Ocean warming blamed for projected 80 percent decline in Gulf of Alaska cod catches for 2018

"To have less sea ice you have less habitat for the ice algae to grow on and overall you have less supply of food from ice algae to the eco-system," Dr. Tom Brown, marine ecologist at the Scottish Association for Marine Science.

Climate change is rapidly and intensively proceeding in the Arctic. Over the past few decades, the mean temperature in the High North has risen twice as fast as the global average.

As a result of these warming temperature changes, the North Pacific Fishery Management Council has warned the Alaskan fishing communities to expect a devastating decline in Alaskan Cod populations due to warming ocean waters. 

The notice (pdf) to cod fishermen reads in part:

The Pacific cod stock in the Gulf of Alaska has drastically declined. Scientific information suggests that this decline is the result of an unusually warm mass of water (the ‘blob’) that persisted from 2014 through 2016. The warm water increased the metabolism of cod while reducing available food, resulting in poor body condition and increased mortality. The warm water also impacted cod egg production and larval survival, greatly reducing recruitment during these years. The lower number of adult and juvenile cod will affect the population and fishery for several years to come. Management of Gulf of Alaska cod is now focused on maintaining the spawning stock and increasing the likelihood that the fishery will remain viable in the future. Accordingly, catch limits for Pacific cod were set at very low amounts for 2018 and 2019.

The Anchorage Daily News reports on the disaster.

Gulf cod catches for 2018 will drop by 80 percent to just under 29 million pounds in federally managed waters, compared to a harvest this year of nearly 142 million pounds. The crash is expected to continue into 2020 or 2021.

Cod catches in the Bering Sea also will decline by 15 percent to 414 million pounds. In all, Alaska produces 12 percent of global cod fish.

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"It's almost like a double, triple, quadruple disaster because it's not just one year," said Julie Bonney, director of the Alaska Groundfish Data Bank. She added that the cod decline will decrease revenues for fishermen who use longline, pots, jig and trawl gear and will make it more difficult for processors to fill their market demands. It also will be a huge hit to the coffers of local communities, which get a 3 percent tax on all fish landings.

Larval cod and many other Arctic larval fish species depend on the algae that grows on the underside of sea ice for survival. The Arctic is predicted to be largely ice-free by the summer by 2030. The continuing loss of the sea ice may very well spell doom for the polar food web which provides most of the world’s seafood. 

Disappearing sea ice could lead to collapse of vital polar food chain

Research is showing algae produce a unique chemical called Ice Proxy 25 (IP25), which can be traced through the food chain.

Dr Tom Brown, a marine ecologist at the Scottish Association for Marine Science, said: "You can see the transfer from ice algae to zooplankton.

"You can see that fish are eating the plankton, that seals are eating the fish and that polar bears are eating seals, because IP25 is present all the way to the top of the food chain."

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Dr Eva Leu, a marine biologist at Akvaplan-niva in Norway, said the bloom was so important that other organisms were synchronised to take advantage.

"The crucial thing about ice algae is that they are the earliest available food source. There’s no other alternative," she said.

"If you have an ecosystem that to start with is relying on Arctic sea ice, the question is where are these organisms going if the sea ice is completely gone?"

Human activity is having many effects on the Arctic’s marine system. Oil exploration, overfishing and climate change are negatively impacting whale activity for example.

Sky News reports on Canada’s Lancaster Sound which has such nutrient rich waters that it is referred to as the 'Serengeti of the Arctic'. They note that there is an estimated 100,000 narwhals, 30,000 belugas, 6,500 bowhead whales in the area.

But with Lancaster Sound ice-free for longer period each year, more ships pass through the area - some using the North West Passage as a shortcut between Europe and Asia, and others to take iron ore from a nearby mine.

The industrial noise drowns out the sounds whales make to navigate, hunt and communicate. It can have catastrophic consequences.

In 2008, more than 1,000 narwhal were so frightened by the loud seismic 'booms' used to find oil and gas reserves that they retreated to an area of sea that freezes over each autumn.

There was only one small hole in the ice for the mammals to breathe. Almost all drowned.

The Canadian government has announced that Lancaster Sound will be designated a Marine Protected Area, preventing further exploration for fossil fuels and other commercial exploitation.

Huge Gangs Of Killer Whales Chasing Down And Harassing Alaskan Fishing Boats For Food

After decades of peaceful coexistence, killer whales in Alaska are tired of fishers taking their food.

Now, huge gangs of the massive creatures have begun stalking fishing boats in the Bering Sea, and then robbing them as soon as they have a catch — stripping hooks clean save a for a few halibut.

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Groups will swarm around a boat and track it for miles, sometimes becoming aggressive as they wait for a catch.

One pod of 50 whales stuck with Captain Robert Hanson for days, stealing about 12,000 pounds of halibut.

“The pod tracked me 30 miles north of the edge and 35 miles west,” Hanson wrote in a letter to the North Pacific Fisheries Management Council, according to the Anchorage Daily News. “I drifted for 18 hours up there with no machinery running and they just sat with me.”

Orca’s are not alone in feeding off long lines as their food disappears in the Bering Sea.