Warming Coastal Waters Will Impact Fisheries, Tourism
By Frank Carini / ecoRI News
columnist
Atlantic bluefin tuna are a popular catch off the Rhode
Island coast. The species has been listed in various
states of decline during the past few decades.
Since Rhode Island calls itself the Ocean State, hypes
its beaches, named calamari the official state appetizer, paid to place
unappetizing stuffie installations made of
Styrofoam in airports around the country, and relies heavily on coastal tourism
for its economic survival, it stands to reason its elected officials, business
owners, residents, and visitors are concerned about the health of the planet’s
marine waters, especially those that lap the local coastline and play host to
squid and quahogs.
They should be. The Northwest Atlantic Ocean — southern
New England’s coast sits in the middle of it — is among the planet’s
fastest-warming marine waters.
“Climate-driven changes in the oceans are projected to
yield an average increase of 1° to 6°C in sea surface temperatures by 2100,
which is likely to have profound effects on marine ecosystems and the
communities, businesses, and fisheries that rely on them,” according to a study published in August.
The life- and economy-sustaining marine ecosystem is
vulnerable to human influences. There is a limit to the abuse the oceans can
take and still function as the planet’s lungs and circulatory system.
The incessant burning of fossil fuels, the dragging of industrial fishing gear along the seafloor, overfishing, and the dumping — directly and indirectly — of so much of our waste into the ocean is changing its composition. Biodiversity in the world’s marine waters is rapidly declining. Corals are bleaching. The oceans are warming, acidifying, and plastifying. The saltwater system is dying, or at least running a high fever. It is sick.
“New England’s ocean is facing a crisis on multiple
fronts,” said Priscilla Brooks, vice president of ocean conservation at the Conservation
Law Foundation (CLF). “Climate change, overfishing, pollution, and habitat
destruction are combining to dangerously affect marine life which, if left
unchecked, does not bode well for the future of our ocean.”
Simply put, we need to start treating the marine
environment better. In fact, we need to provide some universal health care.
Many people living in this region, in fact, are troubled by the oceans’ current
condition.
A recent CLF poll found
that New Englanders are increasingly worried about ocean health. They cited
polluted runoff, plastic, climate change, overfishing, and habitat and species
loss as significant concerns. Respondents strongly preferred establishing
protected areas to mitigate these threats.
We could also stop killing the oceans’ top predators.
Findings from the August study — titled “Widespread habitat loss and redistribution of marine top predators in a changing ocean” — could have a significant impact on southern New England fisheries, seafood consumers, and recreational anglers.
The study, conducted by the Woods Hole
Oceanographic Institution in Falmouth, Mass., and published in the journal
Science Advances, found highly migratory fish predators in the rapidly warming
Northwest Atlantic Ocean and Gulf of Mexico could lose about 40% of their
suitable habitat — nearly 70% for some — by the end of the century.
Atlantic bluefin tuna, a popular species commonly fished
off the Ocean State coast, is one of the Northwest Atlantic Ocean species
projected to be impacted by warming waters and habitat loss. Of the three
bluefin species, the Atlantic is the largest, and has been listed in various
states of endangerment during the past few decades.
Other iconic Rhode Island species, such as cod and
lobster, have been moving north for a while. Once-abundant winter flounder is
difficult to find.
In their place, southerly species are appearing more
frequently (spot and ocean sunfish) and more unwanted guests are arriving
(jellyfish that have an appetite for fish larvae and, in the summer, lionfish, a venomous
and fast-reproducing fish with a voracious appetite).
Humans have been devouring ocean life for the past century.
The cover story —
titled “Net Losses” — of the May 15, 2003, issue of the journal Nature reported
that only 10% of all large fish — both open-ocean species including tuna,
swordfish, and marlin and large groundfish such as cod, halibut, skates, and
flounder — are left in the sea. Most alarming, the study found industrial
fisheries take only 10-15 years to decimate any new fish community they
encounter to one-tenth of what it was before.
The study’s lead author noted that since the onset of
industrialized fisheries, in 1950, “we have rapidly reduced the resource base
to less than 10% — not just in some areas, not just for some stocks, but for
entire communities of these large fish species from the tropics to the poles.”
Little has changed during the past two decades.
Thirty-seven percent of the world’s sharks and rays are
threatened with extinction because of overfishing, loss and degradation of
habitat, and climate change.
In a study published in 2014, the authors
estimated that the biomass of predatory fish species declined by about 75% from
1910 to 2010.
Seafood consumers can slow — perhaps even stop — this
large-fish carnage and help protect a stressed ecosystem.
Many consumers prefer predatory fish such as tuna,
swordfish, rays, and sharks to species lower on the food web such as anchovies,
sardines, and scup, which provides strong incentives for fishermen to catch the
bigger fish.
This ongoing mass slaughter of large-fish populations has
implications that go far beyond providing a supply of seafood that consumers
prefer to eat. Predators keep prey populations in balance, and the loss of
these fish can cause nutritional cascades through food webs that impact marine
ecosystems.
For instance, in the absence of predators, grazers often
flourish. This leads to a feeding frenzy on kelp and seagrasses, which provide
ecosystem services and habitat and promote ecological stability. When removed,
dead zones can last for decades.
The butchering of large predatory fish isn’t the only
human activity changing the oceans’ makeup. The burning of fossil fuels has
been steadily acidifying marine waters for the past 160 years.
That’s bad news for the Ocean State’s official appetizer.
Woods Hole Oceanographic Institution research has
found squid — both predator and prey — are vulnerable to the acidic conditions
that higher carbon dioxide levels create, and may face greater challenges to
survival as the ocean acidifies.
Perhaps we should start thinking about a new state
appetizer. But don’t make it stuffies. Ocean acidification will also negatively
impact molluscs, including quahogs.
Frank Carini can be reached at frank@ecori.org. His
opinions don’t reflect those of ecoRI News.
