Oysters, clams and scallops face high risk from ocean
acidification, new study finds
Shellfish make up a lucrative business in the US,
bringing in $1bn annually. But climate change puts the
industry at risk, especially in Massachusetts’ Cape Cod
Ocean acidification threatens the $1bn US shellfish industry
Photograph: Alamy
As oceans become more acidic, the US shellfish business is facing
“high economic risk” in 15 out of 23 coastal states, according to
a study published Monday in the Nature Climate Change journal.
Massachusetts tops the list of states facing the highest risk, the
study concluded.
Shelled mollusks such as oysters, clams and scallops are
extremely sensitive to ocean acidification, according to the
paper. Those species represent lucrative fisheries, and a big part
of the economy in coastal communities that depend on their sale.
The US shellfish industry brings in $1bn annually, according to
the report.
In the Southern Massachusetts fishery alone, shellfish makes up a
$300m-per-year business, with the state giving out 1,350
commercial fishing licenses annually. In the states of Washington
and Oregon, the mollusk business produces approximately $100m in
direct sales. It supports 3,200 jobs in Washington alone.
Researchers identified places where rising carbon dioxide in the
atmosphere, as well as ocean acidification due to algae blooms,
have caused mollusk harvests to decline, and used this information
to map the risk profiles of different coastal communities.
Why are oceans growing more acidic?
Oceans
typically absorb about 30% of the carbon dioxide in the
atmosphere. But consistent air pollution has tilted that balance.
When CO2 levels in the atmosphere increase, CO2 in the oceans also
increase accordingly, making the oceans more acidic.
Meanwhile, rising sewage and chemical waste released into the
oceans introduce nutrients that spur algae populations to bloom in
the oceans. Any algae that isn’t eaten by other marine life then
decomposes, releasing CO2 into the water and further lowering pH
levels.
The higher acidity is threatening marine species such as
shellfish – and, as a result, related seafood businesses.
Massachusetts is most vulnerable
The Southern Massachusetts counties of Cape Cod and the Islands,
south of the cape, are “more economically dependent on shelled
mollusks than any other region”, making them the most vulnerable
communities in the country to ocean acidification, according to an
explainer from the National Resources
Defense Council, an environmental nonprofit.
In other words, Cape Cod gets a huge amount of its income from
shelled mollusks. “Not only do they have lot to lose in terms of
jobs and income, revenue, but they can’t easily swap out and start
fishing something else,” says Lisa Suatoni, one of the authors of
the report.
New Bedford, Massachusetts, is particularly vulnerable because
approximately 80% of its fishing revenue comes from a single
species: the sea scallop, she says. “Their fisheries options are
low, they have a lot of poverty in those areas, low job options –
just so much money on the line.”
The social dimension of shellfish
Massachusetts’ high risk came as a surprise to researchers,
Suatoni says. “In the US, our economic impact so far has been
primarily in the Pacific Northwest,” she says. “Our vulnerability
assessment says that the impacts are going to be much broader
geographically and more hard hitting than people really thought.”
By studying fishing communities at a closer, more granular level,
researchers developed vulnerability profiles that are unique to
each region, allowing for “tailored strategies” for mitigating the
effects of ocean acidification in each place.
While they were at it, the researchers also studied what they
call the “social dimension of ocean acidification”, or the attempt
to answer the question: “Who has the propensity to be harmed by
loss of shellfish?”
By taking into account both the vulnerability of the fisheries
and of the populations that benefit from them, researchers were
able to factor in potential alternatives and ongoing policy
changes in weighing regions’ potential ability to reduce their
risks and adapt.
More policy – and study – needed
Policymakers in some states are already aware of the economic
threats posed by ocean acidification. Former Washington governor
Christine Gregoire signed an executive order aimed at
protecting the state’s $270m shellfish industry in 2012.
Washington, along with Maine and Maryland, have assembled expert
commissions to tackle ocean acidification.
Other policymakers, though, have yet to take notice of ocean
acidification as a serious threat to local economies. Suatoni says
she hopes the report will help change that, and will also act as a
strong message to federal research and monitoring programs, which
aren’t monitoring ocean water in most of the places researchers
have identified as most vulnerable.
Suatoni says that there’s a “real disconnect”, due to
underfunding, with research projects limited mainly to where
marine researchers are already based. Their study was funded by a
National Science Foundation grant.
“Very opportunistically we’re monitoring the backyard of the
marine maps of locations where scientific expertise [exists],” she
says. “Sometimes that overlaps in areas of great social need, but
most often it doesn’t.”
This article was amended on 22 February 2015. A previous version
mistakenly stated that Bedford, Massachusetts, is vulnerable to
ocean acidification, according to a new study. The correct town is
New Bedford, Massachusetts.
the_guardian_on_ocean_acidification.txt · Last modified: 2015/07/05 15:28 by eda