Researchers can’t tell exactly what’s driving the die-off…”Those ocean life patterns are just not working the way they have in the past,” said Michael Milstein, a spokesman for the National Oceanic and Atmospheric Administration.
From the Oregonian
By Kelly House | The Oregonian/OregonLive
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March 10, 2016
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Nearly a year into a West Coast sardine fishing ban enacted to protect the collapsing population, the fish formerly worth more than $8 million to Oregon’s economy have shown no signs of a comeback.
New federal research indicates numbers of the small, silvery, schooling fish have plummeted further than before the fishing moratorium, dashing any hope of lifting it in 2016.
With the current sardine population hovering at 7 percent of its 2007 peak, fishermen now say they expect to wait a decade or more to revive the fishery.
“I don’t want to take a pessimistic view, but I would think we’ll be shut down until 2030,” said Ryan Kapp, a Bellingham fisherman who advises the Pacific Fishery Management Council on sardines and other fish.
Sardines aren’t struggling in isolation. Other fish near the bottom of the marine food web, such as anchovies and herring, are also down. The shortage of sustenance is rippling upward to create crises for predator species from seals to seabirds.
Researchers can’t tell exactly what’s driving the die-off, nor how long it will last. Some say the crash can be attributed to cyclical boom-and-bust population dynamics sardines have always exhibited.
Others argue overfishing played a role, driving sardine populations down too far and too fast to blame it on a natural population flux.
Then there’s the unavoidable presence of the “warm blob,” a lingering mass of overheated water that for more than two years has wreaked havoc on sea life off the Pacific coast.
“Those ocean life patterns are just not working the way they have in the past,” said Michael Milstein, a spokesman for the National Oceanic and Atmospheric Administration, the federal agency that tracks sardine numbers. “There’s a feeling that a lot of this is environmentally-driven.”
RIPPLES IN THE FOOD CHAIN
The Pacific fishery council’s rules call for a fishery shutdown if the total weight of adult sardines falls below 150,000 metric tons. When the population fell below that threshold last spring, council members scrambled to enact a midseason shutdown.
Federal scientists last month estimated sardine biomass has dropped below 65,000 tons this year.
Even with fishing pressures lifted, sardines could struggle to bounce back in an ocean devoid of their main food source. The lipid-rich coldwater plankton that sardines like to eat have become scarcer in West Coast waters, replaced by tropical species with less appeal to the region’s predators. Scientists suspect the warm blob is causing the plankton shift.
Without that food source, “the whole system can suffer,” said Kerry Griffin, who manages sardines for the Pacific Fishery Management Council.
The end result is ominous for more than just fishermen. Oily sardines are a key food source for larger ocean-going animals. As that option becomes scarce, predators switch to less-nutritious food options and can end up starving.
Scientists believe that chain reaction is already playing out in a big way. A group of National Oceanic and Atmospheric Administration researchers last week released a study linking the sardine collapse to the surge in starving sea lion pups washing ashore along the California coast. The scientists who authored the study say they expect the mass starvation that stranded 3,000 pups last year to continue as long as forage fish numbers remain low.
Similar phenomena have been observed among other species that target small schooling fish for food. Brown pelicans are failing to breed, dead Guadalupe fur seals are washing ashore in California, undersize salmon are returning to Canadian spawning grounds and seabirds are washing ashore weakened or dead on the Oregon coast.
OVERFISHING?
Environmentalists for years warned that a sardine collapse was imminent. Now they have begun lobbying to get more conservative harvest policies in place before the fishery reopens.
Research shows that overfishing intensifies the cyclical downturns of sardines and other small fish, and ocean conservation groups argue current West Coast standards are too permissive to prevent overfishing.
Ben Enticknap, a Portland-based campaign manager for the international conservation group Oceana, said the group is pushing the council to adopt new standards that would trigger a fishing ban once the sardine stock drops below 640,000 metric tons. That trigger point is more than four times higher than the current level.
The group is also lobbying for a rule to prohibit fishermen from hauling in more than 15 percent of the adult population in a given season. In the final years of harvest before last year’s shutdown, fishermen caught as much as 28 percent of the adult sardines in the water.
“Fundamental flaws in management have to be fixed, or this crash will be repeated in the future,” Enticknap said.
CAUTIOUS OPTIMISM
Although the overall results of this year’s sardine count were discouraging, scientists say there’s a glimmer of hope.
Several years of poor reproduction helped drive down the sardine population. In their latest trawl, scientists saw evidence that 2015 was a good spawning year.
It’s too soon to tell whether the reproductive success signals a turning point.
“There are some potentially positive signs there,” Milstein said, but in order to boost population counts, “the young need to survive long enough to make it into the mature population.”
–Kelly House
khouse@oregonian.com
503-221-8178
@Kelly_M_House
http://www.oregonlive.com/environment/index.ssf/2016/03/as_pacific_sardine_collapse_wo.html
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