Constantine Alexander's Journal

Tracking down the whale-shark highway

A whale shark near the Galapagos Islands being measured by a diver using laser photogrammetry. © Jonathan Green/Galapagos Whale Shark Project.

Did you know that August 30 is International Whale Shark Day? Whale sharks are the largest fishes on Earth, growing up to 18 meters (60 feet) long, but they feed mostly on tiny drifting animals such as copepods and, occasionally, small fish such as anchovies. To satisfy their immense appetites, whale sharks travel long distances to find dense swarms of prey.

MBARI biological oceanographer John Ryan recently worked with biologists who have been tracking whale sharks in the Eastern Tropical Pacific Ocean. They discovered that whale sharks in this area spend most of their time cruising along fronts--the dynamic boundaries between warm and cold ocean waters. This study, recently published in the journal PLoS One, could help in the conservation of these endangered animals.

In 2011 and 2012, a team of researchers from Ecuador and England attached satellite tracking tags to 27 whale sharks at Darwin's Arch, a remote location about 200 kilometers (125 miles) northwest of the main Galapagos archipelago, and about two degrees north of the equator. This was the first time whale sharks had been tagged in the Eastern Tropical Pacific. The tagged sharks spent the next four to six months traveling east and west from this location across a 4,000-kilometer expanse of ocean, mostly staying between the equator and five degrees north latitude.

The researchers contacted Ryan to help them figure out how the whale-shark movements related to ocean conditions. This was a challenging task because ocean conditions are continually changing and whale sharks are always on the move.

Sea-surface temperatures, routinely measured by satellites, can reveal the oceanic features that whale sharks encounter during their large-scale movements. Ryan analyzed day-to-day changes in sea-surface temperature across the entire Eastern Tropical Pacific for the months when the whale sharks were being tracked. Because the Equatorial Pacific is often cloudy, Ryan used a combination of infrared and microwave radiation data from satellites (microwave radiation can pass through clouds).

When Ryan first looked at the whale-shark tracks in relation to the satellite data, he was struck by how consistent the tracks were. "The whale sharks could have ranged anywhere in the Eastern Tropical Pacific," he said, "but they were primarily following frontal boundaries between warm and cold water."

Extending across the Eastern Pacific is a distinct boundary between warm water north of the equator and colder water to the south. This boundary is called the North Pacific Equatorial Upwelling Front. Ryan's analysis showed that whale sharks followed this front as if it was an open-ocean highway. When the front moved north and south in huge wave-like meanders, the whale sharks followed these meanders like semi trucks negotiating a winding mountain road.

Darwin's Arch, the whale-shark tagging site, is located right in the middle of the equatorial front. This could explain why whale sharks are often seen in the area, but rarely hang around for very long.

Ryan pointed out that the equatorial front is an environmental transition zone. "To the north of this zone, the water is warm and stable but there's not a lot of productivity," he explained. "To the south the water has high productivity, but is much colder."

He continued, "Previous studies showed that plankton [small, drifting plants and animals] can accumulate in this transitional zone. So this zone may be a good place for whale sharks to find dense food patches, while not getting too chilled by cold water."

Ryan also discovered that, when whale sharks approached the coasts of Central and South America, they followed fronts in these areas as well. Though less extensive than the equatorial front, these coastal fronts also form at boundaries between cold, high-productivity water and warm, less productive water. Whale sharks appear to head for these "secondary highways" in January or February, when the equatorial front typically weakens or disappears.

In an interesting side note, almost all of the whale sharks tracked in this experiment appeared to be pregnant females. The one adult male that was tracked followed a similar path as the females. Two juvenile whale sharks that were tracked followed different paths, farther away from the equatorial front.

In 2016, whale sharks were declared an endangered species, their numbers threatened by shark finning, entanglement in fishing gear, and boat collisions. But one of the biggest challenges in whale-shark conservation is simply coming up with good population estimates. By demonstrating that whale sharks can be found along fronts, this study will make it easier for marine biologists to estimate how many of these gentle giants are out there riding the rolling waves of the whale-shark highways.

Citation: John P. Ryan, Jonathan R. Green, Eduardo Espinoza & Alex R. Hearn; Association of whale sharks (Rhincodon typus) with thermo-biological frontal systems of the eastern tropical Pacific; PLOS ONE, 2017; 12 (8): e0182599; DOI: 10.1371/journal.pone.0182599.

Contact: Kim Fulton-Bennett
Monterey Bay Aquarium Research Institute

 

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A Galápagos seabird's population expected to shrink with ocean warming

Nazca Boobies. Photo by Joe Novella (CC 2.0)

Within the next century, rising ocean temperatures around the Galápagos Islands are expected to make the water too warm for a key prey species, sardines, to tolerate. A new study by Wake Forest University biologists, published in PLOS ONE Aug. 23, uses decades of data on the diet and breeding of a tropical seabird, the Nazca booby, to understand how the future absence of sardines may affect the booby population.

Researchers have studied diet, breeding and survival of Nazca boobies as part of a long-term study at Isla Española in the Galápagos Islands for more than 30 years. In 1997, midway through the study, sardines disappeared from Nazca booby diet samples and were replaced by the less-nutritious flying fish.

As flying fish replaced sardines in the birds' diet, "reproductive success was halved," said Emily Tompkins, a Ph.D. student at Wake Forest and lead author of the study. "If the current links between diet and reproduction persist in the future, and rising ocean temperatures exclude sardines from the Galápagos, we forecast the Nazca booby population will decline," Tompkins said.

David Anderson, Wake Forest professor of biology and co-author of the study, said: "Few connections have been made between ocean warming and population effects in the tropics, making this study significant."

The study increases understanding of one species' response to climate change in tropical oceans, but also suggests that other Galapagos predators that do well when sardines are available must adjust to a new menu within the next 100 years.

Citation: Emily M. Tompkins, Howard M. Townsend & David J. Anderson; Decadal-scale variation in diet forecasts persistently poor breeding under ocean warming in a tropical seabird; PLOS ONE, 2017; 12 (8): e0182545 DOI: 10.1371/journal.pone.0182545.

Contact: Cheryl Walker
Wake Forest University

 

Climate change is luring Kodiak bears away from their iconic salmon streams

A female bear and her cubs on Kodiak Island, Alaska. Photo by Lisa Hupp, U.S. Fish and Wildlife Service.

Kodiak brown bears are abandoning salmon-their iconic prey-due to climate change, according to a new study. The bears are more interested in chowing down on early-arriving red elderberries. The likely result of this "prey switch," the researchers conclude, is a disrupted ecosystem on Alaska's Kodiak Island.

The research was conducted by biologists at Oregon State University, University of Montana's Flathead Lake Biological Station, and Kodiak National Wildlife Refuge. The findings were published this week in the journal Proceedings of the National Academy of Sciences. The bears-the largest in the world-typically gorge on sockeye salmon in the summer. But in 2014, researchers were surprised to see streams in the Kodiak National Wildlife Refuge full of salmon-with no bears in sight. The scene repeated itself the next year.

"Prior to that summer, we found streams that were littered with thousands of shredded salmon carcasses," Will Deacy, a postdoctoral researcher in OSU's College of Agricultural Sciences and lead author on the study. "In 2014 and again in '15, we were stunned to find such a strikingly different scene. There were piles of rotting, intact carcasses that had died after spawning instead of being killed by bears."

It turns out the bears were on the hillsides, feeding on abundant red elderberries, which typically ripen after salmon have finished spawning in streams. Wild fruit, chock full of carbohydrates, is typically an important part of a brown bear's diet, especially when the spawning salmon are gone.

Until recently, the bears would eat fish for most of the summer and then move on to the berries, which typically ripen at the end of the salmon season and are available from late August into early September. Bears are generalists that consume dozens of different foods throughout the year, but sockeye salmon and red elderberries are key foods for them.

The researchers found that due to warm spring temperatures on Kodiak, the berries were developing fruit weeks earlier, at the same time as the peak of the salmon migration; 2014 was one of the warmest years on the island since record-keeping began 60 years ago. Although there will continue to be considerable variation in Kodiak's climate, the warming trend is likely to continue.

The research team analyzed the bears' scat to find direct evidence that the bears were consuming the berries and not the salmon.

"An earlier berry crop shut down one of the most iconic predator-prey scenes in nature," said Jonny Armstrong, an ecologist at OSU and member of the research team. "As climate change reschedules ecosystems, species that were once separated in time are now getting a chance to interact--in this case the berries, bears and salmon. This is going to have large impacts that are hard to predict."

For example, birds that depend on bears pulling salmon out of the stream, could be seriously affected, he said. Other far-reaching effects may include changes in bear demographics due to the change in their diet, evolving salmon populations and impacts on plant pollinators.

"It is a strange, indirect effect of climate change," Deacy said. "These bears eat dozens of different foods throughout the year but now two of them are overlapping. This is causing a disruption in the food web that could have profound implications for the ecology of the island."

The abundance of salmon and berries on Kodiak Island are why there are so many bears there, and why they are so large, said Jack Stanford, director emeritus at the University of Montana's Flathead Lake Biological Station and one of the study's co-authors.

"This overlap in their resources forces the bears to make a choice that could in the long run result in fewer bears and/or unexpected changes in ecosystem structure," Stanford said.

Citation: William W. Deacy, Jonathan B. Armstrong, William B. Leacock, Charles T. Robbins, David D. Gustine, Eric J. Ward, Joy A. Erlenbach & Jack A. Stanford; Phenological synchronization disrupts trophic interactions between Kodiak brown bears and salmon; Proceedings of the National Academy of Sciences, 2017, 201705248; DOI: 10.1073/pnas.1705248114.

Contact: Jonny Armstrong
Oregon State University 

 

Warmer waters from climate change will leave fish shrinking, gasping for air

Infographic Credit: Lindsay Lafreniere.

Fish are expected to shrink in size by 20 to 30 per cent if ocean temperatures continue to climb due to climate change. A new study by researchers at the University of British Columbia provides a deeper explanation of why fish are expected to decline in size.

"Fish, as cold-blooded animals, cannot regulate their own body temperatures. When their waters get warmer, their metabolism accelerates and they need more oxygen to sustain their body functions," said William Cheung, co-author of the study, associate professor at the Institute for the Ocean and Fisheries and director of science for the Nippon Foundation-UBC Nereus Program. "There is a point where the gills cannot supply enough oxygen for a larger body, so the fish just stops growing larger."

Daniel Pauly, the study's lead author and principal investigator of the Sea Around Us at the Institute for the Ocean and Fisheries, explains that as fish grow into adulthood their demand for oxygen increases because their body mass becomes larger. However, the surface area of the gills -- where oxygen is obtained -- does not grow at the same pace as the rest of the body. He calls this set of principles that explains why fish are expected to shrink "gill-oxygen limitation theory."

For example, as a fish like cod increases its weight by 100 per cent, its gills only grow by 80 per cent or less. When understood in the context of climate change, this biological rule reinforces the prediction that fish will shrink and will be even smaller than thought in previous studies.

Warmer waters increase fish's need for oxygen but climate change will result in less oxygen in the oceans. This means that gills have less oxygen to supply to a body that already grows faster than them. The researchers say this forces fish to stop growing at a smaller size to be able to fulfill their needs with the little oxygen available to them.

Some species may be more affected by this combination of factors. Tuna, which are fast moving and require more energy and oxygen, may shrink even more when temperatures increase. Smaller fish will have an impact on fisheries production as well as the interaction between organisms in the ecosystems.

Citation: Daniel Pauly & William W. L. Cheung; Sound physiological knowledge and principles in modeling shrinking of fishes under climate change; Global Change Biology, 2017; DOI: 10.1111/gcb.13831.

Contact: Valentina Ruiz Leotaud
University of British Columbia

 

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New gene catalog of ocean microbiome reveals surprises

HOT crew member Tara Clemente collects water from the CTD rosette for sample processing. Credit: HOT Program, UHM SOEST.

Microbes dominate the planet, especially the ocean, and help support the entire marine food web. In a recent report published in Nature Microbiology, University of Hawai'i at Mānoa (UHM) oceanography professor Ed DeLong and his team report the largest single-site microbiome gene catalog constructed to date. With this new information, the team discovered nutrient limitation is a central driver in the evolution of ocean microbe genomes.

As a group, marine microbes are extremely diverse and versatile with respect to their metabolic capabilities. All of this variability is encoded in their genes. Some marine microorganisms have genetic instructions that allow them to use the energy derived from sunlight to turn carbon dioxide into organic matter. Others use organic matter as a carbon and energy source and produce carbon dioxide as a respiration end-product. Other, more exotic pathways have also been discovered.

"But how do we characterize all these diverse traits and functions in virtually invisible organisms, whose numbers approach a million cells per teaspoon of seawater?" asked DeLong, senior author on the paper. "This newly constructed, comprehensive gene catalog of microbes inhabiting the ocean waters north of the Hawaiian Islands addresses this challenge."

Water samples were collected over two years, and modern genome sequencing technologies were used to decode the genes and genomes of the most abundant microbial species in the upper 3,000 feet of water at the Hawai'i Ocean Time-series (HOT) Program open ocean field site, Station ALOHA.

Just below the depth of sunlit layer, the team observed a sharp transition in the microbial communities present. They reported that the fundamental building blocks of microbes, their genomes and proteins, changed drastically between depths of about 250-650 feet.

"In surface waters, microbial genomes are much smaller, and their proteins contain less nitrogen--a logical adaptation in this nitrogen-starved environment," said Daniel Mende, post-doctoral researcher at the UHM School of Ocean and Earth Science and Technology (SOEST) and lead author on the paper. "In deeper waters, between 400-650 feet, microbial genomes become much larger, and their proteins contain more nitrogen, in tandem with increasing nitrogen availability with depth."

"These results suggest that the availability of nutrients in the environment may actually shape how microbial genomes and proteins evolve in the wild," said DeLong. "Another surprising finding of the study is that the microbial 'genomic transition zone' observed occurs over a very narrow depth range, just beneath the sunlit layer. Below about 650 feet deep, the fundamental properties of microbial genomes and proteins are relatively constant, all the way down to the seafloor."

In collaboration with a computer science group led by professor Bonnie Hurwitz at the University of Arizona, the new database is available to scientists worldwide who are seeking to describe the nature and function of microbes in the global oceans.

"These new data will provide an important tool for understanding the nature and function of the ocean's microbiome today, as well as help predict its trajectory into the future," said DeLong.

Citation: Daniel R. Mende, Jessica A. Bryant, Frank O. Aylward, John M. Eppley, Torben Nielsen, David M. Karl & Edward F. DeLong; Environmental drivers of a microbial genomic transition zone in the ocean’s interior. Nature Microbiology, 2017; DOI: 10.1038/s41564-017-0008-3.

Contact: Marcie Grabowski
University of Hawaii at Manoa

 

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The ocean's fastest shark is being threatened by over fishing

New study shows Shortfin mako shark fishing mortality rate is much higher than previously thought.

Shortfin mako shark in the north Atlantic at Condor Bank, Azores. Credit: Patrick Doll (CC 3.0)

More bad news for sharks. A new study using satellite tracking by researchers from Nova Southeastern University's Guy Harvey Research Institute (GHRI), the University of Rhode Island and other colleagues shows that the fishing mortality rate of the shortfin mako in the western North Atlantic is considerably higher than previously estimated from catches reported by fishermen. These data suggest that this major ocean apex predator is experiencing overfishing, raising serious concerns about whether the current levels of fishery catches in the North Atlantic are sustainable. The new study has been published in the Journal Proceedings of the Royal Society B.

"Traditionally, the data obtained to determine the rate of fishing mortality, a key parameter used to help gauge the health of shark stocks, has depended largely on fishermen self-reporting any mako sharks they may have caught," said Mahmood Shivji, Ph.D., senior author of the study and director of the NSU's GHRI. "The challenge is that not all fishermen report the same way or some may underreport or even not report their mako shark captures at all, so the these catch data are known to be of questionable reliability."

Shivji said that near real-time tracking of mako sharks using satellite tags and directly seeing how many were captured allowed researchers to bypass the dependency on self-reporting by fishermen.

"Using satellite tags for makos and possibly other fished species can be a time-efficient way and a fisheries-independent tool for gathering useful fisheries-interaction data, including answering fundamental questions about the levels of fishing survival and mortality," said Michael Byrne, Ph.D., the paper's lead author and postdoctoral fellow at NSU's GHRI when the study was done. "The tracking data also showed these mako sharks entered the management zones of 19 countries, underscoring how critical it is for countries to work together closely to manage and conserve these long-distance oceanic travelers." When the researchers began to gather, compile, disaggregate and review the data, the results were startling.

An unexpectedly high proportion, 30% of the 40 satellite tagged sharks, were captured in fisheries. After modelling the probability that a mako shark would survive a year without being captured (a 72% chance) and calculating the fishing mortality rates, researchers determined that the rate at which shortfin makos were being killed in fisheries was actually 10 times higher than previously believed.

"From a conservation and protection point of view, this is huge," said Bradley Wetherbee, Ph.D., a research scientist from the University of Rhode Island's Department of Biological Sciences and a member of NSU's GHRI. "It's vital that we have the most accurate data possible to aid decision-makers in managing marine life populations sustainably. If they have inaccurate information, it's much more difficult to make the correct decisions for properly managing populations. Everyone wants the populations managed in a sustainable way."

The tracks of the tagged mako sharks, including the ones captured, can be viewed online on NSU's GHRI shark tracking website.

Globally, many shark species have seen significant declines in their numbers, with fisheries overexploitation cited as a major cause. This can happen in many ways -- some shark species are specifically targeted while others are captured by accident (called bycatch.) No matter how sharks are taken from the world's oceans, the fact remains that the current levels of removal for many species are unsustainable.

The researchers stress that the work they are doing has the goal of providing the most accurate information possible to those in positions to take action to manage mako and other shark species. They both say that the goal is create successful fisheries management and conservation - to avoid declining populations, and to do that, we must have as much accurate data as possible.

"We have to have sustainable approaches to fishing," Dr. Shivji said. "Sharks might get a bit of a bad rap in the media, but these apex predators are vital to the overall health of our oceans. You remove them from the equation and, quite honestly, we don't know how far those ripples will be felt. One thing we do know is it won't be inconsequential."

Citation: Michael E. Byrne, Enric Cortés, Jeremy J. Vaudo, Guy C. McN. Harvey, Mark Sampson, Bradley M. Wetherbee & Mahmood Shivji; Satellite telemetry reveals higher fishing mortality rates than previously estimated, suggesting overfishing of an apex marine predator; Proceedings of the Royal Society B: Biological Sciences, 2017; 284 (1860): 20170658; DOI: 10.1098/rspb.2017.0658.

Contact: Joe Donzelli
Nova Southeastern University

 

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Wildlife royalties - a future for conservation?

Should people who profit from the cultural representation of wildlife pay towards conservation? That is the question asked in new research conducted by zoologists from Oxford University's Wildlife Conservation Research Unit (WildCRU).

Writing in the journal Animals, they muse on whether organisations that profit in some way from wildlife imagery and popularity, could establish a corporate responsibility to contribute a portion of this income to the conservation of the animals represented.

Big cats for example, are a marketing dream. From catwalk trends to product branding and sports team representation, their likeness is everywhere and used to sell everything from patriotism to eggs. In fact, as the face of the British Lion Quality Seal, lions sell about 30 million eggs a day in Britain.

Using the product as an example, the paper argues that if a royalty system were introduced, and each lion stamp were to earn the species one tenth of a penny, then every day lion conservation could receive £28,900.That's £10.5 million a year.

But, the wildlife itself, is in crisis. Again, using lions as an example, the combined effects of everyday human conflicts with local African communities, poaching, habitat loss and trophy hunting mean there are now probably less than 25,000 left in the wild.

When you consider how much revenue could be made from egg sales alone, introducing a royalty for the use of wildlife imagery is both logical and highly lucrative way to fund conservation.

Caroline Good, WildCRU's Recanati-Kaplan post-doctoral fellow in Art and Conservation, said: 'Soccer is the most popular sport in the world and as a result one of the richest. The English Premier League uses a crowned lion as its logo. It is the richest of all the leagues and sells 5m strips a year. Even if the league contributed just £1 for every t-shirt sold per year, it would be enough to employ 4,000 local people to act as lion defenders each year, in areas where the species is under threat. It would also be good for the league's charitable footprint and buy them a lot of good publicity into the bargain.'

On paper it seems like a system that would benefit all involved. But, it requires significant consideration to be effective. A species royalty scheme would primarily benefit carnivorous species and mega fauna, but it would leave less charismatic, 'appealing' wildlife without a financial lifeline. But, as apex predators, who sit at the top of the food chain, all wildlife sharing their habitat stand to benefit from the protection of big cats and mega fauna.

Dr Dawn Burnham, co-author and a researcher at Oxford's WildCRU, said: 'The quest for new mechanisms to fund conservation is a matter of live or death for wildlife. We have increasingly sophisticated Payments for Ecosystems Services and REDD schemes, but its not enough. Our idea for a royalty adds another option and, remembering that so many endangered species are in very poor countries this idea could cost little to the donors while making a huge difference."

Professor David Macdonald, Director of WildCRU, said: 'When you consider the volume of animal symbols, prints, and logos that adorn clothes, food, branding, and buildings, we are heavily indebted to charismatic wildlife. For centuries these species have brought people feelings of luck and protection, helping shape personal, professional, and national identities. It is now our turn to protect them and their habitat.'

Citation: Caroline Good, Dawn Burnham & David W. Macdonald; A Cultural Conscience for Conservation; Animals 2017, 7 (7), 52; DOI: 10.3390/ani7070052.

Contact: Lanisha Butterfield
University of Oxford

 

New NOAA Fisheries research reveals ecosystem cascades affecting salmon

Changing ocean conditions influence bird predation on salmon from San Francisco Bay.

Common murres flying with forage fish (likely anchovy) in their mouths near their breeding ground on the Farallon Islands off San Francisco. Credit: Point Blue Conservation Science.

Interpreting relationships between species and their environments is crucial to inform ecosystem-based management (EBM), a priority for NOAA Fisheries. EBM recognizes the diverse interactions within an ecosystem -- including human impacts -- so NOAA Fisheries can consider resource tradeoffs that help protect and sustain productive ecosystems and the services they provide.

In the coastal ocean of California -- seabird predators, forage fish on which they feed, and the survival of salmon out-migrating to sea are each of particular interest, and an improved understanding of their interactions could in turn improve the management of the ocean ecosystem.

For example, in the California Current, understanding the interactions between predator seabirds, forage fish in the coastal ocean and out-migrating salmon from San Francisco Bay could improve the understanding of salmon early survival in the ocean and a measure of the possible strength of the year class return.

In the Gulf of the Farallones, new research by scientists from NOAA Fisheries' Southwest Fisheries Science Center, Point Blue Conservation Science, H.T. Harvey and Associates, University of California Santa Cruz, U.S. Geological Survey and the U.S. Fish and Wildlife Service found that the common murre, a small ocean seabird, can make a difference in the number of salmon that survive to return as adults. This is especially true when ocean conditions cause the murres to feed primarily on salmon and anchovy. The research has been published online in the Journal of Marine Systems, and will be included in the journal's October print issue.

Large colonies of more than 500,000 common murres nest throughout the Gulf of the Farallones, offshore of San Francisco. In typical years, with nutrient-rich water welling up from the depths, the murres prey primarily on young rockfish around their offshore breeding sites.

When ocean conditions change, and the upwelling falters, young rockfish that are the typical prey for the murres become scarce. Then the murres switch, feeding instead on adult northern anchovies found closer to shore. That's a problem for the young salmon entering the ocean at these near-shore locations, because the murres eat them too.

The finding documents one of the first examples of what biologists call "bottom-up" influences -- changes at the base of the food web -- causing "top-down" effects on West Coast salmon, such as an increase in predation by a species higher in the chain, in this case the common murres.

The murre colony on the Farallon Islands off the California Coast, as viewed from a research study blind atop Shubrick Point, July 2017. Credit: Point Blue Conservation Science

"This is the first example we've found involving salmon where bottom-up drivers are causing top-down impacts," said NOAA Fisheries research biologist Brian Wells, lead author of the research. "The lack of upwelling affects salmon in a top-down way."

The new research shows that salmon survival drops sharply in the years when ocean conditions lead the murres to prey on anchovy and salmon. Even in years when the murres are preying on anchovy, salmon comprise less than 10 percent of the diet of the murres; but the impact can be a significant factor in the survival of salmon. The research concludes that predation by the seabirds can make a difference in the number of salmon that survive to return as adults.

The salmon affected are primarily fall-run Chinook, which are the primary species supporting salmon fisheries off the California Coast. The research helps reveal the complex relationships between species and their environment, which in turn helps NOAA Fisheries anticipate and respond to changes that affect fish, birds and people.

For example, the murres preyed heavily on anchovy and salmon in 2005, which likely contributed to the collapse of the California salmon fishery in 2007 and 2008, the researchers found. Congress appropriated $170 million in disaster relief for fishermen affected by the collapse.

NOAA Fisheries managers can use the details to make better decisions about how best to protect and manage marine species.

"Understanding the dynamics behind these connections can help us anticipate impacts to salmon, which are very important both economically and environmentally," said John Field, a research fisheries biologist at the SWFSC in Santa Cruz. "That can help fisheries managers make smart and informed decisions about how to manage these species into the future."

Citation: Brian K.Wellsa, Jarrod A.Santorab, Mark J.Hendersonc, PeteWarzybokd, JaimeJahncked, Russell W.Bradleyd, David D.Huff, Isaac D.Schroederf, PeterNelsong, John C.Fielda, David G.Ainleyh; Environmental conditions and prey-switching by a seabird predator impact juvenile salmon survival; Journal of Marine Systems, Volume 174, Pages 54-63 (October 2017); DOI: 10.1016/j.jmarsys.2017.05.008. 

Contact: Michael Milstein
NOAA Fisheries West Coast Region

 

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New research findings to standardize first-aid treatment of jellyfish stings

Vinegar and heat are found to be the best treatment of stings from lion's mane jellyfish.

This is a Lion's mane jellyfish in Dingle Harbour, Ireland. Photo: Nuala Moore.

New research from NUI Galway and the University of Hawaii at Manoa has identified the best way to treat a sting from the lions mane jellyfish (Cyanea capillata). The lions mane jellyfish is the most problematic jellyfish in Ireland and the UK with 1000s of bathers being badly stung each year. With over a 1,000 tentacles that can stretch up to four or five metres in length, a bad sting from a lions mane jellyfish can cause severe local reactions and extreme pain.

The research, published in the international journal Toxins shows that the best first aid for a lions mane sting is to rinse with vinegar (or the commercial product Sting No More® Spray) to remove tentacles, and then immerse in 45°C (113°F) hot water (or apply a heat pack) for 40 minutes. The results mirror a recent NUI Galway and University of Hawaii study on stings from the Portuguese man o war and previous work on box jellyfish stings.

Dr Tom Doyle, lead author of the study and Lecturer in Zoology from the School of Natural Sciences at NUI Galway, said: "What most people don't understand is that these jellyfish -- the lions mane, the Portuguese man o war and a box jellyfish, are as different from each other as a dog and a snake.

"Therefore when developing first aid treatment for a jellyfish sting it is very important to test different treatments on these very different types of jellyfish. Now that we have shown that vinegar and hot water work on these three jellyfish species, it will be much easier to standardise and simplify first aid for jellyfish stings where many different types of jellyfish occur."

In Ireland and the UK, current best practices recommend using sea water and cold packs, which is not the correct action for treating these jellyfish stings as it induces significant increases in venom delivery, while rinsing with vinegar or Sting No More® Spray did not.

Dr Doyle now hopes to bring together members of the Jellyfish Advisory Group in Ireland to discuss his latest findings. However, it is important to remember that most jellyfish stings in Ireland and the UK are no worse than a nettle sting.

Citation: Thomas Doyle, Jasmine Headlam, Christie Wilcox, Eoin MacLoughlin & Angel Yanagihara; Evaluation of Cyanea capillata Sting Management Protocols Using Ex Vivo and In Vitro Envenomation Models; Toxins, 2017; 9 (7): 215 DOI: 10.3390/toxins9070215.

Contact: Dr Tom Doyle
National University of Ireland Galway

To support research on the distribution and abundance of jellyfish in Ireland, members of the public can record any sightings at this website. 

 

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Circles in the sand reveal boating damage to marine biodiversity

The findings of a study by Swansea and Cardiff University scientists highlights the need for boating activities along the UK's beautiful coastlines to be conducted in a more environmentally friendly manner.

Seagrass meadows are an important marine habitat in support of our fisheries and commonly reside in shallow sheltered embayments typical of the locations that provide an attractive option for mooring boats. Research led by scientists at Swansea University provides evidence for how swinging boat moorings have damaged seagrass meadows throughout the UK (and globally) and create lifeless halos within the seagrass. The creation of these halos devoid of seagrass fragments the meadow and reduces its support for important marine biodiversity.

The seagrass Zostera marina (known as eelgrass) is extensive across the northern hemisphere, forming critical fisheries habitat and creating efficient long-term stores of carbon in sediments. This is the first research to have quantified this impact on eelgrass.

The study "Rocking the Boat: Damage to Eelgrass by Swinging Boat Moorings", was led by Richard Unsworth and Beth Williams at Swansea University where it formed the basis of Beth's MSc thesis. The research was conducted in conjunction with Benjamin Jones and Dr Leanne Cullen-Unsworth of Project Seagrass and the Sustainable Places Research Institute, Cardiff University has been published in the Open Access journal Frontiers in Plant Science.

Lead author Dr Richard Unsworth, said; "In the present study we examined swinging chain boat moorings in seagrass meadows across a range of sites in the United Kingdom to determine whether such moorings have a negative impact on the seagrass Zostera marina at the local and meadow scale. "We provide conclusive evidence from multiple sites throughout the UK that Z. marina is damaged by swinging chain moorings leading to a direct loss of at least 6 ha of United Kingdom seagrass. Each swinging chain mooring was found to result in the loss of 122 m2 of seagrass. Importantly loss was found to be restricted to the area surrounding the mooring and the impact did not appear to translate to a meadow scale. This loss of United Kingdom seagrass from boat moorings is small but significant at a local scale. This is because it fragments existing meadows and ultimately reduces their resilience to other stressors (e.g. storms, anchor damage and poor water quality).

"Boat moorings are prevalent in seagrass globally and it is likely this impairs their ecosystem functioning and resilience. Given the extensive ecosystem service value of seagrasses in terms of factors such as carbon storage and fish habitat such loss is of cause for concern". "Our research highlights the need for boating activities in and around sensitive marine habitats such as seagrass to be conducted in a sustainable fashion using appropriate environmentally friendly mooring systems" stated Dr Unsworth.

Citation: Richard K. F. Unsworth, Beth Williams, Benjamin L. Jones & Leanne C. Cullen-Unsworth; Rocking the Boat: Damage to Eelgrass by Swinging Boat Moorings; Frontiers in Plant Science, 2017, 8; DOI: 10.3389/fpls.2017.01309.

Contact: Janis Pickwick
Swansea University

 

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