Collecting salmon eggs.

Research by the MSI program relating to the preservation and enhancement of endangered steelhead stocks has been an active focus at the Little Port Walter (LPW) Marine Station since 1996. Current efforts focus on understanding the mechanisms of how small populations maintain (or lose) genetic diversity when subjected to population bottlenecks and genetic “swamping” by larger nearby populations of other wild or artificially enhanced stocks. The essential element in this work is understanding the flow of genetic material between populations and the effects of selection and effective breeding population size on maintaining ecologically stable wild populations.

Occasionally, when a population has been reduced to such low levels that persistence in its native habitat is in jeopardy, recovery measures, such as creating a captive population from a portion of the remaining wild fish, might be required. Maintaining populations in captivity can result in future offspring that are not as viable (fit) in a wild environment as their ancestors due to several factors including inbreeding depression and domestication selection. Recent research at LPW has indicated that standard measurements of fitness in captivity are poor predictors of performance in the wild and that inbreeding depression can be much more debilitating on populations in the wild than previously believed. Research is being conducted at LPW to determine if endangered populations can be maintained in protected, wild environments in numbers large enough to constrain inbreeding depression and reduce domestication selection.

Contact:
Frank Thrower
Auke Bay Laboratories
Alaska Fisheries Science Center, NOAA Fisheries

Ted Stevens Marine Research Institute
17109 Pt Lena Loop Rd
Juneau AK 99801
(907) 789-6055
Frank.Thrower@noaa.gov