Saving Seafood

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

Invasive species exploit a warming Gulf of Maine, sometimes with destructive results

October 28, 2015 — Until two years ago, if you had walked down to the shore of Maquoit Bay at low tide, you would have seen a meadow of eelgrass stretching nearly as far as the eye could see across the exposed seafloor. Here near the head of the bay, the sea grass stretched for two miles to the opposite shore, creating a vast nursery for the shellfish and forage species of Casco Bay, of which Maquoit is a part.

Now there’s only mud.

Green crabs took over the bay in the late fall of 2012 and the spring and summer of 2013, tearing up the eelgrass in their pursuit of prey and devouring almost every clam and mussel from here to Yarmouth. Fueled by record high water temperatures in 2012 and a mild winter in 2013, the green crab population grew so huge that the mudflats of Casco Bay became cratered with their burrowing, and much of the Maquoit and adjacent Middle Bay bottom turned into a lunar landscape.

Eelgrass coverage in Maquoit Bay fell by 83 percent. With nothing rooted to the bottom, the seawater turned far muddier, making life hard on any plants or baby clams that tried to recolonize the bay.

“We were astounded,” says Hilary Neckles of the U.S. Geological Survey’s Patuxent Wildlife Research Center, who linked the destruction to the green crabs. “The ecological ramifications really reverberate throughout the ecosystem, because sea grass is the preferred habitat of so many fish and shellfish species.”

Over the past decade, the Gulf of Maine has been one of the fastest-warming parts of the world’s oceans, allowing warm-water intruders to gain a toehold and earlier invaders such as the green crab to take over. Coupled with declines of the cold-loving species that have dominated the gulf for thousands of years, the ecological effects of even more gradual long-term warming are expected to be serious, even as precise forecasting remains beyond the state of scientific knowledge.

Scientists say the 2012 “ocean heat wave” was an unusual event, and that the 10-year accelerated warming trend is likely part of an oceanographic cycle and unlikely to continue. But the gulf has been consistently warming for more than 30 years, and long-term forecasts project average sea surface temperatures in our region could reach 2012-like levels by mid-century. The events of 2012 and the nearly as warm year that followed likely provide a preview of things to come, of a gulf radically transformed, with major implications for life on the Maine coast.

Genevieve MacDonald, who fishes for lobster out of Stonington, was standing on the dock at Isle au Haut one morning that summer, looked in the water, and couldn’t believe her eyes. There, swimming around the harbor like mackerel, were dozens and dozens of longfin squid, temperate creatures rarely seen in the chill waters of eastern Maine. “If you had a cast net you could have brought in a whole basket full of squid,” she recalls.

Read the full story at Portland Press Herald

RICHARD SPINRAD & IAN BOYD: Our Deadened, Carbon-Soaked Seas

October 15, 2015 — Ocean and coastal waters around the world are beginning to tell a disturbing story. The seas, like a sponge, are absorbing increasing amounts of carbon dioxide from the atmosphere, so much so that the chemical balance of our oceans and coastal waters is changing and a growing threat to marine ecosystems. Over the past 200 years, the world’s seas have absorbed more than 150 billion metric tons of carbon from human activities. Currently, that’s a worldwide average of 15 pounds per person a week, enough to fill a coal train long enough to encircle the equator 13 times every year.

We can’t see this massive amount of carbon dioxide that’s going into the ocean, but it dissolves in seawater as carbonic acid, changing the water’s chemistry at a rate faster than seen for millions of years. Known as ocean acidification, this process makes it difficult for shellfish, corals and other marine organisms to grow, reproduce and build their shells and skeletons.

About 10 years ago, ocean acidification nearly collapsed the annual $117 million West Coast shellfish industry, which supports more than 3,000 jobs. Ocean currents pushed acidified water into coastal areas, making it difficult for baby oysters to use their limited energy to build protective shells. In effect, the crop was nearly destroyed.

Read the full opinion piece from Richard W. Spinrad and Ian Boyd at The New York Times

NOAA Fisheries unveils climate science strategy

September 4, 2015 — As ocean conditions continue to change, putting ocean ecosystems and the communities that rely upon them at risk, NOAA took a first step in providing regional fisheries managers and stakeholders with information they need to reduce the effects of climate change and build resilience.

“NOAA just announced that for the globe the month of July — and actually, the entire year so far — was the warmest ever recorded, driven largely by record warm ocean temperatures,” said Eileen Sobeck, assistant NOAA administrator for fisheries.

“Those warmer waters – along with rising seas, coastal droughts and ocean acidification – are already putting people, businesses, and communities at risk. With this strategy, we’re taking a proactive approach in providing information on current and future conditions to try and reduce impacts and increase our resilience,” pointed out Sobeck.

The NOAA Fisheries Climate Science Strategy identifies seven key steps to increase production, delivery, and use of climate-related information to support the management of fish stocks, fisheries, and protected species. The steps focus on how a changing climate affects living marine resources, ecosystems, and the communities that depend on them, and how to respond to those changes.

Read the full story at IFFO

NOAA’s new Climate Science Strategy outlines efforts to build resilience

August 25, 2015 — As ocean conditions continue to change, putting ocean ecosystems and the communities that rely upon them at risk, today, NOAA took a first step in providing regional fisheries managers and stakeholders with information they need to reduce the effects of climate change and build resilience.

“NOAA just announced that for the globe the month of July—and actually, the entire year so far—was the warmest ever recorded, driven largely by record warm ocean temperatures,” said Eileen Sobeck, assistant NOAA administrator for fisheries. “Those warmer waters – along with rising seas, coastal droughts and  – are already putting people, businesses, and communities at risk. With this strategy, we’re taking a proactive approach in providing information on current and future conditions to try and reduce impacts and increase our resilience.”

The NOAA Fisheries Climate Science Strategy identifies seven key steps to increase production, delivery, and use of climate-related information to support the management of fish stocks, fisheries, and protected species. The steps focus on how a  affects living marine resources, ecosystems, and the communities that depend on them, and how to respond to those changes.

Read the full story at Phys.org

MARK BITTMAN: What oysters tell us about ocean acidification

July 21, 2015 — MARK BITTMAN — This is kind of the good news/bad news department, as so many things are: The good news is that terrific oysters are being farmed in several locations in California; the bad news is that ocean acidification — the absorption of carbon dioxide into the sea, a direct result of high levels of carbon in the atmosphere — is a direct threat to that industry.

I saw both when I visited Hog Island Oyster Co. in Marshall, an operation north of San Francisco on Tomales Bay. (Actually, I’ve eaten at and of Hog Island dozens of times, and even shot video there for a PBS series more than 10 years ago.)

Read the full story and watch the video at The New York Times