Ewen Callaway, New Scientist 30 Jul 09;
Fishery scientists are having a glass-half-full moment. A new global survey of commercial fish stocks concludes that many threatened ecosystems are on the mend, thanks to good stewardship.
And the other half of that glass? Sixty-three per cent of the fish populations they surveyed are still at unsustainable levels, with things looking grimmest in the developing world.
"When you look region by region, you can document solutions and the problems become more manageable," says Boris Worm, a marine ecologist at Dalhousie University in Halifax, Nova Scotia, Canada, who led the study.
This is a considerably rosier picture than the one painted by Worm's group in a controversial 2006 study projecting a worldwide collapse of all existing fisheries by 2048, based on current trends.
"I was one of those who criticised the conclusion that all fish would be gone by 2048 because my personal experience has been very different," says Ray Hilborn, who as a researcher at the University of Washington in Seattle has studied well-managed fisheries in the Pacific Northwest and Alaska, such as Pacific salmon.
CSI: Fisheries
For the latest study, Hilborn teamed up with Worm and others to analyse various data from dozens of fisheries in numerous large ecosystems. The 2006 survey relied principally on gross catch reports, which may have masked nuances in individual fisheries.
In particular, the researchers focused on measuring the total biomass of a species that caught each year. They then related those figures to estimates of fishing levels that would sustain stocks in the long term.
"This was a little bit like a crime-scene investigation for overfishing: where do we see evidence of overfishing and where do we see improvement," Worm says.
Out of 10 regions in North America, northern Europe and Oceania that his team looked at closely, five showed signs of improvement, with diminishing rates of exploitation in recent years. For the most part, fish populations in Alaska and New Zealand never plummeted drastically because of good management from the start.
Fisheries in the Baltic Sea, North Sea and off the coast of the UK and Ireland, however, tend to face continued declines in stocks. And New Zealand and California were the only places where Worm's team projected that fewer than 10 per cent of species would collapse.
'No single solution'
"The big thing to me is that a number of systems were at least heading in the right direction," Worm says.
More discriminate fishing gear targeted to large individuals of specific species, government-imposed catch limits, and the creation of marine reserves all helped rebuild stocks, they say.
"In order to avoid collapse you need to do a number of things, there is not one solution that will get you there," Worm says.
His team examined limited data from Africa, however, the outlook for sustainable fishing appears bleak, with the exception of improvements in the practices of small-scale fisherman in Kenya. For instance, restrictions in industrial countries are already pushing industrialised world fleets south.
Local hardship
"Most counties in Africa are selling fishing rights to industrialised nations which catch large amounts of seafood, effectively out-competing local fisherman," says team member Tim McClanahan, of the Wildlife Conservation Society Marine Program in Mombasa, Kenya.
"It's a real hardship for the local communities to have their fish taken by these big fleets," says Peter Kareiva, a marine biologist at the Nature Conservancy in Seattle, Washington, who was not involved in the survey.
Still, Kareiva sees the new report as a turning point for fisheries science. "Yes, there are certainly extensively overfished stocks and the oceans are in trouble, but there are some examples of decent management and reason for hope," he says. "This doom and gloom doesn't get us anywhere."
Journal reference: Science (DOI: 10.1126/science.1173146)
Having Fish and Eating It Too
Cornelia Dean, Straits Times 30 Jul 09;
Can we have our fish and eat it too? An unusual collaboration of marine ecologists and fisheries management scientists says the answer may be yes.
In a research paper in Friday’s issue of the journal Science, the two groups, long at odds with each other, offer a global assessment of the world’s saltwater fish and their environments.
Their conclusions are at once gloomy — overfishing continues to threaten many species — and upbeat: a combination of steps can turn things around. But because antagonism between ecologists and fisheries management experts has been intense, many familiar with the study say the most important factor is that it was done at all.
They say they hope the study will inspire similar collaborations between scientists whose focus is safely exploiting specific natural resources and those interested mainly in conserving them.
“We need to merge those two communities,” said Steve Murawski, chief fisheries scientist for the National Oceanic and Atmospheric Administration. “This paper starts to bridge that gap.”
The collaboration began in 2006 when Boris Worm, a marine ecologist at Dalhousie University in Halifax, Nova Scotia, and other scientists made an alarming prediction: if current trends continue, by 2048 overfishing will have destroyed most commercially important populations of saltwater fish. Ecologists applauded the work. But among fisheries management scientists, reactions ranged from skepticism to fury over what many called an alarmist report.
Among the most prominent critics was Ray Hilborn, a professor of aquatic and fishery sciences at the University of Washington in Seattle. Yet the disagreement did not play out in typical scientific fashion with, as Dr. Hilborn put it, “researchers firing critical papers back and forth.” Instead, he and Dr. Worm found themselves debating the issue on National Public Radio.
“We started talking and found more common ground than we had expected,” Dr. Worm said. Dr. Hilborn recalled thinking that Dr. Worm “actually seemed like a reasonable person.”
The two decided to work together on the issue. They sought and received financing and began organizing workshops at the National Center for Ecological Analysis and Synthesis, an organization sponsored by the National Science Foundation and based at the University of California, Santa Barbara.
At first, Dr. Hilborn said in an interview, “the fisheries management people would go to lunch and the marine ecologists would go to lunch” — separately. But soon they were collecting and sharing data and recruiting more colleagues to analyze it.
Dr. Hilborn said he and Dr. Worm now understood why the ecologists and the management scientists disagreed so sharply in the first place. For one thing, he said, as long as a fish species was sustaining itself, management scientists were relatively untroubled if its abundance fell to only 40 or 50 percent of what it might otherwise be. Yet to ecologists, he said, such a stock would be characterized as “depleted” — “a very pejorative word.”
In the end, the scientists concluded that 63 percent of saltwater fish stocks had been depleted “below what we think of as a target range,” Dr. Worm said.
But they also agreed that fish in well-managed areas, including the United States, were recovering or doing well. They wrote that management techniques like closing some areas to fishing, restricting the use of certain fishing gear or allocating shares of the catch to individual fishermen, communities or others could allow depleted fish stocks to rebound.
The researchers suggest that a calculation of how many fish in a given species can be caught in a given region without threatening the stock, called maximum sustainable yield, is less useful than a standard that takes into account the health of the wider marine environment. They also agreed that solutions did not lie only in management techniques but also in the political will to apply them, even if they initially caused economic disruption.
Because the new paper represents the views of both camps, its conclusions are likely to be influential, Dr. Murawski said. “Getting a strong statement from those communities that there is more to agree on than to disagree on builds confidence,” he said.
At a news conference on Wednesday, Dr. Worm said he hoped to be alive in 2048, when he would turn 79. If he is, he said, “I will be hosting a seafood party — at least I hope so.”
New Hope For Fisheries
ScienceDaily 30 Jul 09;
Scientists have joined forces in a groundbreaking assessment on the status of marine fisheries and ecosystems. The two-year study, led by Boris Worm of Dalhousie University and Ray Hilborn of the University of Washington and including an international team of 19 co-authors, shows that steps taken to curb overfishing are beginning to succeed in five of the ten large marine ecosystems that they examined.
The paper, which appears in the July 31 issue of the journal Science, provides new hope for rebuilding troubled fisheries.
The study had two goals: to examine current trends in fish abundance and exploitation rates (the proportion of fish taken out of the sea) and to identify which tools managers have applied in their efforts to rebuild depleted fish stocks. The work is a significant leap forward because it reveals that the rate of fishing has been reduced in several regions around the world, resulting in some stock recovery. Moreover, it bolsters the case that sound management can contribute to the rebuilding of fisheries elsewhere.
It's good news for several regions in the U.S., Iceland and New Zealand. "These highly managed ecosystems are improving" says Hilborn. "Yet there is still a long way to go: of all fish stocks that we examined sixty-three percent remained below target and still needed to be rebuilt."
"Across all regions we are still seeing a troubling trend of increasing stock collapse," adds Worm. "But this paper shows that our oceans are not a lost cause. The encouraging result is that exploitation rate – the ultimate driver of depletion and collapse – is decreasing in half of the ten systems we examined in detail. This means that management in those areas is setting the stage for ecological and economic recovery. It's only a start – but it gives me hope that we have the ability to bring overfishing under control."
The authors caution that their analysis was mostly confined to intensively managed fisheries in developed countries, where scientific data on fish abundance is collected. They also point out that some excess fishing effort is simply displaced to countries with weaker laws and enforcement capacity.
While most of the fisheries that showed improvement are managed by a few wealthy nations, there are some notable exceptions. In Kenya, for example, scientists, managers, and local communities have teamed up to close some key areas to fishing and restrict certain types of fishing gear. This led to an increase in the size and amount of fish available, and a consequent increase in fishers' incomes. "These successes are local - but they are inspiring others to follow suit," says Tim McClanahan of the Wildlife Conservation Society in Kenya.
"We know that more fish can be harvested with less fishing effort and less impact on the environment, if we first slow down and allow overfished populations to rebuild," adds co-author Jeremy Collie from the University of Rhode Island. "Scientists and managers in places as different as Iceland and Kenya have been able to reduce overfishing and rebuild fish populations despite serious challenges."
The authors emphasize that a range of management solutions are available to help rebuild fish stocks. They found that a combination of approaches, such as catch quotas and community management coupled with strategically placed fishing closures, ocean zoning, selective fishing gear and economic incentives, offer promise for restoring fisheries and ecosystems. However "lessons from one spot need to be applied very carefully to a new area," says coauthor Beth Fulton of the CSIRO Wealth from Oceans Flagship in Australia, since "there are no single silver bullet solutions. Management efforts must be customized to the place and the people."
According to the authors' analysis, Alaska and New Zealand have led the world in terms of management success by not waiting until drastic measures are needed to conserve, restore and rebuild marine resources. Some other regions are currently recovering from overfishing: fish abundance has recently been increasing above the long-term average in Iceland, the Northeast U.S. Shelf and the California Current.
This new study is a follow-up to a 2006 paper in Science by Worm and others that highlighted a widespread global trend toward fisheries collapse. The results of that paper led to a public disagreement between Worm and Hilborn. Through their subsequent discussions, however, the two scientists recognized a shared sense of purpose. They decided to collaborate on a more detailed assessment of the world's fisheries, and brought together many of the world's most talented fisheries scientists and ecologists for a two-year series of working groups at the National Center for Ecological Analysis and Synthesis (NCEAS) in Santa Barbara, California. The current paper is the result of those meetings.
"Prior to this study, evaluations of the status of world fish stocks and communities were based on catch records for lack of a better alternative. Results were controversial because catch trends may not give an accurate picture of the trends in fish abundance," explains Ana Parma of Centro Nacional Patagónico in Argentina. "This is the first exhaustive attempt to assemble the best-available data on the status of marine fisheries and trends in exploitation rates, a major breakthrough that has allowed scientists from different backgrounds to reach a consensus about the status of fisheries and actions needed."
The analysis includes catch data, stock assessments, scientific trawl surveys, small-scale fishery data and modeling results. The authors liken their strategy to constructing a "Russian doll", with each nested layer of data adding to the strength and value of the whole.
In looking at the tools that have been used to reduce exploitation rate, the authors note that "some of the most spectacular rebuilding efforts have involved bold experimentation with closed areas, gear and effort restrictions and new approaches to catch allocations and enforcement." Laws that explicitly forbid overexploitation and specify clear rules and targets for rebuilding were seen as an important prerequisite, for example in the U.S.
While the study suggests that these tools have long-term benefits, they also come with short-term costs to fishers. "Some places have chosen to end overfishing," says Trevor Branch, a co-author from the University of Washington. "That choice can be painful for fishermen in the short term, but in the long term it benefits fish, fishermen, and our ocean ecosystems as a whole."
Key among the group's recommendations is to fish at rates lower than those producing maximum sustainable yield (MSY), a long-standing and internationally accepted benchmark for total catch. They call for MSY to be reinterpreted as an absolute upper limit rather than a target, in line with U.N. recommendations.
The authors used ecosystem models to calculate a multi-species MSY (or MMSY) that adds up yield across all species, taking account of their interrelations. That analysis suggests that fishing below MMSY yields just as much fish as exceeding that benchmark, but has many ecological benefits including fewer species collapses, an increase in fish size and fish abundance. "Below MMSY there is a fishing-conservation sweet spot," says co-author Steven Palumbi of Stanford University, "where economic and ecosystem benefits converge."
The team also notes that in addition to reducing exploitation rates below MMSY, there are several other measures that can reduce fishing impacts on ecosystems. "Fishing at maximum yield comes at a significant cost of species collapses," explains Heike Lotze, a co-author from Dalhousie University. "But even low levels of fishing do change marine ecosystems and may collapse vulnerable species. That's why we require a combination of measures, including gear restrictions and closed areas, in order to meet both fisheries and conservation objectives."
The authors caution that much work remains to be done to end global overfishing, as a large fraction of global fisheries are not properly managed, reported or regulated. Particularly outside wealthy industrialized nations, prospects for reducing fishing mortality are often more limited unless fishers get access to alternative sources of food and income. Therefore the authors highlight the need for a more global perspective on rebuilding marine resources.
"Fisheries managers currently presiding over depleted fish stocks need to become fast followers of the successes revealed in this paper," says Pamela Mace, a co-author from the New Zealand Ministry of Fisheries. "We need to move much more rapidly towards rebuilding individual fish populations and restoring the ecosystems of which they are a part, if there is to be any hope for the long-term viability of fisheries and fishing communities."
The study was based at the National Center for Ecological Analysis and Synthesis (NCEAS), funded by the National Science Foundation and the University of California, Santa Barbara.
Adapted from materials provided by Communication Partnership for Science and the Sea, via EurekAlert!, a service of AAAS.
World's fisheries at risk of collapse, but recovery is possible: study
Yahoo News 30 Jul 09;
CHICAGO (AFP) – The world's fisheries are at risk of collapse, but recovery is possible if governments act to manage commercial fishing, a comprehensive study published Thursday has found.
Several regions in the United States, Iceland and New Zealand have made significant progress in rebuilding stocks devastated by decades of overfishing through careful management strategies.
But the study, published in the journal Science, found that 63 percent of assessed fish stocks worldwide require rebuilding to reverse the collapse of vulnerable species.
"Across all regions, we are still seeing a troubling trend of increasing stock collapse," said lead author Boris Worm of Canada's Dalhousie University.
"But this paper shows that our oceans are not a lost cause."
Half of the 10 regions examined had managed to decrease their exploitation rate (the proportion of the total fish population that is caught) -- the primary driver of depletion of collapse.
"This means that management in those areas is setting the stage for ecological and economic recovery," Worm said. "It's only a start -- but it gives me hope that we have the ability to bring overfishing under control."
Worm cautioned that the analysis -- the most comprehensive to date -- was mostly confined to managed fisheries in developed countries where long-term data on fish abundance is collected.
The threat of collapse could thus be even higher in the remaining 75 percent of the world's fisheries.
The study found that a range of management strategies helped protect and restore fishing stocks.
Switching to nets that allow smaller fish to escape and closing some key areas to fishing helped Kenya increase the size and amount of fish available and boost fishing incomes.
In many areas, however, take rates will have to be cut in half in order to preserve fish stocks, Worm said in a conference call with reporters.
The study, which Science editor Andrew Sugden called an "important and convincing new analysis" and "a real step forward toward the goal of restoring fisheries" was published in a special issue dedicated to ecological restoration.
In a separate study, researchers found that ecological restoration on land can reverse some, but not all, of the environmental degradation caused by humans.
Spanish and British researchers analyzed 89 assessments of restoration attempts in a wide range of ecosystems around the world.
They found that biodiversity had improved, on average, by 44 percent while ecosystem services like carbon storage and soil and water management increased by 25 percent.
"However, values of both remained lower (14 and 20 percent respectively) in restored than in intact reference ecosystems," lead author Jose Rey Benayas of Spain's Alcala University wrote.
The "unprecedented" restoration of native oysters in Virginia was also documented by researchers who built oyster reefs in nine protected sanctuaries in the Great Wicomico River.
There were less than two oysters per square meter in the river when the reefs were built in 2004.
By 2007, the nine reefs housed 185 million oysters -- nearly as many as can be found in all the waters of neighboring Maryland.
And the highest reefs housed over 1,000 oysters per square meters, nearly ten times typical densities on protected reefs in Chesapeake Bay.
"Similar approaches with other natural and artificial reefs could lead to recovery of the native oyster throughout North America, as well as other ecosystems worldwide where native oysters have been functionally extirpated," wrote lead author David Shulte of the Virginia Institute of Marine Science.
World fisheries collapse can be averted: study
Deborah Zabarenko, Reuters 30 Jul 09;
WASHINGTON (Reuters) - The world's commercial fisheries, pressured by overfishing and threatened with possible collapse by mid-century, could be rebuilt with careful management, researchers reported on Thursday.
In fact, a fisheries expert who in 2006 predicted total global collapse of fish and seafood populations by 2048 is more optimistic of recovery, based on a wide-ranging two-year study by scientists in North and South America, Africa, Australia and New Zealand.
Still, 63 percent of fish stocks worldwide need to be rebuilt, the researchers said.
"I am somewhat more hopeful that we will be in a better state ... than what we originally predicted, simply because I see that we have the management tools that are proven to work," said Boris Worm of Dalhousie University in Halifax, Nova Scotia, Canada. He is a co-author of a paper in the journal Science and also an author of the pessimistic 2006 report.
These tools include: restrictions on gear like nets so that smaller, younger fish can escape; limits on the total allowable catch; closing some areas to fishing; certifying fisheries as sustainable; offering shares of the total allowable catch to each person who fishes in a specified area.
Worm's optimism was provisional, however, because the current research only looked at about one-quarter of the world's marine ecosystems, mostly in the developed world where data is plentiful and management can be monitored and enforced.
Of the 10 major ecosystems they studied, the scientists found five marine areas have cut the average percentage of fish they take, relative to estimates of the total number of fish. Two other ecosystems were never overexploited, leaving three areas overexploited.
HELPING FISHERIES SURVIVE
One key to helping fisheries survive is to revamp a long-used standard called maximum sustainable yield, which means figuring out the highest number of fish that can be caught in an area without hurting the species' ability to reproduce.
The researchers recommended setting fishing limits below the estimated maximum sustainable yield. Maximum sustainable yield should be an absolute upper limit, they said, rather than a target that is frequently exceeded.
Ray Hilborn, a co-author from the University of Washington in Seattle, noted in a telephone briefing that fisheries are also likely to feel pressure from climate change and ocean acidification, which is exacerbated by emissions of the greenhouse gas carbon dioxide.
Hilborn said places with a strong regulations to protect fisheries will probably be in good shape by 2048, but areas that lack this kind of institutional framework could be "quite overfished" by that time.
Tim McClanahan of the Wildlife Conservation Society told reporters that efforts in the developed world to curtail overfishing could mean more overfishing in the developing world, especially in Africa.
The fisheries in the study are: Iceland Shelf, Northeast U.S. Shelf, North Sea, Newfoundland-Labrador Shelf, Celtic-Biscay Shelf, Baltic Sea, Southern Australia Shelf, Eastern Bering Sea, California Current, New Zealand Shelf.
(Editing by Doina Chiacu)
Fish for dinner: Overfishing easing in some areas
Randolph E. Schmid, Associated Press Yahoo News 31 Jul 09;
WASHINGTON – Crabcakes and fish sticks won't be disappearing after all.
Two years after a study warned that overfishing could cause a collapse in the world's seafood stocks by 2048, an update says the tide is turning, at least in some areas.
"This paper shows that our oceans are not a lost cause," said Boris Worm of Dalhousie University in Halifax, Nova Scotia, lead author of both reports. "I'm somewhat more hopeful ... than what we were seeing two years ago."
It's personal as well as scientific.
"I have actually given thought to whether I will be hosting a seafood party then," Worm said, meaning 2048.
Ray Hilborn of the University of Washington challenged Worm's original report, leading the two — plus 19 other researchers — to launch the study that led to the new findings. They're being published in Friday's edition of the journal Science.
The news isn't all good.
Of 10 areas of the world that were studied, significant overfishing continues in three, but steps have been taken to curb excesses in five others, Hilborn and Worm report. The other two were not a problem in either study.
Hilborn noted that 63 percent of fish stocks remain below desired levels. It takes time to rebuild after steps are taken to reduce the catch.
Rebecca Goldburg, director of Marine Science at the Pew Environment Group, commented that "two scientists who once held opposing views about the state of ocean fisheries now agree about the significance of global fisheries declines and the solutions needed to reverse these trends. If fishery managers worldwide heed these important scientific findings, then we have an extraordinary opportunity to restore ocean fisheries."
Michael Fogarty of the U.S. National Oceanic and Atmospheric Administration noted a dramatic recovery of haddock on Georges Bank, off New England, as well as improvements in redfish, scallop and other fish. But still others, such as cod and flounder, remain vulnerable, he said at a briefing.
"We feel confident that the tide of overexploitation can be reversed on a global basis," Fogarty said, citing such steps as exclusion areas, changes in fishing gear, assignments of rights to harvest and incentives for fishers to take a long-term view.
Two areas, Alaska and New Zealand, have led the world in terms of management success by not waiting until drastic measures are needed to conserve, the report said. These areas were not a problem in either study.
Regions where excess exploitation has halted are Iceland, southern Australia, the Northeast U.S., the Newfoundland-Labrador area and the California Current, which flows south along the U.S. West Coast.
Still being overfished, the report said, are the North and Baltic seas and the Bay of Biscay region.
A newly developing problem is the movement of major fishing efforts to the developing world, with foreign fleets operating off east and west Africa under access agreements with local governments. These fleets compete with local fishers and almost all the fish they catch is taken to industrialized countries.
"The prognosis for Africa is not nearly as good as it is for wealthier areas," commented Tim McClanahan of the Wildlife Conservation Society in Mombasa, Kenya.
"Prior to this study, evaluations of the status of world fish stocks and communities were based on catch records for lack of a better alternative. Results were controversial because catch trends may not give an accurate picture of the trends in fish abundance," Ana Parma of Centro Nacional Patagonico in Argentina, said in a statement.
"This is the first exhaustive attempt to assemble the best-available data on the status of marine fisheries and trends in exploitation rates," she said. The new analysis includes catch data, stock assessments, scientific trawl surveys, small-scale fishery data and computer modeling results.
The research was funded by the National Science Foundation and the University of California, Santa Barbara.
A separate study, also in Science, reports that researchers have successfully restored populations of native oysters to the Chesapeake Bay.
The local oyster population had collapsed after years of overfishing. Researchers launched the restoration effort in 2004, constructing artificial reefs in protected areas of the Great Wicomico River in Virginia.
The oysters are thriving in these areas, demonstrating how similar recovery efforts might work elsewhere, according to the researchers from the Virginia Institute of Marine Science of the College of William and Mary.
That research was funded by the U.S. Army Corps of Engineers, Blue Crab Advanced Research Consortium and the National Oceanic and Atmospheric Administration.
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