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The Case of the Missing Fish
Tacoma, WA - Tuesday, June 7, 2005
The case of the missing fish
LES BLUMENTHAL; The News Tribune
Last updated: June 6th, 2005 11:23 AM (PDT)
WASHINGTON – While it might not rival “CSI” or other television whodunits, marine scientists are baffled over the disappearance of more than 170,000 chinook salmon that were expected to return to the Columbia River this spring.
More than 250,000 spring chinook were forecast to return, but only about one-third showed up.
Some scientists suggest that favorable ocean conditions that had helped produce record runs over the past several years have dramatically worsened with the onset of a new El Niño weather condition. Others suggest the fish were devoured by such predators as sea lions, fur seals, mackerel or hake; or Alaskan or foreign fishermen got them.
Some blame the string of dams on the Columbia and Snake rivers for killing the fish when they were juveniles headed downstream for the ocean. Other say low river flows are to blame. Or maybe the forecasts were just wrong.
One way or another, it’s a mystery that devastated the local fishing industry and left scientists concerned other salmon runs might suffer similar fates.
“It’s a real puzzle,” said Nate Mantua, a research scientist with the University of Washington’s Climate Impacts Group. “There is a distinct possibility those fish are just gone – dead.”
Adding to the mystery is the fact that most other West Coast salmon runs, including those on Puget Sound, seem to be fine. No two salmon runs are alike. All face different hurdles as the fish leave fresh water to spend several years in the ocean and then return to spawn in the same creeks and rivers where they were born.
The disappearance of the spring chinook could undercut Bush administration claims that the Columbia River and other runs up and down the coast are on the rebound. Late last month, a federal judge in Portland threw out the administration’s plan to restore the runs on the Columbia and Snake rivers, saying it did not guarantee the protections for salmon required under the Endangered Species Act.
“There are many theories about why these fish didn’t return,” said Charles Hudson of the Columbia River Inter-Tribal Fish Commission. “But you have to wonder whether this is the front end of a deteriorating situation.”
Officials of the National Oceanic and Atmospheric Administration’s fisheries service also are at a loss to explain what happened to the Columbia River spring chinook. But they cautioned there was no reason to panic.
“The heartburn being expressed is like when Wall Street predicts a company will earn 3 percent, and it is only 2 percent,” said Brian Gorman, a NOAA spokesman in Seattle. “It is well within natural cycles.”
A tough – and mysterious – life
Though some salmon runs have been well studied, little is known about the Columbia River spring chinook once they enter the ocean. They travel thousands of miles, a journey that begins in such rivers as the Salmon, Snake, Wenatchee, Entiat, Yakima and Umatilla, takes them to the Gulf of Alaska and then back again.
On their way, they have to run a gauntlet of up to eight hydroelectric dams that can chew up 85 percent of the juveniles as they head downstream. Once they reach the ocean, it is thought they spend about a year gaining weight in near-coastal waters before heading to the deep waters up north.
But only one Columbia River spring chinook has ever been caught on the high seas. In 1956, one was caught south of the Aleutian Islands. Scientists tagged the fish, and it later was discovered spawning along the Salmon River in Idaho.
“A good guess is that their main distribution is the Gulf of Alaska, though they could go as far as Russia and Japan,” said Kate Myers, another University of Washington researcher.
Myers said the chinook like the cold waters of the Gulf of Alaska and can travel to depths of more than 1,000 feet as they feed on squid and smaller fish. One disturbing trend is the chinook in the northern Pacific are becoming smaller than in the past, she said. Where once they could average 35 pounds, now they mostly are between 14 and 20 pounds.
Myers said the chinook are rarely studied when they are in the ocean. Her department has funding for one scientist to ride on a research vessel this year.
One theory: warming ocean trends
One theory for the disappearing fish is that El Niño events – which push warm water across the Pacific to the U.S. West Coast – are becoming more frequent, and the upwelling of deep, cold ocean water that supplies salmon with food and nutrients has been interrupted.
According to one Canadian report, ocean temperatures off Canada’s Vancouver Island were the warmest in 45 years, and some species of squid that usually are found off San Diego have washed up on the island’s beaches.
Mantua said even though the most recent El Niño was mild, ocean temperatures off Oregon and Washington have been four or five degrees above normal.
“There has not been much in the way of upwelling,” he said.
There also has been a sharp increase of predators as hake and mackerel have headed up the coast riding the warm currents. And in the 1970s before they were protected, there were only 50,000 sea lions on the West Coast. Now there are 300,000, and sea lions munching on salmon near Bonneville Dam had to be scared off with underwater firecrackers.
The chinook that should be showing up now are the offspring of the largest run of spring chinook run since records were first kept in 1938.
“One would speculate a record return would return a near record return,” said Hudson.
But Hudson and Glen Spain of the Pacific Coast Federation of Fishermen’s Associations said they believe the dams and the lack of flows down the river system were the principal culprits behind the disappearing fish.
“We have a perfect storm here,” said Spain, adding the dams and flows coupled with changes in the ocean could hint at a decline in other runs.
The mystery of the missing fish might never be solved.
NOAA’s Gorman said everyone was “psyched” for a big run of spring chinook, and there is little solid evidence about what happened.
“We may never know,” he said. “And the implications might not be known for four or five years. We don’t know if it is a blip or the start of a trend.”
Tacoma, WA - Tuesday, June 7, 2005
The case of the missing fish
LES BLUMENTHAL; The News Tribune
Last updated: June 6th, 2005 11:23 AM (PDT)
WASHINGTON – While it might not rival “CSI” or other television whodunits, marine scientists are baffled over the disappearance of more than 170,000 chinook salmon that were expected to return to the Columbia River this spring.
More than 250,000 spring chinook were forecast to return, but only about one-third showed up.
Some scientists suggest that favorable ocean conditions that had helped produce record runs over the past several years have dramatically worsened with the onset of a new El Niño weather condition. Others suggest the fish were devoured by such predators as sea lions, fur seals, mackerel or hake; or Alaskan or foreign fishermen got them.
Some blame the string of dams on the Columbia and Snake rivers for killing the fish when they were juveniles headed downstream for the ocean. Other say low river flows are to blame. Or maybe the forecasts were just wrong.
One way or another, it’s a mystery that devastated the local fishing industry and left scientists concerned other salmon runs might suffer similar fates.
“It’s a real puzzle,” said Nate Mantua, a research scientist with the University of Washington’s Climate Impacts Group. “There is a distinct possibility those fish are just gone – dead.”
Adding to the mystery is the fact that most other West Coast salmon runs, including those on Puget Sound, seem to be fine. No two salmon runs are alike. All face different hurdles as the fish leave fresh water to spend several years in the ocean and then return to spawn in the same creeks and rivers where they were born.
The disappearance of the spring chinook could undercut Bush administration claims that the Columbia River and other runs up and down the coast are on the rebound. Late last month, a federal judge in Portland threw out the administration’s plan to restore the runs on the Columbia and Snake rivers, saying it did not guarantee the protections for salmon required under the Endangered Species Act.
“There are many theories about why these fish didn’t return,” said Charles Hudson of the Columbia River Inter-Tribal Fish Commission. “But you have to wonder whether this is the front end of a deteriorating situation.”
Officials of the National Oceanic and Atmospheric Administration’s fisheries service also are at a loss to explain what happened to the Columbia River spring chinook. But they cautioned there was no reason to panic.
“The heartburn being expressed is like when Wall Street predicts a company will earn 3 percent, and it is only 2 percent,” said Brian Gorman, a NOAA spokesman in Seattle. “It is well within natural cycles.”
A tough – and mysterious – life
Though some salmon runs have been well studied, little is known about the Columbia River spring chinook once they enter the ocean. They travel thousands of miles, a journey that begins in such rivers as the Salmon, Snake, Wenatchee, Entiat, Yakima and Umatilla, takes them to the Gulf of Alaska and then back again.
On their way, they have to run a gauntlet of up to eight hydroelectric dams that can chew up 85 percent of the juveniles as they head downstream. Once they reach the ocean, it is thought they spend about a year gaining weight in near-coastal waters before heading to the deep waters up north.
But only one Columbia River spring chinook has ever been caught on the high seas. In 1956, one was caught south of the Aleutian Islands. Scientists tagged the fish, and it later was discovered spawning along the Salmon River in Idaho.
“A good guess is that their main distribution is the Gulf of Alaska, though they could go as far as Russia and Japan,” said Kate Myers, another University of Washington researcher.
Myers said the chinook like the cold waters of the Gulf of Alaska and can travel to depths of more than 1,000 feet as they feed on squid and smaller fish. One disturbing trend is the chinook in the northern Pacific are becoming smaller than in the past, she said. Where once they could average 35 pounds, now they mostly are between 14 and 20 pounds.
Myers said the chinook are rarely studied when they are in the ocean. Her department has funding for one scientist to ride on a research vessel this year.
One theory: warming ocean trends
One theory for the disappearing fish is that El Niño events – which push warm water across the Pacific to the U.S. West Coast – are becoming more frequent, and the upwelling of deep, cold ocean water that supplies salmon with food and nutrients has been interrupted.
According to one Canadian report, ocean temperatures off Canada’s Vancouver Island were the warmest in 45 years, and some species of squid that usually are found off San Diego have washed up on the island’s beaches.
Mantua said even though the most recent El Niño was mild, ocean temperatures off Oregon and Washington have been four or five degrees above normal.
“There has not been much in the way of upwelling,” he said.
There also has been a sharp increase of predators as hake and mackerel have headed up the coast riding the warm currents. And in the 1970s before they were protected, there were only 50,000 sea lions on the West Coast. Now there are 300,000, and sea lions munching on salmon near Bonneville Dam had to be scared off with underwater firecrackers.
The chinook that should be showing up now are the offspring of the largest run of spring chinook run since records were first kept in 1938.
“One would speculate a record return would return a near record return,” said Hudson.
But Hudson and Glen Spain of the Pacific Coast Federation of Fishermen’s Associations said they believe the dams and the lack of flows down the river system were the principal culprits behind the disappearing fish.
“We have a perfect storm here,” said Spain, adding the dams and flows coupled with changes in the ocean could hint at a decline in other runs.
The mystery of the missing fish might never be solved.
NOAA’s Gorman said everyone was “psyched” for a big run of spring chinook, and there is little solid evidence about what happened.
“We may never know,” he said. “And the implications might not be known for four or five years. We don’t know if it is a blip or the start of a trend.”
