Saving Seafood

Why are Pacific Cod Stocks Crashing?

February 13, 2018 — “The status of Pacific cod is probably the biggest fishery issue facing Kodiak right now, with the quota cut 80 percent for 2018,” said Mike Litzow, a University of Alaska Fairbanks associate professor at the Kodiak Seafood and Marine Science Center.

Pacific cod stocks have collapsed, possibly because recruitment (production of young fish to enter the population) has been very low during a recent string of incredibly warm years in the Gulf of Alaska, he said.

Scientists don’t know why cod stocks are shrinking. The leading hypothesis is that warmer temperatures increase the metabolic rates of young cod, and their food sources don’t supply enough energy.

There’s a sticking point—there’s not enough data to test the theory. Studies of fish ecology and population dynamics in Alaska are overwhelmingly conducted in the summer. Almost nothing is known about wintertime ecology of juvenile Pacific cod.

To help provide answers, Litzow and fisheries oceanographer Alisa Abookire embarked on a pilot study this month to collect information about habitat use, diet and energetics of juvenile cod.

They are sampling the fish with a beach seine and taking ocean water data aboard a semi-enclosed 22 foot skiff. To stay warm they wear insulated paddling suits.

Litzow and Abookire are collaborating with scientists at the Hatfield Marine Science Center in Newport, Ore., who have been studying juvenile cod in Kodiak over the last 12 years. The pilot study is funded by the Ocean Phoenix Fund through the University of Alaska Foundation.

Read the full story at Alaska Native News

 

Scientists looking to understand future ocean acidification effects on commercial fishing

August 26, 2016 — NEWPORT, Ore. — The future is now at the Hatfield Marine Science Center.

In the facility’s laboratories scientists are creating conditions to resemble ocean conditions years from now. The goal is to find out how sea life will react to higher levels of ocean acidification that climate change scientists predict will occur in the not-to-distant future.

Since the Industrial Revolution, humans have been pumping more carbon dioxide into the atmosphere. The ocean absorbs a lot of this CO2, raising its level of acidity. It is feared an ocean that is more acidic will negatively affect sea life, including commercial fishing.

So for those whose livelihoods depend on commercial fishing the scientists’ work is important in understanding what ocean acidification will mean to the fish stocks of the future.

“There is a lot of general concern about the fact that we don’t know a lot about this,” said Lori Steele, the executive director of the West Coast Seafood Processors Association, which is based in Portland. “It’s potentially having an impact, and it’s going to have a much more significant impact, and unless we can really get a handle on it, there’s a potential that fisheries managers aren’t going to be able to do a lot besides controlling fishing.”

Read the full story at KATU

Life on the Line: OSU scientists track effects of a changing ocean on tiny sea life

July 22, 2016 — NEWPORT, Ore. — In a cold mist under gray skies, the Pacific Ocean heaved against the boat as two scientists from Oregon State University pulled a net full of life from the deep.

It was a July day, but it felt like a day in December.

In the net life swarmed, much of it too small to be seen with the unaided eye. The net held the keys to help scientists unlock how creatures of the sea are affected by changing ocean conditions and those effects on the aquatic food chain. And more specifically, the effects to salmon, a fish of much importance to humans.

For 20 years scientists have made bi-monthly trips on what is called the Newport Hydrographic Line, which takes them to the same seven sampling stations along a 25-mile path perpendicular to the coast. The stations are physical points on a map. There are no buoys or other structures that mark their locations. The scientists find them using GPS.

They launch their research vessel, the R/V Elakha, from a dock in Yaquina Bay that sits along a jagged bulge of land on which OSU’s Hatfield Marine Science Center resides. The trips have amassed an extraordinary amount of data about the sea and the life within it. The data is routinely posted on the National Oceanic and Atmospheric Administration’s Northwest Fisheries Science Center website and is used primarily to help forecast salmon runs. But the data has also told the story of changing ocean conditions and its impact on the food chain.

“We can also look at the changes in the bioenergetics of the food chain across the whole 20-year time series,” says OSU research assistant Jennifer Fisher. “It doesn’t just relate to salmon; it relates to sardines and (other) fish. It gives us an idea of ocean acidification, toxic algae – lots of things.”

Fisher has been going on these trips to sea for five years aboard the 54-foot research vessel owned and operated by OSU.

On this day, Fisher, OSU lab technician Tom Murphy and deckhand Dave Weaver use two different cone-shaped nets to capture organisms that live in the sea and that form the basis of the oceanic food chain.

Fisher’s primary interest in the day’s catch is in a tiny crustacean called a copepod. These creatures feed on the sea’s phytoplankton. Copepods are animals with large antennae and are only a millimeter or two in length. Under a microscope their bodies are an elongated oval protected by an exoskeleton. But they are nearly transparent. And inside their bodies scientists have discovered a lipid sac, or stored fat.

Read the full story at KVAL