Nav: Home

Ocean acidification may reduce sea scallop fisheries

September 21, 2018

Each year, fishermen harvest more than $500 million worth of Atlantic sea scallops from the waters off the east coast of the United States. A new model created by scientists at the Woods Hole Oceanographic Institution (WHOI), however, predicts that those fisheries may potentially be in danger. As levels of carbon dioxide increase in the Earth's atmosphere, the upper oceans become increasingly acidic--a condition that could reduce the sea scallop population by more than 50% in the next 30 to 80 years, under a worst-case scenario. Strong fisheries management and efforts to reduce CO2 emissions, however, might slow or even stop that trend.

The model, published in the journal PLoS One, combines existing data and models of four major factors: future climate change scenarios, ocean acidification impacts, fisheries management policies, and fuel costs for fishermen.

"What's novel about our work is that it brings together models of changing ocean environments as well as human responses" says Jennie Rheuban, the lead author of the study. "It combines socioeconomic decision making, ocean chemistry, atmospheric carbon dioxide, economic development and fisheries management. We tried to create a holistic view of how environmental changes might play out across different aspects of the sea scallop fishery," she notes.

Since the oceans can absorb more than a quarter of all excess carbon dioxide in the atmosphere, fossil fuel carbon emissions can cause a dip in ocean pH as well. That acidity can corrode the calcium carbonate shells that are made by shellfish like clams, oysters, and scallops, and even prevent their larvae from forming shells in the first place.

According to Rheuban, no existing studies have been published that can show the specific effects of ocean acidification on the Atlantic sea scallop. To estimate its impact in the model, she and her colleagues incorporated a range of effects based on studies of related shellfish species. Combined with estimates of changing water chemistry, this new model lets scientists explore how plausible impacts of ocean acidification may change the future of the scallop population.

Rheuban and colleagues tested four different levels of impact in each of the four different factors influencing the model, ultimately creating 256 different scenario combinations.One group of scenarios looks at possible pathways of how ocean acidification may impact scallop biology. Another examines different levels of atmospheric CO2, including one future where emissions continue to skyrocket, and one where they fall due to aggressive climate change policy. A third set includes a range of future fuel costs, which themselves are related to climate change policies. Higher fuel costs, Rheuban notes, can lead to fewer active fishing days, reducing stress on the fishery itself, but also reducing profitability and revenues of the industry. The fourth and final set involves different federal fisheries management techniques.

Fishing policies for some shellfish, like oyster, clams, and bay scallops, are regulated by state or local governments, each of which follows its own set of rules. Sea scallop fisheries, however, are located well offshore in a region stretching from Virginia to Maine, so are regulated mostly by the federal government. With only one set of rules covering most sea scallop fisherman, it's possible to fit them into the model.

"The current sea scallop fishery is so healthy and valuable today in part because it is very well managed," says Scott Doney, a co-author from WHOI and the University of Virginia. "We also used the model to ask whether management approaches could offset the negative impacts of ocean acidification."

In all of the model's possible scenarios, high levels of CO2 in the atmosphere consistently led to increased ocean acidification and fewer sea scallops, despite introducing stricter management rules or even closing part of the fishery entirely.

"The model highlights the potential risks to sea scallops and likely other commercial shellfish fisheries of unabated carbon emissions to the atmosphere" adds Doney.

Over the next 100 years, under the worst-case ocean acidification impacts, the model's 'business-as-usual' scenario shows a sea scallop decline of more than 50%, while a scenario with proactive climate policy shows only a 13% reduction.

"The model shows that reductions in fossil fuel emissions due to climate policy might have a big impact on the sea scallop fishery," concludes Rheuban.
-end-
Also collaborating on the study were Scott C. Doney of WHOI and the University of Virginia, Sarah R. Cooley of the Ocean Conservancy, and Deborah R. Hart of the NOAA Northeast Fisheries Science Center. The research was supported by NOAA Grant # NA12NOS4780145 and the WestWind Foundation.

The Woods Hole Oceanographic Institution is a private, non-profit organization on Cape Cod, Mass., dedicated to marine research, engineering, and higher education. Established in 1930 on a recommendation from the National Academy of Sciences, its primary mission is to understand the oceans and their interaction with the Earth as a whole, and to communicate a basic understanding of the oceans' role in the changing global environment. For more information, please visit http://www.whoi.edu.

Woods Hole Oceanographic Institution

Related Ocean Acidification Articles:

New threat from ocean acidification emerges in the Southern Ocean
Scientists investigating the effect of ocean acidification on diatoms, a key group of microscopic marine organisms, phytoplankton, say they have identified a new threat from climate change -- ocean acidification is negatively impacting the extent to which diatoms in Southern Ocean waters incorporate silica into their cell walls.
Coral skeleton crystals record ocean acidification
The acidification of the oceans is recorded in the crystals of the coral skeleton.
Ocean acidification boosts algal growth but impairs ecological relationships
Shrimp fed on marine algae grown in acidic water do not undergo a sex change that is a characteristic part of their reproductive life-cycle, report Mirko Mutalipassi and colleagues at Stazione Zoologica Anton Dohrn in Italy in a study publishing June 26 in the open-access journal PLOS ONE.
Ocean acidification 'could have consequences for millions'
Ocean acidification could have serious consequences for the millions of people globally whose lives depend on coastal protection, fisheries and aquaculture, a new publication suggests.
Southern Ocean acidification puts marine organisms at risk
New research co-authored by University of Alaska indicates that acidification of the Southern Ocean will cause a layer of water to form below the surface that corrodes the shells of some sea snails.
Ocean acidification harms cod larvae more than previously thought
The Atlantic cod is one of the most important commercial fish species in the world.
Business as usual for Antarctic krill despite ocean acidification
A new IMAS-led study has found that Antarctic krill are resilient to the increasing acidification of the ocean as it absorbs more C02 from the atmosphere due to anthropogenic carbon emissions.
Ocean acidification may reduce sea scallop fisheries
Each year, fishermen harvest more than $500 million worth of Atlantic sea scallops from the waters off the east coast of the United States.
Can seagrass help fight ocean acidification?
Seagrass meadows could play a limited, localized role in alleviating ocean acidification in coastal ecosystems, according to new work led by Carnegie's David Koweek and including Carnegie's Ken Caldeira.
Study shows ocean acidification is having major impact on marine life
Carbon dioxide emissions are killing off coral reefs and kelp forests as heat waves and ocean acidification damage marine ecosystems, scientists have warned.
More Ocean Acidification News and Ocean Acidification Current Events

Top Science Podcasts

We have hand picked the top science podcasts of 2019.
Now Playing: TED Radio Hour

Risk
Why do we revere risk-takers, even when their actions terrify us? Why are some better at taking risks than others? This hour, TED speakers explore the alluring, dangerous, and calculated sides of risk. Guests include professional rock climber Alex Honnold, economist Mariana Mazzucato, psychology researcher Kashfia Rahman, structural engineer and bridge designer Ian Firth, and risk intelligence expert Dylan Evans.
Now Playing: Science for the People

#540 Specialize? Or Generalize?
Ever been called a "jack of all trades, master of none"? The world loves to elevate specialists, people who drill deep into a single topic. Those people are great. But there's a place for generalists too, argues David Epstein. Jacks of all trades are often more successful than specialists. And he's got science to back it up. We talk with Epstein about his latest book, "Range: Why Generalists Triumph in a Specialized World".
Now Playing: Radiolab

Dolly Parton's America: Neon Moss
Today on Radiolab, we're bringing you the fourth episode of Jad's special series, Dolly Parton's America. In this episode, Jad goes back up the mountain to visit Dolly's actual Tennessee mountain home, where she tells stories about her first trips out of the holler. Back on the mountaintop, standing under the rain by the Little Pigeon River, the trip triggers memories of Jad's first visit to his father's childhood home, and opens the gateway to dizzying stories of music and migration. Support Radiolab today at Radiolab.org/donate.