Constantine Alexander's blog

Study reveals how fishing gear can cause slow death of whales

Scientists from NOAA Fisheries Service approaching the young North Atlantic right whale they disentangled on January 15 off the coast of Cape Canaveral, Fla. Credit: NOAA with permission from EcoHealth Alliance

Using a "patient monitoring" device attached to a whale entangled in fishing gear, scientists showed for the first time how fishing lines changed a whale's diving and swimming behavior. The monitoring revealed how fishing gear hinders whales' ability to eat and migrate, depletes their energy as they drag gear for months or years, and can result in a slow death.

The scientists in this entanglement response suction-cupped a cellphone-size device called a Dtag to a two-year-old female North Atlantic right whale called Eg 3911. The Dtag, developed at Woods Hole Oceanographic Institution (WHOI), recorded Eg 3911's movements before, during, and after at-sea disentanglement operations.

Immediately after Eg 3911 was disentangled from most of the fishing gear, she swam faster, dove twice as deep, and for longer periods. The study, by scientists at WHOI, the Georgia Department of Natural Resources, the Florida Fish and Wildlife Conservation Commission, and NOAA Fisheries, was published online May 21 in the journal Marine Mammal Science.

"The Dtag opened up a whole new world of Eg 3911's life under water that otherwise we weren't able to see," said Julie van der Hoop, lead author of the study and a graduate student in the MIT/WHOI Joint Program in Oceanography.

North Atlantic right whales were nearly eradicated by whaling and remain endangered today, with a population of 450 to 500. About 75 percent bear scars of fishing lines that cut into their flesh.

Born in 2009, Eg 3911 was first sighted entangled and emaciated by an aerial survey team on Christmas Day 2010, near Jacksonville, Florida. Fishing gear was entangled around her mouth, wrapped around both pectoral fins, and trailed about 100 feet behind her tail.

Teams aboard boats attempted to cut away the fishing gear on Dec. 29 and 30, 2010, but were not successful because the whale was evasive. A multiagency team tried again on Jan. 15, 2011. First, they applied a Dtag. Then they administered a carefully calculated sedative with a dart gun developed for large whale drug delivery by Paxarms NZ in collaboration with Dr. Michael Moore, director of the Marine Mammal Center at WHOI and a marine mammal veterinarian. The becalmed whale allowed the team to approach and remove nearly all the fishing gear.

The Dtag measured 152 dives that Eg 3911 took over six hours. There were no significant differences in depth or duration of dives after sedation, but "the whale altered its behavior immediately following disentanglement," the scientists reported. "The near-complete disentanglement of Eg 3911 resulted in significant increases in dive duration and depth."

"Together, the effects of added buoyancy, added drag, and reduced swimming speed due to towing accessory gear pose many threats to entangled whales," the scientists wrote. Buoyant gear may overwhelm animals' ability to descend to depths to forage on preferred prey. Increased drag can reduce swimming speeds, delaying whales' timely arrival to feeding or breeding grounds. "Most significant, however, is the energy drain associated with added drag," they said.

To calculate that drain, the scientists, in a separate experiment, towed three types of fishing gear from a skiff, using tensiometers to measure the drag forces acting on Eg 3911. They then calculated how much more energy whales would require to compensate for the drag. The results: Entangled whales have significantly higher energy demands, requiring 70 to 102 percent more power to swim at the same speed unentangled; or alternatively, they need to slow down their swimming speed by 16 to 20.5 percent.

The study provides the first data on the behavioral impacts of sedation and disentanglement and the energetic cost of entanglement in fishing gear due to drag.

On Feb. 1, 2011, an aerial survey observed Eg 3911 dead at sea.

"She didn't make it," van der Hoop said. The whale was towed ashore for a necropsy. "We showed up on the beach that night. I remember walking out there and seeing this huge whale, or what I thought was huge. She was only 10 meters long. She was only two years old. And all these people who had been involved in her life at some point, were there to learn from her what entanglement had caused."

The necropsy showed that effects of the chronic entanglement were the cause of death.

"No fisherman wants to catch a whale, and I wish no fisherman a hungry day," said Moore. "There needs to be a targeted assessment of how the fishery can still be profitable while deploying less gear so we can reduce the risk of marine mammals encountering fishing gear in the first place. At WHOI, we have hosted workshops talking with fisheries managers and fishermen about what might change so that they can continue to catch fish and stop catching whales."

A dedicated network of scientists, veterinarians, and emergency responders support the Marine Mammal Health and Stranding Response Program (MMHSRP), which was formally established under the Marine Mammal Protection Act, is coordinated by NOAA Fisheries Service and coordinates the Atlantic Large Whale Entanglement Response Program. WHOI scientists have been long-standing contributors to the MMHSRP and routinely participate in rescues for marine mammals that are stranded, injured or entangled. Response efforts by the network for endangered species, such as North Atlantic right whales, are authorized by NOAA/NMFS Permit No. 932-1905-MA-009526 issued to the MMHSRP.

Contact: Media Relations Office
media@whoi.edu
508-289-3340
Woods Hole Oceanographic Institution

The Woods Hole Oceanographic Institution is a private, non-profit organization on Cape Cod, Mass., dedicated to marine research, engineering, and higher education. Established in 1930 on a recommendation from the National Academy of Sciences, its primary mission is to understand the ocean and its interaction with the Earth as a whole, and to communicate a basic understanding of the ocean's role in the changing global environment.

 

Why we need to put the fish back into fisheries

Atlantic Cod

Overfishing has reduced fish populations and biodiversity across much of the world's oceans. In response, fisheries are increasingly reliant on a handful of highly valuable shellfish. However, new research by the University of York shows this approach to be extremely risky.

The research, published today in the journal Fish and Fisheries, shows that traditional fisheries targeting large predators such as cod and haddock, have declined over the past hundred years. In their place, catches of shellfish such as prawns, scallops and lobsters have rocketed as they begin to thrive in unnaturally predator-low environments often degraded by the passage of trawls and dredges.

In many places, including the UK, shellfish are now the most valuable marine resource. The research by the Environment Department at York suggests that although a shellfish-dominated ecosystem appears beneficial from an economic perspective, it is highly risky. Like simplified agricultural systems, these shellfisheries are unstable in the long-term and at great risk of collapse from disease, species invasions and climate change. Warming and acidification of our oceans due to greenhouse gas emissions is expected to affect shellfish worst. Ocean acidification, in particular, will limit the ability of scallops and other shellfish to form proper shells, and lead to widespread mortality.

Lead author, Leigh Howarth, says: "Prawns are now the most valuable fishery in the UK, with catches currently worth over £110 million a year. But this fishery has come to exist only after we overexploited populations of cod, haddock and other predators. If shellfish now collapsed the social consequences for fishermen would be devastating. There are simply very few remaining species left to target."

The study reports similar findings from all over the world. In the United States and Canada, catches of lobster, scallops and crab have also come to dominate following the collapse of cod. However, disease and climate change again put these species at great risk. While in the Black Sea, Baltic and off the west coast of Africa, overfishing of large predators have caused the ecosystems to become overrun with jellyfish, resulting in severe oxygen depletion and eruptions of hydrogen sulphide, thereby wiping out important food chains across 100,000 square kilometres of seabed.

Co-author Dr Bryce Stewart adds: "Shellfish make a valuable contribution to our fisheries. But we cannot just assume everything is rosy. There is an urgent need for continued improvements in management of finfish fisheries, and an ecosystem approach which rebuilds the diversity, resilience and productivity of our oceans into the future."

Co-author Professor Callum Roberts concludes: "The rise of shellfish has been welcomed by many as a lifeline for the fishing industry. However, such changes are not a result of successful management, but rather a result of management failure, a failure to protect stocks and their habitats in the face of industry innovation and overfishing. This study highlights why the UK needs to urgently act to protect our seas. We need more marine protected areas to stop our seas from becoming a wasteland and to restore the diversity and productivity of fisheries well into the future".

Contact: David Garner
david.garner@york.ac.uk
44-019-043-22153
University of York

"Fish thermometer" reveals long-standing, global impact of climate change

Credit: The Pew Ocean Science Division of The Pew Charitable Trusts

Climate change has been impacting global fisheries for the past four decades by driving species towards cooler, deeper waters, according to University of British Columbia scientists.

In a Nature study published this week, UBC researchers used temperature preferences of fish and other marine species as a sort of "thermometer" to assess effects of climate change on the world's oceans between 1970 and 2006.

They found that global fisheries catches were increasingly dominated by warm-water species as a result of fish migrating towards the poles in response to rising ocean temperatures.

"One way for marine animals to respond to ocean warming is by moving to cooler regions," says the study's lead author William Cheung, an assistant professor at UBC's Fisheries Centre. "As a result, places like New England on the northeast coast of the U.S. saw new species typically found in warmer waters, closer to the tropics.

"Meanwhile in the tropics, climate change meant fewer marine species and reduced catches, with serious implications for food security."

"We've been talking about climate change as if it's something that's going to happen in the distant future – our study shows that it has been affecting our fisheries and oceans for decades," says Daniel Pauly, principal investigator with UBC's Sea Around Us Project and the study's co-author. "These global changes have implications for everyone in every part of the planet."

• Download "Warming Oceans Are Reshaping Fisheries" (PDF)

Contact: William Cheung
w.cheung@fisheries.ubc.ca
778-837-7252
University of British Columbia

Scientists find impact of open-ocean industrial fishing within centuries of bird bones

A Hawaiian petrel flies over part of its Pacific Ocean foraging grounds. Credit: Jim Denny

The impact of industrial fishing on coastal ecosystems has been studied for many years. But how it affects food webs in the open ocean―a vast region that covers almost half of the Earth's surface―has not been very clear. So a team of Smithsonian and Michigan State University scientists and their colleagues looked to the ancient bones of seabirds for answers, revealing some of the dramatic changes that have happened within open-ocean food webs since the onset of industrial fishing. The team's research is published this week in the Proceedings of the National Academy of Sciences.

Few records of species that live in the open ocean date back more than 60 years, and the sheer size of open-ocean regions makes their food webs difficult to study. The Hawaiian petrel (Pterodroma sandwichensis), a crow-sized oceanic bird, offered the team a solution. These birds range widely over the northeast Pacific, and their diets integrate food webs from that vast area.

400 to 1,000-year-old bones from an endangered seabird, the Hawaiian petrel. These bones represent a small fraction of those collected from the species. They offer a window into the lives of seabirds before and after the arrival of humans in the open ocean environments of the Pacific. Credit: Brittany Hance, Smithsonian Institution

What the petrels have eaten is recorded in the chemistry of their bones. By extracting protein from bones and feathers and studying stable isotopes of carbon and nitrogen in the protein, the scientists were able to assess the birds' diet and how it changed over centuries. What they found from bones 100 to 4,000 years old were nitrogen isotope ratios that were consistently high, indicating a diet of relatively large prey. Those less than a century old, after industrial fishing started, had low ratios, revealing a shift to smaller fish, squid and other prey.

"The question is, have the effects of open-ocean fishing gone beyond targeted species, like tuna," said Anne Wiley, lead author, Smithsonian postdoctoral researcher and former MSU doctoral student. "Our study is among the very first to show that it has, and because Hawaiian petrels eat such a wide variety of prey over a large area, our results suggest that fishery influence may be widespread and profound in the Pacific. Understanding the influence of fisheries on open-ocean food webs has been one of the great mysteries of biological oceanography."

The team's isotope records are unusual because they are from all the known populations of the species, which breed on different Hawaiian Islands. The records show that separate populations of Hawaiian petrels hunted in different areas of the open ocean for thousands of years. The scientists revealed a foraging shift in multiple Hawaiian petrel populations, emphasizing that the petrels' diets changed across a very broad expanse of the ocean. This sudden shift in the past 100 years suggests a relatively rapid change in the composition of oceanic food webs in the Northeast Pacific.

"Conservation efforts for endangered seabirds take place mainly on land at breeding colonies where there are obvious threats like introduced predators," said Helen James, coauthor and research zoologist at Smithsonian's National Museum of Natural History. "Our study suggests we should pay more attention to the lives of these birds at sea."

Further studies are needed to explore how the change in foraging is affecting the Hawaiian petrel. Similar shifts down the food chain in other species have been associated with decreases in population size―potentially a bad sign for the Hawaiian petrel, which already has a small population restricted to the Hawaiian islands and is listed as "vulnerable" by the International Union for Conservation of Nature and Natural Resources.

Contact: John Gibbons
gibbonsjp@si.edu
202-633-5187
Smithsonian

North Atlantic seaweed is safe to eat

Dulse

Seaweed has been eaten for thousands of years by people all over the world, and it can be considered a tasty and healthy food item. This is the conclusion from professor Ole G. Mouritsen, Department of Physics, Chemistry and Pharmacy at the University of Southern Denmark, who has scientifically studied the species dulse (Palmaria palmata).

Dulse has traditionally been eaten by populations along North Atlantic coasts in countries such as Iceland, Ireland, England, Scotland, France, Norway and along the North American and Canadian Atlantic coasts. Dulse has particularly fine gastronomic qualities, and it can be commercially grown in tanks.

Previously other scientists from i.a. the Danish Veterinary and Food Administration have cautioned that dulse may contain dangerous levels of the neurotoxin kainic acid, which, when consumed in large doses, can lead to brain damage. Professor Mouritsen´s research now shows that dulse contains only extremely small doses of kainic acid, and that a person needs to eat 150 kg fresh dulse in one go in order to experience the poisoning effect observed in animal studies.

"Dulse is - when you observe common sense rules for freshness and hygiene when handling food - perfectly safe to eat. No person can eat 150 kg in one go", says professor Mouritsen.

He and his colleagues also measured dulse´s content of heavy metals, inorganic arsenic and iodine - substances that may occur in seaweeds and may be harmful in large doses.

Dulse contains only very small concentrations of iodine, arsenic, mercury, cadmium and lead, and they are all below the WHO-defined limits. Nor the content of vitamin K is alarmingly high.

"Not even people who take blood thinning medicine need to worry if they eat dulse in moderation," says professor Mouritsen.

Two well-known seaweed species (Sargassum muticum and Sargassum fusiforme) are known to have a very high content of inorganic arsenic, which increases the risk of cancer. S. fusiforme is not found in North Atlantic waters, but can be purchased in stores. S. muticum is found in North Atlantic waters.

For his own part professor Mouritsen is not nervous to harvest and eat seaweed from North Atlantic waters.

"There are many delicious, healthy and safe seaweed species in North Atlantic waters. Just stay away from old seaweed washed up on the beach and harvest only seaweed from clean waters", he adds.

Dulse is a particularly delicate seaweed, he points out, and he is supported by restaurant chefs. Through time dulse has been one of the most popular seaweed species in the parts of the western world with a tradition for eating seaweed.

"Dulse has a very appealing taste. It tastes best as dried and can be added to bread, omelets, soups and fish dishes. It can be fried and served as a crisp substitute for bacon or sprinkled over a salad", suggests professor Mouritsen.

Other interesting edible seaweed species from North Atlantic waters are:

• Winged kelp (Alaria esculenta). Raw in salads. Roasted and granulated with fresh fruit.
• Oarweed (Laminaria digitata). Cooked in soups.
• Sugar kelp (Saccharina latissima). Raw in salads or packed around fish.
• Sea lettuce (Ulva sp). Raw in salads or dried and crushed into bread, dressings or omelets. Good source of iron.
• Bladder Wrack (Fucus sp). Blanched - watch it change color from light brown to green when it hits the boiling water.

Citation: Journal of Applied Phycology, March 2013: On the human consumption of the red seaweed dulse (Palmaria palmata (L.) Weber & Mohr) by Ole G. Mouritsen, Christine Dawczynski, Lars Duelund, Gerhard Jahreis, Walter Vetter, Mark Schroeder. DOI: 10.1007/s10811-013-0014-7

Contact: Birgitte Svennevig
birs@sdu.dk
45-65-50-29-36
University of Southern Denmark

The Future of Arctic Research: A Long-Term Framework for International Cooperation and Coordination

Live webchat URL: https://conx.adobeconnect.com/canada Discuss global cooperation on the impact of climate change on our oceans.  Ask Commander Blake McBride, Associate Director of Meteorology/Oceanography and Arctic Technologies at the U.S. Navy, about research and simulation exercises the U.S. Navy has been conducting on climate change, the disappearance of sea ice, and the implications for marine safety and security.  The webchat will be moderated by Michelle Cook, U.S. Consulate General Calgary, and Magdalena Muir from the University of Calgary’s Arctic Institute of North America. Format: This program will be a video webchat in English.  Please click on the URL above to participate.
Speaker
Commander Blake McBride, Associate Director of Meteorology/Oceanography and Arctic Technologies, U.S. Navy
Moderators
Michelle Cook, U.S. Consulate General Calgary
Magdalena Muir, University of Calgary’s Arctic Institute of North America

Date	Monday, April 29, 2013
Time	12:00 (EDT) | 16:00 (UTC)
	Time Zone Converter
Duration	1h 0m
Language	English
Regions	Global, Western Hemisphere, WHA
Themes	Climate Change, Energy ,Environment, Science and Technology, Peace & Security

 

A billion-dollar business puts species and people at risk

Nassau Grouper at The Pinnacle, Saba, Netherlands Antilles. Image taken by Clark Anderson/Aquaimages.

At least 12% of groupers – globally-important food fish species that live on coral and rocky reefs – face extinction, putting the livelihoods of hundreds of thousands of people around the world at risk, finds a report published today by the International Union for Conservation of Nature Species Survival Commission’s (IUCN SSC) Grouper and Wrasse Specialist Group.

The overall percentage of threatened groupers could be much higher as there is insufficient data for about 30% of the species, according to The IUCN Red List of Threatened Species™.

The study points to overfishing and the booming international luxury seafood trade as major threats to the survival of some grouper species, and to the livelihoods of those who depend on them for food and income. Its authors call for urgent conservation and management efforts to prevent further declines of these species.

“The declines in some grouper fisheries are alarming,” says Yvonne Sadovy, Co-Chair of the IUCN SSC Grouper and Wrasse Specialist Group and lead author of the study. “Most of them are not managed at all and their natural ability to reproduce can’t keep up with increasing demand. The rapidly growing international trade in groupers further reduces their populations.”

More than 300,000 tons of groupers – or 90 million individuals – were caught globally in 2009, mostly in Asia, where they are particularly sought-after for the luxury restaurant trade. Groupers are the foundation of the US$ 750 million international live reef fish market centered in Hong Kong and growing in mainland China, where consumers are ready to pay over US$ 200 per kilogram of the species. They are also important food fish in developing countries like Indonesia and the Philippines, where pressure to export reef fish is growing, according to the study.

Groupers are among those species that are most vulnerable to fishing because of their longevity, late sexual maturation and the fact that many form large mating groups known as ‘spawning aggregations’. Despite their economic importance, few grouper fisheries are regularly monitored or managed, and many are in decline.

In the US Caribbean, the Nassau Grouper (Epinephelus striatus), which is commonly fished during its brief aggregation periods, has been essentially wiped out. Of the several dozen well-documented breeding grounds, only two continue to support large numbers of the species, and these have also been considerably reduced. In Southeast Asia and the Pacific, several species are considered to be threatened by the international trade, including the Square-tailed Coral Grouper (Plectropomus areolatus), also often taken from its spawning aggregations.

“Overfishing is like mismanaging a bank account,” says Matthew Craig, Co-Chair of the IUCN SSC Grouper and Wrasse Specialist Group and one of the authors of the report. “The current fish population is our principle balance, hopefully earning interest in the form of new fish born. If those initial assets are continually withdrawn faster than the interest accumulates, the principle, that is the fish out there now, will be quickly depleted. It’s easy to see how rapidly we could lose all the money, or in this case, all of the fish.”

Improved management by source countries with priority given to local food security considerations, as well as better monitoring and control of international trade are urgently needed to reduce threats to these species, according to the authors.

The study, Fishing groupers towards extinction: a global assessment of threats and extinction risks in a billion dollar fishery, was published in the journal Fish and Fisheries. It is based on data accumulated by experts over a period of 20 years.

Citation: Sadovy de Mitcheson, Y., Craig, M. T., Bertoncini, A. A., Carpenter, K. E., Cheung, W. W. L., Choat, J. H., Cornish, A. S., Fennessy, S. T., Ferreira, B. P., Heemstra, P. C., Liu, M., Myers, R. F., Pollard, D. A., Rhodes, K. L., Rocha, L. A., Russell, B. C., Samoilys, M. A. and Sanciangco, J. (2013), Fishing groupers towards extinction: a global assessment of threats and extinction risks in a billion dollar fishery. Fish and Fisheries, 14: 119–136. DOI: 10.1111/j.1467-2979.2011.00455.x

'Sustainable fishing' certification too lenient and discretionary, study finds

The certification of seafood as "sustainable" by the nonprofit Marine Stewardship Council is too lenient and discretionary, a study by a consortium of researchers has found.

"When consumers want sustainable fish there are two options to meet the demand: fisheries can become more sustainable or the definition of sustainable can be watered down to be practically meaningless—with MSC seafood, the definition has been repeatedly watered down," said Jennifer Jacquet, a clinical assistant professor in New York University's Environmental Studies Program and one of 11 authors of the study, which appears in the journal Biological Conservation.

The expansion of fishing in the oceans—further offshore, deeper, and for different species—has led to the depletion of many marine fish populations. In response, market-based efforts aimed at consumers, which include "eco-labeling," have emerged to change demand. Among these was the establishment of the London-based Marine Stewardship Council (MSC) in 1997. A joint project between World Wildlife Fund and Unilever, MSC was created as a conservation tool—intended to provide "the best environmental choice in seafood" to consumers and to create positive incentives that would improve the status and management of fisheries.

However, conservation groups have raised concerns about MSC's certification process, calling into question the organization's claim that its eco-labeling program is "the best environmental choice in seafood." Its certification process is paid for by the fisheries, with rates dependent on the size and complexity of the fishery. MSC estimates that most certifications cost between $15,000 and $120,000. Since its founding, MSC has attached its certified label to more than 170 fisheries, with fishery clients spending between $2.3 and $18.7 million on certification.

To gauge the viability of MSC's labeling program, the researchers examined 19 formal objections—raised primarily by environmental groups and amounting to one-third, by weight, of all MSC-certified seafood—to certifications MSC has granted to fisheries for Chilean sea bass, Antarctic krill, and others. Objections are heard by an independent adjudicator appointed by MSC. In all but one of these 19 cases, the certification was upheld.

In the Biological Conservation analysis, the researchers sought to determine whether these fisheries, in fact, met the MSC's principles for certification.

The MSC uses three major principles that third-party certifiers interpret in determining whether a fishery is "sustainable" and may use the MSC label: sustainability of the target fish stock; low impacts on the ecosystem; and effective management. However, the researchers found many of these fisheries—representing 35 percent of eco-labeled seafood—did not meet MSC standards.

For instance, the longline fishery for swordfish in Canada appears to violate the "low impacts on the ecosystem" principle. This fishery has high levels of bycatch—sea life accidentally caught in pursuit of other fish. The targeted catch of 20,000 swordfish per year results in bycatch of approximately 100,000 sharks as well as 1,200 endangered loggerhead and 170 critically endangered leatherback turtles.

"The MSC's narrow definition of sustainability is out of step with the general public perception of what that term means," said Claire Christian, one of the study's co-authors and a policy analyst at the Antarctic and Southern Ocean Coalition. "When the MSC labels a swordfish fishery that catches more sharks than swordfish 'sustainable,' it's time to re-evaluate its standards."

The Alaska pollock fishery, one of the largest fisheries in the US, also received MSC certification even though, the researchers noted, several court rulings had determined that the fishery was not in compliance with national law—an indication that it didn't meet MSC's "effective management" principle.

The authors believe the MSC needs to enforce the principles it created for certified fisheries. Otherwise, consumers believe they are buying "the best environmental choice" in seafood, when in fact there is a very good chance they are not.

Citation: Claire Christian, David Ainley, Megan Bailey, Paul Dayton, John Hocevar, Michael LeVine, Jordan Nikoloyuk, Claire Nouvian, Enriqueta Velarde, Rodolfo Werner, Jennifer Jacquet. A review of formal objections to Marine Stewardship Council fisheries certifications.

Contact: James Devitt
james.devitt@nyu.edu
212-998-6808
New York University

Research enables fishermen to harvest lucrative shellfish on Georges Bank

Gulf of Maine Map Showing Georges Bank. Illustration by Jack Cook, Woods Hole Oceanographic Institution

Combined research efforts by scientists involved in the Gulf of Maine Toxicity (GOMTOX) project, funded by NOAA's Ecology and Oceanography of Harmful Algal Blooms (ECOHAB) program, and administered by the National Centers for Coastal Ocean Science (NCCOS), have led to enhanced understanding of toxic algal blooms on Georges Bank. This new information, coupled with an at-sea and dockside testing protocol developed through collaboration between GOMTOX and U.S. Food and Drug Administration (FDA) investigators, has allowed fishermen to harvest ocean quahogs and surf clams in these offshore waters for the first time in more than two decades.

The shellfish industry estimates the Georges Bank fishery can produce up to 1 million bushels of surf clams and ocean quahogs a year, valued $10 – 15 million annually. "There is a billion dollars' worth of shellfish product on Georges Bank that is property of the United States but that can't be harvested because of the threat of toxicity, and 99.9% of the time, it is good wholesome product," says Dave Wallace of North Atlantic Clam Association and a GOMTOX participant. "In an unusual and unique partnership, we worked with GOMTOX scientists, the FDA, and the states of Massachusetts, Rhode Island, New Jersey and Delaware and now that huge resource can go into commerce, which helps the entire country."

"We are extremely pleased that research funded by NOAA can provide such an economic boost to New England shellfisheries," says Robert Magnien, Director of NCCOS' Center for Sponsored Coastal Ocean Research. "It is a clear example of how research authorized by the Harmful Algal Bloom and Hypoxia Research and Control Act can protect both public health and local economies through collaborations between academic scientists, state and federal regulatory agencies, and the shellfish industry."

An elevated area of the sea floor between Cape Cod and Nova Scotia, Georges Bank is one of the best fishing grounds on Earth. But since 1990, it has been closed to harvesting of surf clams and ocean quahogs after harmful algal blooms (also referred to as "red tides") caused paralytic shellfish poisoning (PSP) that sickened fishermen. For decades scientists speculated the blooms on Georges Bank were fueled by coastal blooms in the Gulf of Maine.

More recent research by GOMTOX investigators, however, has shown that Georges Bank is home to a separate and distinct population of the toxic algae, which is described in a recently published paper by Woods Hole Oceanographic Institution (WHOI) scientist Dennis McGillicuddy and other members of the GOMTOX team.

It has been known for many years that the phytoplankton Alexandrium fundyense is the cause of the harmful algal blooms that occur to varying severity each spring and summer along the coastal Gulf of Maine, sometimes extending as far south as Cape Cod and the adjacent islands. The algae's seed populations or "cysts" germinate from seabeds starting in early spring and bloom at the sea surface, until all of the necessary nutrients in the water are consumed. As the nutrients run out, the cells form cysts and fall to the seafloor, as seed for the following spring. High concentrations of the toxic algae can cause closure of shellfish beds and cost the region many millions of dollars.

Precisely why the blooms vary in severity has been much more difficult to determine, and has involved extensive seasonal sampling of water and sediments, study of coastal currents, environmental and oceanographic conditions, availability of nutrients, and the development of a computer program to model all of the variables.

Harmful Algae-Alexandrium fundyense.
Photo courtesy Don Anderson, Woods Hole Oceanographic Institution

Researchers got the first signal that something very different was happening on Georges Bank during a research cruise to count Alexandrium cells in sea water samples in spring/summer 2007. "We devised our sampling strategy to look at the cells' transport pathways from coastal waters onto the Bank," says McGillicuddy. Throughout the coastal Gulf of Maine, the numbers were very low. But when the research team started sampling at Georges Bank, they found very high concentrations of Alexandrium in the water, despite the fact that the bloom had not really begun along the coast of Maine.

"I'll never forget the moment we hit a big patch of cells on Georges Bank," says Dave Townsend, a GOMTOX scientist from the University of Maine and co-author of the paper. "We extended our sampling to go all the way across Georges Bank and we were still hitting them. We had to turn around and completely reorganize our sampling strategy based on what we were seeing in the microscope."

For such a large bloom to occur, the researchers reasoned the number of cysts on Georges Bank must be similar to the quantities needed to initiate a bloom along the coast. Yet, their fall 2007 survey to map the cyst distribution in the seabed on the Bank found very few cysts – quantities not likely to cause a large bloom along the coast.

In the three-year course of intensive study on Georges Bank since then, blooms have occurred every year, in concentrations that would typically lead to toxicities in coastal shellfish beds. Yet, a parallel effort by the fishing industry and federal testing labs to analyze shellfish samples from Georges Bank found the bivalves to be clean of toxins. So while toxins were produced at and near the surface, they were not delivered to the surf clams and ocean quahogs in the seabed in quantities sufficient to threaten human health.

The system on Georges Bank was indeed a riddle: Few cysts, yet large blooms; a large bloom, yet little to no toxicity in the shellfish. Applying the same detailed analyses to the offshore population of Alexandrium that they applied to coastal populations, the scientists discovered the optimum growing conditions for Alexandrium on Georges Bank were colder and saltier than those of their coastal relatives. Their analysis uncovered how the currents in the region can isolate Georges Bank to create colder and saltier conditions. If the conditions are favorable, the researchers say, Alexandrium populations can double every three days, and in a month's time, grow from concentrations of 10 cells per liter to 10,000.

Further setting the Georges Bank population apart was the finding by GOMTOX colleagues at University of Massachusetts, Dartmouth's School for Marine Science and Technology (SMAST), working in collaboration with the FDA, who determined that the toxin content of algae on Georges Bank was different than the coastal Gulf of Maine populations. "The toxins present in Alexandrium cells from Georges Bank were, on average, two times lower than those in the coastal Gulf of Maine," said Chrissy Petitpas, a doctoral student working in Professor Jefferson Turner's lab at SMAST.

Despite this new information and the knowledge that the clams have been shown to be safe for humans to eat at the present time, the fact remains that concentrations of the toxins in the clams on Georges Bank in 1989 and 1990 did reach dangerous levels. Scientists know that coastal shellfish populations are directly exposed to the toxins when the blooms make landfall, but they remain uncertain about the conduit for toxicity from the surface ocean to the deep shellfish beds on Georges Bank, located at about 50m depth.

But, thanks to an innovative screening protocol and regulatory structure developed collaboratively by the FDA, NOAA's National Marine Fisheries Service, the fishing industry, and testing labs approved by the National Shellfish Sanitation Program, a system is now in place to monitor, test, and verify that clams harvested from Georges Bank are safe. The clams are checked by fishermen at sea using the newly available test kit, and re-checked by regulators when the fishing vessels reach the dock. Combined with the weekly monitoring of shellfish beds along the coast during the bloom season to protect human health, these monitoring systems are extremely effective at keeping toxic shellfish off the market.

"Toxin levels in shellfish on Georges Bank have been very low over the last few years. We are confident that this new testing protocol will serve to protect public health should toxin levels rise again in the future," said Stacey DeGrasse, seafood research coordinator in the FDA's Office of Regulatory Science and a major participant in the development of the new offshore testing protocol. "We intend to continue to work closely with NOAA to ensure that the shellfish from this region are harvested safely."

"I've run over 2,500 samples from Georges Bank since mid-March, and all of them have been clean of toxin," says Darcie Couture, a former manager of the marine biotoxins program at the Maine Department of Marine Resources, who now operates the federally permitted testing lab. "We've been fortunate in finding a way that we can safely harvest that product out there."

"Although we can't predict when conditions on Georges Bank will favor a large bloom, our knowledge of the bloom dynamics was used in establishing a suitable management approach," says Don Anderson, a senior scientist at WHOI and the lead investigator on the GOMTOX project.

For the scientists, the work to understand the dynamics of the Georges Bank population continues. New DNA evidence uncovered by Woods Hole Center for Oceans and Human Health researchers Deana Erdner (University of Texas) and Mindy Richlen from Don Anderson's laboratory at WHOI, suggests the Georges Bank Alexandrium population is genetically distinct.

"We thought the Georges Bank population was just the little toe at the end of the coastal population, but it's not. It is separate, and it occupies a distinct niche from the rest of the Alexandrium in this region," says McGillicuddy. "This was a big surprise to us."

The research was funded, in part, by NOAA's NCCOS, with additional support provided by NSF and NIEHS through the Woods Hole Center for Oceans and Human Health.

The Woods Hole Oceanographic Institution is a private, non-profit organization on Cape Cod, Mass., dedicated to marine research, engineering, and higher education. Established in 1930 on a recommendation from the National Academy of Sciences, its primary mission is to understand the oceans and their interaction with the Earth as a whole, and to communicate a basic understanding of the oceans' role in the changing global environment.

NOAA’s Fisheries Service seeks comments on proposal to list scalloped hammerhead sharks under Endangered Species Act

Scalloped hammerhead shark. Credit: NOAA

NOAA’s Fisheries Service, in response to a petition submitted by the WildEarth Guardians and Friends of Animals is proposing to list four populations of scalloped hammerhead sharks under the Endangered Species Act, two as threatened and two as endangered.

However, the species will not be listed in the majority of U.S. waters due to steps fisheries managers and fishermen have already taken to help protect these species. For example, in the U.S. Atlantic, the species is managed under a fishery management plan, with established biological catch levels to control harvest.

NOAA’s Fisheries Service is also finalizing an amendment to the fishery management plan establishing a rebuilding strategy for the northwest Atlantic scalloped hammerhead shark stock, and implementing regulations for U.S. shark fisheries in the Atlantic Ocean, the Gulf of Mexico and the Caribbean.

The listing proposals, which are based on the best scientific data available, cite threats from overfishing and inadequate management of foreign fisheries, with illegal, unreported and unregulated fishing, also known as IUU fishing, as a significant problem. Scalloped hammerhead sharks are found worldwide in coastal warm waters, which makes the problem widespread. In addition, the sharks are killed for their fins, which has significantly contributed to their decline.

“Sharks are a valuable part of our ocean ecosystems, and the sharks we are proposing to list under the Endangered Species Act are in trouble,” said Sam Rauch, assistant NOAA administrator for fisheries. “Sharks worldwide face a number of threats, and these sharks in particular, are facing threats from inadequate worldwide fisheries management to poaching for their fins.”

NOAA’s Fisheries Service will designate critical habitat for the Distinct Population Segments (DPSs) that occur in U.S. waters, if it is determined to be prudent. Of the DPSs NOAA Fisheries proposes to list, only the central and southwest Atlantic, Indo-West Pacific and eastern Pacific DPSs have areas of their range in U.S. waters.

Earlier this year, the President directed that agencies, when designating critical habitat, carefully consider all public comments on relevant science and economic impact, including those that suggest methods for minimizing regulatory burdens. Any potential future critical habitat designation will include a full analysis of economic impact, including impact on jobs, and will strive, to the extent permitted by law, to avoid unnecessary burdens and costs to states, tribes, localities and the private sector.

When a species is listed as endangered, scientists consider it in danger of extinction throughout all or a significant portion of its range. When a species is listed as threatened, scientists consider it likely to become an endangered species within the foreseeable future.

Under the proposal, two DPSs of scalloped hammerhead sharks in the eastern Atlantic and eastern Pacific would be listed as endangered, while two DPSs -- the central and southwest Atlantic population, and the Indo-West Pacific population -- would be listed as threatened. This announcement is also the final negative finding for two other populations, one that spans the U.S. northwest Atlantic to the Gulf of Mexico and another in the Central Pacific (spanning the Hawaiian archipelago).

The proposed endangered listings prohibit imports, exports and commercial activities dealing in the species. Scalloped hammerhead sharks are not a significant component of catch or bycatch by U.S. commercial and recreational fishers. Also, in the U.S. Western Pacific territories, scalloped hammerhead sharks are not a component of subsistence fisheries and are rarely caught or seen.

NOAA’s Fisheries Service anticipates few effects from these proposed listings to fishers under U.S. jurisdiction and on the activities of other federal agencies.

WildEarth Guardians and Friends of Animals filed a petition in August 2011 with NOAA’s Fisheries Service to list the scalloped hammerhead shark as threatened or endangered under the Endangered Species Act. NOAA’s Fisheries Service later determined that the petition provided sufficient information to demonstrate that listing may be warranted, and initiated a status review of the species.

NOAA’s Fisheries Service is seeking comments from the public on the proposed listing of scalloped hammerhead sharks for 60 days. NOAA’s Fisheries Service is seeking also comments on the proposed DPSs, as well as their population structure, habitat use, abundance and distribution. The agency is also seeking information on threats and planned activities that may affect the proposed DPSs and any efforts being made to protect the sharks.

After publishing a proposed rule, NOAA’s Fisheries Service considers the public comments and new information that may have been provided. NOAA’s Fisheries Service has one year to publish a final determination on whether to list the species.

You may submit public comments via the Federal eRulemaking Portal or by visiting the comment page on the Office of Protected Resources website. NOAA’s Fisheries Service will also accept written comments mailed to: Office of Protected Resources, NOAA Fisheries, 1315 East-West Highway, Silver Spring, MD 20910; or faxed to 301-713-4060, Attn: Maggie Miller

NOAA’s mission is to understand and predict changes in the Earth's environment, from the depths of the ocean to the surface of the sun, and to conserve and manage our coastal and marine resources.