacturing cost of its CSG cells to be at US$116/m2 for cells with a conversion efficiency of 8-9%.

Pacific Solar also estimated that their cell efficiency is improving at a rate of about 1%/year towards a maximum value of about 12-13%, comparable to the efficiency of traditional single crystalline cells. The company compared their cost to a conventional first generation solar cell that, at the time, had a cost of $100/m2 for the moduling alone (Green et al. 2004).

CdTe cells have a superstrate configuration and use a heterojunction. Superstrate means that the glass in the cell is not just used as a backing but aids in the illumination and protection of the cell. A heterojunction is where two semiconductors of different band gaps meet. Natural doping occurs during the deposition, so no dopants need to be added. Efficiencies of 1011% were achieved by 2007. The drawback of these cells is the toxicity of the Cd and the scarcity of Te. These issues call into question whether CdTe cells ought to be pursued further (Aberle 2009).

The CIGS solar cells also have the problem of a limited supply of indium, but for the moment, prices of materials are low and the cell has shown the highest conversion efficiency of any of the thin film cells (19.9% in lab, 13.5% in modules). CIGS solar cells are also very durable and suitable for multiple junction cells because the band gap is adjustable (Green et al. 2004).

The main drawback of these cells is the complexity of the absorber layer, which involves five elements (Cu, In, Ga, Se, and S). The complexity makes it difficult to

32

make large scale cells uniform throughout (Aberle 2009).

Thin film solar cells are ideal for large spaces, where a lot of cells can be installed because of the lower production cost.

When space is limited, the lower conversion efficiency is an obstacle, and it might make more sense to go with the traditional c-Si cells. Thin film solar cells have the potential to bring costs down significantly, but their efficiency needs to be optimized and the manufacturing equipment costs need to come down (Fraas 2014).

2.2 Dye-sensitized solar cells In the 1990s, dye-sensitized solar cells (DSSC), a distinct technology, were developed to challenge the traditional solar cell model. These cells are fundamentally different than the ones described above.

DSSC separate the light absorption part of the cell from the charge transport part.

The dye sensitizer absorbs the light, and then uses the energy to induce an electron transfer reaction (Wei 2010).

When initial studies were being conducted, the focus was on the use of conventional flat electrodes. However, the efficiency of the DSSC relies on the cell’s surface area when it came to effective electron injection into the semiconductor. Flat cells with smooth surfaces were therefore not the best option. This led to a movement towards the use of nanoporous TiO2, which allows for an exponentially larger surface area, possibly by a thousand-fold. A very useful secondary effect of using TiO2 is its efficient chargecarrying capacity. The first such solar cell was reported in 1991, with a conversion efficiency of 7.1% (O’Regan & Grfitzeli

33

1991). Up until that point, there had not been any reported conversion efficiencies above 1% for DSSCs (Fraas 2014). Traditional theory on solar cells cannot explain how DSSCs work. They do not require a very pure semiconductor nor a built-in electrical field. The internal workings and mechanisms of the cell are very complex, particularly at the oxide/dye/electrolyte interface. DSSCs are further complicated because the mechanisms change depending on external factors, such as solar irradiation and temperature. Researchers are still not sure about the mechanisms involved in all aspects of the cell: the system as a whole works better than predicted when the process is broken down into its component parts (Hagfeldt et al. 2010).

The general setup is as follows: It uses two transparent conducting oxide (TCO) electrodes. The working electrode has a mesoporous TiO2 layer coated with the photosensitizer, and is a few microns thick.

The counter electrode is finely divided with Pt depositions. The space in-between is filled with an organic electrolyte that has a redox mediator, usually a mix of iodine/ iodide in a low viscosity solvent (Kalyanasundaram 2010). Redox mediators have the same role as a redox electrolyte.

DSSCs possess several key advantages over silicon based cells. The purity of the semiconductor is not essential, the SEI is easier and cheaper to form, and direct energy transfer from protons to chemical energy is possible (Wei 2010). One exciting aspect of DSSCs is that almost all parts of the cell are modifiable - the semiconducting oxide substrate, the dyes, the electrolytes, the redox mediator, and the counter electrode. Furthermore, the cells can be manufactured in a variety of shapes and

colors and can be transparent. This flexibility means that the cells can be incorporated into new mediums, such as windows and cars. DSSCs have both low production costs and much lower investment costs, because the production infrastructure is not as complicated or expensive.

The cells are both lightweight and flexible with no foreseeable shortage of feedstock that might limit production (Hagfeldt et al. 2010).

2.3 Polymer solar cells Polymer cells are another innovation in solar cell technology. Bulk heterojunction (BHJ) polymer solar cells (PSC) have a transparent Indium Tin Oxide (ITO) positive electrode and a low function metal negative electrode. In between, there is a blended layer of a conjugated polymer (Li 2012). PSCs have a high absorption coefficient, which allows for thin-film development and low material consumption (Walker et al. 2010). Planar junctions have the drawbacks of a small donor-acceptor interface and the necessity of long carrier lifetime for the electrons and holes to be able to reach the electrodes. The blending of the two materials gives rise to the bulk heterojunction and takes care of the limitations of a planar junction. The BHJ, while a major breakthrough, is not ideal since the phase separation of the donor and acceptor do play an important role when trying to achieve the collection direction of electrons and holes (Walker et al. 2010). When compared with the more traditional cells mentioned in section 2.1, PSCs have a simpler structure and fabrication process, are low cost, lightweight, and can be modified to be flexible. However, at this time, the power conversion efficiency being displayed by these cells is not com-

mercially viable. In order for high performance PSCs to be realized, the donor and acceptor in the cell need to be optimized (Li et al. 2012).

Higher efficiency of PSCs is directly linked to how well the cell meets the following requirements: having a narrow band gap between the HOMO (highest occupied molecular orbital) of the donor and the LUMO (lowest unoccupied molecular orbital) of the acceptor, broad and strong absorption band in the visible light region, low lying HOMO of the donor, high lying LUMO of the acceptor, and increased charge mobility. Donor-acceptor copolymerization broadens absorption and allows for the tuning of the energy levels. Copolymers are polymer chains that have to different types of monomers.

The copolymers tend to have intramolecular charge transfer absorption bands at a longer wavelength direction, so the available spectrum is broadened. At the same time, the HOMO depends mostly on the donor and the LUMO depends mostly on the acceptor so the energy levels can be modified.

Each aspect cannot be optimized independently of the others. Narrowing the bandgap affects the efficiency of exciton dissociation and open circuit voltage, changing the LUMO and HOMO levels affects the absorption, and improving solubility through the addition of nonpolar side chains affects charge carrier mobility and morphology. Optimization requires difficult compromises between the different aspects (Li 2012).

Although PSCs are still undergoing optimization, their tunable properties, compared with inorganic semiconductors, by

34

attaching functional substituents to the polymer and fullerene makes them very attractive. Flexible side chains such as alkyl and alkoxy groups can improve solubility and energy levels can be changed with donating electrons or withdrawing functional groups. Attaching electron withdrawing groups to the polymer and electron donating groups to the fullerene can increase the open circuit voltage (Li 2012).

2.4 Quantum dot solar cells The continuing development of nanotechnology has opened up many new and exciting possibilities. One of these is the use of semiconductor nanocrystals in a new type of solar cell. When trying to optimize solar cells, nanotechnology is of interest for the size dependent properties that influence efficiency. These include the quantized charging effects in metal nanoparticles and size quantization effects in semiconductor nanoparticles. New research into improving how well-defined the geometrical shapes of nanostructures are, is also of interest, because morphology is an important factor in efficiency.

Semiconductor nanocrystals are used in three types of solar cells at this point: metal-semiconductor junction PV cells, semiconductor nanostructure-polymer solar cells, and quantum dot sensitized solar cells (QDSSC). Utilizing quantum dots, tiny particles of semiconducting material, has certain advantages: the size quantization makes it possible to modify the charge transfer across different sized particles, and they have the potential ability to better harness the energy of hot electrons as electrons that have a very high kinetic energy or induce more than one charge carrier with a single photon. It has been

35

shown using PbSe nanocrystals that two or more excitons can be caused with one photon that has more energy than the bandgap (Fraas 2014).

Quantum dots have also been looked at as a way to improve PSCs. Combining the polymer with CdSe has been shown to improve charge separation and the generation of photocurrents. It has been shown that CdSe nanorods blended with P3HT creates a large interfacial area at the junctions. Through continuous optimization of the polymer—semiconductor interface, the carrier mobilities and efficiency should increase. This technique couples a short bandgap semiconductor (CdSe) with another semiconductor in order to improve charge separation through rectification (Fraas 2014).

The same combination of semiconductors is used with QDSSCs. The quantum dots have been shown to increase photocurrent and power conversion efficiency in comparison with the standard film. Although QDSSCs are very analogous to DSSCs, the power conversion at this point is much lower. One method that has been explored with some success to improve the efficiency is doping with optically active transition metal ion quantum dots. The ions act as long-lived charge carriers to boost efficiency (Santra & Kamat 2012).

3. Conclusion The solar cell technologies described in the later parts of this review are still very much in the optimization and laboratory testing phases, but they are exciting innovations and potential solutions which could greatly reduce the cost of solar cell technology and make the solar cells

themselves more sustainable. However, in order to fully replace fossil fuels with solar energy, the question of storage comes into play. A very large limitation of solar energy is that the same amount of energy is not constantly available everywhere to the same degree, especially at night. Right now, the solar energy that is converted to electricity is stored in batteries or is offloaded to the grid so other people can use it. If batteries become satisfied, the panels sit useless. However, our best option for solar energy to truly replace fossil fuels currently appears to be the conversion of energy poor molecules to energy rich molecules. These solar fuels would store the suns energy and be used at a later time when they are needed. The catalyst needed for these chemical reactions must be much better than anything that is available currently. Catalysts such as platinum work great, but what is needed is something that is immensely abundant, environmentally friendly, and lasts long term while being as strong or stronger a catalyst than platinum. Solar fuel cells are nowhere near the commercialization stage, but solar-fuel plants may be possible before 2050 (Gray 2009).

References Aberle, A. G. (2009). Thin-film solar cells. Thin Solid Films. 517(17), 4706-4710.

Knier, G. (2011). “How Do Photovoltaics Work?”

NASA Science. NASA, Retrieved November 27, 2015 from http://science.nasa.gov/science-news/ science-at-nasa/2002/solarcells/ Fraas, L, M. (2014). Low-Cost Solar Electric Power.

Cham: Springer International Publishing, 31-43.

Gray, H. B. (2009). Powering the planet with solar fuel. Nature Chemistry, 1(1), 7-7.

line silicon on glass (CSG) thin-film solar cell modules. Solar energy, 77(6), 857-863.

Hagfeldt, A., Boschloo, G., Sun, L., Kloo, L., & Pettersson, H. (2010). Dye-sensitized solar cells. Chemical reviews, 110(11), 6595-6663.

“How PV Cells Work.” (2007). Florida Solar Energy Center. University of Central Florida. Retrieved November 27, 2015, from http://www.fsec.ucf.edu/en/ consumer/solar_electricity/basics/how_pv_cells_ work.htm.

Kalyanasundaram, K. (2010). Dye-sensitized solar cells. EPFL press.

Kamat, P. V. (2008). Quantum dot solar cells. Semiconductor nanocrystals as light harvesters. The Journal of Physical Chemistry 112(48), 18737-18753.

Li, G., Zhu, R., & Yang, Y. (2012). Polymer solar cells. Nature Photonics, 6(3), 153-161.

Li, Y. (2012). Molecular design of photovoltaic materials for polymer solar cells: toward suitable electronic energy levels and broad absorptions. Accounts of Chemical Research, 45(5), 723-733.

McQuarrie, D. A. (2008). Quantum Chemistry. University Science Books.

Mauzeroll, J. (2015). “ECHEM.” CHEM 367. McGill University. Lecture.

O’Regan, B., & Grfitzeli, M. (1991). A low-cost, high efficiency solar cell based on dye-sensitized colloidal TiO2 films. Nature, 353(6346), 737–740.

Santra, P. K., & Kamat, P. V. (2012). Mn-doped quantum dot sensitized solar cells: a strategy to boost efficiency over 5%. Journal of the American Chemical Society, 134(5), 2508-2511.

Walker, B., Kim, C., & Nguyen, T. Q. (2010). Small molecule solution processed bulk heterojunction solar cells. Chemistry of Materials, 23(3), 470-482.

Wei, D. (2010). Dye sensitized solar cells. International journal of molecular sciences 11(3), 1103-1113.

Xiao, W., Dunford, W. G., & Capel, A. (2004) A novel modeling method for photovoltaic cells. Power Electronics Specialists Conference. PESC 04. 2004 IEEE 35th Annual. Vol. 3. IEEE, 2004.

Green, M. A., Basore, P. A., Chang, N., Clugston, D., Egan, R., Evans, R., ... & Young, T. (2004). Crystal-

36

37

Hibiscus flower in Bocas del Toro, Panama by Sophie Kronk

38

Environmental Evaluation of the Chilibre Chilibrillo Cave

by Munib Khanyari & Alexandre Dallaire ABSTRACT: We, students from McGill University on a Panama Field Study Semester paired up with Sociedad Mastozoológica de Panama (SOMASPA), a Panamanian mammal conservation organization, to conduct a part of a project titled ‘Environmental Evaluation of the Chilibre Chilibrillo Cave’ in Chilibre, Panama. Our project was divided into two parts, exploring the cave and studying its roosting bat population. The overall aim was to provide the necessary information for setting a conservation strategy for the cave. In addition, we interviewed locals on topics related to the caves and bats. Our initial inroads led us to map out exact dimensions of the cave. We also obtained significant trends in humidity and temperature with increasing distance from cave entrance; humidity increased, whilst temperature decreased. Additionally, across 4 mistnetting nights, we caught a total of 76 individual bats of 9 different species.

These included omnivorous, insectivorous, frugivorous and nectarivorous bats.

Panama is a country with immense bat diversity (117 species). The IUCN Red List registers all the 9 species as “Least Concern”. Lastly, interviews with locals revealed that the area and its cave suffer from elevated levels of trash, pollution and contamination. Additionally, there is an evident lack of knowledge amongst the majority of the locals about the ecological importance of bats. In conclusion, this project provides the baseline information needed to evaluate the Chilibre Chilibrillo cave and its bats and seeks continuation into the future.

Introduction Due to its predominantly volcanic origins, Panama has several caves. The majority of them are seldom studied and many of these serve as refuge for multiple species, especially bats. For a relatively small country, Panama boasts an enormous variety of bat species; its most abundant mammalian taxa (117 species). But as a developing country with an increasing industry-based population, Panama’s natural ecosystems

39

face constant anthropogenic and environmental pressures.

These aspects fall perfectly under the mandate of our host organization, SociedadMastozoológica de Panamá (SOMASPA), that works towards mammal conservation.

SOMASPA was contacted after a local group from Panama’s Chilibre region, named ComitéChilibreChilibrillo, raised concerns of decreasing bat numbers and increasing environmental degradation of

the area. Though the cave is central to the Chilibre area, both its cave and bat species have seldom been studied. Our work, conducted as a part of our internship during the Panama Field Study Semester, sought to build off of the evaluation conducted

by SOMASPA and the country’s environmental authority (ANAM). We, students from McGill University, focused on two aspects of a broad-ranging environmental evaluation of the area: the cave and its bats.

the Panama province almost equidistant to Colon and the capital, Panama city.

The cave’s exact location is 09.15N and 79.62W. The region has tropical monsoon climate with TO-PA soil classification, comprising mainly sandstone dolostone, and limestone. Most of Chilibre’s soil is alluvial deposits of sedimentary rocks.

These geological elements are what have shaped the structure and composition of the cave (ANAM 2010).

The former included mapping the cave and understanding trends in two abiotic factors of the cave: humidity and temperature. The latter included inventorying bat species via mist-netting to understand the roosting population within the cave.

Lastly, in order to inform future conservation activities, interviews were conducted with willing community-members to understand their association to the caves, environmental degradation and perception of bats. In order to contribute to the area’s long-term conservation, this pilot study aimed to lay the groundwork for a future assessment of the cave, its surroundings and its bats.

Referring to concepts mentioned by Judson (1974) about cave surveying for expeditions, we delimited a method. First we marked all entrances of the cave. Subsequently, we ventured into the cave marking and measuring each straight-line segment using flagging and measuring tape, until the end of the cave was reached. Any points that fork off the ‘main straight-line path’ were counted and measured in the same manner, and registered as subsidiary routes. Following this, height and width were measured at every 5m (distance can be determined upon obtaining total distance inside the cave). Subsequently, starting from the entrance of the main cave, walking inwards, we took readings(at each 5 m interval) of humidity and air temperature. The time at which these readings were taken was recorded and each subsequent trial was done at this same time.

Study Site

Fig. 1: Map showing location of Chilbre in relation to Panama City and Colon. Retrieved from Google Earth Images

As seen Figure 1, Chilibre is a town in

Method

On the other hand, for the bats we tried to find roosts within the cave by following the recommendations given by Venables (1943). The main technique to study bat population was mist-netting (Gardner et al. 1989). A net was placed in each of three locations (main entrance, subsidiary entrance and ~50m away from main entrance in bushes). This was done for 4

40

nights between February and April 2015 keeping in mind the moon cycle, as a brighter moon lessens probability of bat captured by mist-nets (Venables 1943).

Upon capturing a bat in the mist-net, it was identified via morphology and the following information was recorded (see figure 2 below): i)

Forearm length of bat

ii)

Sex and presence of eco-parasites

iii)

Weight of bat

iv)

Before Releasing, a collar with a specific code was placed across the neck

point inside the caves (points 13 and 15) had an average humidity of 80.6%, which is 15.3 % higher than the outside average.

It is clear from the graph that there is a positive correlation between distance into the cave and humidity. The R2 value for the main path was 0.89634 (R=0.94675), while the R2 for the subsidiary path was 0.95033 (R=0.97485). Both these values are significant even when an alpha value of 0.01 is considered, proving a strong positive correlation.

The trend for temperature is seen to be opposite. The average outside temperature was 30.8oC, while the average temperature in the furthest point inside the

Fig. 2: Procedure done on bats after capture in mist-nets. Photo Credit: Munib Khanyari

Figure 3, a digitized hand-drawn map of the cave, was obtained from cave exploration. As seen in figure 4, the mean outside humidity was recorded as 65.3%. On average this is lower than any other point inside the cave, barring one. The furthest

41

cave was 28.8oC. Subsequently, R2 values were obtained, which were 0.8887 (R = 0.94271) for the main path and 0.91096 (R= 0.95444) for the subsidiary path. This shows that with increasing distance away from the cave entrances, there is a de-

Fig. 3: Digitized hand-drawn map of Chilibre cave with demarcated straight-line sections and 5 m intervals

Fig.4: Graph showing the distance from nearest cave entrance against humidity and temperature.

Each point on the x-axis can be matched and spotted on map displayed above in figure 3. The blue line represents path 1(red path) whilst the red line represents the shorter path(green path)

42

crease in temperature; an inverse relation.

Additionally, it can be seen from the above values that the R values for temperature are lower than the R values for humidity, suggesting that the latter had a stronger relationship.

These results are interesting, as both a higher humidity and lower temperature inside caves, (Artia 1996) in relation to general tropical temperature and humidity outside, provide ideal roosting areas for bats. This is because a lower temperature results in lower thermoregulatory stress for the bats, whilst a higher humidity has the potential for reducing evaporative loss of energy (Fenton 1997; Trajano 1996).

Studies by Proctor & Studier (1970) and Lacki (1984) have proved an inverse relationship between humidity and evaporative loss in bats. However, these studies focused on energy loss during flight, not necessarily during roosting. It would thus be interesting to see if this holds true for roosting as well. In fact, an increase in humidity might be good for bats, especially when they start off flight to go out of caves to forage at night. It may be energetically safer to come out of rest and start highenergy demanding activities like flying in an environment that isn’t too physically draining. This would be even more crucial for bats that may undergo overnight torpor, where fluctuations of energy demands are more strained (Lacki &Bookhout 1983) In hindsight, it is important to realize that all humidity and temperature readings were taken between 11001200hrs on survey days. To better evaluate the abiotic factors and their potential daily variation, it would have been better to take 3 sets of readings across 3 different times of day, one early in the morn-

43

ing (~0800hr), second around noon (the set we already have) and a final one just before dusk (~1800hrs). It is also important to take this kind of data throughout the year to measure trends across seasons (Generally the dry season is from November to April, roughly the time we worked; whereas the wet season is approximately between May and October). This can be overlaid with species composition data, especially for bats to see if these abiotic factors affect them.

Lastly, this data provides a great opportunity to conduct comparative studies with other caves to see if trends are conserved across sites. Comparisons would be especially helpful in Panama and other Neotropical countries. Trends could be verified firstly, just with the distance and these abiotic factors (humidity and temperature) and, secondly and more importantly, with abiotic factors and bat composition.

All across the 4 capture nights, we trapped a total of 76 bats from 9 different species.

According to the IUCN Red list, all these species were categorized as “Least Concern�. The most commonly caught species were Phyllostomus discolor (23) and Pteronotus gymnonotus (25). Interestingly, we caught 20 of the 23 Phyllostomus discolors on one particular night (April 19th 2015) as seen in figure 5 above. Trajano (1997) showed the tendency of the Phyllostomus genus to stay faithful to a particular cave or roosting site within a cave.

With insufficient data to see whether it was simply out of luck that we captured or lacked Phyllostomus discolor on different nights, we cannot draw any conclusions on this peculiar phenomenon so far. Continued mist-netting is required to prove any such trend.

Table no.1: Species, diet and no. of individuals captured by mist netting at the Chilibre caves over four nights; Feb. 12th, Mar. 10th, Mar. 11th and Apr. 19th 2015

Figure 5: Number of individual bats captured per species per date, by mist-netting, at the Chilibre cave. The mist netting was done using three different mist net sites

Brown (1968) shows how different bat species’ activities peak at different times during the night. Our mist-net efforts were mainly concentrated between 1800-2200hrs. Our restricted timing of mist-netting mainly due to our lack of experience and man-power(2-3 person/ mist netting nights), surely biases our bat capture data. For example, a study by Brown (1968) suggests that Artibeus jamaicensis’ activity peaks around 0100hrs

and is in fact found both in forest and cave roosts. By not mist-netting equally across throughout the night we potentially misrepresented the species composition. This could be resolved by increased mist-netting effort, especially through other hours of the night.

Caves generally aren’t monopolized by one bat species. Literature suggests three particular species of the ones we captured

44

share their roosts with each other majority of the times: Phyllostomus discolor (83%), Glossophaga soricina (77%) and Carollina perspicillata (73%) (Graham 1988). In fact, studies show that Carollina perspicillata is very common neotropical bat that feeds primarily on piper plants. Its abundance probably reflects the general abundance of the species, as there is no evidence of their particular dependence on caves as a shelter (Trajano 1985).

The Phyllostomus hastatus was the only omnivorous and also the largest species according to its size and weight. Interestingly one individual was found predating another small bat (Pteronotus gymnonotus) that was attached to one of our mistnets. This shows a potential cannibalistic relation between some species of bats.

Furthermore, Graham (1988) showed that Uroderma bilobatum never shared its roosts with other species. This leads us to believe, that it potentially did not roost in the cave but was merely caught in our net. This can also be supported by Lewis(1992). The author says this species makes its own roost by tent-making in foliage. We propose that our Uroderma bilobatum got caught whilst feeding on various fruit trees around the entrance of the cave.

The Pteronotus personatus species is a cave dwelling species and prefer warm caves and co-exist with other bat species (De La Torre & Medelin 2010). This leads us to propose that this particular species is roosting within the cave.

Lastly, Pteronotus mesoamericanus is said, according to the IUCN Red list (Miller et al. 2008) to prefer moist areas and caves

45

but can also roosts in other sites like tree hollows. In addition, they also share roosts with other bat species. Thus, this seems to be convincing evidence that this species is also roosting within the cave.

As a result, we can suggest that one of the captured species, Uroderma bilobatum, is not roosting within the cave. For Artibeus jamaicensis, we are uncertain due to reasons discussed above. The remaining seven species are most likely roosting within the cave. Even though we can say that these seven species are roosting within the cave due to previous studies of their natural history, we cannot assume that they form the entire diversity of the cave. Hence, it is imperative to extend this project into a long-term study and continue mist-netting as long as possible.

According to Simmons et al. (1979) insectivorous bats have a well-defined echolocation system to locate prey while in flight.

Due to varying echolocation ability, it is possible that there is variability in capture as species might have differential perception of a mist-net. Therefore, possibilities of using other, potentially non-invasive techniques, such as identifying bats by recording echolocation wavelengths should be considered. This especially has merit in recording species of insectivorous bats that usually fly high above the mist-net height (Whitaker 1988).

Ecological Importance of Bats Bats are ecologically very important. They pollinate multiple plants including bananas, cacao, guava and over 300 other species. They also contribute to seed dispersal and insect control, factors that directly affect the environment they inhabit (Shaz-

ima 1978). Interestingly, bats are highly important to caves, as their droppings (guano) act as nutritive inputs upon which cave food-chains are based as the lack of light restricts photosynthetic activity. Additionally, some bats are bio-indicators of the health of the plants that they feed on.

In today’s world of climate change and environmental degradation, mere monitoring of taxa isn’t enough, rather it is imperative to identify bio-indicator taxa that might show measurable response to these events. Several studies have linked decreasing bat populations and diversity with events of drought, changes in precipitation cycle, deteriorating water quality, fragmentation of forests, amongst others (Barclay 1991; Jones et al. 2009). Hence, projects concerning bats such as this one aren’t only important for the immediate habitat of these species but the environment in general, which is needed by us, humans, to survive.

Community’s Perspective To supplement our ecological data, we conducted a semi-structured interview to understand the community’s perspective on the cave, their knowledge of bats and views on future action. The locals, consisting of households within 1km2 of the cave mouth, were interviewed. Upon being asked if people used caves, 64% said they have visited and guided people, 29% said they have never visited and 7% said they have solely visited but not guided personnel within the cave. Subsequently, we asked what the main environmental problems facing the caves were, in their opinion. Interestingly, 40% of the people chose ‘others’ as an answer (these included air pollution, infrastructural development, etc.). 24% suggested that the main threat

came from the physical and chemical contamination of the stream that flows through the cave, 16% were convinced that the garbage, mainly around the entrance, was the biggest threat, whilst 20% of the people thought that no real environmental problem existed. Lastly, we asked people what they thought the importance of bats was. An astonishing 56% said none and a further 11% seemed to be convinced that bats only had negative impacts (such as spreading diseases and infections). 22% said their importance as insect control was crucial whilst 11% suggested pollination was their main ecological importance. This last question was of particular interest, as Mickelburgh (2002) also mentions the prevalence of misinformation amongst communities as one of the biggest threats to bat conservation.

Conclusions and Recommendations This project was a novel exploration of the Chilibre Chilibrillo cave. We mapped out this cave and also showed that with increasing distance into the cave (away from the entrances) there is a significant increase in humidity and a significant decrease in temperature. Additionally, we caught 76 individuals of 9 different bat species. Their diet spread across omnivory, frugivory, insectivory and nectarivory.

We believe 7 of these species reside inside the cave, but sustained effort is required to concretely conclude the cave’s entire roosting population. In all, protecting these bats and their home, the cave, is even more important due to their influence on the whole ecosystem.

The International Union for Conservation of Nature (IUCN) has recently begun creating a ‘red list’ of ecosystems;

46

that quantifies the levels of threats to each ecosystem and placing them in a hierarchy of conservation importance. Caves, like all other ecosystems, need continued research in order for us to understand the threats, their importance and finally ways to conserve them. The Chilibre Chilibrillo cave has the potential to be a candidate for a long-term study; now that research has been initiated, especially knowing that a committed local group, ComitĂŠ Chilibre Chilibrillo seeks its conservation.

This committee needs to work closely with Autoridad Nacional del Ambiente de Panama(ANAM), to take appropriate conservation measures such as increased environmental awareness within the surrounding communities.

as a our Scientific Advisors. Other people from SOMASPA also participated, namely Julio Sanchez, Rogelio Samudio and Angel Sosa. From University of Panama we had help from Karla Ramos, Aleksei Valdes and Mario Arosema. We would also like to thank Abel Vega and Ignacio Ochoa, as our guides and safety advisors for their constant presence at the Chilibre Chilibrillo cave with us. We would like to extend special thanks to Ilke Geladi and Rachael Ryan, fellow McGill students for helping us with mist-netting. Lastly and perhaps most importantly, we would like to thank Professor Ana Spalding and Mr. Victor Frankel, who helped guide us through this internship as a part of our Panama Field Study Semester credit load.

Furthermore, there needs to be continued mist netting through the year to incorporate seasonal variation in data along with daily variation. Another tactic would be to incorporate a social element into the project; for example, an informative and interactive movie or educational program on the cave and its bats. Another important point could be to mobilize locals along with government support in cleaning areas of the cave within reach, as this is a big concern that can be dealt with rather effectively by local effort.

References

In conclusion, subsequent projects building on the success of our pilot project have the potential to be broad ranging and effective for the cave, its bats and the Chilibre community.

Acknowledgements We would like to give a special thanks to our supervisors Julieta Carrion de Samudio and Rafael Samudio of SOMASPA,

47

Artia, H.A. (1996). The Conservation of CaveRoosting Bats in Yucatan, Mexico. Biological Conservation, 76, 177-185 Barclay, R.M. (1991). Population structure of temperate zone bats in relation to foraging behaviour and energy demand. Journal of Animal Ecology, 60, 165-178.

Brown, J.H. (1968). Activity Patterns of Some Neotropical Bats. Journal of Mammology. 49(4), 754757.

De La Torre, J.A., & Medelin, R.A. (2010). Pteronotus personatus (Chiroptera: Mormoopidae). Mammalian Species. 42(1) , 244-250.

Fenton, B. (1997). Science and Conservation of Bats, Journal of Mammalogy, 1-14 Gardner, J., Gardner, E. & Hofmann, J. (1989). A portable mist-netting system for capturing bats with emphasis of Myotis sodalist (Indiana bat), Bat Research News, 30, 1-8 Graham, G.L. (1988). Interspecific Associations among Peruvian Bats at Diurnal Roosts and Roost Sites. Journal of Mammology. 69(4), 711-720.

Jones, G., Jacobs, D.S., Kunz, T.H., Willing, M.R., & Racey, P.A. (2009). Carpe noctem: the importance of

bats as bio-indicators. Endangered Species Research, 8, 93-115.

Judson, D. (1974) Cave Surveying for Expeditions, Geographical Journal, 140(2), 292-300

Lacki, M.J. (1984). Temperature and humidity-induced shifts in the flight activity of little brown bat.

Ohio Journal of Science, 84(5), 264-266.

Lacki, M.J., & Bookhout, T.A. (1983). A Survey of bats in Wayne National forest, Ohio. Ohio Journal of Science, 83, 45-50.

Lewis, S.E. (1992). Behavioral of Peter’s Tent-Making Bat, Uroderma bilobatum, at Maternity Roosts in Costa Rica. Journal of Mammology. 73(3), 541546.

Mickelburgh, S.P., Hutson, M., & Racey, P.A. (2002).

A Review of the Global Conservation Status of Bats.

Oryx. 36(1), 18-34.

Proctor, J. & Studier, E. (1970). Effects of ambient

temperature and water vapor pressure on evaporative water loss in Myotis lucifugus. Journal of Mammalogy, 51, 799-804 Shazima, M., & Shazima, I. (1978). Bat pollination of passion flower, Passiflora mucronata, in Southeastern Brazil. Biotropica, 10(2), 100-109.

Simmons, J., Fenton, B., & O’Farrell, J. (1979). Echolocation and Pursuit of Prey by Bats. Science. 203, 16-21.

Trajano, E. (1985). Ecologia de populações de morcegos cavernícoles em uma regiāo cárstica do sudeste do Brasil. Revista Brasileira de Zoologia, 2(5), 255-320.

Trajano, E. (1995). Protecting caves for the bats or bats for the caves? Chiroptera Neotropica,1(2), 1-3.

Venables, L. (1943) Observations at a Pipistrelle bat roost, Journal of Animal Ecology, 12(1), 19-26

Whitaker, J.O., & Kunz, T.H. (1988). Food habits analysis of insectivorous bats. Ecological and Behavioural Methods for Study of Bats, 171-189.

48

Moments in the Andean highlands

by Sophie Kronk

These photos were shot with film during a stay in the Ecuadorian Andes conducting research on the spatial distribution of landslide risk and community disaster response.

49

Chimborazo Volcano, Ecuador’s highest peak

A puppy finding shade outside a auto repair shed in the mountains surrounding BaĂąos.

50

About the Contributors Alexandre Dallaire is currently finishing a double major degree in Mathematics and Biology at McGill. Alexandre is deeply interested in the concepts of ecology and prior to work in Panama, had also experienced working with bats in Costa Rica.

Julia Epstein

was raised in Los Angeles, California. She is a student and photographer currently studying Political Science and Environment at McGill University.

Jessica Ford is a McGill Biology student with a minor in Natural History. She

is passionate about sea turtles, and endeavours to conserve the species. When not saving the turtles, Jessica enjoys spending time in museums, kayaking, cycling, and poetry.

Daniel Galef is a U3 student at McGill University and (maybe) the school’s most

prolific writer. If you have enjoyed reading his work in the Daily, the Tribune, the Bull & Bear, Hirundo, Steps, and about a dozen others, then you should go to see his play at this yearâ&#x20AC;&#x2122;s McGill Drama Festival in April! </shamelessness>

Munib Khanyari

recently (Spring 2015) graduated from McGill University, majoring in Environmental Biology, Specialization Wildlife Biology. Munib is currently a National Geographic Young Explorer conducting a project on endemic birds in the Andaman and Nicobar islands. Munib has a special interest in exploration and ecology.

Kate Hanly is a fifth year student studying Environmental Science at the University of Calgary. Currently living in Haida Gwaii, Kate is pursuing her interests in natural resources and sustainability.

Francesca Humi is in her final year, completing a BA in International Development Studies, Environment and Political Science. She spent last semester on the Barbados Field Study Semester and it was her best experience at McGill. As a woman of colour, she is committed to anti-racism and intersectional feminism. She is passionate about social and environmental justice, which she plans to pursue in her future studies and professional path.

51

Sophie Kronk is a U3 student in International Development and Urban Systems. She went on the Panama Field Study Semester in 2015, traveled through Costa Rica, and then received McBurney funding to work in Ecuador.

Benjamin Zank is a U3 honors chemistry-global student with a minor in field studies--Panama. His research interests include the clean energy sector and agriculture.

He is excited for when the people seize the means of production and we have a revolution.

52

About the Editors Dassyn Barris

is a fourth-year student in Ecological Determinants of Health with the School of Environment. She’s interested in policy and its relations to environmental decision-making and public opinion. She also really loves chocolate.

Brayden Culligan

is a first year Political Science student minoring in Environment, International Development Studies, and Communications. His primary passions are in sustainable development and digital media.

Reine Donnestad is a second year Environmental Science student majoring in Renewable Resource Management. She is interested in the distribution of water for the development of healthy communities and thinks dolphins are cool.

Nessa Ghassemi-Bakhtiari graduated from the MSE in 2015 and currently studies at Université de Montréal in Digital Arts and Communications. In a world confronted with climate change, her research-creation explores contemporary identity politics arising from displaced communities and migration. She situates her work at the intersection of sensory ethnography, feminist studies, and climate justice.

Lydia Kaprelian is a third year Environment student studying Ecological Determinants of Health at the Macdonald campus. She’s interested in beekeeping, journalism, and long walks on the beach.

Elena Kennedy is a second year McGill Law student. Her concern for the translational challenges between science and law kept her on the journal after graduating from the MSE in 2014. She is primarily interested in environmental civil liability.

John Lindsay is a third year student studying Environmental Science at Macdonald campus. John spends most of his time studying food sustainability. He also enjoys playing hockey, reading and hanging out with friends.

Sevrenne Sheppard is a third year student in the School of Environment studying Environment, Economics, and Urban Systems Geography. You can find her daydreaming about building happy communities, healthy ecosystems, and inclusive economies.

53

Emma Sutherland is a first-year student in Environment and Development with a minor in Geographic Information Systems and Remote Sensing. She likes to complain about the weather and think about sloths.

Joseph Yang is a fourth year student in Ecological Determinants of Health.

Heâ&#x20AC;&#x2122;s passionate about basketball and discovering new food. The Wolf of Wall Street by Jordan Belfort is his favourite book.

54

BRANCHES

VOLUME 6

WINTER 2016