Saving Seafood

Surface Slicks are Pelagic Nurseries for Diverse Ocean Fauna

February 5, 2021 — The following was released by NOAA Fisheries:

To survive the open ocean, freshly hatched tiny fish larvae must find food, avoid predators, and navigate ocean currents. Their experiences during these great ocean odysseys have long been a mystery, until now. We have discovered that a surprisingly dense and diverse array of marine animals find refuge in so-called “surface slicks” during early life. To view an immersive, interactive version of this story, check out our story map: Hidden World Just Below the Surface.

Surface slicks are home to the larvae of at least 112 marine fish species, including commercially and ecologically important fish such as mahi-mahi, jacks, and billfish. Serving as makeshift nursery habitats, surface slicks are meandering lines of smooth surface water that collect plankton and shelter-providing debris. They are formed from the convergence of ocean currents, tides, and variations in the seafloor.

“These ‘bioslicks’ form an interconnected superhighway of rich nursery habitat that accumulate and attract thousands of young fish, along with dense concentrations of food and shelter,” says Dr. Jonathan Whitney, a research marine ecologist for NOAA and lead author of the study, published today in Scientific Reports. “The fact that surface slicks host such a large proportion of larvae, along with the resources they need to survive, tells us they are critical for the replenishment of adult fish populations.”

That  larvae hosted in slick nurseries grow up and radiate out into neighboring ecosystems. There, they join adult fish populations from shallow coral reefs to the open ocean to the bottom of the deep sea.

What’s more, many forage (prey) fish, like flying fish, spend their larval and juvenile life stages in surface slicks. “These biological hotspots provide more food at the base of the food chain that amplifies energy up to top predators,” says study co-author Dr. Jamison Gove, a research oceanographer for NOAA. “This ultimately enhances fisheries and ecosystem productivity.”

Read the full release here

Newly Identified Fish Nurseries Are Choked With Plastic

November 13, 2019 — Plenty of heartbreaking stories about turtles, seabirds and whales found dead with dozens of plastic bits in their stomachs have surfaced in recent years. But a new study reveals that it’s not just adult sea animals that are getting a gullet full of plastic. Larval fish are inundated with plastic fragments in their nursery habitats and they’re eating those pieces along with their natural food sources, according to the paper published in the journal PNAS.

The finding comes from a recent study looking at where baby fish spend their time. An international team of scientists joined up with NOAA’s Pacific Islands Fisheries Science Center to study an ocean habitat called surface slicks, or long lines of smooth water found paralleling coastlines that are created when internal ocean waves converge.

To do that, the team used remote sensing data to identify slicks along the coast of Hawaii then used tow surveys to scoop up plankton and larval fish in them. They found that larval fish prefer to congregate in slicks, which have lots of tasty zooplankton.

The team found the slicks have more eight times as many larval fish as surrounding waters and act as de facto fish nurseries for the first few months of a fish’s life cycle.

“We found that surface slicks contained larval fish from a wide range of ocean habitats, from shallow-water coral reefs to the open ocean and down into the deep sea—at no other point during their lives do these fish share an ocean habitat in this way,” says study co-author Jonathan Whitney, a NOAA marine ecologist, says in a press release. “Slick nurseries also concentrate lots of planktonic prey, and thereby provide an oasis of food that is critical for larval fish development and survival.”

Read the full story at Smithsonian.com

Baby fish have started eating plastic. We haven’t yet seen the consequences

April 15, 2019 — Not long agoI went snorkeling in the Pacific Ocean, a half mile off the southwest coast of Oahu. The flanks of the Hawaiian island are steep there, and the bottom quickly disappeared beneath us as we motored out to the site. Looking back, I could see the green slopes of the Waianae Range rising to 4,000 feet behind the beach. Normally the mountains shield the water here from the trade winds. But on that day a breeze created a light chop that nearly obscured what I had come to see: a thin, oily slick of surface water, rich in organic particles, in which newborn fish were feeding and struggling to survive their first precarious weeks.

Plunging my face into the sheen, I found myself looking inside a fish nursery: The water was dotted with life you would ordinarily never notice. Fish eggs drifted like tiny lanterns, their yolk sacs glowing in the sunlight. Fish larvae small as ladybugs darted about. A sergeant major damselfish the size of a dime appeared huge by comparison as it fluttered past. Below us, a school of 12-inch, bigeye scad—like mackerel but with enormous eyes—fed on everything that had the misfortune of being small.

My guides that day, oceanographer Jamison Gove and fish biologist Jonathan Whitney of the National Oceanic and Atmospheric Administration in Honolulu, are nearly three years into a research project that aims to make sense of this chaotic scene. The larval stage is the “black box” of fisheries science: Fertilized eggs go in, and young fish come out—but what happens inside remains sketchy. The larval fish are so small and fragile they’re exceedingly difficult to study. The overwhelming majority will never become adults. Yet fish populations around the world, and the animals that eat them, depend on just how many larval fish make it, and in what condition.

Read the full story at National Geographic

NOAA expedition off Kona unearths mysterious deep sea creatures

September 29, 2016 — Nearly three quarters of the Earth is taken up by the ocean but NOAA scientists say less than five percent of its have ever been explored.

NOAA fisheries is on a mission to expand our understanding. Researchers just wrapped up an expedition off the Kona Coast. 20 scientists spent 20 days in waters off West Hawai’i known for it’s thriving ocean environment.

“We’re trying to really pinpoint some of the primary mechanism’s…primary reasons why this ecosystem is so productive,” said Jamison Gove, a NOAA Oceanographer.

Scientists discovered an abundant community of creatures 2,000 feet down that possessed out of the ordinary features.

“Huge teeth… they’re all very strange looking. They have adapted to life where there’s virtually no light, food is incredibly scarce and if you come across a meal you have to be able to grab it,” said Jonathan Whitney, a NOAA Biologist.

The mysterious species are believed to be an important food source to larger marine mammals like dolphins.

Large trawl nets scooped up organisms from the deep depths and near the surface in an area known as the surface slicks. The visibly smooth ribbon like section pulls together floating material and serves as somewhat of a nursery for young marine life.

Read the full story at KITV