Saving Seafood

Evidence Bolsters Classification of a Major Spawning Ground for Atlantic Bluefin Tuna Off the Northeast U.S.

March 4, 2022 — The Slope Sea off the Northeast United States is a major spawning ground for Atlantic bluefin tuna (Thunnus thynnus), a new paper affirms. This finding likely has important implications for population dynamics and the survival of this fish, according to the paper, “Support for the Slope Sea as a major spawning ground for Atlantic bluefin tuna: evidence from larval abundance, growth rates, and particle-tracking simulations,” published in the Canadian Journal of Fisheries and Aquatic Sciences.

“Overall, our results provide important supporting evidence that the Slope Sea is a major spawning ground that is likely to be important for population dynamics,” the paper states. Spawning in the Slope Sea “may offer the species additional resilience in the face of both harvesting and climate change,” the paper adds.

The paper presents larval evidence supporting the recognition of the Slope Sea as a major spawning ground, including that larvae collected in the Slope Sea grew at the same rate as larvae collected in the Gulf of Mexico, indicating that this region is good larval habitat.

“In comparison to everything else we know about this species, the Slope Sea is a perfectly good place to be born as a larva,” said lead author Christina Hernández, who was a doctoral student in the Massachusetts Institute of Technology (MIT) – Woods Hole Oceanographic Institution (WHOI) Joint Program in Oceanography/Applied Ocean Science and Engineering at the time of the study.

Read the full story at the Woods Hole Oceanographic Institution

Data crunchers work to build comprehensive Alaska salmon database

June 2, 2017 — Scientists are gathering temperature data to determine what warming waters mean for salmon.

There’s still a lot scientists don’t know and it’s become a hot topic.

One of the first studies in Alaska was published in the Canadian Journal of Fisheries and Aquatic Sciences this month, as  part of a larger effort to design a statewide database on all things salmon.

The five-year study collected stream and temperature readings in 48 non-glacial streams every 15 minutes to capture high and low temperatures every hour.

Cook Inlet Keeper science director Sue Mauger led the effort and has been working for over a decade monitoring temperatures in salmon streams on the Kenai Peninsula.

Her results provide a baseline for salmon habitat in the Cook Inlet Basin.

“This kind of information that’s on a large regional scale but is site specific gives us that real important tool to decide where should we do one type of protection or conservation activity versus another kind of development  project,” she said.

Mauger studied multiple streams in a single watershed, streams fed by wetlands, lakes and at high and low elevations.

All of these factors play into how susceptible each stream is to climate change, which she said is a concern.

Read the full story at KTOO