Saving Seafood

The declining size of North Atlantic right whales threatens the endangered species, new study finds

May 13, 2022 — As female North Atlantic right whales decline in size, they’re producing fewer calves, which could have grave consequences for the critically endangered species, according to a new study.

Scientists found in an earlier study that right whales have been shrinking, a phenomenon they attributed to frequent entanglements in fishing gear. The previous study found that entanglements place greater stress on the whales by forcing them to drag heavy fishing gear over long distances, which consumes their energy, reduces the fat reserves they need to reproduce, and makes them more susceptible to a range of diseases.

Some 85 percent of right whales have been entangled at least once, and of those, a majority have been entangled multiple times, scientists say. Entanglements and vessel strikes have been the leading cause of death and serious injuries to the whales, whose population has plummeted by about 30 percent over the past decade.

In the latest study, published on Thursday by the journal Marine Ecology Progress Series, scientists determined that the declining body length and girth of the whales have likely resulted in their low birth rates in recent years.

Read the full story at the Boston Globe

Changing Ocean Conditions Affect Quality of Prey for Atlantic Salmon, Other Species

March 29, 2016 — The following was released by NOAA:

Researchers have found that changes in ocean conditions in the Northwest Atlantic during the past 40 years have altered the food web, changing the quantity and quality of important prey species. These food-web changes are thought to have influenced the survival and abundance of Atlantic salmon and many other ecologically, commercially, and culturally important species.

“Salmon are a good barometer of what is happening in the marine ecosystem,” said Mark Renkawitz, a salmon researcher at NOAA’s Northeast Fisheries Science Center (NEFSC) and lead author of a study on salmon foraging and the changing food web in the Northwest Atlantic published in Marine Ecology Progress Series. “They are like a canary in the coal mine. Dams and decreasing marine survival rates have been the primary drivers of the declines for many populations. In taking a closer look at the marine part of a salmon’s life, we found that changes in salmon diet may be a big factor.”

Atlantic salmon have a broad range, extending from the US and Portugal in the south to Canada and Russia in the north. After a freshwater phase, juveniles migrate to sea for a year or more, with North American and European salmon stocks congregating at common marine feeding areas like the waters off West Greenland during summer and fall. There, salmon feed on abundant and energy-rich prey such as capelin, a small forage fish. This diet promotes rapid growth and maturation, allowing salmon to undertake long migrations back to their natal rivers to spawn.

Changes in ocean conditions have significantly changed the quality of capelin, the primary prey for both North American and European origin Atlantic salmon feeding at West Greenland. Since the early 1970s, the North American portion of the stock complex at West Greenland has declined approximately 54 percent, and similar declines have been documented for the European stock complexes.

Read the release from NOAA