Too Much of a Good Thing Addressing the Sargassum Influx in Central America By Anna Pate
Image source: National Geographic
Spring 2022 Capstone Studio University of Minnesota Twin Cities Master of Landscape Architecture
Book Contents Project Introduction 01-02 Understanding Sargassum 03-17 Research Questions 18 Site Context and Analysis 19-21 Design 22-38 Sources Cited 39-41 Acknowledgments 42
Project Introduction
Ambergris Caye
Bel ize
Bar rier
Ree f
The United States of America
The Bahamas
San Pedro Turks & Caicos Islands Dominican Republic
Cuba
Mexico
Belize
Cayman Islands
Jamaica
Haiti
U.S. Virgin Islands
Puerto Rico
Honduras Guatemala El Salvador
My first experience with Sargassum was in the summer of 2020 when I was privileged enough to stay in Belize for a month. I spent the majority of my time there on the Island of Ambergris Caye which is just off the coast of Belize. Belize shares a border with Mexico to the north and Guatemala to the West. This place is home to the Belize Barrier Reef, the second longest barrier reef in the world. Ambergris Caye is the largest of Belize’s many cayes with about 15,000 people. And the island is about 25 miles from north to south. 01
Nicaragua
Costa Rica
e V nezuela Panama
Guyana Suriname Colombia
Ecuador
Brazil Peru
French Guyana
When I got off the plane in San Pedro, the main city in Ambergris, I was struck by this overwhelming rotten egg smell. By the time we got to our accommodations, I had been told that this smell is the result of the seasonal Sargassum Seaweed influx that’s been washing up onto the beaches and decaying. This photo is what I saw when I went out and looked at the beach. I figured that this was just unfortunate timing, but didn’t think much of it until I was out on the dock one day and my partner and I witnessed what must have been thousands of Sardines skirting the surface of the water around us and eventually dying, floating to the surface, and washing onto shore. A google search explained to me that the presence of Sargassum on the shoreline depletes the water of oxygen, and the marine life doesn’t stand a chance. This Sargassum influx is abnormal. I became engrossed in research around this topic and the negative impact it’s having on communities. My curiosity naturally lead me to explore this as my Capstone Topic. 02
Sargassum: An Introduction Sargassum is a genus of brown macro-alga that has approximately 150 different species, and only two of those species are pelagic meaning they spend their entire life cycle floating on the surface of the ocean. These two pelagic species are S. fluitans and S. natans. Pelagic Sargassum travel with the surface currents of the ocean as well as wind. So what keeps this seaweed afloat? Located near the stipe/stem of the plant are round vesicles or air bladders that help with boyance and gas exchange (Sharma, 2016). Reproduction occurs clonally at a rapid rate in these species by vegetative fragmentation. Fragmentation of the thallus happens with mechanical injury or death and decay of old parts (Sharma, 2016). Sargassum are relatively narrow in width, but can grow more than 1 meter in length (Sharma, 2016). These individual Apical Meristems clump together and make up large Sargassum mats in the ocean that can be hundreds and even thousands of miles in size.
Apical Meristem Vesicles/Air Bladders
Top Stipe
10 mm
Leaves
Receptacles Bottom Stipe Holdfast 03
Sargassum fluitans
Sargassum Biomass Carbohydrates (Polysaccharides) 11-59%
What is Sargassum made of?
Ash 9-47% Secondary Metabolites <0.5%
Water 82-87%
Dry Biomass
Fats (Lipids) <4%
Heavy Metals ??% Proteins 2-15%
Vitamins & minerals ?%
Cadmium Zinc Lead Arsenic
Fibers 7-33%
*Graphic adapted from Sargassum Uses Guide: A resource for Caribbean researchers, entrepreneurs and policy makers (Desrochers et al., 2020)
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“If conditions for its growth continue to be favorable, it can double its biomass in less than 20 days “ (Sargassum Returns to the Beaches, 2022) Increased ocean acidity, temperatures, and nutrient runoff from three main rivers are creating favorable growth conditions for this macroalgae. 05
Bigger Picture Sargasso Sea
Mississippi River
Gre
at A t
lan
tic
Sar gas
sum
Amazon River
Bel
t
Congo River
New blooms have been found to be started near the mouth of the Amazon River and Congo River as a result of deforestation and increased nutrient runoff leading into the ocean. These blooms are carried by surface currents along what is known as the Great Atlantic Sargassum Belt, and wash up into the shores of many tropical caribbean countries and up into the gulf of mexico and florida. The patterns of where exactly the Sargassum ends up seem to differ slightly year to year. However, the Sargasso Sea in the North Atlantic Ocean has remained a constant for hundreds of years, kept in a healthy circulation by the northern atlantic ocean currents. This sea is proof that Sargassum is not inherently bad. 06
The Sargasso Sea: A Habitat to Many “The Golden Floating Rain forest” The Sargasso Sea, otherwise known as ‘The Golden Floating Rainforest’ is over one thousand miles wide and three thousand miles long, occupying almost two thirds of the North Atlantic Ocean (Monterey Bay Aquarium Research Institute, 2014). For reference, this is very similar in size to the contiguous United States. An incredible amount of aquatic species use the Sargasso Sea for food, shelter, breeding grounds, feeding grounds, and overall structure in an otherwise vastly open ocean. For example, both the Humpback and Sperm Whales will pass through the Sea during migration to feed on smaller fish. Juvenile Sea Turtles drift in the Sargassum in order to avoid predators until they are large enough to fend for themselves. Seahorses use the seaweed as a structure to grasp onto. To Dolphins, Sargassum is a toy that they will drag around with them while taunting other dolphins to play along.
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Sargasso Sea
Common Species that Utilize Sargassum
American Eel
Shrimp
Sargassum Frogfish
Dolphin Tuna Porbeagle Sharks
Hundreds of Species of Fish
Dolphinfish
Seahorse Sea Turtles
Humpback Whale
Crab
Sperm Whale
Conger Eel
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So What is the Issue? Like most plants, Sargassum has been around for a very long time. Allegedly, Christopher Columbus is the first known person to have reported seeing the floating mats of Sargassum in the North Atlantic Ocean in the 15th Century (Samurovic, 2019). However, in the last 12 years it became more evident that the amount of Sargassum washing up onto the shores of Tropical Caribbean countries every spring and summer was starting to increase. By 2018, the Caribbean experienced the largest amount of Sargassum to inundate their beaches in a single month - over 20 million metric tonnes....for reference, 20 million metric tonnes of Sargassum is approximately the weight of 80,000 school buses. So what’s causing this increase? Scientist and Environmentalists say that an increase in nutrient runoff from three of the world’s largest rivers are playing a huge role. The Mississippi, Amazon, and Congo rivers carry large amounts of nutrients into the ocean from increased industrialization, agriculture and livestock, and a decrease in natural vegetation that would act as a filter. Another factor that’s causing ideal growing conditions for Sargassum is an increase in ocean temperature and acidity. This issue is likely only going to get worse, so what’s next?
2011 First signs of Sargassum influxes
2018
2019
20Million tonnes in June alone
27 million tonnes across the region between June and August
“Nutrient levels in the Amazon basin are increasing, driven mainly by nitrogen and phosphorous from fertilizers used in areas of rainforest recently converted to farmland” (Lamb, 2018)
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2020 12.7Million tonnes in June
*Adapted from Sargassum White Paper
Source: Satellite-Based Sargassum Watch System (SaWS)
Estimated Total Amount of Sargassum in the Tropical Atlantic (2018-2020) Million Metric Tons 25 20 15
10 2018 2020
5
2019
0 Jan
Feb
Mar
Apr
May
Jun
July
Aug
Sep
Oct
Nov
Dec
Seasonal Influx “In the last few days, there have been amounts washing *Adapted from USF Outlook Bulletin
up and in places that I didn’t see even in 2018” - Rosa Rodríguez Martinez (Stevenson, 2022) 10
Drying
Decomposing (Releasing H2S)
Alive Once Sargassum washes up onto the beach, wave action will compact the seaweed. At this point the process of decomposition begins. Decomposing Sargassum emits Hydrogen Sulfide which is toxic in large amounts, at the least causes irritation of the nose, throat and mouth, and smells like rotten eggs. Sandfleas and other irritating pests make a home of these decomposing piles. Not only this, but the lack of oxygen in the water will lead to mass fish and aquatic wildlife die off. 11
“Sergio León, former head of the state’s employers’ federation in Mexico, said the seaweed invasion ‘has definitely affected us. It has affected our image on the domestic and international level obviously not just visually but in term of environmental damage and pain’”
Economy
cost of removal tourism decline
potential reuse
fertilizer
Sargassum influx and its impact on the economy, ecology and health of local communities.
eutrophication
Ecology harm to coral reef
heavy metals leaching into soils
Public Health
hydrogen sulfide and ammonia toxicity
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What Are Communities Doing About It?
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Removal: Many of the smaller properties on the beach simply rely on people using pitchforks to shovel the Sargassum into wheelbarrows which they can then wheel to other places on the property or wheel onto trucks that will dump the Sargassum elsewhere. This method is time consuming and costly to property owners during the heavy Sargassum influx months. Some resorts have mechanical machines to make this job go faster, however the ATV vehicles, construction equipment and trucks are extremely bad for compaction and erosion of the beach area, and often disturb wildlife. Another approach has been to use water equipment like small boats to net the Seaweed or pull it on board with conveyor systems. This approach seems easier to extract Sargassum while it is still in the water rather than struggling to remove it from the beach. Often times the Sargassum is then transfered to land vehicles and transported elsewhere.
“Current Composting or mulching techniques lead to the gradual accumulation of heavy metals like arsenic in our soils” -PhycoMExUK
Where Does it Go? Just like the removal of Sargassum, where is goes afterword is also largely left up to the landowner. In terms of what many resort owners are doing, “Some have been tossing the mounds collected from the beach into disused limestone quarries, where the salt and minerals collected in the ocean can leech into groundwater [...] Others toss it into woodlands or mangrove swamps, equally bad” (stevenson, 2022) says Rosa Rodriguez Martinez, a biologist in the beach-side town of Puerto Morelos who studies reefs and coastal ecosystems for Mexico’s National Autonomous University. In Belize, many people have been using the Sargassum piles from the beach as fertilizer or compost. Without first being treated to remove heavy metals, minerals, and salt this will likely have negative environmental impacts in the long run. 14
Sargassum as a Resource
Focuses for Belize Fertilizer
Algas Organics Fertilizer-Johannan Dujon (St.Lucia)
Building Material
Sargablocks -Omar Vasquez (Mexico)
*Graphic from Sargassum Uses Guide: A resource for Caribbean researchers, entrepreneurs and policy makers (Desrochers et al., 2020)
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Processing Precedent Project: Milorganite - Milwaukee Organic Nitrogen Fertilizer Milwaukee, WI. One of the oldest recycling efforts in the United States. Since 1926 10 billion pounds of waste has been diverted from landfills. Using large-scale processes that mimic nature, microbes digest the nutrients found in the water. The cleaned water is returned to Lake Michigan while the microbes are kiln-dried into small pellets.
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Processing
Sargassum Biomass
Rather than wasting fresh water to remove salt from Sargassum, this is a two-catalyst process that releases sugars from the seaweed. the result is a substitute product for palm oil. (Coxworth,2020)
Bio-Gas can be reused in the HTL process by helping to heat the biomass.
Gas
Catalyst process
Oil
Hydrothermal Liquefaction
Liquid
Bio-Char can then be sun-dried and used as a binder material in making Sargassum building blocks.
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Bio-Char
Both the oil and liquid hold important nutrients that can then be used as a fertilizer.
Research Questions
1. How can I design a landscape infrastructure that streamlines the collection, processing, and reuse of Sargassum to reduce negative impacts to marine species and the local community, ideally rebuilding some of the economic loss that Ambergris Caye has experienced with increased seasonal sargassum influx?
2. Not only this, but how can I design a space that is a catalyst for research and education related to Sargassum and it’s recent influx?
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Site Context and Analysis
19
San Pedro
Bar rier Bel
ize
Ambergris Caye
Ree f
Mexico
Belize Esri, NASA, NGA, USGS, CONANP, Esri, HERE, Garmin, METI/NASA, USGS
Population: ~15,000 Size: ~25 miles north to south
Guatemala
Honduras CONANP, Esri, HERE, Garmin, FAO, NOAA, USGS, Esri, USGS
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Development
Existing Low Density Resort Existing Low Density Residential
Roads
Roads
Vegetation
Lowland Broad-leaved Dry Forest Mangrove and Litoral Forest Wetland
Existing Low Density Resort Hotel/Residential Future Low Density Residential Future Low Density Resort Hotel/Residential
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Urban
Design
22
Sargassum Stations & Floating Barriers
rier
Ree f
Bacalar Chico Station and Research & Interpretive Center
Escape Away Station
Bel
ize
Bar
I believe that the best way to reduce negative impacts of Sargassum to the ecology and community is by using a series of floating Sargassum barriers similar to those used to control oil spills in the ocean. These barriers have been tested and proven as an effective method, though they have yet to be used at this large of a scale. They are offset from the shore about 400-500 feet keeping the beaches clean. Connecting these barriers is a series of 5 collection and processing centers. Approximately every 1 km is a break in the barriers for boat passage.
Barrier Reef Station
Boca Del Rio Station
Mahogany Bay Station
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Bacalar Chico Station + Research and Education Center Bacalar Chico Station and Research & Interpretive Center
On top of the processing center, here I have designed a research and interpretation center for locals, tourists, and people from all over the world wishing to engage in research, education, and ultimately conversations around Sargassum and this relatively new phenomena. I can picture engineers, scientists, oceanographers, marine biologists, landscape architects, artists, thinkers, doers, and the average family here to consider a new future that inevitably includes large amounts of Sargassum.
Bacalar Chico Station
Bacalar Chico Station
Escape Away Station
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Bacalar Chico Station & Research and Interpretive Center
Packaging Building
Drying Fields
SargaBlock Operation
Stock Storage
Research + Interpretive Center
Processing (HTL)
Belize Tropical Research and Education Center (TREC)
Collection
Sargassum-free Zone
Sargassum-free Zone Sargassum Zone
1”=300’
25
0’
150’
300’
Sargassum Research & Interpretive Center Interpretive Orchard Trail
Vegetable Garden
Classroom Plaza
Interpretive Orchard Trail
Main Island Road
Research Housing Watch Tower
Parking
Parking Sargassum Museum + Education Center
Research Center
Trail to Belize TREC
Community Events Plaza
“Dive Shop” Kayaks, paddle boards, snorkel and scuba gear.
“Dive Shop” Kayaks, paddle boards, snorkel and scuba gear.
1”=100’ 0’
50’
100’
26
Classroom Plaza
Sargassum Museum: Made from Seaweed blocks
Vegetable Trial Gardens: Testing Seaweed Fertilizers
27
Sargassum Concrete Stamp
Classroom/Demonstration Space
Sargassum Demonstration and Test Pool
Interpretive Orchard Trail Fruit trees treated with Sargassum fertilizer
Interpretive Trail
Flame Tree trail Markers
Interpretive Signage
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Seaside Dock Floating Sargassum Barriers
29
Processing Dock
Sargassum Collection Zone
Kayak Tours
[page intentionally left blank]
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Southern Stations
Boca Del Rio Station
Mahogany Bay Station
Mahogany Bay Interpretive Trail grabs the attention of tourists on South Ambergris. A water taxi will take people from here to the Interpretive center on North Ambergris
Distribution Center
Boca Del Rio Station Mahogany Bay Station
Mahogany Bay Station
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Boca Del Rio Station
Barrier Reef Station
Northern Stations
Escape Away Station
Barrier Reef Station
Escape Away Station
Barrier Reef Station
Distribution Center
Escape Away Station
Barrier Reef Station
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Barrier Reef Station
Mangrove Buffer Packaging Building Drying Field 2
Mangrove Vegetation and Lagoon
SargaBlock Operation
Vegetation Buffer
Drying Field 1
Vegetation Buffer
Mangrove Vegetation and Lagoon
Loading Deck
Processing (HTL)
Collection
Sargassum-Free Zone
Sargassum Zone
Sargassum-Free Zone Flo
at in
g
33
1”=150’ Ba
rri
er
0’
75’
150’
[page intentionally left blank]
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Floating Sargassum Station
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This piece of the design is more speculative in nature than what I have shown so far. Imagine a place where people can go meet the Sargassum where it normally exists, in the deep ocean. Though the engineering of this piece is not perfected or completed by any means, I still find its design exploration valuable. The island functions to usher in Sargassum as a place to study and explore perhaps a small piece of what the sargasso sea feels like. The nodal part of the floating station is equipped with docks for Sargassum collection vessels to come in, collect sargassum, and take it back to land. Though the details of the design are incomplete, I can imagine in some of these section drawings how people might begin to explore under and around the Sargassum itself, interacting with marine animals much in the same way that we interact with our coral reefs. A change of perspective is so incredibly valuable.
“Then it is a question of what we know and play with today, and what we leave open. We do not know this so precisely but we aim to leave open a creative dialogue between present and future” -Catherine Mosbach 36
Design Process
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Ambergris Caye
Bel ize
Bar rier
Ree f
The United States of America
The Bahamas
San Pedro Turks & Caicos Islands Dominican Republic
Cuba
Mexico
Belize
Cayman Islands
Jamaica
Haiti
U.S. Virgin Islands
Puerto Rico
Honduras Guatemala El Salvador
Nicaragua
Costa Rica
e V nezuela Panama
Guyana Suriname Colombia
Ecuador
39
Brazil Peru
French Guyana
To end this book I just want to say that if you asked me this time last year what I might choose for my Capstone topic, I never would have guessed that it would be located in Belize. I definitely didn’t expect that it would revolve around a stinky and beautiful and curious type of seaweed, but I’m so glad that it did. Though I may not work with anything incredibly similar to this in my career, I think this TYPE of work is something that we as landscape architects will be doing an increasing amount of as our world shifts and changes and we are tasked with new environmental issues. A very big task indeed, but that’s where cross discipline collaboration and an always curious mind will come in handy. Thank you. 40
Image Sources
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Source: Calico Construction Products
Source: The Roxbury Latin School
Source: OdySea Aquarium
Source: Algas Organics
Source: Emily Mkrtichian for UNDP Mexico
Source: Garden Tabs
Source: The Coconut Company
Source: Tree Journey
Source: citrus.com
Source: Adventure Kayak Outfitters
Source: Field To Frame
Source: National Park Service
Source: CanadaDocks.com
Source: TheOceanCleaner.com
Source: TheOceanCleaner.com
Image Sources
Source: Texas Boom Company
Source: Mexiconewsdaily.com
Source: REUTERS
Source: KWS
Source: Wisconsin Watershed District
Source: The Home Depot
Source: Cayman Compass
Source: The San Pedro Sun
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Bibliography
Coxworth, B. (2020, May 13). Inexpensive process converts waste seaweed into bio-fuel, fertilizer and more. New Atlas. Retrieved May 4, 2022, from https://newatlas.com/good-thinking/waste-seaweed-bio-fuel-fertilizer/ Monterey Bay Aquarium Research Institute. (2014, September 23). Big changes in Sargasso Sea’s seaweed populations. ScienceDaily. Retrieved April 1, 2022 from www.sciencedaily. com/releases/2014/09/140923131448.htm Samurović, K. (2019, September 23). The largest seaweed bloom ever took place in 2018. Geography Realm. Retrieved April 2, 2022, from https://www.geographyrealm.com/the-largest-seaweed-bloom-ever-took-place-in-2018/#:~:text=Christopher%20Columbus%20was%20the%20first,entire%20sections%20of%20the%20Atlantic. Sargassum Returns to The Beaches. (2022, March 12). The San Pedro Sun. https://www.sanpedrosun.com/community-and-society/2022/03/12/sargassum-returns-to-the-beaches/#:~:text=Its%20current%20biomass%20is%20estimated,year%20of%20high%20Sargassum%20concentration Sharma, D. (2016, February 4). Notes on Sargassum (with diagram): Alage. Biology Discussion. Retrieved April 1, 2022, from https://www.biologydiscussion.com/algae/life-cycle-algae/ notes-on-sargassum-with-diagram-alage/21227 Stevenson, M. (2022, May 3). Mexico’s Caribbean beaches awash in foul-smelling sargassum algae. Times. Retrieved May 4, 2022, from https://chicago.suntimes.com/business/2022/5/3/23055666/sargassum-mexico-beaches-caribbean-algae-tourism-riveria-maya#:~:text=Yet%20the%20University%20of%20South,very%20bad%20year%20for%20Mexico
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Acknowledgments As Jane Goodall says in the acknowledgments of her book Reason For Hope, “For I too have ridden on the back of an eagle - an eagle whose every feather is someone who has helped me [...] the people who have been there to reach out a helping hand, to comfort and encourage when things went wrong, those who have provided inspiration and helped me to find the energy to continue [...] so many feathers on the eagle. For my eagle, of course, is the symbol of the great spiritual power that I believe carries us all. That supports us when our commitment and determination are put to the test. From which, if we will, we can gain strength and new energy even when we are at our most exhausted. If we have faith, and if we ask” -Jane Goodall in Reason For Hope So, I’d like to thank all the feathers on my eagle: Thank you to Sydney and Jerry Kirsch and Deb Robotham for welcoming me into your home on Ambergris Caye, telling me all that you know about Sargassum, and sparking my interest in studying this topic. To my fearless Capstone leaders (professors), John Koepke and Rebecca Krinke, thank you for encouraging me along the way and believing in my vision when I doubted myself. To my Capstone Committee members, Jessica Rossi-Mastracci, Karen Lutsky, and Kyle Franta, I thank you so much for taking time out of your days and weeks to help me iterate on, and strengthen this project. You were each chosen to be on my committee because of the way that I look up to you and your work, and I’m so grateful that I had the opportunity to learn from you all one more time. Thank you to my mentor, Grace Chryssomallis, for guiding me through my time at the University of Minnesota and taking interest in each and every one of my projects from start to finish. To my classmates and friends, I don’t even know where to start. We will forever share a unique bond having gone through this difficult and eye-opening experience together. We carried each other through difficult times, and became each others biggest cheerleaders. I’m so inspired by every one of you, and I cannot wait to see what you all accomplish. Finally, to my family. Thank you for your endless love and support as I trudged my way through this degree and through this project. It wasn’t always pretty, but you believed in me. I love you all so much. 44