Saving Seafood

Global fisheries: Benefits, trade-offs of alternative approaches to recovering depleted fisheries

May 18, 2016 — The dangers for the world’s seas and oceans are many — from climate change and warming waters to overfishing related to the needs of growing world populations. As a major 2015 paper in the journal Science noted, extinction of many species is a looming reality, given the current decline in quality of aquatic ecosystems. The perils for large marine mammals, sharks and other large fish are well known to the public. But there are many other dangers. For example, the rapid rate of ocean acidification, which appears to be unprecedented in Earth’s history, threatens to decimate shellfish populations.

Of course, debates about overfishing and sustainable management practices rage in virtually every fishery across the world. These policy debates are seldom simple to resolve and involve complex tradeoffs: Traditional fishing rights versus government regulation; short-term profits versus longer-term sustainable growth; local population food needs versus larger ecological and stewardship concerns. Organizations such as the U.S. National Oceanic and Atmospheric Administration (NOAA) and the Food and Agriculture Organization (FAO) of the United Nations keep statistics on the state of fisheries and their relative health. The FAO’s annual The State of World Fisheries and Aquaculture provides a comprehensive overview. For U.S. reporters and editors covering these issues on the nation’s coasts, it is worth getting to know some of the long and complex policy and regulatory history in this area, which for nearly four decades has been governed by the Magnuson-Stevens Fishery Conservation and Management Act.

Read the full story at Journalist’s Resource

West Coast fisheries are at risk as climate change disturbs the ocean’s chemistry

April 20, 2016 — The West Coast’s abundant fisheries are at risk as the region’s waters become more acidic, a group of scientists warn.

Researchers from the West Coast Ocean Acidification and Hypoxia Science Panel released a report this month that projects dire changes to ocean chemistry and marine life, and recommends ways to avert it, including restoring kelp forests and eelgrass beds and combating marine pollution.

The panel convened in 2013 to study how global carbon emissions are lowering pH and reducing oxygen levels in the ocean off the West Coast.

“Although ocean acidification is a global phenomenon, emerging research indicates that the U.S.-Canadian West Coast will face some of the earliest, most severe changes in ocean carbon chemistry,” the report says.

Because of the way the Pacific Ocean circulates, the West Coast is exposed to more acidic water than other areas of the globe. Oyster production in the Pacific Northwest has already declined, as changes in ocean chemistry tamper with shell formation, and scientists warn that popular game fish and other species are also at risk.

Read the full story from the Los Angeles Times

Ocean souring on climate change

April 18, 2016 — The West Coast’s famously abundant fisheries are at risk as the region’s waters become more acidic, a group of scientists have warned.

The researchers, with the West Coast Ocean Acidification and Hypoxia Science Panel, this month released a report that projects dire changes to ocean chemistry and marine life, and recommends ways to avert it, including restoring kelp forests and eelgrass beds, and combating local marine pollution.

The panel, including Andrew Dickson, a professor of marine chemistry at Scripps Institution of Oceanography, convened in 2013 to study how global carbon emissions are lowering pH and reducing oxygen levels in the ocean off the West Coast.

“Although ocean acidification is a global phenomenon, emerging research indicates that the U.S.-Canadian West Coast will face some of the earliest, most severe changes in ocean carbon chemistry,” the report states.

Read the full story at The San Diego Union-Tribune 

Rising Carbon Dioxide Levels Threaten Corals and Oysters

April 5, 2016 — Tiny, thin-shelled oysters; crumbling coral reefs; fish unable to make sense of odors; decimated plankton populations. Those are some of the nightmare scenarios conjured by the prospect of a rapidly acidifying ocean caused by unchecked carbon dioxide emissions from fossil fuel burning.

Here’s the chemistry: when carbon dioxide and water mix, they form a weak acid, called carbonic acid. Add enough carbon dioxide, and the pH, or acidity, of the water will start to change. Of course, the ocean is a big place with a lot of water, and it naturally contains other chemicals that can help stabilize the pH.

On the other hand, the ocean has absorbed more than a quarter of all human-produced carbon dioxide since the industrial revolution. The result: globally, the pH of the ocean has dropped by an average of 0.1 pH units. That may not sound like much but, since the pH scale is logarithmic, it translates to a 25 to 30 percent increase in acidity. And, as ocean water becomes more acidic, the carbonate that many animals use to build their calcium skeletons and shells becomes scarcer.

Read and listen to the full story at WCAI

Shellfish Farmers Fear Ocean Acidification May Affect Harvests in 2016

January 8, 2016 — Ocean acidification was blamed for the shutdown of the Washington oyster fishery last year and B.C. could be next, partially for the same reason, said Rob Saunders, owner of Island Scallops at Qualicum Beach.

Speaking to TheProvince, Mr Saunders said that Island Scallops, which provides seed oysters and scallops for farmers, lost 90 per cent of its oyster larvae last year.

Acidic water affects the oysters’ ability to grow a hard shell. It takes two years for oysters to mature for harvest, and Mr Saunders said oysters may be in short supply this year.

Read the full story at The Fish Site

Ocean acidification poses threat to lobsters

December 18, 2015 — PROVIDENCE — Lobsters are already slowly moving out of southern New England as waters warm, but the iconic crustacean faces another future threat as the climate changes.

As oceans absorb more carbon and become increasingly acidic, juvenile lobsters likely will have a harder time growing and forming strong shells to protect them from predators, according to a recent University of Rhode Island study.

“I’m not sure yet what the mechanism is that is affecting their growth,” URI doctoral student Erin McLean, who led the research, said. “But it takes energy for them to regulate the increased acidity, which is energy they cannot then put toward growth.”

And it’s not just lobsters that could be harmed by the oceans’ changing pH levels. Shellfish populations in Rhode Island and Massachusetts in general are among the most vulnerable in the United States to ocean acidification, according to a recent study in the journal Nature Climate Change.

The study identified the two states among 15 at-risk areas in the nation because colder, northern waters, such as Narragansett Bay, Buzzards Bay and Nantucket Sound, are absorbing more carbon dioxide from the atmosphere and acidifying faster than warmer waters.

Other more localized factors are also playing a part, including nutrient pollution from fertilizers and sewage systems that can add more carbon to the water and the flow of fresh water from poorly buffered rivers, such as the Blackstone in Rhode Island or the many waterways that drain into the Gulf of Maine, which lack minerals to mitigate the effects of acid. Shallow coastal waters also are more susceptible to changes in the ocean’s chemistry.

About a quarter of all carbon emissions from power plants, cars and other sources are absorbed by the oceans, making them more acidic and reducing carbonate levels. Shellfish use carbonates to make their shells, and when fewer of the compounds are available, organisms must expend more energy to build shells and less on eating and survival, researchers say.

Read the full story at Providence Journal

Fish Stocks Are Declining Worldwide, And Climate Change Is On The Hook

December 14, 2015 — For anyone paying attention, it’s no secret there’s a lot of weird stuff going on in the oceans right now. We’ve got a monster El Nino looming in the Pacific. Ocean acidification is prompting hand wringing among oyster lovers. Migrating fish populations have caused tensions between countries over fishing rights. And fishermen say they’re seeing unusual patterns in fish stocks they haven’t seen before.

Researchers now have more grim news to add to the mix. An analysis published Monday in the Proceedings of the National Academy of Sciences finds that the ability of fish populations to reproduce and replenish themselves is declining across the globe.

“This, as far as we know, is the first global-scale study that documents the actual productivity of fish stocks is in decline,” says lead author Gregory L. Britten, a doctoral student at the University of California, Irvine.

Britten and some fellow researchers looked at data from a global database of 262 commercial fish stocks in dozens of large marine ecosystems across the globe. They say they’ve identified a pattern of decline in juvenile fish (young fish that have not yet reached reproductive age) that is closely tied to a decline in the amount of phytoplankton, or microalgae, in the water.

Read the full story at NPR

 

Baby fish will be lost at sea in acidified oceans

December 15, 2015 — The ability of baby fish to find a home, or other safe haven, to grow into adulthood will be severely impacted under predicted ocean acidification, University of Adelaide research has found. 

Published today in the journal Proceedings of the Royal Society B, the researchers report the interpretation of normal ocean sound cues which help baby fish find an appropriate home is completely confused under the levels of CO2 predicted to be found in oceans by the end of the century.

“Locating appropriate homes is a crucial step in the life cycle of fish,” says Tullio Rossi, PhD candidate with the University’s Environment Institute. “After hatching in the open ocean, baby fish travel to reefs or mangroves as safe havens to feed and grow into adults.

“Baby fish can find those places through ocean noise: snapping shrimps and other creatures produce sounds that the baby fish follow.

“But when ocean acidity increases due to increased CO2, the neurological pathways in their brain are affected and, instead of heading towards those sounds, they turn tail and swim away.”

Read the full story at Science Daily

Maine isn’t doing enough to protect the Gulf from the effects of climate change

October 30, 2015 — When the Maine Legislature’s commission on ocean acidification reported its findings – that the state’s fisheries and aquaculture industries were threatened by this baleful byproduct of global warming – officials here were not exactly spurred to action.

Acidification, driven by increased carbon dioxide from the atmosphere and freshwater runoff from extreme rainfall in river basins, has been implicated in failures at oyster hatcheries and mussel farms, and has been shown to weaken clams and other shell-building animals vital to Maine’s fishing and aquaculture industries. But bills introduced in the last session – one each by a Democratic marine scientist and a Republican lobsterman – to implement many of the panel’s findings were withdrawn, one for lack of resources, the other for lack of support from Gov. Paul LePage’s administration.

“I could see the bill wasn’t going to go anywhere and that the governor was going to veto it,” Rep. Mick Devin, a Democrat from Newcastle, says of legislation he sponsored to allow the commission to continue its work for another three years.

Patricia Aho, who was the commissioner of environmental protection until she resigned in August, opposed Devin’s bill, saying the status quo was sufficient. “Since the issues of climate change and ocean acidification are inextricably linked, we think it will be more efficient to consider this issue in the broader context of climate change and adaptation programs,” she said in written testimony to legislators.

Devin’s bill and another one sponsored by Rep. Wayne Parry, a Republican from Arundel, were carried over to the next legislative session. Parry’s bill would have put a bond issue on the ballot that would borrow $3 million to fund several of the expert committee’s recommendations: collecting data, monitoring waterways, and performing tests in coastal waters to better assess the impact of acidification on wildlife and commercial fish species. It was withdrawn after failing to make it to the top of an informal list of bonding priorities drawn up by legislative leaders.

Read the full story at Portland Press Herald

 

Ocean acidification threatens future of aquaculture, shellfish industries

October 29, 2015 — In seawater tanks in a refrigerated room at the Darling Marine Center, the baby mussels are thriving.

Two months ago they were near-invisible larvae, swimming around in the tanks. Now tens of thousands of the tiny mollusks, each just a few millimeters long, have attached themselves to the different kinds of rope scientists have been testing here, and are eating the lab’s stock of algal food at an impressive clip.

Mick Devin, the lab manager at this University of Maine marine research facility, has been overseeing this experiment, part of an effort to master the art of hatching mussels, something mussel farmers – who grow their product on lines hanging in seawater – have never previously needed to do.

“Mussel farmers have been able to just throw their lines out and collect all the larvae they want from nature,” Devin says. “But mussel populations are down drastically in this state, so that may not be working so well now.” Hatcheries, he expects, may have to step up in the not-too-distant future.

Mussels have been vanishing from stretches of coastline where they once were ubiquitous, and scientists remain uncertain as to why. Green crabs, whose population exploded after an “ocean heat wave” in 2012, may have stripped many sections clean. But warmer water and increased rainfall – both problems expected to grow in Maine as a result of global climate change – may be creating a far worse problem: an acid sea.

“We know this affects larval development in bivalves, (and) chances are it will result in decreased numbers, whether it’s a natural population on a bed or one in a farm,” says Paul Rawson of the University of Maine’s School of Marine Sciences, who is in charge of the research. “We need to make sure the technology is in place so the farms will have a reliable source of seed.”

The world’s oceans are turning more acidic. Since the Industrial Revolution, carbon dioxide levels in the atmosphere have grown by more than 70 percent and now stand at the highest level in at least 800,000 years. As the oceans absorb additional CO2, they’ve become 30 percent more acidic over this period. By 2050, scientists estimate surface pH levels will be lower – that is, more acidic – than at any time in several million years and by 2100 more acidic than any time in the past 300 million years – two or three times more so than today.

Read the full story at Portland Press Herald