Climate change Archives - Page 84 of 148

Fishermen And Scientists Join Forces To Track Effects Of Climate Change

August 14, 2020 — Last October, lobstermen fishing off the coast of southern New England noticed the lobsters getting more active. That’s fairly common, says Mark Sweitzer, a commercial fisherman out of Port Judith, Rhode Island.

“It’s not unusual for there to be a big pop of lobster in September or October,” says Sweitzer. “Fall’s our best fishing.”

But along with the lobster came something more unusual: a temperature spike on the seafloor, about 150-200 feet down. The temperature jumped from about 50 degrees to 60 — “a big, big change,” says Sweitzer — and stayed there for 38 days, from October 10 to November 15.

Sea surface temperature can change rapidly, rising or falling with strong winds or a storm. But at the bottom, temperature changes much more slowly. “So to get a temperature change that big on the bottom, that is major,” says Sweitzer. “Something caused that to happen. That wasn’t a few warm nights.”

Read the full story at WBUR

Regulators find shad, an important fish, are ‘depleted’

August 11, 2020 — Overfishing, dams and pollution are among the factors that have steeply reduced the population of an ecologically important fish on the East Coast, regulators have said.

The Atlantic States Marine Fisheries Commission recently completed an assessment of the population of American shad and found it to be “depleted,” the commission said. Changing ocean conditions and climate change have also likely played a role in reducing the fish’s population from historic levels, it said.

Read the full story at the Associated Press

Species may swim thousands of kilometers to escape ocean heat waves

August 11, 2020 — When an intense heat wave strikes a patch of ocean, overheated marine animals may have to swim thousands of kilometers to find cooler waters, researchers report August 5 in Nature.

Such displacement, whether among fish, whales or turtles, can hinder both conservation efforts and fishery operations. “To properly manage those species, we need to understand where they are,” says Michael Jacox, a physical oceanographer with the National Oceanographic and Atmospheric Administration based in Monterey, Calif.

Marine heat waves — defined as at least five consecutive days of unusually hot water for a given patch of ocean — have become increasingly common over the past century (SN: 4/10/18). Climate change has amped up the intensity of some of the most famous marine heat waves of recent years, such as the Pacific Ocean Blob from 2015 to 2016 and scorching waters in the Tasman Sea in 2017 (SN: 12/14/17; SN: 12/11/18).

“We know that these marine heat waves are having lots of effects on the ecosystem,” Jacox says. For example, researchers have documented how the sweltering waters can bleach corals and wreak havoc on kelp forests. But the impacts on mobile species such as fish are only beginning to be studied (SN: 1/15/20).

Read the full story at Science News

Pollution, Hurricanes, and the Pandemic Spell Trouble for Gulf Shrimp and Seafood Industries

August 5, 2020 — Today researchers announced the size of the Gulf of Mexico dead zone, the official measurement NOAA uses to track its size year over year. This comes on the heels of bad news from another NOAA report indicating that the volume of Gulf shrimp landings in June 2020 was the lowest ever recorded.

Researchers found that the dead zone measured 5,048 square kilometers, slightly larger than the state of Rhode Island. This year’s dead zone is much smaller than predicted, not because nitrogen pollution flowing into the Gulf was lower, but because Hurricane Hanna dispersed it at the time it was measured.

Hurricanes have dispersed the dead zone in previous years, causing its size to be smaller than expected given data on nitrogen pollution flowing into the Gulf in the same year. In fact, earlier this year Louisiana University and NOAA researchers predicted, assuming no hurricane, that nitrogen loading levels in the Gulf would cause a dead zone that was 20,000 square kilometers, which is about the size of New Hampshire.

On its face, this may seem like a silver lining. But these hurricanes will likely make tracking the dead zone size even more challenging in the years ahead. And with climate change expected to increase hurricane size and intensity in the Gulf between now and the end of the century, it’s clear that there are long-term challenges to measuring the Gulf dead zone. To make matters worse hurricanes have a negative impact on Gulf fishing industries, too.

Read the full story at the Union of Concerned Scientists

Smaller-than-expected Gulf of Mexico ‘dead zone’ measured

August 5, 2020 — The following was released by NOAA:

NOAA-supported scientists have determined this year’s Gulf of Mexico “dead zone”— an area of low to no oxygen that can kill fish and marine life — is approximately 2,116 square miles, or equivalent to 1.4 million acres of habitat potentially unavailable to fish and bottom species.

The measured size of the dead zone is the third smallest in the 34-year record of surveys. The average hypoxic zone over the past five years is 5,408-square miles, which is 2.8 times larger than the 2035 target set by the Hypoxia Task Force.

The annual dead zone survey was led by scientists at Louisiana State University and the Louisiana Universities Marine Consortium during a research cruise from July 25 to August 1 aboard the R/V Pelicano.

Read the full release here

New research plan sets the course for NOAA’s ocean acidification science

July 30, 2020 — The following was released by NOAA:

Today, NOAA unveiled its new 10-year research roadmap to help the nation’s scientists, resource managers, and coastal communities address acidification of the open ocean, coasts, and Great Lakes.

“Ocean acidification puts the United States’ $1 billion shellfish industry and hundreds of thousands of jobs at risk,” said Kenric Osgood, Ph.D., chief of the Marine Ecosystems Division, Office of Science and Technology at NOAA Fisheries Service. “Understanding how ocean acidification will affect marine life and the jobs and communities that depend on it is critical to a healthy ocean and blue economy.”

The research plan sets out three major objectives for ocean, coastal, and Great Lakes acidification research, and includes regional chapters for coastal zones around the U.S., Great Lakes, territories – including Puerto Rico and American Samoa – and deep ocean regions. The three national research objectives are:

1) Expand and advance observing systems and technologies to improve the understanding of and ability to predict acidification trends and processes;

2) Understand the ways acidification is impacting ecologically and economically important species and the ecosystems they live in, and improve our ability to predict how these ecosystems and species may respond to acidification and other stressors; and

3) Identify and engage stakeholders and partners, assess needs, and generate products and tools that support management decisions, adaptation, and resilience to acidification.

Read the full release here

Sharks are “functionally extinct” from many of the world’s reefs, new global survey finds

July 28, 2020 — Sharks are absent on many of the world’s coral reefs, suggesting that they are “too rare to fulfill their normal role in the ecosystem, and have become ‘functionally extinct,’” according to a new landmark study.

Conducted by Global FinPrint and published in the journal Nature, the study involved surveying 371 reefs in 58 countries. Sharks were not found on nearly 20 percent of reefs, “indicating a widespread decline that has gone undocumented on this scale until now,” Global FinPrint said in a press release.

Read the full story at Seafood Source

Submerged Aquatic Vegetation: A Habitat Worth SAV-ing

July 27, 2020 — The following was released by NOAA Fisheries:

The term used for a rooted aquatic plant that grows completely under water is submerged aquatic vegetation (SAV). These plants occur in both freshwater and saltwater but in estuaries, where fresh and saltwater mix together, they can be an especially important habitat for fish, crabs, and other aquatic organisms. We work to protect this important habitat, ensuring that it remains healthy and has a chance to thrive.

NOAA: Lobsters will look for cooler water

July 24, 2020 — Cape Cod is known for its lobsters as much as for its oysters and quahogs. But it’s getting too warm in these waters for the tasty crustacean.

Researchers have projected significant changes in the habitat of commercially important American lobster and sea scallops on the Northeast U.S. continental shelf. They used a suite of models to estimate how species will react as waters warm, and it suggests that American lobster will move further offshore and sea scallops will shift to the north in the coming decades, a recent statement from NOAA Fisheries warned.

Findings from the study were published recently in Diversity and Distributions. They pose fishery management challenges as the changes can move stocks into and out of fixed management areas. Habitats within current management areas will also experience changes — some will show species increases, others decreases, and still others no change.

“Changes in stock distribution affect where fish and shellfish can be caught and who has access to them over time,” said Vincent Saba, a fishery biologist in the Ecosystems Dynamics and Assessment Branch at the Northeast Fisheries Science Center and a co-author of the study.

Read the full story at Wicked Local

How Ultra-Black Fish Disappear in the Deepest Seas

July 16, 2020 — Alexander Davis admits that he can be a glutton for punishment. He staked part of his Ph.D. on finding some of the world’s best-camouflaged fishes in the ocean’s deepest depths. These animals are so keen on not being found that they’ve evolved the ability to absorb more than 99.9 percent of the light that hits their skin.

To locate and study these so-called ultra-black fishes, Mr. Davis, a biologist at Duke University, said he relied largely on the luck of the draw. “We basically just drop nets and see what we get,” he said. “You never know what you’re going to pull up.”

When he and his colleagues did cash in, they cashed in big. In a paper published Thursday in Current Biology, they report snaring the first documented ultra-black animals in the ocean, and some of the darkest creatures ever found: 16 types of deep-sea fish that are so black, they manifest as permanent silhouettes — light-devouring voids that almost seem to shred the fabric of space-time.

“It’s like looking at a black hole,” Mr. Davis said.

To qualify as ultra-black, a substance has to reflect less than 0.5 percent of the light that hits it. Some birds of paradise manage this, beaming back as little as 0.05 percent, as do certain types of butterflies (0.06 percent) and spiders (0.35 percent). A feat of engineering allowed humans to best them all with synthetic materials, some of which reflect only 0.045 percent of incoming light. (“Black” paper, on the other hand, returns a whopping 10 percent of the light it meets.)

Read the full story at The New York Times