Saving Seafood

Bottom trawling experiment delayed in Northern Bering Sea

March 7, 2024 — NOAA postponed the Northern Bering Sea Effects of Trawling Study (NETS), a controversial bottom trawling experiment. Tribal and environmental groups, determined to sue to block the project’s progress, accepted the decision to postpone the study this year.

NETS was set to be an experiment to examine the impacts of commercial bottom trawling in a banned area in the Bering Sea. According to the official study, shifts in fish populations due to climate change may increase the need for bottom trawling in the future. Bottom trawling, also known as dragging on the seafloor, produces about one-half as much food as global beef production, according to a 2022 NF article.

The study was designed to be a multi-year project conducted by the Alaska Fisheries Science Center, part of the National Marine Fisheries Service (NMFS). The decision to postpone came in a letter from the director of NOAA Fisheries, Janet Coit, who directly emailed tribal organizations that opposed the study.

The letter sent on Feb. 23 said, “To provide more space for continued dialogue, NOAA Fisheries has decided not to move forward with the NETS research project this year. We value our responsibilities to and partnerships with Alaska Native communities and want to ensure NOAA is creating space for respectful dialogue and trust building.”

Read the full article at The National Fisherman

Trawling Boats Are Hauling Up Ancient Carbon From the Ocean Depths

January 18, 2024 — The fillet of flounder sitting on your plate comes with a severe environmental cost. To catch it, a ship running on fossil fuels spewed greenhouse gases as it dragged a trawl net across the seafloor, devastating the ecosystems in its path. Obvious enough. But new research shows that the consequences extend even further: Trawl nets are hauling up both food and a huge amount of carbon that’s supposed to be sequestered in the murky depths.

In a paper publishing in the journal Frontiers in Marine Science, researchers have tallied up an estimate of how much seafloor carbon the bottom-trawling industry stirs into the water and how much of that is released into the air as CO2 each year, exacerbating global warming. It turns out to be double the annual fossil fuel emissions produced by the entire world’s 4 million–vessel fishing fleet.

“At least 55 to 60 percent of the CO2 created by trawling—scraping the seafloor—is going to come into the atmosphere within nine years,” says lead author and ecosystem ecologist Trisha Atwood, who focuses on carbon cycling at Utah State University and National Geographic’s Pristine Seas program. “It now suggests that countries should be looking at this industry, and that their carbon footprint goes a lot further than maybe they were thinking, just in terms of the amount of gas that they burned to get out to their fishing grounds.”

Read the full article at Wired

Bottom-trawl gear to blame for most of this year’s fishery-related killer whale deaths, NOAA says

December 5, 2023 — A federal investigation into the unusually large number of Bering Sea and Aleutian killer whales found dead this summer determined that most but not all of the deaths were killed by entanglement in fishing gear.

The National Oceanic and Atmospheric Administration’s Alaska Fisheries Science Center on Friday released some details about the deaths in the Bering Sea and Aleutians, which had spurred sharp criticism of seafood trawling practices.

Of the nine killer whales that were found ensnared in bottom-trawling gear, six were killed by those entanglements but two others were already dead before they were netted, the investigation found. The other whale was seriously injured by the gear entanglement but escaped alive, the agency said.

In addition to the nine whales found in bottom-trawl gear, there were two other cases of dead killer whales found entangled in other types of fishing gear.

Read the full story at the Alaska Beacon

Response paper aims to debunk the theory that bottom trawling releases as much carbon as air travel

December 2, 2023 — Bottom trawling, a fishing method that entails towing a net along the ocean floor to capture target species, does not release as much carbon as air travel, according to a response paper that sought to debunk research published in 2021 and picked up by global media outlets, including The Guardian.

The response paper, “Quantifying the carbon benefits of ending bottom trawling,” released in May 2023, claims that Sala et al. – the authors of the original research – overestimated trawling’s carbon output by two to three orders of magnitude, or 100 to 1,000 times more than they should have, in the model they used, contending that the discrepancies are due to incorrect fundamental assumptions of the carbon cycle and flawed validation.

Read the full article at SeafoodSource

New review shows bottom trawling is sustainable (when well-managed)

July 20, 2023 — The following is an excerpt from an article published by Sustainable Fisheries UW:

Seafood produced by bottom trawling can have a lower environmental impact than chicken or pork, according to a new review paper published yesterday. Writing in the ICES Journal of Marine Science, Hilborn et al. 2023 argues that banning bottom trawling would increase negative environmental impacts by increasing terrestrial protein production.

Hilborn et al. 2023, reviewed dozens of papers about bottom trawling impact, including stock sustainability, bycatch, ecosystem impact, and carbon footprint. Though bottom trawling is generally the most impactful kind of fishing, well-managed bottom trawl fisheries produce food with a much lower environmental impact than any terrestrial animal protein.

A review paper summarizes the current knowledge on a particular topic by combing through and presenting conclusions from recent publications. In this case, Hilborn et al. 2023 reviewed the existing literature on the environmental impacts of bottom trawling and summarized four major impacts: Sustainability of target species, impact on benthic ecosystems, bycatch and discard, carbon emissions.

The key to reducing impacts and sustaining fisheries is management. Bottom trawling can be a low-impact form of food production in places with effective management. Bottom trawling can be highly destructive in areas with little capacity for environmental management (like many developing nations in Asia).

In this post, we summarize the findings from the four major impacts, discuss what effective bottom trawling management looks like, and compare the environmental impact of bottom trawling to other forms of food production.

Read the full article at Sustainable Fisheries UW

Officially bogus: Bottom trawling does not release as much carbon as airline travel

June 15, 2023 — Remember the headlines that claimed bottom trawling released as much carbon as all of air travel? We thought those claims were probably bogus when first reported, but Hiddink et al. 2023, a response paper published May 2023, now makes those claims Officially Bogus.

The original headlines came from Sala et al. 2021, a paper published in Nature that garnered more media coverage than any marine science paper of the past decade. We’ve covered the science and follow-ups over the last few years, but here’s a quick summary:

Sala et al. 2021 advocated for increasing the number of marine protected areas (MPAs) that restrict fishing. The paper used three different models that claimed benefits from MPAs:

  1. Food security – MPAs would increase food availability via more abundant fisheries.
  2. Biodiversity – MPAs would enhance ocean biodiversity.

Carbon/climate change – claimed that bottom trawling released as much carbon as all air travel, thus selling MPAs as a climate change solution via carbon sequestration. The paper suggested selling carbon credits from MPAs to fund the creation of more MPAs.

These three claims have quickly fallen apart, however. The original food security model was retracted, and the modified one by Sala et al. 2021 had similar issues. A response published last year points out that the biodiversity and carbon claims were based on the assumption that fishing disappears rather than being displaced. And now, Hiddink et al. 2023 demonstrates that the carbon model overestimated carbon benefits by 2-3 orders of magnitude, i.e., 100-1000 times.

Hiddink et al. 2023 notes two main reasons why the model in Sala et al. 2021 misfired:

  1. The fundamental assumptions of the carbon cycle were incorrect.
  2. The validation of those assumptions was also incorrect.

Here, we explain the carbon cycle in ocean sediment and discuss the potential for bottom trawling to contribute to carbon emissions. We also break down the carbon model from Sala et al. 2021 and show why it was incorrect based on Hiddink et al. 2023’s analysis.

Read the full article at Sustainable Fisheries

Scientists examine Gulf of Alaska sea floor to see effects of bottom trawling

June 8, 2022 — A group of researchers is hoping that data collected from the Gulf of Alaska’s sea floor will shed new light on the effects of bottom trawling.

Scientists from the conservation group Oceana, which is based in Juneau, spent eight days aboard a research vessel circumnavigating the Kodiak archipelago late May. Jon Warrenchuck is a senior scientist and fisheries campaign manager with Oceana.

“The Gulf of Alaska is a very special place and a very productive ecosystem,” Warrenchuck said. “Our timing of our survey here in the spring means we saw just an abundance of life, from the phytoplankton to the fish to the birds feeding at the surface.”

The focus of the trip, though, was to document life at the very bottom of the sea to better understand the impacts of commercial trawling, Warrenchuck said.

Read the full story at KTOO

Bottom-trawling fishing severely restricted off West Coast starting in January

November 19, 2019 — The most extensive ban on bottom trawling — dragging weighted nets on the sea floor — became law Tuesday after fishing groups and environmentalists agreed to protect more than 140,000 square miles of seafloor habitat along the West Coast, including beds of lush coral around the Farallon Islands.

The new regulations, which will take effect Jan. 1 after being published in the Federal Register on Tuesday, will restrict fishing over 90% of the seafloor along the coast from Canada to Mexico, the largest contiguous area protected from bottom trawling in the world.

At the same time, about 3,000 square miles of sandy seafloor previously closed to fishing under the 2002 Rockfish Conservation Area rules were reopened after it was determined that rockfish populations had recovered in those areas.

“It’s monumental,” said Geoffrey Shester, the senior scientist for the conservation group Oceana, which has fought for years to limit bottom trawling, long considered the most damaging method of fishing in the ocean. “It puts the West Coast at the top of the barrel for global leadership in protecting our seafloor.”

Read the full story at the San Fransisco Chronicle 

MSC science director: Greater resolution needed in global fishing impact studies

October 25, 2018 — Michel Kaiser, the recently-appointed science and standards director at the Marine Stewardship Council (MSC), has stressed the need for higher resolution data when estimating the global fishing footprint, in an opinion piece on the Conversation.

The discussion comes after the publication of a report in February which estimated that 55% of the planet’s oceans had been affected by fishing activities. However, Kaiser said this study, which was created from analysis of squares roughly 3000 square kilometers in area, produces a figure that is off by a factor of ten when compared to a more recent August study produced using higher resolution data (1-3 sq. km).

The MSC science director also noted a study published in October 2018 looking into the global footprint of bottom trawling. The paper looked at 24 regions of the global continental shelf, each analyzed using squares of less than 9 sq. km. The team, from the State University of New Jersey, discovered that 24% of the measured areas had been affected by bottom trawling, one of the most destructive fishing practices.

Read the full story at Undercurrent News

NOAA Shipyard Update: NEFSC Fall Research Cruises Will Continue

September 22, 2017 — The following was released by NOAA Fisheries:

The annual NEFSC Fall Bottom Trawl Survey will be conducted on the NOAA Ship Pisces, which is a fishery survey research vessel similar to the Bigelow. Only Georges Bank and Gulf of Maine will be surveyed. The two most southerly areas, the Mid-Atlantic and Southern New England have been dropped.

If all goes smoothly in preparing the Pisces to support the survey, October 16 is the target start date carrying on through November 20.

Fishing gear will be moved from the Bigelow onto the Pisces, and some devices will be installed for monitoring trawl performance while the gear is fishing. Supplies and equipment needed for the survey are already aboard the Bigelow, and will be transferred to the Pisces. The modifications to Pisces are underway.

In a typical year, the Fall Bottom Trawl Survey occupies an average of 377 stations across the Northeast Continental Shelf from the Cape Hatteras to the northern Gulf of Maine in four segments, or legs. Each leg covers a different area beginning in the south and ending in the north.

The number of stations in the Georges Bank and Gulf of Maine survey areas will be similar to past years. Fewer data will be collected at each station because Pisces has less fish handling capacity than the Bigelow. However, samples critical for stock assessments will be collected, including lengths, weights, and hard parts used for aging fish (usually scales and ear bones). Two other NEFSC research cruises planned for this fall were also delayed by the Bigelow repair, and will be conducted on other ships.

The first leg of the Fall Ecosystem Monitoring cruise has been moved to the NOAA Ship Gordon Gunter, an oceanographic research vessel. This cruise collects oceanographic data and plankton samples and has been conducted from the Gunter in the past. There is no firm plan for Leg 2 of this cruise, but the Bigelow is an option if it is ready as scheduled. A beaked whale sighting survey was moved onto a chartered vessel, the R/V Sharp, operated by the University of Delaware, and has been completed with fewer objectives than originally planned.

Meanwhile, repairs continue on schedule for the NOAA Ship Henry Bigelow. The ship is expected back in service in early November 2017.

Read this update on the Northeast Fisheries Science Center website.