Pacific Northwest orcas declining for lack of salmon

Posted on June 7, 2012 by Bob Berwyn

New study suggests shipping traffic a smaller factor

A pod of orcas in the Pacific. PHOTO COURTESY NOAA.

By Summit Voice

SUMMIT COUNTY —Recovering Chinook salmon populations in the Pacific Northwest is probably the key to killer whale conservation efforts, according to new research based on measurements of hormone levels in the marine mammals.

The southern resident killer whales, living in coastal waters of the Pacific Northwest, have been struggling and some researchers think it’s primarily because of increase ship traffic in the region.

According to the National Oceanic and Atmospheric Administration, they are also  threatened by pollution and other human activities in many parts of their range.

But new research suggests the marine mammals are struggling mainly because of inadequate prey.The study was led led by Katherine Ayres, who completed the work while at University of Washington in Seattle. (more…)

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Feds claim progress on recovering fisheries

Posted on May 28, 2012 by Bob Berwyn

A flounder in seagrass. PHOTO COURTESY NOAA.

Several valuable species have been rebuilt to sustainable levels

By Summit Voice

SUMMIT COUNTY — Federal fisheries experts say that collaborative efforts have helped rebuild stocks of several valuable commercial and recreational fisheries, including Bering Sea snow crab, Atlantic coast summer flounder, Gulf of Maine haddock, northern California coast Chinook salmon, Washington coast coho salmon, and Pacific coast widow rockfish — all fully rebuilt to healthy levels.

Those are record results for a single, year, the National Marine Fisheries Service said in a report, declaring that experts have been able to recover 27 U.S. marine fish populations to sustainable levels in the past 11 years. (more…)

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Hatchery salmon overwhelming natural populations

Posted on February 11, 2012 by Bob Berwyn

All is not well in the Mokelumne

Spawning salmon. PHOTO COURTESY NOAA.

SUMMIT COUNTY — Hatchery raised salmon are overwhelming populations of wild-raised Salmon in some of California’s rivers, masking the fact that too few wild fish are returning to sustain a natural population in the river.

“We expected to find hatchery fish, but the sheer number of hatchery fish returning to spawn in the wild is surprising,” said Rachel Johnson, a fishery biologist affiliated with the Institute of Marine Sciences at UC Santa Cruz and with the Bay-Delta Office of the U.S. Bureau of Reclamation. “It looked like a healthy population of fish returning to spawn, but the reality is that without the hatchery fish the wild stocks are not sustaining themselves.”

The study focused on the Mokelumne River, one of the major salmon producing streams for fall-run Chinook salmon in California. Throughout the Central Valley rivers, returning fall-run Chinook salmon numbers have rebounded since a disastrous year in 2007, which led to the unprecedented closure of the commercial salmon fishing season for consecutive years in 2008 and 2009. (more…)

Filed under: biodiversity, Environment, Summit County news | Tagged: , , , , | 2 Comments »

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