Slipped Through the Net: Europe Misses by More Than 30 Years the International Goal of Rebuilding Its Fish Stocks

ScienceDaily — At the Development Summit in Johannesburg in 2002, the European countries agreed to rebuild their fish stocks to levels that can produce the maximum sustainable yield, no later than 2015. According to scientists of the Excellence Cluster "Future Ocean," that goal is already out of reach: Of 54 analysed stocks, only saithe, western horse mackerel and Baltic sprat have a sufficiently large stock size and are fished at a sustainable rate. The state of 12 stocks, including North Sea cod, plaice and halibut, is so bad that they can not recover sufficiently until 2015, even if all fishing was halted. Other stocks could reach the target if fishing pressure was reduced substantially, but that has not happened so far.

These results were published by Dr. Rainer Froese, Leibniz Institute of Marine Sciences (IFM-GEOMAR) und Prof. Dr. Alexander Proelß, Walter-Schücking-Institute of International Law of the University of Kiel, in the journal Fish and Fisheries. The German scientists, both members of the interdisciplinary Excellence Cluster "Future Ocean," point out that the continuous overfishing of European stocks constitutes a breach of the precautionary principle, which is a binding principle of Community law.

"The precautionary principle is a binding legal principle for the organs of the European Commission and for the Council of Ministers. The current practice of continuous overfishing violates international law as well as Community law," says Prof. Dr. Alexander Proelß, expert of international law at the Walter-Schücking-Institute.

The obligation to manage fish stocks such that they can produce the maximum sustainable yield is part of the Law of the Sea (UNCLOS) of 1982, which entered into force in 1994. In the "Johannesburg Plan of Implementation" (2002), the European Union as well as Norway, Russia and Iceland, agreed to rebuild their fish stocks to the level that can produce the maximum sustainable yield, no later than 2015. "Until now, the provisions of the Law of the Sea have not been introduced into national law, and the plan of implementation had no visible impact on European fisheries management," says Proelß.

On the contrary: the fishing quotas for 2010 decreed by the Council of Ministers again exceed by far the catches that would allow the rebuilding of the stocks. "If this practice continues, Europe will miss by more than 30 years the goal that it has propagated," says Dr. Rainer Froese, fisheries biologist at the Kiel Leibniz Institute of Marine Sciences (IFM-GEOMAR).

Yet, catches from sustainably managed stocks could be substantially higher. "Our analysis suggests that landings could be 79% higher if stocks had been managed according to the international agreements," says Froese. "However, in European waters stocks are intentionally managed such that they stay close to the brink of collapse. This policy makes no sense from an ecological or economic point of view."

Source: http://www.sciencedaily.com/releases/2010/01/100121155224.htm

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Mercurial Tuna: Study Explores Sources of Mercury in Ocean Fish

ScienceDaily— With concern over mercury contamination of tuna on the rise and growing information about the health effects of eating contaminated fish, scientists would like to know exactly where the pollutant is coming from and how it's getting into open-ocean fish species.

A new study published in the journal Environmental Science & Technology uses chemical signatures of nitrogen, carbon and mercury to get at the question. The work also paves the way to new means of tracking sources of mercury poisoning in people.

The study, by researchers at the University of Michigan, Harvard School of Public Health, the Louisiana Universities Marine Consortium and the National Institute of Nutrition and Seafood Research in Norway, appears in the journal's March 1, 2010 issue.

Mercury is a naturally occurring element, but some 2,000 tons of it enter the global environment each year from human-generated sources such as coal-burning power plants, incinerators and chlorine-producing plants. Deposited onto land or into water, mercury is picked up by microorganisms, which convert some of it to methylmercury, a highly toxic form that builds up in fish and the animals -- and people -- that eat them.

The primary way people in the United States are exposed to methylmercury is by eating fish and shellfish. Health effects include damage to the central nervous system, heart and immune system, and the developing brains of young and unborn children are especially vulnerable.

In the current study, the researchers wanted to know if tuna and other open-ocean fish pick up methylmercury by eating contaminated fish that live closer to shore or by some other means. They studied 11 species of fish, including red snapper, speckled trout, Spanish mackerel and two species of tuna. Seven of the species studied live in the shallow, coastal waters of the Gulf of Mexico; the two tuna species live far out in the ocean and are highly migratory; the remaining two species spend parts of their lives in both habitats.

It's no mystery how the coastal fish acquire methylmercury, said Joel Blum, who is the John D. MacArthur Professor of Geological Sciences at U-M. "We know that there's a lot of mercury pollution in the coastal zone. A large amount of mercury comes down the Mississippi River, and there's also air pollution and deposition of mercury from the highly industrialized coastal Gulf region." In this environment, methylation occurs in the low-oxygen conditions of the lower water column and sediments, and the methylmercury wends its way up the food web, becoming more concentrated at each step along the way.

"It's much less clear how methylmercury gets into open-ocean fish species, some of which don't come anywhere close to shore but can still have very high levels," said the study's lead author, David Senn, formerly of the Harvard School of Public Health, and now a senior researcher at the Swiss Federal Institute of Aquatic Science and Technology. Scientists have proposed three possibilities.

One is that open-ocean fish visit coastal areas to feed, picking up methylmercury from the coastal food web. Another possibility is that small organisms that acquire methylmercury in coastal regions are washed out to sea, where they enter the open-ocean food web. In the third scenario, mercury is directly deposited into the open ocean, where it undergoes methylation.

By looking at three chemical signatures in the fish -- nitrogen isotopes, carbon isotopes and mercury isotopes -- Senn, Blum and colleagues learned that coastal fish and open-ocean fish are feeding from two separate food webs.

"That rules out the first explanation, that these tuna were getting their methylmercury by feeding off coastal fish," Senn said.

"We think it's unlikely that the mercury is being methylated in coastal sediments and then washed out to the open ocean, so the most likely alternative is that there is deposition and methylation of mercury in the open ocean," Blum said. The finding runs counter to the long-held view that the open ocean is too oxygen-rich to support methylation, but it is consistent with recent studies suggesting more methylation may be occurring in that environment than was previously thought.

"It turns out there are probably low-oxygen microenvironments on tiny particles of organic matter, where methylation may be able to occur," Blum said.

One of the biggest differences the researchers found between coastal and open-ocean fish was in their mercury "fingerprint." The fingerprint is the result of a natural phenomenon called isotopic fractionation, in which different isotopes of mercury react to form new compounds at slightly different rates. In one type of isotopic fractionation, mass-dependent fractionation (MDF), the differing rates depend on the masses of the isotopes. In mass-independent fractionation (MIF), the behavior of the isotopes depends not on their absolute masses but on whether their masses are odd or even.

The researchers found that open-ocean fish have a much stronger MIF fingerprint than do coastal fish, a discovery that opens the door to new ways of analyzing human exposure to mercury.

"We can do an isotopic analysis of the mercury in your hair, and by looking at this mass-independent signal, tell you how much of the mercury is coming from inorganic sources, such as exposure to mercury gas or amalgams in your dental fillings, versus how much is coming from the fish that you eat," Blum said. "We think this could become a widespread technique for identifying sources of mercury contamination."

Senn and Blum's coauthors are Edward Chesney of the Louisiana Universities Marine Consortium; Michael Bank and James Shine of Harvard School of Public Health; and Amund Maage of Norway's National Institute of Nutrition and Seafood Research.

The research was funded by a National Oceanic and Atmospheric Administration grant to Harvard School of Public Health and by the University of Michigan.

Source: http://www.sciencedaily.com/releases/2010/03/100302111918.htm

About Oceanic Defense
We are an international non-profit organization with members in over 60 countries, spanning 6 continents with 1 mission; healthy aquatic ecosystems free from human abuse and neglect. Oceanic Defense teaches people to protect our oceans by acting responsibly as consumers and by making smart decisions in our daily lives. Whether we are buying groceries, commuting to work, planning a vacation or advocating within our own communities; each action we take or decision we make either helps or hurts our oceans. We empower people to be part of the solution rather than part of the problem and work together to protect our blue planet.

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Mercurial Tuna: Study Explores Sources of Mercury to Ocean Fish

ScienceDaily — With concern over mercury contamination of tuna on the rise and growing information about the health effects of eating contaminated fish, scientists would like to know exactly where the pollutant is coming from and how it's getting into open-ocean fish species.

A new study published in the journal Environmental Science & Technology uses chemical signatures of nitrogen, carbon and mercury to get at the question. The work also paves the way to new means of tracking sources of mercury poisoning in people.

The study, by researchers at the University of Michigan, Harvard School of Public Health, the Louisiana Universities Marine Consortium and the National Institute of Nutrition and Seafood Research in Norway, appears in the journal's March 1, 2010 issue.

Mercury is a naturally occurring element, but some 2,000 tons of it enter the global environment each year from human-generated sources such as coal-burning power plants, incinerators and chlorine-producing plants. Deposited onto land or into water, mercury is picked up by microorganisms, which convert some of it to methylmercury, a highly toxic form that builds up in fish and the animals -- and people -- that eat them.

The primary way people in the United States are exposed to methylmercury is by eating fish and shellfish. Health effects include damage to the central nervous system, heart and immune system, and the developing brains of young and unborn children are especially vulnerable.

In the current study, the researchers wanted to know if tuna and other open-ocean fish pick up methylmercury by eating contaminated fish that live closer to shore or by some other means. They studied 11 species of fish, including red snapper, speckled trout, Spanish mackerel and two species of tuna. Seven of the species studied live in the shallow, coastal waters of the Gulf of Mexico; the two tuna species live far out in the ocean and are highly migratory; the remaining two species spend parts of their lives in both habitats.

It's no mystery how the coastal fish acquire methylmercury, said Joel Blum, who is the John D. MacArthur Professor of Geological Sciences at U-M. "We know that there's a lot of mercury pollution in the coastal zone. A large amount of mercury comes down the Mississippi River, and there's also air pollution and deposition of mercury from the highly industrialized coastal Gulf region." In this environment, methylation occurs in the low-oxygen conditions of the lower water column and sediments, and the methylmercury wends its way up the food web, becoming more concentrated at each step along the way.

"It's much less clear how methylmercury gets into open-ocean fish species, some of which don't come anywhere close to shore but can still have very high levels," said the study's lead author, David Senn, formerly of the Harvard School of Public Health, and now a senior researcher at the Swiss Federal Institute of Aquatic Science and Technology. Scientists have proposed three possibilities.

One is that open-ocean fish visit coastal areas to feed, picking up methylmercury from the coastal food web. Another possibility is that small organisms that acquire methylmercury in coastal regions are washed out to sea, where they enter the open-ocean food web. In the third scenario, mercury is directly deposited into the open ocean, where it undergoes methylation.

By looking at three chemical signatures in the fish -- nitrogen isotopes, carbon isotopes and mercury isotopes -- Senn, Blum and colleagues learned that coastal fish and open-ocean fish are feeding from two separate food webs.

"That rules out the first explanation, that these tuna were getting their methylmercury by feeding off coastal fish," Senn said.

"We think it's unlikely that the mercury is being methylated in coastal sediments and then washed out to the open ocean, so the most likely alternative is that there is deposition and methylation of mercury in the open ocean," Blum said. The finding runs counter to the long-held view that the open ocean is too oxygen-rich to support methylation, but it is consistent with recent studies suggesting more methylation may be occurring in that environment than was previously thought.

"It turns out there are probably low-oxygen microenvironments on tiny particles of organic matter, where methylation may be able to occur," Blum said.

One of the biggest differences the researchers found between coastal and open-ocean fish was in their mercury "fingerprint." The fingerprint is the result of a natural phenomenon called isotopic fractionation, in which different isotopes of mercury react to form new compounds at slightly different rates. In one type of isotopic fractionation, mass-dependent fractionation (MDF), the differing rates depend on the masses of the isotopes. In mass-independent fractionation (MIF), the behavior of the isotopes depends not on their absolute masses but on whether their masses are odd or even.

The researchers found that open-ocean fish have a much stronger MIF fingerprint than do coastal fish, a discovery that opens the door to new ways of analyzing human exposure to mercury.

"We can do an isotopic analysis of the mercury in your hair, and by looking at this mass-independent signal, tell you how much of the mercury is coming from inorganic sources, such as exposure to mercury gas or amalgams in your dental fillings, versus how much is coming from the fish that you eat," Blum said. "We think this could become a widespread technique for identifying sources of mercury contamination."

Senn and Blum's coauthors are Edward Chesney of the Louisiana Universities Marine Consortium; Michael Bank and James Shine of Harvard School of Public Health; and Amund Maage of Norway's National Institute of Nutrition and Seafood Research.

The research was funded by a National Oceanic and Atmospheric Administration grant to Harvard School of Public Health and by the University of Michigan.

Source: http://www.sciencedaily.com/releases/2010/03/100302111918.htm

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About Oceanic Defense
We are an international non-profit organization with members in over 60 countries, spanning 6 continents with 1 mission; healthy aquatic ecosystems free from human abuse and neglect. Oceanic Defense teaches people to protect our oceans by acting responsibly as consumers and by making smart decisions in our daily lives. Whether we are buying groceries, commuting to work, planning a vacation or advocating within our own communities; each action we take or decision we make either helps or hurts our oceans. We empower people to be part of the solution rather than part of the problem and work together to protect our blue planet.

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Mercury levels of whale-eating town's residents 10 times average

Friday 22nd January, 06:40 AM JST, TOKYO — Levels of mercury in hair samples of residents of Taiji, Wakayama Prefecture, which is known for customarily eating small whales caught by coastal whaling, are about 10 times the average in Japan, possibly due to consumption of whale meat with high concentration of mercury, one of researchers who conducted the survey said Thursday.

Hair samples were collected from 30 men and 20 women living in the whaling town with a population of about 3,400 through local collaborators between December 2007 and July 2008 for testing, Tetsuya Endo, an associate professor at Health Sciences University of Hokkaido, said.

The survey showed the average total mercury levels in the men’s and women’s hair samples were 21.6 parts per million and 11.9 ppm, respectively, while the levels of average Japanese men and women are 2.55 ppm and 1.43 ppm, he said. The highest concentration level discovered in the survey was 67.2 ppm in a male aged in his 50s, as a total of three people exceeded the level of 50 ppm for no observed adverse effect set by the World Health Organization, Endo said.

Endo expressed alarm that contamination levels among some of the residents appeared to be high enough to develop health problems according to oversea standards.

"It’s necessary to conduct more detailed research on their health conditions and the current status of contamination," he said. "We should also make efforts to curb consumption of whale meat which is highly contaminated with mercury."

The researchers, also including Koichi Haraguchi at Daiichi College of Pharmaceutical Sciences in Fukuoka, will publish the survey result in an international science magazine on oceanic pollution.

According to Endo, the researchers also discovered high levels of mercury in products made from local marine mammals and fishes, such as pilot whales, dolphins, tunas and skipjack, distributed in and around the community.

In particular, the total contamination levels in the red meat from 22 samples of pilot whales, a cetacean commonly consumed in the town, averaged 9.6 ppm, with the level for methyl mercury alone coming to 5.9 ppm, both well beyond the tentative national regulation figures of 0.4 ppm and 0.3 ppm, respectively. Among the 50 residents tested, the average total mercury level in those who eat pilot whale once a month or more was 24.6 ppm, while the levels in those who eat it only once every several months or not at all were 15.5 ppm and 4.3 ppm, respectively.

No epidemiologic survey has been conducted in Taiji although health hazards to the residents from the consumption of whale products are suspected, according to Endo.

Source: http://www.japantoday.com/category/national/view/mercury-levels-of-whale-eating-towns-residents-10-times-japan-average

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About Oceanic Defense
We are an international non-profit organization with members in over 60 countries, spanning 6 continents with 1 mission; healthy aquatic ecosystems free from human abuse and neglect. Oceanic Defense teaches people to protect our oceans by acting responsibly as consumers and by making smart decisions in our daily lives. Whether we are buying groceries, commuting to work, planning a vacation or advocating within our own communities; each action we take or decision we make either helps or hurts our oceans. We empower people to be part of the solution rather than part of the problem and work together to protect our blue planet.

Join us on Facebook:
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How Arctic Food Webs Affect Mercury in Polar Bears

ScienceDaily — With growing concerns about the effects of global warming on polar bears, it's increasingly important to understand how other environmental threats, such as mercury pollution, are affecting these magnificent Arctic animals.

New research led by biogeochemists Travis Horton of the University of Canterbury and Joel Blum of the University of Michigan lays the groundwork for assessing current and future effects of mercury deposition and climate change on polar bears.

The study appears in the December issue of the journal Polar Research.

Mercury is a naturally occurring element, but some 150 tons of it enter the environment each year from human-generated sources such as coal-burning power plants, incinerators and chlorine-producing plants. Deposited onto land or into water, mercury is picked up by microorganisms, which convert some of it to methylmercury, a highly toxic form that builds up in fish and the animals that eat them. As bigger animals eat smaller ones, the methylmercury is concentrated -- a process known as bioaccumulation. Sitting at the top of the food chain, polar bears amass high concentrations of the contaminant.

Although that much is known, the details of how mercury moves through different food webs -- particularly in the Arctic, where snow and ice contribute to mercury deposition -- are not well understood. To tease out that information, Horton, Blum and co-workers studied polar bear hair samples from museum specimens collected in the late 19th and early 20th centuries, before mercury emissions from human-generated sources began to escalate.

By looking at three chemical signatures -- nitrogen isotopes, carbon isotopes and mercury concentrations -- the researchers learned that polar bears get their nutrition (and mercury) from two main food webs. At the base of one web are microscopic plants that float on the surface of the ocean (known as phytoplankton). The foundation of the second web is algae that live on sea ice.

The study showed that polar bears that get most of their nutrition from phytoplankton-based food webs have greater mercury concentrations than those that participate primarily in ice algae-based webs.

While it's tempting to speculate that declining sea ice, due to global warming, may force polar bears to depend more on phytoplankton-based webs, thus increasing their mercury exposure, the study doesn't directly address that issue. It does, however, provide other useful information, said Blum, who is the John D. MacArthur Professor of Geological Sciences and a professor of ecology and evolutionary biology.

"If you want to understand the potential effects of changing ecosystems on polar bears, you need to be aware of the existence of these two food webs, which may possibly be affected by sea ice," Blum said. "This work provides background information that will be important in our in-depth understanding of mercury bioaccumulation in polar bears."

In addition to Horton and Blum, the paper's authors are Zhouqing Xie, who was at U-M when the research was done and now is at the University of Science and Technology of China; Michael Hren, who was at Yale University when the work was done and now is a postdoctoral fellow at U-M; and C. Page Chamberlain of Stanford University.

Source: http://www.sciencedaily.com/releases/2009/12/091208170915.htm

Interview with A Taiji Boat Captain

by: Steven Thompson’s guest blog as an ‘observer’ in Taiji, Japan:

Last year in Taiji I was told by a dolphin fishermen union member that dolphins are never let back into the wild because the fishermen are afraid the freed dolphins will communicate with other dolphins in the world about how sinister the Taiji fishermen really are.

We went whale watching on Oct 4th from Katsuura. Fishing and whale watching is available in Katsuura. Dolphin boats from the larger town of Katsuura take tourists to a sort of a dolphin aquarium where they are netted in the middle of the bay in Ocean water where they are and fed if they do tricks.

Fishing is everywhere and we saw many boats with fishermen fishing for one fish, katsuo using a line but there are still lots of boats that don't go out. I talked to a man who talked about harder economic times.

I am up at 5:30am to find a clear day brewing. It is a good day to go out for whale and dolphin watching. We drive about 4 minutes to meet the proud Captain, his first mate and a group of 4 college students on a weekend break. We are all excited at the prospect of watching whales and dolphins frolic in the wild, excited enough to spend about $60 US each for the privilege.

We motor about two hours straight out to sea to find a wonderful view of the wide ocean. The first mate serves drinks. The captain throws out fishing lines. We share jokes.

Life in this corner of Japan lulls people into a sunny, happy, friendly stupor. There are no problems in our town. The Captain’s family is illustrative of the happy life.

Today the Captain made more than $420 US. Whales or no whales, people will still pay. His wife
is quick with a friendly smile. Two of their lovely daughters I met seemed fun loving. One of his granddaughters ran around the docks with her Chihuahua named Charmie.

The idyllic picture is only interrupted by the Captain’s hands shaking. This is perhaps due to mercury poisoning perhaps not.

I am looking for ways to encourage activism among people who travel to Katsuura and Taiji. The dolphin killers keep such a low profile. Most locals have never taken the time to climb the hill next to the Whale Museum and look down at the Killing Cove with the ropes strung, ready to cover the embarrassment of ending lives filled with beauty and grace.

I am fighting the lull myself. I look forward to my next meal, my next humorous light conversation with locals.

Before eating another meal of katsuo sashimi prepared by the Captain’s wife, I interview the Captain. I have joked and cajoled the captain long enough that he knows my position. He even knows I am an activist. I bait him and he knows it.


Here is a rough translation:
Me: It’s too bad we didn’t see any whales or dolphins. Why couldn’t we? Could it have something to do with the Taiji fishermen?

He: No, it’s the end of the season, there are no more dolphins or whales in the area…less food for the dolphins…and there was rough weather a few days ago..
Me: It doesn’t sound quite right. Are you saying that the Taiji fishermen won’t find dolphins? Isn’t the season opening for them?

He: Yes, that’s true…but they go much farther out.

Me: How far?

He: Well, we went out about 20 km from shore and they will easily go out double that.

Me: So you expect them to find dolphins today?

He: I did hear radio chatter, they didn’t find any today either.

Me: I see by the way, do you eat dolphin?

He: No.

Me: Whale?

He: Of course. It’s delicious.

Me: But wouldn’t it be great to have a sea filled with dolphins all the time?

He: This is not easy to do…change takes time.

I can easily see why most people we meet in both Katsuura and Taiji know very little about the Taiji Drive hunts. Many people we meet casually in restaurants or while walking down the street know nothing about Taiji’s dolphin killing or dolphin selling business. For locals, mercury contamination seems to be a complete and utterly shocking unknown.

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The Cove premieres at the Tokyo Film Festival in Japan Wednesday October 21, 2009

How Mercury Emissions Reach Tuna And Other Seafood, And Why Mercury Contamination Is Likely To Worsen

ScienceDaily — A new landmark study documents for the first time the process in which increased mercury emissions from human sources across the globe, and in particular from Asia, make their way into the North Pacific Ocean and as a result contaminate tuna and other seafood. Because much of the mercury that enters the North Pacific comes from the atmosphere, scientists have predicted an additional 50 percent increase in mercury in the Pacific by 2050 if mercury emission rates continue as projected.

“This unprecedented USGS study is critically important to the health and safety of the American people and our wildlife because it helps us understand the relationship between atmospheric emissions of mercury and concentrations of mercury in marine fish,” said Secretary of the Interior Ken Salazar. “We have always known that mercury can pose a risk, now we need to reduce the mercury emissions so that we can reduce the ocean mercury levels.”

"This study gives us a better understanding of how dangerous levels of mercury move into our air, our water, and the food we eat, and shines new light on a major health threat to Americans and people all across the world,” said EPA Administrator Lisa P. Jackson. “With this information in hand, plus our own mercury efforts, we have an even greater opportunity to continue working with our international partners to significantly cut mercury pollution in the years ahead and protect the health of millions of people.”

Water sampling cited in the study shows that mercury levels in 2006 were approximately 30 percent higher than those measured in the mid-1990s. This study documents for the first time the formation of methylmercury in the North Pacific Ocean. It shows that methylmercury is produced in mid-depth ocean waters by processes linked to the “ocean rain.” Algae, which are produced in sunlit waters near the surface, die quickly and “rain” downward to greater water depths. At depth, the settling algae are decomposed by bacteria and the interaction of this decomposition process in the presence of mercury results in the formation of methylmercury. Many steps up the food chain later, predators like tuna receive methylmercury from the fish they consume.

One unexpected finding from this study is the significance of long-range transport of mercury within the ocean that originates in the western Pacific Ocean, off the coast of Asia.

“Mercury researchers typically look skyward to find a mercury source from the atmosphere due to emissions from land-based combustion facilities. In this study, however, the pathway of the mercury was a little different. Instead, it appears the recent mercury enrichment of the sampled Pacific Ocean waters is caused by emissions originating from fallout near the Asian coasts. The mercury-enriched waters then enter a long-range eastward transport by large ocean circulation currents,” said USGS scientist and coauthor David Krabbenhoft.

Scientists sampled Pacific Ocean water from 16 different sites between Honolulu, Hawaii and Kodiak, Alaska. In addition, the scientists constructed a computer simulation that links atmospheric emissions, transport and deposition of mercury, and an ocean circulation model.

In the United States, about 40 percent of all human exposure to mercury is from tuna harvested in the Pacific Ocean, according to Elsie Sunderland, a coauthor of the study. Methylmercury is a highly toxic form of mercury that rapidly accumulates in the food chain to levels that can cause serious health concerns for those who consume the seafood. Pregnant women who consume mercury can pass on life-long developmental effects to their children. That is why in 2004 EPA and FDA issued the landmark Joint Guidance on the Consumption of Fish specifically targeted towards pregnant women and nursing mothers. Previous studies show that 75 percent of human exposure worldwide to mercury is from the consumption of marine fish and shell fish.

Scientists have known for some time that mercury deposited from the atmosphere to freshwater ecosystems can be transformed (methylated) into methylmercury, but identifying the analogous cycles in marine systems has remained elusive. As a result of this study we now know more about how the process which leads to the transformation of mercury into methylmercury.

In addition to USGS mercury expert David Krabbenhoft, the authors include Elsie Sunderland, Harvard University; John Moreau, University of Melbourne, Australia (until recently a USGS, NRC Post Doctoral Candidate); William Landing, Florida State University; and Sarah Strode, Harvard University.

Source: http://www.sciencedaily.com/releases/2009/05/090501195628.htm

Oceanographers Examine Mercury Levels Of Pelagic Fish In Hawaii

ScienceDaily — In the open ocean, species of large predatory fish will swim and hunt for food at various depths, which leads to unique diets in these fish. Oceanographers and geologists in the School of Ocean and Earth Science and Technology (SOEST) at the University of Hawaiʻi at Mānoa (UHM) and colleagues have found that those fish that hunt deeper in the open ocean have higher mercury concentrations than those that feed near the surface of the ocean because their deep water food has higher mercury.

This research was detailed in the August 18th early edition of the prestigous journal the Proceedings of the National Academy of Sciences.

Mercury is a naturally-occurring trace element distributed throughout the Earth's oceans, land and air. The general public is interested in mercury levels in fish because the organic form, methylmercury, can be toxic at elevated levels if ingested by humans and animals.Mercury enters open ocean food webs, where it bioaccumulates, leading to higher levels in large predatory animals.

Researchers looking at mercury levels in the open ocean have indicated that deeper waters have elevated levels relative to the surface waters. "Building on this information, we thought that deeper-dwelling open ocean animals might have more mercury, as well as the predatory fishes that feed on them," says Anela Choy, a Department of Oceanography Graduate Student at UHM and lead author in this study. This was indeed the case, and the results of their work show that large pelagic fish like bigeye tuna and swordfish that feed deeper in the ocean have elevated total mercury levels relative to their shallower-dwelling counterparts like yellowfin tuna and mahi-mahi. "We show that this is because the food items that they eat also have varying levels of mercury", continues Choy. "Deeper-living micronekton prey (small fishes, squids, and crustaceans) have higher mercury levels relative to more surface-dwelling prey animals. This is important knowledge for scientists studying animals in the open ocean because it helps them to understand how energy and matter cycle, as well as show who is eating who in the vast, blue water environment. Although not the focus of this study, the results may also help provide information to the fish-consuming public on mercury levels in popular commercial species."

To study the mechanisms governing bioaccumulation in open ocean fish, the researchers, who also included Brian N. Popp and Jeffrey C. Drazen, also from UHM, and John Kaneko from the Honolulu company PacMar Inc, collected nine predatory pelagic fish species with different diets in waters surrounding Hawaiʻi, along with a representation of the types of prey these fishes eat. The predatory fish collected represented a wide variety of depths at which they search for food, varying from shallow-ranging predators (0 – 300 meters) to deep-ranging predators (up to 1000 meters). Total mercury levels of these fish were measured, along with an analysis of animals in their stomachs. The authors found that while the sex of a fish and the location where a fish was caught d! id not a ffect mercury concentrations, the size, age and species of fish did. However, for similar sized fish of different species, deeper-ranging predators still had more mercury than shallow-ranging ones. This study shows for the first time, that in addition to the size and age of a fish, or where it swims/lives, that the depth at which a fish feeds influences the amount of mercury it has in it's tissues.

"After looking more closely at these different mid-water prey organisms, a number of interesting questions have opened up," says Choy. "As these organisms are the primary food items for large pelagic fishes that humans like to eat, we need to understand more about how they fit into the open ocean ecosystem in order to sustainably manage our fish populations."

It is important to understand that ocean biology is connected across depths by the movements and hunting behaviors of animals. "The deep sea is remote, hard to study, and often ignored but our results clearly show how its biology is directly connected to human interests, both fishing and health," says Drazen. "Some of the fishes we enjoy at the dinner table grew on a diet of strange and exotic creatures from 1000s of feet deep in the ocean."

The original research was funded by University of Hawaiʻi Sea Grant College Program at UHM, the State of Hawaiʻi, JIMAR (Pelagic Fisheries Research Program (PFRP)), and the National Oceanographic and Atmospheric Administration. The need for a detailed study came after Popp attended a PFRP meeting on the UHM campus and he saw a data table from the State Department of Health of mercury concentrations in Hawaiian pelagic fishes that was published in the newspaper The Honolulu Advertiser. "The table was very crude showing only the average and range of mercury contents in each fish," says Popp." The fishes were listed from lowest m! ercury a t the top and highest mercury at the bottom -- it hit me that the order in the list roughly followed the depth the fish are typically caught in the ocean." Fortunately for Popp and Drazen, Choy, who had completed her undergraduate degree and was doing consulting work within the local seafood industry, and was also interested in this topic. Says Choy, "after interacting with the public, I found that many people were concerned with mercury levels in fish, and I eventually became interested in the oceanographic/ecological aspect of it."

The researchers have recently received funding from the Pelagic Fisheries Research Program, within the Joint Institute for Marine and Atmospheric Research (JIMAR) at UHM to continue using mercury, along with other chemical tracers to elucidate the structure and function of the open ocean food web in Hawaiian waters. Concludes Choy, "We hope this will provide crucial information for ecosystem-based fishery managers and ecosystem modelers."

Source: http://www.sciencedaily.com/releases/2009/09/090901091733.htm

Exposure To Low Doses Of Mercury Changes The Way The Arteries Work

ScienceDaily — An international team of researchers has shown that mercury is another important factor in cardiovascular disease as it changes the way arteries work. One of the possible sources of exposure of humans to mercury is by eating contaminated fish.

The main effects of mercury affect the central nervous system and renal function. Over recent years the scientific community has reported an increase in cardiovascular risk following exposure to mercury, “although the mechanisms responsible for this increase are not completely known”, state the authors of the new study that has been published recently in the American Journal of Physiology-Heart and Circulatory Physiology explain.

Ana María Briones is a researcher at the Universidad Autónoma of Madrid (UAM) and is one of the authors of the study. Briones explains the aim of the investigation to SINC: “Because the relationship between mercury and cardiovascular risk has been explained recently, and that cardiovascular risk is known to be related to changes in vascular function, we intended to see whether a relationship existed between mercury and changes in vascular responses”.

The aim of the study was to evaluate whether really low concentrations of mercury, administered over a prolonged period of time, “could have a prejudicial effect on vascular response”, that is to say, on the way the arteries behave.

Data confirm that low doses of mercury have a harmful effect on vascular function. Mercedes Salaices, one of the other authors of the study, emphasises that the impact of mercury “could be compared to the impact produced by other more traditional cardiovascular risk factors such as hypertension, diabetes or hypercholesterolaemia”.

The researchers analysed whether chronic exposure to mercury causes an endothelial dysfunction in resistance and conductance arteries. Treatment with mercury induces an increase in oxidative stress, which is responsible – at least in part – for the deterioration in vascular responses. “Arteries contract more and relax less because there is less nitric oxide”, the vasodilator factor that is attacked by oxidative stress, underlines Briones.

The risk of exposure to mercury today

Humans have been exposed to different metal pollutants such as mercury, although the possible consequences to health are not known in depth. At the present time, exposure to mercury is due, mainly, to the consumption of polluted fish, to the administration of anti-fungal agents and Thimerosal antiseptics in vaccines and to the inhalation of mercury vapour from some dental re-constructions

The European Environment Agency (EEA) recommended a reference blood mercury concentration of 5.8 nanograms per milliliter (ng/ml). It is considered that there are no adverse effects below this level. Data reveal that the concentration of mercury in the general population is less than 1 ng/ml, whereas in workers who suffer exposure in polluted zones, the levels are between 7 and 10. The percentage reaches up to 5.6 ng/ml amongst people who eat fish on a regular basis.

SHARKS KILL PEOPLE - Through Methyl Mercury Poisoning

Ok, granted, the title of this article is a little over the top I confess. The fact of the matter is we as people are much more dangerous to sharks than they are to us...unless we eat them. Shark meat has some of the highest concentrations of methyl mercury know to cause birth defects and neurological problems.

The consequences of such a poisoning are for an infant mental development disturbances and for an adult heavy damage to the central nervous system. These express themselves by headache, memory difficulties or depressions." Besides kidney damages, cancer and massive damages of the brain threatens.

For a long time it was assumed and now it is certain: Shark meat is poisonous!! By a new method of analysis, patented by Professor Klaus Heumann of the University of Mainz (Germany), alarming concentrations of methyl mercury were found in shark steaks.

A study - given by the shark protection organization Sharkproject - proved that there is up to 1400 microgram of methyl mercury per kilogram blue shark steak. These are 420 microgram of methyl mercury in a normal 300 gram shark steak portion and this is 60 times more than a 70 kg heavy consumer per day may have.
The danger value is 0.1 microgram per kilogram body weight and day. This value was specified by EPA (Environmental Protection Agency) in a toxicologist committee and is considered as new international standard. A consumer might take only 5 gram blue shark steak or 12.7 gram of smoked rock salmon (smoked dogfish) per day. Each higher dose can have serious consequences.

Methyl mercury is most dangerous for the human body. Toxicologist Dr. Hermann Kruse of the University of Kiel (Germany) explains why: "It is one of the biologically most active and most dangerous poisons for humans. In addition methyl mercury is a "Trojan horse" which can pass easily each protection barrier as to the separation mechanism between the blood circulation of a mother and her unborn child as well as the blood-brain barrier of each adult.

Who thinks that a smoked rock salmon (smoked dogfish) or a small blue shark steak from the food discounter now and then is not precarious is wrong because the half-life of methyl mercury is high. The human organism needs 60 to 80 days to halve the poison concentration in the body.

But not only sharks are affected by this heavy metal load. The same applies to all large predatory fish who take up the poison over their natural food chain. For example also tuna and swordfish count for this.

The management of the German fish restaurant chain North Sea already reacted to the arguments of the animal conservationist organization and wants to go completely without any shark products. These results also would have to alarm now the food branch and the Ministries of Health.
Best would be if everyone stopped immediately buying and consuming all kind of shark products and stopped the consumption of tuna and swordfish.

(Source: "Tauchen"-Magazine and Sharkproject)