Fisheries Management & Legislative Report

The waters off the coast of New England are warming more rapidly than almost any other ocean region on earth. Scientists are now studying the resulting ecosystem changes, and their findings could provide a glimpse of the future for many of the world’s coastal communities.

After hauling in the cages at his island oyster farm near Biddeford, Maine, Mark Green's boat is loaded with crusty marine life. Baskets of oysters are there, but so are green crabs — invasive and inedible. "My boat will be full," Green says. "The bottom will just be this undulating mass of green crabs by the end of the day. I mean thousands." A native of Europe, green crabs have been present on the U.S. East Coast for more than a century, but until a couple of years ago they didn't cause much trouble in Maine. Now, thanks to rapidly warming waters, their population has exploded. While they don't bother the tough‐shelled oysters, the crabs are laying waste to the region's softshell clams — another important commercial stock — and devastating its seagrass meadows, which Green, an environmental scientist at St. Joseph's College in nearby Standish, calls "the most crucial habitat that exists in an estuary."

"It's crazy," Green says. The seething, skittering masses of green crabs and mudflats depleted of clams and seagrass are just a few signs of big changes underway in the Gulf of Maine, the pool of Atlantic waters stretching from Cape Cod to southern Nova Scotia. Scientists report that the gulf's waters are warming faster than 99.85 percent of the rest of the world's oceans, and the marine ecosystem is reorganizing itself apace. The changes are so striking — and the fishery they affect is so important to the region's economy and identity — that they are under close watch by the area's many marine scientists. Observers say the gulf has become a "living laboratory" for how climate change could play out in marine ecosystems around the world.

"At minimum what we're seeing now is a window to what we expect our average conditions to be in the middle or towards the end of the century," says Andrew Pershing, chief scientific officer at the Gulf of Maine Research Institute. "We're kind of seeing a glimpse of the future. Pershing cautions that it remains unclear how much of the warming trend is driven by climate change and how much is simply a result of the gulf's natural variability, and he suggests that the gulf could cool again somewhat in the short term.

But it is clear, Pershing says, that only three other places on earth are heating up as fast as the Gulf of Maine. Using longterm ocean‐temperature data, Pershing and a colleague documented the gulf's rapid warming — including an uptick of roughly three degrees Celsius over the past decade. In 2012, a massive, unprecedented oceanic heat wave descended on the entire northwest Atlantic with the gulf at its epicenter, making it the warmest year on record. Last year proved to be the second warmest ever documented, but Pershing says 2014 may beat that — despite last winter's frigid "polar vortex."

Scientists are also documenting other dramatic environmental transformations in the gulf related to rising greenhouse gas emissions, says Jon Hare, oceanography branch chief for the National Oceanic and Atmospheric Administration's Northeast Fisheries Science Center in Narragansett, Rhode Island. Ocean water is becoming fresher, most likely due to Arctic ice melting into the Labrador Sea, one of the gulf's main water sources. Precipitation is increasing, particularly heavy precipitation during storms. And forthcoming research from NOAA confirms that the gulf is becoming more acidic due to rising atmospheric carbon dioxide levels, Hare says. All of this is happening against a backdrop of more familiar problems, like overfishing, pollution, and chronic low‐oxygen hotspots, which scientists say can combine to stress organisms and make it difficult to pinpoint why they may be struggling.

"Across the physical spectrum there have been a lot of changes," Hare says, and the gulf's marine life is responding fast, starting at the very bottom of the food web. Hare says there is evidence that seasonal blooms of phytoplankton and zooplankton are changing their timing, magnitude, and species composition, and that these shifts could reverberate throughout the ecosystem, although further research is needed to understand how.

Most striking to Hare and other observers are the species from further south that are turning up in waters once too cold for comfort. Strange sightings peaked during the warmest years of 2012 and 2013, although some reports have continued to roll in this year, they say. Longfin squid, normally found only in the southern gulf and below, rushed north into the gulf's coastal waters in greater numbers than anyone could remember, prompting a squid‐fishing spree from the tip of Cape Cod to New Brunswick in Canada. Maine lobstermen hauling their traps found triggerfish, typical of the Carolinas and south, and scientists reportedly even spotted tropical species like filefish and snowy grouper in Maine waters.

One species generating a lot of chatter is the black sea bass, an aggressive, territorial reef fish that used to range mainly from the Gulf of Mexico to Cape Cod. Gulf of Maine lobstermen were surprised when it began showing up regularly in traps a few years ago, says Marissa McMahan, a doctoral student at Northeastern University in Boston. McMahan grew up crewing on her father's lobster boat, but didn't see her first black sea bass until 2012. A dozen appeared in their traps that summer, she says. When fall came, McMahan went off to graduate school and decided to focus her research on the species. The next summer her father sent around 40 black sea bass from his traps for her to examine. She heard similar accounts from other fishermen, whom she relies on for samples and reports of sightings. "It skyrocketed, the amount of fish that they were catching as bycatch. I mean, it went through the roof."

McMahan says many fishermen and scientists are concerned black sea bass, voracious eaters, may be developing a taste for juvenile lobsters as they settle into their new home in the gulf. On the bright side, she says, they are also wondering whether sea bass might turn into a new commodity, since the species generates a good price in its native range, where it's fished commercially.

Meanwhile, the gulf's native species are shifting fast, too. Populations of cod and northern shrimp, once fishing industry pillars, have plummeted. This month officials announced historic emergency measures to protect cod that effectively shut down the gulf's iconic fishery, at least until spring, after survey results showed stocks around 3 percent of what would constitute sustainable levels. This follows the closing of the northern shrimp season altogether for a second year in a row due to dwindling stocks across the entire North Atlantic. What remains of the cod and the shrimp populations appear to be moving north into cooler waters, leaving devastated fishing families in their wake.

By contrast, the lobster fishery is flourishing. It now dominates the region's post‐cod fishing economy, and it's probably no coincidence that cod was once a major lobster predator, scientists say. But even the lobsters' abundance may be precarious. They've been shedding their shells earlier and earlier in the spring, and during the 2012 heat wave they molted a full month earlier than usual. A staggering early catch flooded the market that year and caused prices to plunge. Though the catch has stabilized and lobstermen are making money again, there is some uneasiness about the future.

Green points out that only two studies have explored how lobsters might respond to ocean acidification, with contradictory results. And a disease that rots their shells seems to be creeping slowly northward, he notes, after quickly wiping out lobster industries to the south within a year or two.

Many observers see an ecosystem‐wide pattern that extends beyond commercial stocks and will require a great deal more research to fully understand.

"There's this big change happening in the Gulf of Maine in general, for whales and turtles and dolphins and gulls and fish and lobsters and just everything," says Kathleen Hunt, a research scientist at the New England Aquarium in Boston who studies whales and sea turtles. "Every population I know of is changing its distribution. It's either appearing where it didn't used to be or it's disappearing from where it did used to be, or it's starving, or it's getting a new disease. "Clearly there's a big shift going on, which I can't help but suspect is global warming," she adds. "But as scientists we're not allowed to say that yet till we see if it's a 20‐year trend or not."

No one wants to wait that long for answers. New research initiatives are looking directly at how climate change is playing out in the Gulf of Maine, with the goal of helping fishermen and managers adapt to what may be one of the fastest‐changing ecosystems in the world. NOAA, for instance, has developed new methodology for quickly assessing how vulnerable marine species are to climate change, starting with 79 species from the northeastern U.S. and southeastern Canada, including the gulf. Hare, the project lead, says he expects the techniques will be applied elsewhere.

Scientists are starting to think of the region as a case study for other parts of the world that remain relatively stable for now, Pershing says. "What we've seen is something that everybody around the world is going to be seeing at one level or another, maybe at a more gradual rate, maybe at a faster rate," Pershing says. "But we've seen it here, and I think we have a real duty to learn from it."

Link to original article here.

Three years ago, the Chesapeake Bay was hit by an unusually large “dead zone,” a stretch of oxygen‐depleted water that killed fish from the Baltimore Harbor to the mid‐channel of the Potomac River and beyond, about a third of the bay.

Another giant dead zone returned last summer, smaller than the first but big enough to rank as the estuary’s eighth largest since state natural resources officials in Virginia and Maryland started recording them in the 1990s.

In a future of climate change, those behemoths might not seem so unusual, according to a new report by the Smithsonian. As the global temperatures warm, they will create conditions such as rain, wind and sea‐level rise that will cause dead zones throughout the world to intensify and grow, the report says. Ninety‐four percent of places where dead zones have been recorded are areas where average temperatures are expected to rise by about 4 degrees Fahrenheit by the turn of the century. In addition to the Chesapeake Bay region, that includes the Black and Baltic seas and the Gulf of Mexico, where a dead zone equal to the size of Connecticut took shape in August.

“Over 40 percent of the world’s population lives in coastal areas,” said Keryn B. Gedan, codirector of a conservation program at the University of Maryland and a researcher at the Smithsonian Environmental Research Center in Cambridge, Md. “We depend on these resources. No one wants to see a fish kill or harmful algal bloom at their local beach.”

Gedan was a co‐author of the study with Andrew H. Altieri of the Smithsonian Tropical Research Institute in Panama. They found that the number of dead zone events have doubled each decade since the 1950s and that humans have likely contributed to their growth in intensity and size. “We just don’t know how much of this doubling is due to climate change or nutrient runoff,” Gedan said. More studies with more “sophisticated modeling” are needed to determine that, she said.

Dead zones are summer plagues that happen when waters warm. As the water temperatures increase, three key events pave the way for a catastrophe that kills any fish, crab, oyster and shrimp that relies on oxygen. The metabolism of animals in the water revs up, turning them into hungry eaters that use more oxygen as they search and feed on algae. Algae that feeds on nutrient pollution that runs off farms in rains and pours out of overflowing sewers bloom and perish in a rapid and enormous death spiral. Microbes feed on the dead algae in a frenzy that sucks out oxygen to a point where it can no longer sustain life.

In a warming world, this process, which currently starts around May, will likely start sooner unless steps are taken to reduce the overabundance of nitrogen, phosphorous and other pollutants that flow into water. Gedan said the Chesapeake Bay cleanup plan is one example of how government can act to mitigate climate driven impacts that create dead zones. Previous research supports that assertion. A study of the bay’s water quality by researchers for Johns Hopkins University and the University of Maryland Center for Environmental Science found that dead zones have been reduced since pollution limits were first implemented in the 1980s.

They studied water‐quality data for the Chesapeake from 1949 to 2009 and found “evidence that cutting back on the nutrient pollutants pouring into the bay can make a difference,” the study’s lead author, Rebecca R. Murphy, a doctoral student at Johns Hopkins, said when the study was released in 2011.

There is no certainty that cleanup plans such as the bay’s so‐called pollution diet, which calls for the governments in six states and the District to reduce sewer overflows and nutrient runoff from farms, can counteract changing climate and its accompanying ill effects. Downpours, wind storms and sea‐level rise are a lot to overcome. Downpours cause sewers to overflow, wind storms wipe fertilizers off yards and push them down drains and sea‐level rise threatens to drown wetlands that block pollution’s path to rivers that feed bays and oceans.

Unlike crabs and bivalves such as oysters, striped bass, an iconic Maryland and Virginia fish, could swim to the shallows to escape deeper oxygen depleted water. But as the weather warms and raises the temperature in shallow water, that refuge could go away.

High temperatures in shallows cause “thermally induced hypoxia,” the report said. “This combination is predicted to reduce habitat for striped bass. In extreme situations, the temperatures of shallow water may exceed thermal tolerance of organisms, leaving them with the dilemma of choosing death by hypoxia at depth or by thermal stress in the shallows.”

Darryl Fears has worked at The Washington Post for more than a decade, mostly as a reporter on the National staff. He currently covers the environment, focusing on the Chesapeake Bay and issues affecting wildlife. Link to original article here.

A team of scientists, in a groundbreaking analysis of data from hundreds of sources, has concluded that humans are on the verge of causing unprecedented damage to the oceans and the animals living in them.

“We may be sitting on a precipice of a major extinction event,” said Douglas J. McCauley, an ecologist at the University of California, Santa Barbara, and an author of the new research, which was published on Thursday in the journal Science.

But there is still time to avert catastrophe, Dr. McCauley and his colleagues also found. Compared with the continents, the oceans are mostly intact, still wild enough to bounce back to ecological health.

“We’re lucky in many ways,” said Malin L. Pinsky, a marine biologist at Rutgers University and another author of the new report. “The impacts are accelerating, but they’re not so bad we can’t reverse them.”

Scientific assessments of the oceans’ health are dogged by uncertainty: It’s much harder for researchers to judge the well-being of a species living underwater, over thousands of miles, than to track the health of a species on land. And changes that scientists observe in particular ocean ecosystems may not reflect trends across the planet.

Dr. Pinsky, Dr. McCauley and their colleagues sought a clearer picture of the oceans’ health by pulling together data from an enormous range of sources, from discoveries in the fossil record to statistics on modern container shipping, fish catches and seabed mining. While many of the findings already existed, they had never been juxtaposed in such a way.

A number of experts said the result was a remarkable synthesis, along with a nuanced and encouraging prognosis.

“I see this as a call for action to close the gap between conservation on land and in the sea,” said Loren McClenachan of Colby College, who was not involved in the study.

There are clear signs already that humans are harming the oceans to a remarkable degree, the scientists found. Some ocean species are certainly overharvested, but even greater damage results from large-scale habitat loss, which is likely to accelerate as technology advances the human footprint, the scientists reported.

Coral reefs, for example, have declined by 40 percent worldwide, partly as a result of climate-change-driven warming.

Some fish are migrating to cooler waters already. Black sea bass, once most common off the coast of Virginia, have moved up to New Jersey. Less fortunate species may not be able to find new ranges. At the same time, carbon emissions are altering the chemistry of seawater, making it more acidic.

“If you cranked up the aquarium heater and dumped some acid in the water, your fish would not be very happy,” Dr. Pinsky said. “In effect, that’s what we’re doing to the oceans.”

Fragile ecosystems like mangroves are being replaced by fish farms, which are projected to provide most of the fish we consume within 20 years. Bottom trawlers scraping large nets across the sea floor have already affected 20 million square miles of ocean, turning parts of the continental shelf to rubble. Whales may no longer be widely hunted, the analysis noted, but they are now colliding more often as the number of container ships rises.

Mining operations, too, are poised to transform the ocean. Contracts for seabed mining now cover 460,000 square miles underwater, the researchers found, up from zero in 2000. Seabed mining has the potential to tear up unique ecosystems and introduce pollution into the deep sea.

The oceans are so vast that their ecosystems may seem impervious to change. But Dr. McClenachan warned that the fossil record shows that global disasters have wrecked the seas before. “Marine species are not immune to extinction on a large scale,” she said.

Until now, the seas largely have been spared the carnage visited on terrestrial species, the new analysis also found.

The fossil record indicates that a number of large animal species became extinct as humans arrived on continents and islands. For example, the moa, a giant bird that once lived on New Zealand, was wiped out by arriving Polynesians in the 1300s, probably within a century.

But it was only after 1800, with the Industrial Revolution, that extinctions on land really accelerated.

Humans began to alter the habitat that wildlife depended on, wiping out forests for timber, plowing under prairie for farmland, and laying down roads and railroads across continents.

Species began going extinct at a much faster pace. Over the past five centuries, researchers have recorded 514 animal extinctions on land. But the authors of the new study found that documented extinctions are far rarer in the ocean.

Before 1500, a few species of seabirds are known to have vanished. Since then, scientists have documented only 15 ocean extinctions, including animals such as the Caribbean monk seal and the Steller’s sea cow.

While these figures are likely underestimates, Dr. McCauley said that the difference was nonetheless revealing.

“Fundamentally, we’re a terrestrial predator,” he said. “It’s hard for an ape to drive something in the ocean extinct.”

Many marine species that have become extinct or are endangered depend on land — seabirds that nest on cliffs, for example, or sea turtles that lay eggs on beaches.

Still, there is time for humans to halt the damage, Dr. McCauley said, with effective programs limiting the exploitation of the oceans. The tiger may not be salvageable in the wild — but the tiger shark may well be, he said.

“There are a lot of tools we can use,” he said. “We better pick them up and use them seriously.”

Dr. McCauley and his colleagues argue that limiting the industrialization of the oceans to some regions could allow threatened species to recover in other ones. “I fervently believe that our best partner in saving the ocean is the ocean itself,” said Stephen R. Palumbi of Stanford University, an author of the new study.

The scientists also argued that these reserves had to be designed with climate change in mind, so that species escaping high temperatures or low pH would be able to find refuge.

“It’s creating a hopscotch pattern up and down the coasts to help these species adapt,” Dr. Pinsky said. Ultimately, Dr. Palumbi warned, slowing extinctions in the oceans will mean cutting back on carbon emissions, not just adapting to them.

“If by the end of the century we’re not off the business-as-usual curve we are now, I honestly feel there’s not much hope for normal ecosystems in the ocean,” he said. “But in the meantime, we do have a chance to do what we can. We have a couple decades more than we thought we had, so let’s please not waste it.”

Link to original article here.