SEAW ORDS TheMarineOption Program Newsletter
September 2020
Volume XXXV, Number 4
Aloha, and welcome to the September issue of Seawords! We're so excited to be back on campus for the fall semester! It's safe to say that this is a very strange start to the school year; nevertheless, it's fantastic to be back and learning once more. In honor of the new role technology is playing in our lives, we'll be highlighting a different form of marine technology each month to illuminate how scientists collect much of their data (page 22). This issue covers a variety of topics. Turn to page 6 to read about blue holes, or mysterious caverns in the ocean floor. On page 14, learn about scalloped hammerhead sharks, a coastal denizen of Hawaiian waters. Read about marine migration from heat waves on page 16. W hat would you like to see more of in Seawords?Send in your thoughts, and follow us on Twitter and Instagram at @mopseawords!
Zada Boyce-Quentin, SeawordsEditor
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Contents 2: LETTER FROM THE EDITOR 4: THE UBIQUITY OF MICROPLASTICS 6: SUPERMASSIVE BLUE HOLE 12: LIDAR: LASERSTO THE DEEP 14: ANIMAL OF THE MONTH 16: MARINE MIGRATION 20: MARINE MAMMAL OF THE MONTH 22: THE HISTORY OF ROVS
Photo Credits Fr ont Page: Scalloped hammerhead shark. By: Kris-Mikael Krister, Flickr. Tabl e of Contents: Coral reef. By: USFW S Pacific Island, Flickr. Page 12: Left and right: Close up coccolithophores. Both by: Zeiss Microscopy, Flickr. Page 14: Group of scalloped hammerhead sharks. By: John Voo, Flickr. Back Cover : Nudibranch. By: Elias Levy, Flickr. SEPTEMBER 2020
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Reef in theMaldives. Photoby: tchami, Flickr.
THE UBIQUITY OF MICROPLASTICS By: Geor gia Johnson-King, UHM MOP Student 4 | Seawords
Australian marine researchers at Flinders University have discovered that the Maldives archipelago has incredibly high levels of microplastics covering the beaches and circulating in the intertidal waters, with microplastics virtually everywhere. According to the study published August 2nd in the journal of Scienceof thetotal environment, microplastics were ubiquitous in the surveyed areas. The study was conducted on the island of Naifaru, focusing on 22 sites. The Maldives were chosen due to their immense marine biodiversity, and the renowned level of microplastics the island chain accumulates. The research team measured the concentrations of microplastics and found most particles were the same size as the prey consumed by marine life. This study is part of a larger shift in the marine conservation community dedicated to tracking the ?microplastic cycle"- how microplastics move and where they accumulate. Flinders conservation biologist Karen Burke Da Silva explained why the size of the microplastics was cause for concern stating: ?They get into the smallest fish and invertebrates, which are then consumed by larger fish.? This accumulation of microplastics in so many forms of aquatic life has raised concerns as studies have shown that their presence can cause a disruption in reproductive systems, growth, appetite, feeding behavior, tissue inflammation, and liver damage. The research confirms a worrying fact; the amount of microplastics in the oceans has been vastly underestimated. Not only are primary microplastics entering the waters, but old plastic refuse is constantly decomposing and sloughing off tiny plastic particles. Prior figures assumed a microplastic concentration of around 50 trillion accumulated particles, but this is now considered to be a naively hopeful estimate. In fact, more and more studies show that microplastics are in fact all around us- in the air, in our food and drinking water, and more. There is a desperate need for more information on microplastics; this research focused on a specific area, but their findings concerning the pervasiveness of these tiny plastic particles indicate trouble on a much broader scale.
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Aerial view of a bluehole. Photoby: Seann McAuliffe, Flickr.
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SUPER MASSIVE BLUE HOLE By: Amiti Mal oy, UHM MOP Student SEPTEMBER 2020
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Most people are familiar with the term ?black hole.? This astronomical phenomenon is so well recognized that it is referenced often in music, sci-fi, and pop culture. A similar, but far less widely known name, is that of the "blue hole." Blue holes are massive voids found on the ocean floor, formed by submerged springs producing sinkholes in porous rock.W hile the result of this gradual multi-century erosion of limestone which forges these openings can be seen in aerial views of shallower waters because of their water depth-color contrasts, possibly thousands of other waterbed sinkholes are not visually detectable. Like the most famous black hole, ?Powehi,?meaning ?adorned fathomless dark creation?in Hawaiian, the most famous blue hole also has a name, albeit a bit more playful: ?Green Banana.? The most widely accepted legend of the name?s origin credits the fishermen who first discovered the hole, who was pulling up nets when he saw a case of green bananas floating in the vicinity. Green Banana is situated about 42 miles off the coast of Florida, west of Sarasota, in the Gulf of Mexico. At least 425 feet deep, it spans over one hundred feet in diameter, though the true basin size has yet to be determined. Instead of sucking in like black holes, blue holes spew freshwater amidst the salty seas. For this reason, blue holes are sometimes referred to by fisherman as ?springs.?This phenomenon was captured as early as the 1530s when observed by Spanish explorer Hernando de Soto near Key West. According to Dr. Emily Hall, ?If you?re swimming further away from the holes, it?s pretty barren-there?s not a whole lot out there on the bottom of the Gulf, but when you get closer you see soft corals and sea grasses, and then when you get to the hole it just explodes with life, it?s really amazing.? In 1993, one of the first research teams to reach the base of the Green Banana included explorers Curt Bowen, Frank Richardson, David Miner, Jim Cutway, Larry Borden, and W in Remley with Bowen and Richardson as their deep divers. The crew set off on a four day mapping mission of Green Banana. After four days of diving, the crew successfully reached the bottom at a maximum depth of 435 fsw with a sloping silt mound observed starting at 8 | Seawords
394 fsw. Bowen hypothesizes that the ocean floor covering the Gulf of Mexico, if seen void of water, ?would probably look like Swiss cheese.? Determining the size parameters of Green Banana was a major accomplishment, but it only answered a fraction of the questions explorers have about this blue hole and the anomaly in general. Since then, Bowen?s ?Swiss cheese?analogy is getting some support; senior Mote Marine Laboratory scientist Jim Culter indicated that around 20 underwater sinkholes have been scientifically verified off Florida?s west coast so far with most likely double that number present. One of the reasons for limited progress in determining an accurate count in this area is the difficulty of identifying potential blue holes from above. According to Dr. Hall, these challenges also add to the intrigue. She explains, ?You?re in the middle of the Gulf of Mexico and you don?t see anything all around?and suddenly ?this hole opens up, and it?s booming with life.? Dr. Hall dubbed these clear water escapes as ?oases?which commonly contain a vibrant ecosystem of plants, sponges, and schools of fish. The typically smaller entrances of blue holes also create complications in
Diversdescending intobluehole. Photoby: aquaimages, Wikimedia. SEPTEMBER 2020
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Diversinsidea bluehole. Photoby: Mal B, Flickr. 10 | Seawords
research. The National Oceanic and Atmospheric Administration (NOAA) explains that this narrow entrance creates serious limitations and generally bars the use of automated submersibles. Hall?s research mission plan, funded by NOAA, includes the lowering of a 600-pound triangular prism-shaped lander into the Green Banana. The goal is that with its help, the divers will be able to collect sediment samples and water for testing, and conduct a complete biological survey of the Green Banana. This team is experienced with exploring blue holes. They recently completed a survey of the nearby 350 feet deep ?Amberjack?blue hole, during which they unexpectedly discovered two dead smalltooth sawfish, an endangered species. Surprises like that are why Hall says, ?The excitement comes from the idea that this exploration - we don?t know what we will see down there biologically and chemically. We have an idea but every time we go down there we find something new.? The pioneering research mission at Green Banana took place last month and hopes to answer Dr. Hall?s questions ?W hat?s going on out there?W ill they tell us anything about the future?? The findings have yet to be released.
Blueholefrom below. Photoby: Tim Sheerman-Chase, Flickr. SEPTEMBER 2020
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LiDAR: Lasers to the Deep By: Alexandrya Robinson, UHM MOP Student As technology advances, so does the methodology for gathering data. Recently, new developments in satellite imagery allowed scientists at Bigelow Laboratory for Ocean Sciences and Old Dominion University to gather data deeper than was previously possible. Using satellites, beams of light were bounced off of suspended particles in the water column to understand particulate dispersion. This technology, called light detecting and ranging, or LiDAR, was used on a 2018 cruise studying the ocean in the Gulf of Maine, specifically algae bloom density. Because of the highly reflective nature of algae, especially coccolithophores due to their distinguishing plate structure, LiDAR is a useful tool for scientists to gather information about the extent of algal blooms. Previously, most studies of algal blooms and other large-scale marine events relied on satellite photography; however, this method does not allow for as comprehensive a picture because these cameras are generally unable to perceive anything below about 10 meters deep. The monitoring of blooms in the Gulf of Maine has been an ongoing project, but the bloom observed by the team from Bigelow was the largest one that has been seen in thirty years. The plates of the coccolithophores made for easily identifiable signatures for the LiDAR system. This, in turn, allowed for easily observed modifications to the environment that coccolithophores created.
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Coccolithophorebloom. Photoby: NASA Goddard SpaceFlight Center, Flickr.
Most notably to one of the leads of this team, Dr. Barney Balch, was how the coccolithophore bloom "profoundly change[d] how light behaves in the environment." Though LiDAR has been used for marine research in the past, this new application allows scientists to gain more insight into algal blooms, particularly those composed of coccolithophores. This is exciting because coccolithophores play a big role in oceanic processes around the world. Due to this cruise and the findings of the team, Dr. Balch reports that this is an amazing advancement that not only adds to the knowledge base of research on coccolithophores, but holds promise for future research into how organisms modify their environment and how scientists understand ecosystems. Since the initial cruise in 2018, similar studies have been conducted in the Sargasso Sea and off the coast of New York to test the method?s efficiency in a range of environments. Dr. Balch is optimistic that this system will provide a far more in-depth and reliable way to study marine ecosystems from above. SEPTEMBER 2020
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Animal of t
Scalloped Hammerhead
By: Haley Chasin, U Did you know that the scalloped hammerhead shark has three other names, including bronze hammerhead, kidney-headed hammerhead, and the southern hammerhead?All hammerheads are easily distinguishable by the unique shape of their heads, also known as cephalofoils. These have sensory cells that are used to find food, including teleost fishes (i.e. mackerel, herring, sardines, etc.), cephalopods, smaller sharks, and stingrays. They have very small mouths compared to their body size, which can be as large as 13 feet or 4 meters. The ?scallop?indentations on their cephalofoils are also what makes the scalloped hammerhead different from other related species. Scalloped hammerhead sharks are viviparous, meaning they give birth to live young that feed off a placenta until they are born. Once the pups grow up, they live around coastal embayments and river mouths. Unlike most sharks, scalloped hammerheads have been known to aggregate in groups from time to time. Females also tend to go back to the place that they were born to breed and give birth, meaning that they are philopatric. Scalloped hammerheads have a large migration that is estimated to be hundreds of kilometers from their breeding grounds. They use body movements to communicate by shaking their head, using a sharp, curved movement of their body or spinning on an axis. Most scalloped hammerhead sharks can live for 10-32 years, but some can live to be as old as 55 years. Scalloped hammerheads live in warm tropical or temperate waters and are found mostly at greater depths. They tend to move from offshore hunting grounds to island shelves, seamounts, enclosed bays, and estuaries, where they find much of 14 | Seawords
the Month:
d Shark (Sphyrna lewini)
UHM MOP Student
Scalloped Hammerhead Shark Diet: Small fish, squid, other sharks, rays Size: Up to 13 feet long Range: Found in temperate and tropical waters worldwide Habitat: Typically shallow coastal waters, though can be found deeper as well IUCN Red List: Critically endangered
their prey. Conservation practices to protect these endangered species are taking place, but due to their large heads these sharks tend to get caught in fishing nets and are also hunted by the fin trade industry. For more information about this and how you can help, visit https:/ / www.sharkallies.com/ stop-the-fin-trade. The HIMB Shark Lab recently conducted research to see how these animals keep warm while doing deep dives of up to 800 meters. Sharks breathe by opening their mouths and letting water flow through them; they take the oxygen from the water and distribute it through their bodies. The researchers found that scalloped hammerhead sharks may hold their breath underwater by closing their mouths or gills when they descend. If they get too cold they lose metabolic and muscle function, so being able to understand this is important for their survival. To learn more about the HIMB shark lab, go to: https:/ / himbsharklab.com/ . SEPTEMBER 2020
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Marine Migration: The Consequences of Marine Heat W aves By: Zada Boyce-Quentin, SeawordsEditor 16 | Seawords
School of fish. Photoby: Artur Rydzewski, Flickr.
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The archetypical summer is one of long, sundrenched days set to a soundtrack of the hum of the air conditioner and droning of mosquitoes. Brassy skies and a blazing sun have everyone longing for the respite promised by the water. Though we often make our way to the beach as an escape from oppressive temperatures, the seas themselves are feeling the heat. Marine heat waves, a phenomenon where parts of the ocean experience extremely high temperatures for an extended period of time, are becoming increasingly common globally. Perhaps the most notorious of these was the ?Blob?, a heat wave in the northeastern Pacific which lasted for two years. The effects of these on coral reefs has been well-documented; many reefs have suffered extensive bleaching as the result of unlivable temperatures. In turn, this causes problems for the species which depend on these ecosystems for shelter, food, and breeding grounds. W hen the water heats up so dramatically, stationary or drifting organisms have no choice but to quickly adapt or perish. But what happens to nektonic organisms, which can flee if they must? Michael Jacox and his team from NOAA are investigating the consequences of marine heat waves to look at the scope of these in relation to unaffected waters in order to determine how far species might be displaced in their attempt to escape the unfavorable conditions. Because most fishes are ectothermic, or unable to regulate their own temperature, they are particularly susceptible to external conditions. Cold blooded animals overheat quickly in a rapid warming event. As a result, marine heat waves often force fishes and Marineheat wavein theGulf of Maine. Photoby: Stuart Rankin, Flickr. other oceanic organisms to retreat hastily to cooler temperatures. Jacox and his research partners found that sometimes this can mean traveling great distances from their home range; according to his research, ?in past marine heatwave events along the West Coast, there have been over 1,000 kilometers [620 miles] of displacement.?As the occurrence of marine heat waves increases due to climate change, these journeys are becoming more common for a wide variety of species. However, simply moving to cooler waters may not solve the problem. Fishes and other 18 | Seawords
Seabirdsresting. Photoby: ThomasQuine, Flickr.
organisms that are able to move freely, and lucky enough to survive the voyage to cooler waters, may encounter problems with finding suitable habitats or the right kind of food. Additionally, these moves can wreak havoc on ocean food webs and fisheries as large populations vacate areas they once inhabited. In coral reefs, this is especially concerning because lower fish populations have been shown to correlate with increased algae growth. As corals struggle to survive the increasing water temperatures, they can easily become outcompeted by algae. Seabirds, too, may struggle to find fish that have migrated due to heat. During the Blob event, a mass die-off of seabirds was one of the main indicators that there was a problem in the sea. Kathy Kuletz, author of a study about the effects of the Blob on bird populations, stated that this event ?is a very prominent example of thermal displacement.?Research on forced marine migration due to marine heat waves is still relatively new; there are many questions currently left unanswered about this phenomenon. However, this problem is not confined only to the ocean. The issue of terrestrial climate migration is quickly gaining public awareness; current models indicate significant loss of arable land to unbearable heat and drought within our lifetime, forcing millions of people to relocate to survive. Areas in Southeast Asia, North Africa, and South America are already seeing this and are producing the first wave of what may soon become a tsunami of ?climate refugees.?W hat most people fail to realize is that this same scenario is playing out for the oceans as well, and its impact may have equally devastating consequences for human populations. W hile individual action is important to reduce greenhouse gas emissions, the bigger and far more crucial battle requires each of us to use our voices to demand immediate policy changes around the world in order to combat the effects of climate change. SEPTEMBER 2020
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Spinner dolphins. Photoby: Daniel Parks, Flickr.
Marine Mammal of the Month: Hawaiian Spinner Dolphin By: Brenna Loving, UH W indward CC MOP Student 20 | Seawords
Hawaiian Spinner Dolphin Diet: Small fish, squid, shrimp Size: Up to 6 feet long; around 200 lbs Range: Tropical and subtropical waters in the Pacific Habitat: Shallow bays or lagoons during the day; move to deeper waters to hunt IUCN Red List: Least concern
W hen observing aquatic wildlife of the Hawaiian waters, it is easy to identify the Hawaiian spinner dolphins (Stenella longirostris) by their iconic aerobatics and spins. These motions are typically interpreted as a way to communicate with other individuals in the pod. Most commonly, it is to signal danger, movement, or mating intention. W hen not flying out of the water, these dolphins can be identified by their long rostrum, a triangular dorsal fin, and a black and grey color pattern. Hawaiian spinner dolphins typically live up to 25 years, grow up to 6 ft in length, and weigh 200 lbs. Similar to other species of dolphins, the spinners are very intelligent and social, swimming and hunting for food in pods of up to hundreds at a time. Typically, spinner dolphins feed on small fish, squids, and shrimp. Unlike other dolphins, spinners rest in shallow, sandy waters during the day to care for their calves, and move to deeper waters at night to hunt for food. W hile resting, they generally ?mill,?or swim slowly back and forth as half of their brain remains alert to detect predators and ensure continued breathing. Unfortunately, this habit commonly results in unwanted attention from humans on the beaches and in shallow waters. Getting too close to these animals while they are resting during the day can pose many threats to the health of an individual dolphin as well as to the rest of the pod. Not only is it unsafe to swim near these dolphins, it is also illegal to make contact with them. W hile these animals are beautiful and fascinating to observe, always remember to keep your distance and observe responsibly! SEPTEMBER 2020
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The Histor W hat is an ROV? ROVs, or Remotely Operated Vehicles, are tools frequently used by scientists to explore and collect data from regions of the ocean which would otherwise be inaccessible. Because ROVs must be capable of conducting many kinds of research, they can vary greatly in terms of size and design.
How do ROVs work? As previously stated, ROVs often vary depending on the function they are meant to fulfill. However, common features include a camera, thrusters for movement, mechanical arms to grab and lift, and a cable tethering the robot to the boat on the surface. Observation class ROVs are smaller and used for recording pictures and videos, while work class ROVs are larger and perform other tasks.
An ROV in action. Photoby: NOAA Photo Library, Flickr.
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ry of ROVs The first ROV, named POODLE, was built in 1953 by Dimitri Rebikoff. However, it was not until the 1960s, when the US Navy began to take an interest in the technology, that ROV development began to accelerate. Funds were diverted to the creation of a Cable-Controlled Underwater Recovery Vehicle (CURV), which was used to recover sunken torpedoes and other materials lost to the deep sea. CURV opened the door to future developments as more organizations saw the potential of ROVs; deep sea drilling, marine archaeology, and other fields depend on this technology to be their eyes and hands in waters unsafe for humans. Today, the term ROV refers to a diverse group of machines which are used for a wide variety of missions. You can even watch some of these online; visit https:/ / schmidtocean.org/ technology/ live-from-rv-falkor/ to see videos of their ROV dives! An ROV being deployed. Photoby: Marum, Wikimedia.
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Vol u m e XXXV, Nu m ber 4 Editor : Zada Boyce-Qu en tin 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) 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.