Saving Seafood

Decade of Data Shows Rapid Decline in Pelagic Fish and Invertebrates in Deep Gulf

October 21, 2026 — Following the Deepwater Horizon oil spill, scientists across the region jumped into action to monitor its impacts. One particular effort focused on pelagic nekton—the small critters like fish, shrimp, and cephalopods that swim freely in the ocean and serve as the base of pelagic food webs. The Deep-Pelagic Nekton Dynamics of the Gulf (DEEPEND) Consortium led this project to quantify long-term trends in the offshore fauna of the Gulf. While observed declines in these critical prey groups can’t be tied directly to the spill, scientists have not identified another likely explanation.

Tracking the Shift: A Decade of Deepwater Science

The first pelagic nekton sampling effort took place as soon as possible following the spill, with sampling occurring almost continuously for 9 months in 2011. These data represent the benchmark of pelagic nekton to which past and future numbers can be compared. The numbers were also similar to data collected during the 1980s and 1990s.

The next sampling involved six efforts across four consecutive years (2015–2018), followed by three more in 2021–2023. Overall, these efforts comprise more than a decade of abundance and composition data for pelagic nekton in the Gulf of America.

During each of these events, the project team sampled discrete depths from 0 to 1,500 meters in the Gulf using a 10-square-meter Multiple Opening/Closing Net and Environmental Sensing System, or MOCNESS, with 3 millimeter mesh. Once net tows were complete, the science teams identified and counted each of the animals collected in each sample.

In addition to traditional net-sampling methods, the team also used echosounders to measure acoustic backscatter in the water column during the day and at night. This allowed them to independently estimate relative abundance of animals in fine spatial detail. Scientists also collected tissue samples from three dominant lanternfish species to monitor changes in genetic diversity.

Read the full article at NOAA Fisheries

In the ocean’s twilight zone, a fish that could feed the world – or destroy it

September 29, 2022 — In 1789, the explorers Alessandro Malaspina and José de Bustamante set sail from Cádiz on Spain’s first scientific expedition around the world. For five years, Malaspina and Bustamante studied and collected animals and plants across the Spanish empire, which stretched along the North, Central and South American Pacific coasts, and westwards to the Philippines.

In 2010, another Spanish expedition set off from Cádiz, tracing much of the original route and studying what the oceans are like today.

The team measured pollutants, plastics and chemicals that were not there in Malaspina and Bustamante’s time. They collected samples of seawater and plankton. And all the way through the 31,000-mile voyage, the ship’s sonar was switched on, listening for echoes from below. Their chief targets? Small silver fish that look like sardines or anchovies – only with bigger eyes and rows of spots that glow in the dark.

They are lanternfish: there are about 250 species and they are not only the most common fish in the oceans’ twilight zone but the most abundant vertebrates on the planet. Huge numbers were first noticed during the second world war, when naval sonar operators saw echoes from what appeared to be a solid seabed, one that rose to the surface at night and fell back down at daybreak. In fact, the pulses of sound were echoing off the swim bladders – the internal gas-filled bubbles – of billions of lanternfish, as they congregated in dense layers hiding in the deep, then at sunset swam up thousands of metres to feed at the surface. Every night, along with other animals, such as the squid that prey on them, lanternfish undergo the greatest animal migration on the planet.

Before the 2010 Malaspina expedition, studies based on trawl surveys estimated that the twilight zone contains about a gigatonne (1bn tonnes) of fish. But this was most likely an underestimate, it turns out, because lanternfish avoid being caught by swimming away from the open nets. The Malaspina acoustic survey did not rely on nets, and in 2014 its research led to new estimates of the abundance of twilight-zone fish, ranging between 10 and 20 gigatonnes.

The prospect of such a colossal harvest raised an old question: could fish from the twilight zone help to feed a growing human population?

Read the full article at the Guardian

Federal regulators: Don’t even think about fishing for these forage species

April 7, 2016 — No one’s fishing in large numbers for lanternfish, bristlemouth, pelagic squid or a handful of other forage-fish species targeted for protection in California by federal regulators this week.

And no one will be fishing for them anytime soon, under the new rule, which has been the subject of debate among fishers and environmentalists for more than five years. It aims to proactively protect the Pacific Ocean ecosystem by banning commercial fishing of round and thread herring, Pacific saury and sand lance, and certain smelts across the West Coast that are preferred meals of predators commonly fished here.

“The fishery management council wasn’t interested in being surprised by a potential new fishery,” said Yvonne deReynier, a NOAA spokeswoman. “Because of this rule, now people can’t just decide they want to go fishing without checking in and getting permission from fishery management. This is a big-picture concern of our council. The council wants to ensure there are going to be enough prey for mid- and higher-level trophic species that feed on these.”

Before the rule was finalized Monday, new forage-fish commercial fisheries could start relatively easily. Now they can’t begin without extensive study, regulation and permission by the Pacific Fishery Management Council to ensure they’re not overfished or otherwise harmed.

Read the full story at The Long Beach Press-Telegram