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Study: English Channel all fished out

Scientists call for network of protected areas

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The English Channel. Photo courtesy NASA.

Staff Report

FRISCO — The English Channel is all but fished out, leaving fishermen scraping the bottom of the barrel in their quest for a commercial haul.

Sharks, rays, cod, haddock and many other species at the head of the food chain are at historic lows with many removed from the area completely, according to UK marine biologists, who analyzed catches over the past 90 years and found significant evidence of the practice of fishing down the food web.

“It is clear from our analyses that fishing pressure has caused significant changes to food webs of the English Channel over the past 90 years,” said Plymouth University Professor Jason Hall Spencer, with the School of Marine Science and Engineering, and the Marine Institute.

The report, published in the PLOS ONE journal, used catch statistics from the International Council for the Exploration of the Seas to establish a ‘mean trophic level’ for catches – an average for how far up the food chain the fish are located. Continue reading

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Oceans: Mediterranean fish in steady decline

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Albanian fishermen tend nets in Saranda. bberwyn photo.

Unregulated coastal fisheries, juvenile catch threaten sustainability

Staff Report

FRISCO — Stocks of commercially valuable fish in the Mediterranean Sea are disappearing steadily because of a lack of good planning and management, as well as inadequate enforcement of existing regulations. Without action, some species are likely to disappear, scientists warned last week in a report showing that fisheries resources in the Mediterranean have deteriorated in the past 20 years.

The report evaluated nine fish species and called for stringent monitoring of Mediterranean fishing activities, better enforcement of fisheries regulations, and advanced management plans in Mediterranean waters. The findings were published July 10 in the Cell Press journal Current Biology.
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Better planning needed to protect ocean resources

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Zoning coastal waters could help preserve marine resources for future generations. bberwyn photo.

Scientists call for ‘zoning’ of coastal waters

By Summit Voice

FRISCO — Piecemeal planning and conservation efforts won’t be enough to preserve valuable ocean resources for future generations, a leading group of environmental and marine scientists said last week, calling on countries around the world to cooperate on zoning coastal waters in an approach that would mirror common land-use planning efforts.

Effective long-term conservation is crucial because about 20 percent of the world’s population  — mostly in developing countries — lives within 60 miles of the coast. Growing populations and worsening climate change impacts ensure that pressures on tropical coastal waters will only grow, they warned. Continue reading

Biodiversity: Pacific great white sharks may be more abundant than previously believed

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Are Pacific Ocean great white sharks endangered?

New study suggests there’s no need for endangered species listing

Staff Report

FRISCO — While California is considering endangered species status for great white sharks, some recent research suggests the apex ocean predators are doing just fine, and that populations appear to be growing.

George Burgess, director of the Florida Program for Shark Research, said the wide-ranging study is good news for shark conservation. The study, to be published June 16 in the journal PLOS ONE, shows that conservation measures are working.

Scientists reanalyzed 3-year-old research that indicated white shark numbers in the Eastern North Pacific were alarmingly low, with only 219 counted at two sites. That study triggered petitions to list white sharks as endangered.

“White sharks are the largest and most charismatic of the predator sharks, and the poster child for sharks and the oceans in general,” said Burgess, whose research program is based at the Florida Museum of Natural History on the UF campus. “If something is wrong with the largest, most powerful group in the sea, then something is wrong with the sea, so it’s a relief to find they’re in good shape.” Continue reading

Deadly starfish disease explodes on Oregon coast

Northern rainbow star afflicted with sea star wasting disease. This species had virtually disappeared from central California kelp forests as of February 2014. Photo: Steve Lonhart / NOAA MBNMS

Northern rainbow star afflicted with sea star wasting disease. This species had virtually disappeared from central California kelp forests as of February 2014. Photo: Steve Lonhart / NOAA MBNMS.

Biologists fully expecting local extinctions

Staff Report

FRISCO — As scientists continue to puzzle over the cause of a devastating starfish disease, the outbreak this month spread rapidly north along the coast of Oregon, where ocean experts are now expecting a widespread die-off with some local extinctions of starfish possible.

Sea star wasting syndrome is a traumatic process in which, over the course of a week or less, the sea stars begin to lose legs, disintegrate, ultimately die and rot. They sometimes physically tear their bodies apart. Various epidemics of the syndrome have been observed in the past, but none of this extent or severity, according to information released by Oregon State University. Continue reading

Oceans: Study finds that regional humpback whale populations should be classified as distinct subspecies

Northern and southern humpbacks rarely mingle

A humpback whale near Hawaii. Photo courtesy NOAA.

A humpback whale near Hawaii. Photo courtesy NOAA.

By Bob Berwyn

FRISCO — Humpback whales in the North Pacific, the North Atlantic and the Southern Ocean are much more genetically distinct than previously thought, and should be recognized as separate subspecies, according to biologists who carefully analyzed DNA from hundreds of whales around the world.

The findings could bolster conservation strategies for the whales, which were nearly hunted to extinction during the 20th century. While some humpback whale populations have made a strong recovery since the end of the whaling era, other isolated populations may need additional help to recover.

The findings could help federal biologists in the U.S. as they consider a proposal to designate North Pacific humpbacks as a single “distinct population segment” under the Endangered Species Act and illustrate the complexity studying and managing marine mammals on a global scale.

The bottom line, according to the paper published last week in the Proceedings of the Royal Society B last week,  is that humpback whales of the North Pacific, North Atlantic and Southern Hemisphere are on independent evolutionary trajectories. Continue reading

Biodiversity: Study shows continued threat to green sea turtles in Central America

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A green sea turtle cruises the sea bottom in this NOAA image.

Relentless fishing pressure pinches population

Staff Report

FRISCO — Endangered green sea turtles aren’t getting much of a break in Central America, where a 20-year assessment shows steeply declining catch rates in Nicaragua — as much as 56 percent in the past two decades, according to conservation scientists with the Wildlife Conservation Society and the University of Florida.

The researchers estimate that more than 170,000 green turtles were killed between 1991 and 2011, with catch rates peaking in 1997 and 2002 and declining steeply after 2008, likely resulting from over-fishing. The trend in catch rates shows a clear need for limits on this legal fishery, according to the report’s authors.

“The significant decrease in the catch rates of green turtles represents a concern for both conservationists and local, coastal communities who depend on this resource,” said Dr. Cynthia Lagueux, lead author of the study. “We hope this study serves as a foundation for implementing scientifically based limits on future green turtle take.” Continue reading

Oceans: Study highlights threats to sharks and rays

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Majestic manta rays are among the species identified as facing a significant threat. Photo courtesy NOAA.

‘Unless binding commitments to protect these fish are made now, there is a real risk that our grandchildren won’t see sharks and rays in the wild …’

By Summit Voice

FRISCO — Overfishing is putting about 25 percent of the world’s sharks and rays at risk of extinction, according to ocean experts who took a close look at the global distribution, catch, abundance, population trends, habitat use, life histories, threats and conservation measures.

Previous studies have documented local overfishing of some populations of sharks and rays, but this is the first survey of their status throughout coastal seas and oceans. According to the findings, 249 of 1,041 known shark, ray and chimaera species globally fall under three threatened categories on the IUCN Red List.

“We now know that many species of sharks and rays, not just the charismatic white sharks, face extinction across the ice-free seas of the world,” said Nick Dulvy, a Simon Fraser University Canada Research Chair in Marine Biodiversity and Conservation. “There are no real sanctuaries for sharks where they are safe from overfishing,” Dulvy said. Continue reading

Study tracks natural variability of ocean acidity

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Ocean acidification will have impacts on most life in the coastal zone. bberwyn photo.

‘For vulnerable coastal marine ecosystems, this may be adding insult to injury …’

By Summit Voice

FRISCO — In addition to the long-term threat of ocean acidification resulting from increased atmospheric greenhouse gases, marine organisms also must deal with short-term spikes of increased acidity.

Those acute episodes are caused by a variety of natural factors, including temperature and algal activity, according to a new study led by researchers with Duke University, who took a close look at natural cycles of acidity in a North Carolina estuary.

“The natural short-term variability in acidity we observed over the course of one year exceeds 100-year global predictions for the ocean as a whole,” said  Zackary I. Johnson, a molecular biologists at Duke’s Nicholas School of the Environment. Continue reading

Conservation groups challenge feds on naval training

Lawsuit highlights potential impacts to marine mammals from sonar and underwater explosives

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An orca and calf. Photo courtesy NOAA.

By Summit Voice

FRISCO — Conservation advocates say federal authorization of a five-year U.S. Navy plan for testing and training activities off Hawai‘i and Southern California doesn’t do nearly enough to protect marine mammals from the impacts of sonar noise and underwater explosions.

The plan acknowledges that the training could cause up 9.6 million instances of harm to whales and dolphins and other marine mammals. The use of active sonar and explosive are known to cause permanent injuries and deaths to marine mammals.

According to the lawsuit filed this week Hawai‘i federal court, the plan violates federal environmental laws. The National Marine Fisheries Service didn’t evaluate alternative plans that would have required the Navy to avoid biologically important areas, the conservation groups said in a press release. Continue reading

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