Scientists see improved ocean conditions for young salmon

March 10, 2019

SEATTLE (AP) — Young salmon entering the ocean could see improved ocean conditions off the Washington and Oregon coasts, according to federal scientists.

Researchers in a conference call with reporters said Friday the ocean is more hospitable for salmon several years after an unusually warm water event, the Seattle Times reported.

Surveys in 2018 confirmed that tiny animals that stoke the food web were thriving. An important forage fish, anchovies, increased in number.

Subsurface temperatures, however, continued to be warmer than average in some areas. Researchers also found numerous pyrosomes, also called sea pickles, a warm-water animal that is not supposed to be in Northwest waters.

“We are seeing several signs of recovery, but not all of them. We are not quite out of the woods yet,” said Chris Harvey, National Oceanic and Atmospheric Administration research biologist at the Northwest Fisheries Science Center.

The forecast for Columbia River chinook salmon in 2019 is for below-average returns. Extensive ocean acidification and poorly oxygenated waters also were predicted.

Salmon begin life in freshwater but take to saltwater and grow at sea before returning to spawn. Ocean conditions affect how many fish return for fishermen and killer whales.

Lack of food is the single biggest threat to the survival of endangered southern resident killer whales in Puget Sound. Poor ocean conditions that depress salmon survival have added to the whales’ troubles.

The warm water event, dubbed The Blob, began forming off the West Coast in late 2014 and disrupted the marine food web.

Improved conditions for young salmon will not help killer whales looking to feed on adult salmon this year, which continue to feel the effects of warm water. Returns of some Columbia River runs are forecast to be at about half of their 10-year average.

Four-year-old chinook salmon that southern killer whale residents target are forecast to be scarce nearly everywhere across the whales’ vast migratory range from Washington to British Columbia.

Scientists on Friday did not forecast better salmon returns for southern residents.

“Perhaps a little in the years to come; we would have to really wait and see,” Harvey said.

Another warm water event could be harmful, said Jameal Samhouri, a marine ecologist at the Northwest Fisheries Science Center.

“One concern we have is whether the next big marine heat wave will come really soon, and not leave time for salmon and other animals to recover,” Samhouri said. “That is something we are really watching out for. Is this the new normal?”


Information from: The Seattle Times, http://www.seattletimes.com

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