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Ocean survival – using juvenile abundance and rigor to predict adult returns |
Dick Beamish, PBS |
How hatchery and wild survival of coho and chinook salmon in the early marine period relates to the number of adult returns. Coho salmon that enter the Strait of Georgia remain within the strait until fall. The marine survival from about mid-May to mid-September declined from about 15%, 10 years ago to about 2% today. We will discuss how it might be possible to improve the early marine survival. Wild chinook early marine survival is between 3 and 18 times better than hatchery fish. The poor hatchery survival is also related to release timing with the early releases having much lower survival. Better survival may be achieved with later releases and more kelp in the near shore areas. |
