Saving Seafood

Oceanographers record the largest predation event ever observed in the ocean

November 4, 2024 — There is power in numbers, or so the saying goes. But in the ocean, scientists are finding that fish that group together don’t necessarily survive together. In some cases, the more fish there are, the larger a target they make for predators.

This is what MIT and Norwegian oceanographers observed recently when they explored a wide swath of ocean off the coast of Norway during the height of spawning season for capelin—a small Arctic fish about the size of an anchovy. Billions of capelin migrate each February from the edge of the Arctic ice sheet southward to the Norwegian coast, to lay their eggs. Norway’s coastline is also a stopover for capelin’s primary predator, the Atlantic cod. As cod migrate south, they feed on spawning capelin, though scientists have not measured this process over large scales until now.

Reporting their findings in Communications Biology, the MIT team captured interactions between individual migrating cod and spawning capelin, over a huge spatial extent. Using a sonic-based wide-area imaging technique, they watched as random capelin began grouping together to form a massive shoal spanning tens of kilometers. As the capelin shoal formed a sort of ecological “hotspot,” the team observed individual cod begin to group together in response, forming a huge shoal of their own. The swarming cod overtook the capelin, quickly consuming over 10 million fish, estimated to be more than half of the gathered prey.

Read the full article at PHYS.org

Underwater pile driving noise causes alarm responses in squid

December 17, 2019 — Exposure to underwater pile driving noise, which can be associated with the construction of docks, piers, and offshore wind farms, causes squid to exhibit strong alarm behaviors, according to a study by Woods Hole Oceanographic Institution (WHOI) researchers published Dec. 16, 2019, in the journal Marine Pollution Bulletin.

“This study is the first to report behavioral effects of pile driving noise on any cephalopod, a group including squid, cuttlefish, and octopuses,” says lead author Ian Jones, a student in the Massachusetts Institute of Technology-Woods Hole Oceanographic Institution Joint Program in Oceanography.

Squid use natural alarm and defense behaviors like inking, jetting, and changing color and patterns on their skin for communication and also for survival when they’re trying to avoid capture. Squids’ changeable skin gives them the ability to create extraordinary camouflage, enabling them to blend into the background and avoid becoming a meal.

Jones and his colleagues in the Sensory Ecology and Bioacoustics Lab at WHOI exposed longfin squid (Doryteuthis pealeii) to pile driving sounds originally recorded near the construction site of the Block Island Wind Farm in Rhode Island. The squid exhibited the same types of natural alarm and defense behaviors when they were exposed to the noises, but it’s what they did next that surprised the researcher team.

“The alarm behaviors occurred within the first several noise impulses, but they diminished quickly within the first minute of playback,” Jones says. “That suggests a learned lack of response to the noise, as the squid perceive the noise stimulus may not pose an immediate threat, unlike the imminent threat of a nearby predator. This phenomenon is called habituation.”

Read the full story at Science Daily

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

Robotic Fish Moves Like The Real Thing — So It Can Observe The Real Thing

March 21, 2018 — Scientific advancement: It’s all in the wiggle.

OK, it’s a lot more complicated than that. But when a team of researchers at MIT unveiled their robotic fish Wednesday, one of the keys they emphasized was the graceful undulation of the prototype’s tail — which, besides being rather eye-catching, serves a crucial role in the robot’s ultimate mission: giving scientists the ability to unobtrusively observe marine wildlife remotely.

“Because the fish moves through undulating movement rather than thrusters, the impact it has on how the water moves around it is much more like what is expected of physical fish,” Daniela Rus, director of the school’s Computer Science and Artificial Intelligence Lab, tells NPR.

In other words, unlike many of the vehicles currently used in underwater scientific observation, their Soft Robotic Fish — or SoFi, for short — doesn’t rely on propellers or jet-based propulsion. Those methods have the tendency to generate loud noise and turbulence, which, according to the paper Rus and her colleagues released Wednesday, “have the potential to scare marine life and to prevent closeup observations.”

Instead, SoFi has a tail built with soft material and powered by soft artificial muscles, allowing it to move in a way that’s a little less intrusive and, for that reason, a little more likely to get close to aquatic life acting naturally. With visibility reduced underwater, this could mean its camera has a better chance at snapping some candid shots to pass on to marine biologists.

During their tests, the robot “did not seem to impact the activity of the other fish around it,” Rus says. “We saw fish swimming by it. We saw schools of fish doing their thing. When our fish went by the other fish did not seem to change what they were in the middle of doing.”

Now, it must be noted that SoFi is far from the only robotic fish to make a splash, so to speak. The team from MIT notes that other researchers have made initial steps toward soft robots capable of mimicking the behavior of fish, mantas and octopi. And just last month, NPR’s Olympics correspondents marveled at the robot fish on display at Pyeongchang.

Read the full story at NPR

 

New manual outlines steps for fishermen, communities to take in crisis

GLOUCESTER, Mass. (March 25, 2016) — The concept first began to crystallize in Angela Sanfilippo’s mind about four years ago, when the president of the Gloucester Fishermen’s Wives Association realized she needed to start putting some things down on paper.

Sanfilippo, both in her roles with fishing-based community groups and her own experience as a wife, daughter and sister of fishermen, had helped develop a series of protocols to help fishermen avoid calamities on the water and help the Gloucester fishing community deal with fishing tragedies when they occur.

“I just thought that we should start putting these things in writing because we’re not going to be around forever,” Sanfilippo said.

Thus was born the idea that burst into reality Thursday when the Fishing Partnership Support Services unveiled its RESCUES manual in an event at the U.S. Coast Guard’s Station Gloucester.

The title of the manual, assembled with assistance from staffers at the Massachusetts Institute of Technology’s Sea Grant College program and Harvard University’s T.H. Chan School of Public Health, is an acronym for “Responding to Emergencies at Sea and to Communities Under Extreme Stress.”

Read the full story at the Gloucester Daily Times

Northeast Consortium and NEFMC Announce Funding for New Collaborative Research Projects

NEWBURYPORT, Mass. — July 8, 2015 — The following was released by the New England Fishery Management Council:

The Northeast Consortium, a University of New Hampshire-based institution established in 1999 to foster collaborative research, under contract to the New England Fishery Management Council, announces funding for three new research projects that will focus on spawning groundfish in waters off the New England coast.

Awards totaling over $335,000 will support a mapping study examining the distribution of spawning cod on Georges Bank, an acoustic and trawl survey of winter-spawning cod in Ipswich Bay, an inshore area off the coast of MA, and work on winter flounder spawning activities offshore in the Gulf of Maine.

The result of a supplemental request for proposals issued last February, projects were required to articulate collaborations between commercial fishermen and scientists, and could include, among other approaches, research that enables the Council to improve groundfish spawning protection by increasing the understanding of groundfish spawning activity or aggregations of spawning groundfish.

Here are more project details.

Project Title: Mapping the distribution of Atlantic cod spawning on Georges Bank using fishermen’s ecological knowledge and scientific data
Lead Institution: University of Massachusetts – Dartmouth, School for Marine Science and Technology; Co-Principal Investigators: Steven X. Cadrin, Gregory DeCelles, and Douglas Zemeckis

Purpose: To map the spatial and temporal distribution of cod spawning on Georges Bank using existing scientific information and data acquired from interviews with current and retired fishermen who fish for cod on Georges Bank. The information is needed to better understand cod population structure and essential fish habitat in this region.

Project Title: Synoptic acoustic and trawl survey of winter-spawning cod in Ipswich Bay, western Gulf of Maine Lead Institution: Gulf of Maine Research Institute; Project Leader: Graham Sherwood
Purpose: To expand our knowledge of the winter-spawning component of Atlantic cod by conducting a synoptic acoustic and trawl survey of Ipswich Bay. Improved knowledge of spawning dynamics in this area will lead to more fine-scale (in both time and space) management options.

Project Title: Identifying offshore spawning grounds of Gulf of Maine winter flounder
Lead Institution: University of New Hampshire; Project Leader: Elizabeth A. Fairchild
Purpose: To determine where winter flounder in the Gulf of Maine are spawning offshore and when, by studying their populations during the spawning season at offshore sites identified by commercial fishermen as locations where large numbers of adult winter flounder are seen during the spawning season.

 NEC/NEFMC – Cooperative Research Projects Funded 

These awards represent a continuation of the 2014 partnership established between the Consortium (NEC) and the Council. The NEC has representation from four research institutions: the University of New Hampshire, University of Maine, Massachusetts Institute of Technology, and the Woods Hole Oceanographic Institution, with Dr. Chris Glass at the University of New Hampshire, in the lead as its Director.

The Council is a group of 18 fishery officials that includes representatives from each New England coastal state, the federal government, and appointees from the region, all of whom are charged with managing the groundfish complex (cod, haddock, pollock and several species of flounder), in addition to other regional fish stocks. Funding collaborative research is fully consistent with its interest in understanding and improving this resource.

Read the release here