SEAW ORDS TheMarineOption Program Newsletter
January 2022
Volume XXXVII, Number 1
Al oha and W el come to the Januar y issue of Seawords! Hau?oli Makahiki Hou! (Happy New Year!) I?m so incredibly grateful for this opportunity and I can?t wait to begin this new journey! Mahalo nui to our departing editor Zada as well as Jeff and Cindy for all their support and help in putting out my first issue as the new editor! In this issue learn about the fascinating Christmas Island red crab migration on page 4. Explore how humans impact various aquatic environments, from microplastics in coral skeletons (page 8), to the warming of the Arctic Ocean (page 12), to the ecological state of London?s River Thames (page 18). On page 14, check out January?s creature of the month: the elusive moray eel! W hat would you like to see more of in Seawords?Send in your thoughts, and follow us on Twitter and Instagram at @mopseawords!
Abbie Jeremiah, SeawordsEditor
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Contents 2: LETTER FROM THE EDITOR 4: ITS THAT TIME OF YEAR AGAIN: THE CHRISTMAS ISLAND RED CRAB 8: MICROPLASTIC MAYHEM 12: THE ATLANTIFICATION OF THE ARCTIC OCEAN 16: CREATURE OF THE MONTH: MORAY EEL 20: NIGHT OF THE LIVING DEAD IN LONDON'S RIVER THAMES 22: MOP CALENDAR
Photo Credits Front Page: W hitemouth Moray Eel. By: Matt Kieffer, Flickr. Table of Contents: Hapuna. By: Abbie Jeremiah Back Cover: By: mountainamoeba, Flickr.
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Christmas Island red crab. Photo by: budak, Flickr.
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It's That Time of Year Again: The Chr istmas Isl and Red Cr ab By: Lucian Anderson, UHM MOP Student JANUARY 2022
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Christmas Island is an Australian territory located in the Indian Ocean, 300 kilometers from the Indonesian Island of Sumatra and 1,500 kilometers from Australia. In the times of European exploration, newfound lands were named after holidays when they were settled or found by these explorers; for example, Easter Island was discovered by European settlers on Easter. The same applies for Christmas Island, spotted on Christmas Day in 1643 by the British East India Company. Almost two-thirds of the island is now occupied by the Christmas Island National Park. Among this island's famous inhabitants is the Christmas Island red crab. The Christmas Island red crab grows up to 11.6 centimeters in length. It is distinctively cherry red, hence its name. So what makes this critter no larger than the size of a deodorant stick so special?Every year the inhabitants of Christmas Island prepare for the mass migration of the Christmas Island red crabs that walk the island in numbers so large that they paint the landscape in that vibrant red shade. An exact number of the crab population has not been calculated, but an estimate of up to 50 million crabs has been proposed. The migration generally starts sometime in October or November, just before summer starts in the southern hemisphere. W hen the crabs begin their journey is related to the first rainfall of the wet season as well as the last quarter of the moon. These two events, depending on the time between them, can cause either a speedy or relaxed migration, because these marine crabs need to keep themselves wet. The rainfall provides them with enough moisture to sustain them during the journey. Millions of crabs leave their burrows in the national park shortly after the first rainfall-- the males lead the migration, with females following shortly behind. Their migration takes them from the forests to the shoreline, where they will mate. The males arrive at the beach first and wait for the females. Once the females arrive, they outnumber the males. The crabs line up at the shoreline and replenish themselves with the tides-- this is also where the males create burrows for the eggs. Due to the high numbers of crabs, they must often fight each other for space to accomplish this task. Once the burrows are made, the males and females will mate in or near these. Once the mating is completed, the males will dip into the ocean to replenish themselves before traveling across the island again back to their homes.
Christmas Island red crabs. Photo by: Ian Usher, Wikimedia.
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Red crab megalopa. Photo by: Christopher Andrew Bray, Wikimedia.
The females, however, stay behind at the burrows. Sometime within three days of the mating process, they lay their eggs-- up to 100,000 of them which are kept in their brood pouches. Their job then is to keep the eggs moist over the two weeks the fertilized eggs need to develop further. Once the moon is in its last quarter at dawn, the female will release the eggs into the ocean. The eggs usually hatch once they come in contact with the ocean. The resultant larvae are also cherry red; in their vast numbers, they can make the water as red as cherry Kool-Aid. In a couple weeks, the crabs become functional larvae with appendages. After this, the second mass migration begins. Millions of juvenile crabs crawl across the island into the forests. These young crabs are an essential part of many local species? diets; as larvae they are eaten by fish, manta rays, and whale sharks, and as juvenile crabs they are eaten by birds. Each one is roughly half a centimeter long, and it takes them a few weeks to crawl from the tides to the forests. Some years, not many crabs survive. Every decade or so a sizable number of juvenile crabs survive the trek to the forests, keeping the population balanced. To conserve the crabs, the inhabitants of Christmas Island have adapted their infrastructure and policy to ensure the crabs can safely complete their journey. Crab bridges are built over busy roads. Less busy roads are closed during the day for the crabs to cross. Billboards are posted to let tourists and residents know of the crabs' migration across the island. The locals even have a radio broadcast updating listeners about the status of the crab migration. David Attenborough witnessed the event and filmed himself sitting down as the crabs crawled over him. He called it one of his best filmed moments. This year, the migration began on November 18th, causing some residents to be unable to leave Red crab crossing sign. Photo by: David Stanley, Flickr. their homes because of all the crabs in the area. JANUARY 2022
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M I C R O PL A ST I C M A Y H EM B y : A l ex a n d r y a R ob i n s o n
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Microplastics. Photo by: Wolfram Burner, Flickr.
Plastics Linked to Disease in Coral. Photo by: ACR Centre of Excellence, Flickr.
Oceans have been unintentional resting places for human trash and waste for years, including around 20,000 tons of microplastics. But what are microplastics? They are the result of larger pieces of plastic waste breaking down through chemical processes or mechanical weathering; the size ranges defined by NOAA are particles of plastic between 20-5,000 micrometers (anything smaller is considered a nanoplastic). These microplastics infiltrate all levels of the ocean and
can be incredibly harmful. Organisms can consume these indigestible plastics and starve to death, leaching additional chemicals and organic pollutants into the ocean. Microplastics thus move up the food chain and may cause negative health effects in humans such as liver problems and endocrine disruption. New research shows that microplastics have now been found inside the skeletons of coral. Researchers noticed that wild coral
populations close to the surface of the ocean (where around three percent of all microplastics exist) contained visible plastic debris in their skeletal structure, leading to inquiries focused on how this could possibly occur. The Department of Animal Ecology & Systematics at Justus Liebig University led an 18-month study investigating how microplastics ended up in the skeleton of corals. It was concluded that up to 84 particles of plastic per cubic centimeter were present, and that the more growth the coral underwent, the more particles were present, illustrating that the accumulation of plastic was steady as the corals grew. The team was able to apply the data found in this study to estimate that corals?microplastic uptake could explain the disappearance of between 0.09%and 2.82%of available plastic volume in the ocean. This statistic translates to an estimated 6 billion to JANUARY 2022
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Coral. Photo by: Doug Finney, Flickr.
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7 quadrillion particles forever stored in coral every year. Coral growth has been quietly and systematically removing pollution from the oceans illuminating just how valuable these organisms are. Not only do coral reefs create a home for biodiversity to thrive in the ocean, but researchers now understand that coral is also cleaning our oceans little by little. Further research is necessary to understand the repercussions for the corals as they continue to absorb microplastics. Studies show that many corals show health problems after four weeks; some bleached and experienced tissue loss. Understanding how human-made pollution continues to affect coral reefs outside of the laboratory is vital and important questions still remain. How can microplastics change the stability of reef structures in the long-term?Does the continued incorporation of microplastics into corals pose a threat to an already vulnerable organism?
Photos by: Chesapeake Bay Program, Flickr. Microplastics in the Chesapeake Bay Watershed.
" ... a n est i m at ed 6 bi l l i on t o 7 qu a d r i l l i o n [ m i c r op l a st i c ] p a r t i cl es a r e f o r ev er st o r ed i n c o r al ev er y y ea r ...."
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Arctic Ocean. Photo by: Sentinel Hub, Flickr.
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The Atlantification of the Arctic Ocean By: Brenna Loving, UH W indward CC MOP Student As researchers have known for years, temperatures in the Arctic have been rising rapidly as a result of increasing climate change. W hat has recently come to light, however, is a factor that has played a larger role in the rising temperatures than previously thought. The movement of water from the Atlantic Ocean into the Arctic, known as Atlantification, has been a natural phenomenon discovered to have been occurring for the past 800 years as found through reconstruction of sediments between Norway and Greenland. Interestingly, the temperature increase during that time period remained gradual until the beginning of the 20th century. However, there is a discrepancy between the reconstruction and model simulators. This is resulting in some changes in the estimates of how and why this early Atlantification came about. This makes it increasingly difficult to create further hypotheses and future planning for how to manage the rising temperatures in the Arctic as global warming ensues. Scientists are still unsure why there was such a large spike in temperatures in the early 20th century, and how much of that change can be attributed to human involvement. One belief is that the Atlantic Meridional Overturning Circulation (AMOC), also known as the conveyor belt of circulating currents, played a role in early Atlantification during a period of weakness in the AMOC after a cooling in the 1800?s. The AMOC is now facing further instability due to human-attributed climate change, which is posing a plethora of new threats to climates around the globe, and possibly furthering the process of Atlantification. This warming of the Arctic ocean is one of the most detrimental aspects of climate change we are facing today. As the ice melts due to rising temperatures and Atlantification, more ice continues to melt as a result, thus changing the marine environment too quickly for the ecosystem to adapt accordingly. As long as humans continue to burn fossil fuels and encourage the effects of climate change, the Arctic will remain vulnerable and increasingly at risk of detrimental effects. JANUARY 2022
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Moray eel. Photo by: tchami, Flickr.
Cr eatur e of the Month: Mor ay Eel By: Haley Chasin, UHM MOP Alumna JANUARY 2022
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Moray eel. Artwork by: Alyssa Perez, UHM MOP Student.
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A moray eel peeking out from its hiding place among the nooks and crannies of a coral reef is a common sight in Hawai ?i. With over 30 species residing on the islands, these fascinating creatures have a place not only in the marine ecosystems of Hawai ?i but also in its culture. Moray eels, or puhi, are ?aumakua, or ancestral spirit guardians sent to protect, and are also associated with Ku, the god of war. These eels are also found in Hawaiian folklore, frequently as an obstacle which must be overcome. Moray eels, which make up the family Muraenidae, are a kind of fish which can be classified in two groups?the sharp-toothed morays, which most often feed on fish and octopuses, while the blunt-toothed morays prefer to hunt crustaceans. Morays hunt at night, relying more on their strong sense of smell than their eyesight to track prey. Some studies have even found the eels to use interspecies cooperative hunting. Instead of utilizing negative pressure to swallow their prey, moray eels have a second set of jaws in their throat called pharyngeal jaws. When they feed, they launch the pharyngeal jaws forward into their mouth, where they grasp the prey and transport it back to the throat. Physically, moray eels are defined by their snake-like bodies and elongated caudal fins, posterior nostrils located high on their head, extraneous facial pores, lateral lines, and distinct teeth. Notably, morays have neither pelvic nor pectoral fins, and lack scales as well. Their bodies are generally less than 5 feet long, with patterns that differ between species for camouflage. These make it easy for the eels to hide in small spaces, evading predators and hiding from prey until they are ready to strike. Moray eel skin is also intriguing due to the layer of toxic mucus which coats it. These eels have thick skin and a high density of goblet cells (cells that secrete mucins) in their epidermis, allowing the mucus to be produced at a higher rate than in other eel species. This mucus has a variety of roles in the eel?s life, from letting them more easily slide into nooks and crannies on the reef to protecting them from parasites. Many morays begin their lives as males and shift to a female biology as needed?a trait referred to as hermaphroditism?but some are synchronous hermaphrodites, being both male and female simultaneously. Their larvae are flat and transparent, surviving as planktonic organisms for 3 months to a year in the open ocean before settling in reef habitats. These eels rarely present a danger to humans and generally only bite when provoked. Still, as always, it is best to be cautious when entering a reef ecosystem, as these organisms tend to hide in small, concealed spaces. Seeing an eel on the reef is always a treat-- stay conscientious and enjoy the ocean!
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NIGHT OF THE LIVING DEAD IN LONDON'SRIVER THAMES BY: Chloe Molou, UHH SeawordsLiaison
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The Thames. Photo by: Fernando Garcia Redondo, Flickr.
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River Thames. Photo by: Caetano Candal Sato, Flickr.
More than 50 years after parts were declared biologically dead, London's River Thames seems to be teeming with life, according to a recent report by the Zoological Society of London. The famous waterway became highly polluted during the Industrial Revolution, with toxic runoff and raw sewage entering the river and eventually causing the ?Great Stink?in 1858, which forced the British government to develop proper waste disposal systems for the city. A century later, the British National History Museum would declare parts of the river biologically dead, with oxygen levels too low to sustain life. Now, the Thames is home to 115 species of fish, and 92 species of wildfowl. Two types of seals are among the returning wildlife, as both the harbor and the gray seal can now be spotted in the Thames. Another exciting return is made by the migratory wading bird, the avocet. After habitat loss caused the bird to become an extinct breeding species in Britain by 1842, the population has more than doubled over the last three decades in the tidal Thames. Seahorses, eels, and sharks have also made a return, with tope, starry smooth hound, and spurdog sharks appearing in the waterway. The report also revealed promising trends with long-term increases in dissolved oxygen, which is beneficial to fish populations, as well as long- and short-term decreases in phosphorus concentrations, which can be attributed to the improved sewage treatment works that stop harmful nutrient levels entering the river. However, the report does warn of a long-term increase in nitrate concentration which will affect water quality, as well as the effects of climate change which have already caused recorded water temperature and sea levels higher than historical baselines. W hile things seem promising for the famous Thames, there is still work to be done to ensure that this estuary can continue to rejuvenate life, as well as encouraging more cities around the world to continue clean-up efforts in their central water bodies.
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The Thames barrier. Photo by: Graeme Maclean, Flickr.
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Vol u m e XXXVII, Nu m ber 1 Editor : Abbie Jer em iah Dr. Cyn th ia H u n ter (em in en ce gr ise) Jeffr ey Ku wabar a (em in en ce gr ise) W r itin g Team : Br en n a Lovin g, Ch l oe M ol ou , Lu cian An der son , Al exan dr ya Robin son , H al ey Ch asin , an d Geor gia Joh n son -Kin g Seawor ds- M ar in e Option Pr ogr am Un iver sity of H awai ?i , Col l ege of Natu r al Scien ces 2450 Cam pu s Road, Dean H al l 105A H on ol u l u , H I 96822-2219 Tel eph on e: (808) 956-8433 Em ail : <seawor ds@ h awaii.edu > W ebsite: <h ttp:/ / www.h awaii.edu / m op> Seawor ds is th e m on th l y n ewsl etter n ewsl etter of th e M ar in e Option Pr ogr am at th e Un iver sity of H awai?i. Opin ion s expr essed h er ein ar e n ot n ecessar il y th ose of th e M ar in e Option Pr ogr am or of th e Un iver sity of H awai?i. Su ggestion s an d su bm ission s ar e wel com e. Su bm ission s m ay in cl u de ar ticl es, ph otogr aph y,ar t wor k , or an yth in g th at m ay be of in ter est to th e m ar in e com m u n ity in H awai ?i. an d ar ou n d th e wor l d. All photos ar e taken by M OP unless other wise cr edited.