How Will Cod React to Global Warming? Researchers Subject Fish to High CO2 Levels to Find Out

May 8th, 2014, By Eva Tallaksen, undercurrentnews.com

cod in high co2Scientists in Tromso, Norway, are exposing cod broodstock to high CO2 to find out how the fish will cope as the seas get warmer, and more acidic.

“The idea is to find out, how will ocean acidification affect aquaculture and wild fish?” said Christopher Bridges, zoology professor at the university of Dusseldorf.

It is hoped larvae scooped from five tanks at Nofima’s national cod breeding center will soon yield some clues.

Each tank contained 60 cod broodstock averaging 3-5 kilos in size, exposed to different levels of temperatures and acidity. The fish spawned March and April, and their larvae, which hatched in the past two weeks, are currently being tested.

“The key aspect will be to look at the larvae’s survival rate,” said Bridges.

If global warming continues as some scientists think, the oceans’ CO2 levels could reach 1,000 to 1,200 ppm (parts per million) by 2100, up from just under 400ppm today.

That would take the seas’ pH level down to 7.8, from 8.1 today.

Most the research into the seas’ growing acidity has focused on the impact on fish eggs or larvae, or on habitats. But few have so far focused on its impact on broodstock, said Bridges.

Bridges is one of the scientists involved in the project, which is led by the publicly-funded German Bioacid initiative. Cooperating in the project are Germany’s Geomar and Alfred Wegner Institute, working in Norway under the EU FP7 support project Aquaexcel using the facilities of Nofima.

In two of the tanks, the cod were kept at normal acidity levels (400ppm), but one tank had a temperature of 5 degrees Celcius, and the other 10 degrees. In two other tanks, the fish were exposed to CO2 levels of 1,200 ppm, again with one tank at 5 degrees and the other at 10 degrees.

These four tanks all used broodstock from farmed fish, bred by Nofima’s center. A fifth tank was filled with fish from the wild, but these were caught too late to be used for the experiment.

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Update of Fisheries Law Pits West Coast Against East Coast

Two recent articles have come out based on a paper co-written with one of our board members, Suzanne Iudicello, and our Director, Brad Warren. This is the second article.

Seattle Times. May 10th, 2014. By Kyung M. Song

The Magnuson-Stevens Act was enacted in 1976 to protect fisheries collapsing from overfishing and poaching by foreign trawlers. But the upcoming fourth reauthorization of the main federal fisheries law has split American fishing factions by coastlines.

WASHINGTON — The nation’s chief fisheries law was enacted in 1976 in a climate of alarm: the oceans were losing fish faster than they could reproduce, and most of the diminishing harvests were being scooped up by an armada of Soviet and Japanese factory trawlers.

In response, Congress passed the legislation now commonly called the Magnuson-Stevens Act. It asserted exclusive American fishing rights out to 200 miles from shore. It also entrusted the federal government to protect Alaska pollock, Atlantic haddock and hundreds of other stocks from overfishing and to guard the water’s bounty for perpetuity.

Today, the fight to ensure sustainable fisheries has turned entirely domestic.

The Magnuson-Stevens Act expired last September. Republicans in the House Natural Resources Committee and Democrats in the Senate Commerce Committee have released separate bills to update the 2006 reauthorization.

The dueling drafts have split fishing factions by coastlines. Bering Sea crabbers and West Coast commercial groundfish harvesters, for instance, want the law’s conservation measures left largely intact.

But some of their counterparts in New England and the Gulf of Mexico are demanding key changes. The collapse or overexploitation of such iconic stocks as cod and red snapper have battered their livelihoods and curtailed sport fishing, and the fishermen want more elastic mandates on overfishing and on rebuilding depleted fish populations.

Meanwhile, recreational anglers, a sizable economic force, are pressing harder than ever to amend the law to secure longer, predictable fishing seasons and permission to hook bigger trophy fish.

The schism has hardened despite — or because of — the fact that U.S. fisheries on the whole are rebounding from catastrophic overfishing that pushed some species to possible extinction.

In 2006, “overfishing was so endemic everyone realized we needed to take measurable steps,” said George Geiger, former chairman the South Atlantic Fishery Management Council, one of eight regional councils responsible for overseeing the law.

“There is much more acrimony associated with this reauthorization.”

High stakes

The heightened tension reflects high stakes. Commercial fishermen hauled in $5.1 billion worth of fin fish and shellfish in 2012, the latest economic data available. That in turn generated another $34 billion in income for processors, wholesalers and all who touch the seafood on its journey to the table.

In Washington, the seafood industry supports 61,000 jobs, fourth-highest behind California, Massachusetts and Florida, says the National Oceanic and Atmospheric Administration (NOAA). Seattle is home to major seafood processors and most of the Alaska crabbing fleet.

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