Saving Seafood

How will Fish in the Northeast Respond to Climate Change?

April 27, 2016 — A new study, published by the journal PLOS ONE found 82 species of marine fish and invertebrates in the northwest Atlantic (or the northeast US) to be vulnerable to climate change (A write up of the study by the New York Times can be found here). These 82 species encompass every commercially managed fishery in the region as well as a few popular recreational species and endangered species.

Not all species were predicted to experience negative effects from climate change – only about half were likely to be negatively affected. 20 percent will be positively affected by climate change and the rest will be neutral, said Jon Hare, NOAA oceanographer and lead author of the paper. However a majority of the species studied did show a high potential for a change in habitat distribution, which could create significant management challenges

“Peter Baker, director of Northeast U.S. oceans for the Pew Charitable Trusts, said the report should be a motivator for fishing managers to protect more ocean habitat and preserve marine species.”

Comment by Doug S. Butterworth, Marine Resource Assessment and Management Group, University of Cape Town

In this paper, Hare et al. report the results of the application of Vulnerability Assessment methodology to assess the extent to which abundance or productivity of species on the Northeast US Continental Shelf may alter in response to climate change. More particularly, they consider, inter alia, directional effects (whether negative, neutral or positive) and potential for changes in distribution. The determinations are based on expert opinions which lead the authors to draw firm conclusions, e.g. that climate change is expected to negatively affect about half the species they consider.

The environmental conditions associated with the habitat preferences of different species may be determined from empirical studies for which considerable data are available. Hence there is a clear basis in data and analyses to formulate the opinions that have been consolidated in this report.

What is much less clear, however, is what bases could defensibly have been used by experts to comment on directional effects for abundance and particularly productivity under projected changes in environmental variables under climate change. The productivity, and consequently to a large extent, the abundance, of a population of a fish or invertebrate species is driven by the (typically) annual recruitments to that population. The inferences drawn by these experts must consequently have been based on knowledge of how environmental variables affect such recruitment.

Yet the difficulties of reliably establishing such relationships are well known in fisheries assessment science. The classic article on this topic by Ram Myers (When do environment-recruitment correlations work?) pointed to the failure of almost all such relationships that had been proposed when tested with new data.

This then begs the questions of what bases the experts contributing inferences concerning directional effects to the Hare et al. study used for their determinations and how reliable those inferences might be. If they are reliable, why are they generally not being used in the fisheries assessments from which advice on catch limits is formulated?

I agree with Hare et al. when they argue that the expert opinions they collated “can guide future monitoring, research, and monitoring studies.” However, they go further to state that their results can be used by managers to “guide management actions” (they provide examples of species for which they suggest decreasing fishing mortality). Should they not first meet the burden of justifying the bases on which the experts who contributed to their study drew their inferences about directional effects, and also explain the associated implications for the reliability of knowledge about fishery recruitment-environmental variable relationships?

Read the original post at CFOOD

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

Warm ocean could mean early boom in 2016 lobster catch

March 3, 2016 — ROCKPORT, Maine (AP) — Maine’s lobster catches will likely peak early this year, which could mean an abundance of cheap lobster for consumers and bad news for the state’s signature industry, a group of scientists reported on Thursday.

Maine’s busy summer lobster fishing season typically picks up around early July, the same time the state’s tourism industry gets in gear. But scientists with the Portland-based Gulf of Maine Research Institute predict this year’s lobster season will get rolling two or three weeks early.

The scientists, who unveiled their findings during the Maine Fishermen’s Forum in Rockport, pinned the early lobster season on warming ocean temperatures. Along Maine’s coast, temperatures are 2 to 3 degrees Fahrenheit higher than normal. That means lobsters are likely to move inshore, shed their shells and become more easily trapped earlier this summer, they said.

An early lobster season can disrupt Maine’s valuable lobster supply chain, which is partially dependent on big July and August catches, and make prices plummet. Prices at the dock fell 16 percent in 2012, a year of early catches, and prices to consumers fell, too. The 2014 haul shattered state value records because of a high-volume catch that arrived on schedule.

Read the full story from the Associated Press at New Jersey Herald

Scientists say ocean warming is driving lobsters northward

March 2, 2016 — It’s too early to know what Maine’s 2015 lobster landings will look like, but there’s no doubt that the number will be huge.

In 2014, the last year for which the Department of Marine Resources has figures, Maine’s fishermen landed more than 123 million pounds of lobster — the third year in a row that landings topped 120 pounds — worth a record $457 million.

While last year’s numbers aren’t in, fishermen and dealers talk about a bonanza fishery, and mild weather saw the fishery stay active into December.

In a sense, the landings are unsurprising.

According to a 2015 Atlantic States Fisheries Management Commission stock assessment, the abundance of lobsters in the Gulf of Maine and on Georges Bank showed a meteoric rise starting in 2008 and is now at an all-time high. In southern New England, though, the story is completely different.

From a peak in 1997, the southern New England stock fell swiftly to a point where, by 2004, it was well below what scientists consider the threshold of sustainability. Things leveled off briefly; then the resource began an ongoing plunge again in 2010.

According to last year’s assessment, the Gulf of Maine-Georges Bank stock is not depleted and is not being overfished. The estimated lobster population from 2011 to 2013 was 248 million lobsters, which is well above the abundance threshold — a red flag for fisheries managers — of 66 million lobsters.

In contrast, in the years 2011 to 2013, the southern New England stock was depleted at an estimated 10 million lobsters. The “red flag” abundance level is 24 million lobsters.

Read the full story at The Ellsworth American

MAINE: Questioning our Changing Oceans’ panel discussion at forum

March 1, 2016 — Climate change and its impact on the ocean and the fishing industry is the topic of the March 3 session of the Maine Fishermen’s Forum, the Boothbay Register reported.

Thursday’s session will be held from 1 p.m. to 4 p.m. at the Samoset Resort in Rockport.

“As a fisherman, I’m seeing things on the water that I have never experienced before, and I have questions about what this means that I can’t easily answer.” Gerry Cushman, a lobsterman out of Port Clyde and board member for the Maine Fishermen’s Forum, told the newspaper. “I spend most of my life on the water so the Maine Fishermen’s Forum is one of the few times, as a fisherman, I have the time to focus on the future of my industry.”

Read the full story at Maine Biz

 

Fisheries scientists plan for a changing Bering Sea

February 21, 2016 — The North Pacific Fishery Management Council heard a draft plan for addressing climate change in the eastern Bering Sea earlier this month.

The plan was put together by scientists at the Seattle-based Alaska Fisheries Science Center, which is part of the National Marine Fisheries Service. Mike Sigler, program leader for the habitat and ecological processes research program at the science center, said the plan pulls together work that scientists there are already doing, and research they’d like to undertake.

“We have a clear understanding of species like walleye pollock, northern rock sole, red king crab, what will happen to them, and we can make quantitative forecasts of where they’re going. They’re not completely certain, but we have some good ideas of ecological processes,” Sigler said. “But then, we don’t have such good understanding for other species, like yellowfin sole, and we’re making a qualitative assessment of their vulnerability to climate.”

Eventually, the group wants to provide fisheries managers, like the North Pacific council, with a better look at what might be coming in 10 years — or even further down the road. One of the first parts of the plan is just putting together that qualitative assessment for more than a dozen species, which he expects to happen this year.

Read the full story from Alaska Dispatch News

 

Acidic Ocean Leads to Warped Skeletons for Young Coral

February 19, 2016 — Rising emissions of carbon dioxide create twin threats for coral in oceans around the world: warmer temperatures, which can cause mass bleachings, and ocean acidification, which can hinder the animals’ ability to build reefs.

But a new study published on Friday in the journal Science Advances suggests that ocean acidification may be the bigger worry in some waters.

Studying a chain of remote Australian islands in the Indian Ocean, researchers found that more acidic waters (those that have absorbed more atmospheric carbon dioxide) cause serious skeletal deformities in juvenile coral in subtropical waters.

Using 3-D imaging techniques, they saw that young coral from the Houtman Abrolhos islands developed skeletons that were missing sections or had very porous and fragile surfaces.

Other studies have shown similar effects of ocean acidification, but the researchers also discovered something that had not been seen in earlier studies of tropical coral development — higher temperatures didn’t have a negative effect on coral skeleton formation.

Read the full story at the New York Times

Climate cycle could determine the reproductive success of menhaden

February 19, 2016 — Scientists have long puzzled over what drives the reproductive success of Atlantic menhaden, a tiny but critical East Coast fish.

A new study, published in the ICES Journal of Marine Science and supported by the Lenfest Ocean Program, provides a partial answer: An oceanic climate cycle known as the Atlantic Multidecadal Oscillation, or AMO.

The finding is likely to be useful in improving the way scientists assess the species and the way managers set catch limits.

Menhaden is a small, oily fish that provides food for striped bass, bluefish, and several other species, as well as bait for fishermen.

It also is the target of the largest fishery on the East Coast, which is centred in Virginia and catches menhaden for use in nutritional supplements, animal feed, and fertilizer.

Setting catch limits has proved challenging, in part because no one has been able to say what drives recruitment—a technical term for how many young fish are produced. Recruitment largely determines how much fishing a population can sustain.

Tom Miller of the University of Maryland, and one of the authors of the study, explained that it is very difficult to understand and manage this stock.

To address this, the researchers used a statistical model designed for disorderly data like those on the abundance of young menhaden. They considered 16 factors that might be driving that abundance, including climatic cycles, intensity of fishing, temperature, salinity, and predator abundance.

Read the full story at FIS