Bad News For Sand Shrimp, Ocean Salmon Fishing

Scientists at Oregon State University are studying the huge decline in sand, or mud shrimp populations on the Oregon Coast. The problem seems to be an introduced parasite called Griffen’s isopod, which attacks the shrimp by entering through the gill chamber. Once inside the shrimp, the parasite sucks the host’s blood, destroying the shrimp’s ability to reproduce. Griffen’s isopod effectively turns the shrimp into a zombie, not killing them immediately. So many shrimp in Oregon’s estuaries are still alive, but unable to reproduce. Griffen’s isopod is non-native species that was probably introduced to the West Coast through ballast water from an Asian ship as the parasite occurs naturally in China and Japan.

The effect of the sand shrimp’s decline is not immediately known. The shrimp are an important food source for fish and birds, and losing a large amount of biomass has an effect on the entire system. How much of an effect is unclear. Sand shrimp are filter feeders, and their decline may mean lower water quality and silt build up.

In some areas of Oregon, the isopod has been less effective in destroying the sand shrimp populations, and researchers at OSU are currently trying to find out why. Researchers are comparing distributions from last year and previous years to determine patterns. Researchers add that some estuaries are more successful at larvae recruitment, which means not all hope is lost.

Ocean Chinook Season Probably Not Happening For 2009
Historic low returns of Chinook salmon in the Sacramento River system means the likely shut down of commercial fishing off Oregon and California for 2009. Biologists estimate a return of just over 66,000 fall Chinook for 2008, despite an ocean fishing closure. The Sacramento River fish are in trouble: recent poor ocean conditions when these fish went out, water draw-downs, introduced species and poor water quality all factor in to the low returns expected for this year.

Last year’s closure of commercial salmon fishing was the largest such shutdown ever. The State of Oregon estimated that the closure meant the loss of $45 million and over 750 jobs. Oregon applied for federal aid and probably will again this year. According to the Pacific Fisheries Management Council, the value of Oregon’s ocean salmon fisheries is about 3% of the average for 1979-1990. With closures looming, the value is not likely to change.

The bright spot in ocean fisheries will be the large number of Coho salmon predicted to return to the Oregon Coast in 2009. Recreational anglers aren’t likely to be as restricted as last year, according to ODFW. The Columbia River is expected to have a return of approximately 1.3 million fish.

See you on the water,
Action Jackson

(Please send comments or questions to Action Jackson at 268-6944 or www.actionjacksonfishing.com)