Saving Seafood

New Research Reveals Clearer Picture of Upwelling That Feeds West Coast Marine Ecosystem

May 13, 2019 — The following was released by NOAA Fisheries:

Great volumes of nutrient-rich water welling up from the deep ocean fuel the West Coast’s great diversity of marine life. Now scientists using satellite images, research buoys, ocean models, and other ocean monitoring tools have brought the upwelling into much sharper focus, measuring even the velocity of the water and the amount of nutrients that it delivers.

Scientists described new “upwelling indices,” which represent a breakthrough in understanding the biological engine that drives the West Coast marine ecosystem.

“Upwelling is vital to marine life along the West Coast, but the tools we were using to monitor it hadn’t changed much in almost 50 years,” said Michael Jacox, a research scientist at NOAA Fisheries’ Southwest Fisheries Science Center who developed the new indices. “Now we’re bringing state-of-the-art tools and the latest science to bear to help us understand how upwelling supports and shapes the California Current Ecosystem.”

Given the ecological importance of upwelling, scientists and managers are eager for indices that allow them to monitor its variability and understand its impacts on coastal ocean ecosystems.

Jacox, of the Southwest Fisheries Science Center and NOAA’s Earth System Research Laboratory, and other researchers from NOAA Fisheries, and the University of California at Santa Cruz, recently published the new upwelling measurements new upwelling measurements in the Journal of Geophysical Research: Oceans and the indices are also available online. Maps based on the indices reveal through color-coding where upwelling is most pronounced, such as off Cape Mendocino in California.

Upwelling occurs along certain coastlines around the world where winds and the Earth’s rotation sweep surface waters offshore, drawing deep, cold, and salty water full of nutrients up to the surface. These nutrients fuel growth of phytoplankton that form the base of the marine food web, and ultimately nourish the West Coast’s ocean ecosystem from sardines to sperm whales.

Read the full release here

Shipwrecks may help tropical fish adapt to climate change

May 10, 2019 — When Chris Taylor presses play, footage of blue wrasse and greater amberjack fills the screen. The fish whirl and spin against a vivid backdrop of corals, sponges, and algae. When Taylor, an ecologist at NOAA’s National Centers for Coastal Ocean Science in Beaufort, North Carolina, asks visitors to the Centers where they think the video was taken, he’s not surprised to hear the Florida Keys or the Caribbean. But the guesses are invariably wrong.

“These highly structured reefs are right off our coast,” Taylor says. “There are all of these brightly colored fishes that defy expectations.”

A new study in Nature Communications Biology by Taylor and Avery Paxton, a marine ecologist who divides her time between NOAA and the Duke University Marine Laboratory, shows artificial deepwater reefs off the coast of North Carolina increased the number of tropical and subtropical fishes at the northern edge of their ranges. These findings have important implications for fishes in warming waters. As ocean temperatures rise, artificial reefs may facilitate the movement of these species towards the poles, where they may be able to find a habitat that is more suitable in the future.

Read the full story at National Geographic

Study: Fishery consolidation in Alaska leaves fishermen vulnerable

May 9, 2019 — Alaskan commercial fishermen are specializing more and more, leaving them more vulnerable to the immense uncertainty fishermen have to contend with, according to a new study.

Targeting a diverse array of fish types in different regions can allow fishermen to weather the ups and downs instigated by fish population changes, new regulations, deflating markets and environmental disasters. But fishermen in Alaska are increasingly specializing. Fewer fishermen are on the water than three decades ago, and those who remain are participating in fewer fisheries, according to the study, which was published in Fish and Fisheries.

“Across different fisheries and regions of Alaska, there are fewer people fishing than there used to be and their fishing portfolios have become less diverse,” Anne Beaudreau, the lead author of the study and an associate professor at the University of Alaska Fairbanks, told SeafoodSource.

Individual fishery quota systems, plus the high cost of permits and other institutional barriers, have made it more difficult for new players to enter Alaskan fisheries, according to the study.

Though fishermen could, in theory, diversify their portfolio of permits, those management restrictions and high costs often prevent them from doing so, leading to more specialization. Permits can cost hundreds of thousands of dollars depending on the fishery, Beaudreau said.

Read the full story at Seafood Source

UN report: Humans accelerating extinction of other species

May 7, 2019 — People are putting nature in more trouble now than at any other time in human history, with extinction looming over 1 million species of plants and animals, scientists said Monday.

But it’s not too late to fix the problem, according to the United Nations’ first comprehensive report on biodiversity.

“We have reconfigured dramatically life on the planet,” report co-chairman Eduardo Brondizio of Indiana University said at a press conference.

Species loss is accelerating to a rate tens or hundreds of times faster than in the past, the report said. More than half a million species on land “have insufficient habitat for long-term survival” and are likely to go extinct, many within decades, unless their habitats are restored. The oceans are not any better off.

“Humanity unwittingly is attempting to throttle the living planet and humanity’s own future,” said George Mason University biologist Thomas Lovejoy, who has been called the godfather of biodiversity for his research. He was not part of the report.

“The biological diversity of this planet has been really hammered, and this is really our last chance to address all of that,” Lovejoy said.

Conservation scientists convened in Paris to issue the report, which exceeded 1,000 pages. The Intergovernmental Science-Policy Platform on Biodiversity and Ecosystem Services (IPBES) included more than 450 researchers who used 15,000 scientific and government reports. The report’s summary had to be approved by representatives of all 109 nations.

Read the full story at the Associated Press

North Atlantic Ocean productivity has dropped 10 percent during Industrial era

May 7, 2019 — Virtually all marine life depends on the productivity of phytoplankton — microscopic organisms that work tirelessly at the ocean’s surface to absorb the carbon dioxide that gets dissolved into the upper ocean from the atmosphere.

Through photosynthesis, these microbes break down carbon dioxide into oxygen, some of which ultimately gets released back to the atmosphere, and organic carbon, which they store until they themselves are consumed. This plankton-derived carbon fuels the rest of the marine food web, from the tiniest shrimp to giant sea turtles and humpback whales.

Now, scientists at MIT, Woods Hole Oceanographic Institution (WHOI), and elsewhere have found evidence that phytoplankton’s productivity is declining steadily in the North Atlantic, one of the world’s most productive marine basins.

In a paper appearing today in Nature, the researchers report that phytoplankton’s productivity in this important region has gone down around 10 percent since the mid-19th century and the start of the Industrial era. This decline coincides with steadily rising surface temperatures over the same period of time.

Matthew Osman, the paper’s lead author and a graduate student in MIT’s Department of Earth, Atmospheric, and Planetary Sciences and the MIT/WHOI Joint Program in Oceanography, says there are indications that phytoplankton’s productivity may decline further as temperatures continue to rise as a result of human-induced climate change.

“It’s a significant enough decine that we should be concerned,” Osman says. “The amount of productivity in the oceans roughly scales with how much phytoplankton you have. So this translates to 10 percent of the marine food base in this region that’s been lost over the industrial era. If we have a growing population but a decreasing food base, at some point we’re likely going to feel the effects of that decline.”

Osman and his colleagues looked for trends in phytoplankton’s productivity using the molecular compound methanesulfonic acid, or MSA. When phytoplankton expand into large blooms, certain microbes emit dimethylsulfide, or DMS, an aerosol that is lofted into the atmosphere and eventually breaks down as either sulfate aerosol, or MSA, which is then deposited on sea or land surfaces by winds.

Read the full story at MIT News

Place-Based Management Can Protect Coral Reefs in a Changing Climate

April 30, 2019 — Researchers from the state Department of Health and the University of Hawai‘i at Mānoa have developed and applied a new technology in Hawai‘i that identifies where coral reef ecosystems and associated fisheries are vulnerable to human activities and where to focus management actions to minimize anthropogenic impacts.

The authors of the newly published study in the journal Ecological Applications identified specific locations on land where improved wastewater management and landscape practices would yield the greatest benefits for downstream reefs in terms of mitigating harm to coral communities and associated reef fish populations.

Expansion of coastal development, along with wastewater discharge and fertilizers, can harm coral reefs and their fisheries through increases in sediment and nutrient runoff. Consequent reef degradation directly affects ecological resilience, food security, human well-being, and cultural practices in tropical island communities around the world.

The researchers focused on the ahupua‘a (land divisions) of Hāʻena on Kaua‘i and Ka‘ūpūlehu on Hawai‘i Island, at opposite ends of the main Hawaiian Islands, where native Hawaiian communities are taking action to manage their resources through a place-based management approach.

Read the full story at Big Island Now

N.C. Study: Warmer Water Linked to Higher Proportion of Male Flounder

April 30, 2019 — If southern flounder live in warmer water during a critical window of early development, a higher percentage become male – more than 90 percent in some cases – research from North Carolina State University found. Having a high proportion of adult males over the long term could threaten both wild populations and the valuable commercial fishing industry, which depends on larger female flounder.

Field research and lab experiments showed that a four-degree Celsius difference in average water temperature during juvenile development shifted the male-female ratio from about 50-50 to as much as 94-6, says Jamie Honeycutt, an NC State postdoctoral researcher and lead author of an article about the research in Scientific Reports. That difference is within the range of expected ocean temperature increases under climate change models.

Environmental factors such as water temperature influence sex determination in southern flounder, as well as in other fish and reptiles, Honeycutt explains. Flounder stick to shallow waters that serve as nurseries until after they become male or a female, hanging around estuaries until reaching maturity before returning to the ocean to spawn at about age 2.

“We think that southern flounder have a genetic sex-determining system similar to humans, who have two X chromosomes for a female and an X and a Y for a male. In flounder, if an individual is a genetic male, it is destined to be male,” Honeycutt says. “However, if a genetic female is exposed to temperature extremes, then it can develop as a functioning male.”

Read the full story at North Carolina State University

During abrupt warming, lobsters in acidic water have reduced heart function, fewer infection-fighting cells

April 25, 2019 — Ocean acidification and warming may be an unhealthy combination for lobsters, say University of Maine scientists.

The heart rates of lobsters (Homarus americanus) who lived 60 days in water with predicted end-century  pH levels became erratic significantly sooner during an abrupt warming event than those of lobsters in ocean water with current pH levels.

The findings could be “likened to putting people on a treadmill and finding that people exposed to  fell off the treadmill from exhaustion much sooner than those not exposed,” says Heather Hamlin, a reproductive endocrinologist and associate professor in the School of Marine Sciences.

The lobsters exposed to acidic ocean conditions also had fewer cells that fight infection in their hemolymph (similar to blood), says Amalia Harrington, a recent marine biology Ph.D. graduate.

So while lobsters in acidic  may look and act normal, they experience physiological challenges when exposed to multiple stressors, says Hamlin.

She and Harrington tested adolescent female lobsters transitioning to adulthood. Effects of environmental stressors during this stage could have major impacts on the population of the species, say the researchers, who believe this is the first such study of its kind.

“We’re really trying to get at the ‘hidden’  on this understudied but extremely important stage of the American lobster,” says Harrington.

“Most of the previous work exploring climate change impacts on American lobster has focused on early developmental stages (eggs and larvae). While this is helpful for understanding how environmental change might impact the number of baby lobsters that survive their time in the plankton and make it to the seafloor, it doesn’t really tell us what impact that will have on the population as a whole.”

Read the full story at PHYS.org

Ocean-Dwelling Species Are Disappearing Twice as Quickly as Land Animals

April 26, 2019 — Marine animals are twice as vulnerable to climate change-driven habitat loss as their land-dwelling counterparts, a new survey published in the journal Nature finds.

As Mark Kaufman reports for Mashable, the analysis—centered on around 400 cold-blooded species, including fish, mollusks, crustaceans and lizards—suggests marine creatures are ill-equipped to adapt to rising temperatures and, unlike land animals that can seek shelter in the shade or a burrow, largely unable to escape the heat.

“You don’t have anywhere to go,” Natalya Gallo, a marine ecologist at the Scripps Institution of Oceanography who was not involved in the study, tells Kaufman. “Maybe you can hide under a kelp leaf, but the entire water around you has warmed.”

Speaking with National Geographic’s Christina Nunez, lead author Malin Pinsky, an ecologist and evolutionary biologist at Rutgers University in New Jersey, further explains that ocean dwellers “live in an environment that, historically, hasn’t changed temperature all that much.”

Given that cold-blooded creatures rely on their surroundings to regulate body temperature, relatively stable marine ecosystems have actually made their inhabitants more susceptible to significant temperature changes. And while ocean temperatures are still much lower than those on land, as Anthony J. Richardson and David S. Schoeman point out in an accompanying Nature News and Views piece, marine heat waves, increased carbon dioxide pollution and other products of global warming are driving Earth’s oceans to higher temperatures than ever before.

To assess the threat posed by warming waters, Pinsky and her colleagues calculated “thermal safety margins” for 318 terrestrial and 88 marine animals. According to Motherboard’s Becky Ferreira, this measure represents the difference between a species’ upper heat tolerance and its body temperature at both full heat exposure and in “thermal refuge,” or cooled down sanctuaries ranging from shady forests to the depths of the ocean.

Read the full story at Smithsonian.com

Climate change’s deadliest effects are unfolding under the sea

April 26, 2019 — Think of the dangers climate change poses to animals, and you’ll likely picture skinny polar bears or cliff-diving walruses (collective sob). But it turns out that our overheating planet is actually wreaking the most havoc on creatures out of our sight: marine life.

Sea animals like crabs, lobster, and fish are dying off at twice the rate of land animals, according to a study published in Nature on Wednesday.

The researchers looked at more than 400 cold-blooded animals on land and sea, including lizards, dragonflies, lobsters, and mussels. They found that creatures that people rely on for food (fish, mollusks, shellfish) are among the most vulnerable, especially in the developing world, where many rely on them for a regular protein source.

Read the full story at Grist