A Spatially Explicit Assessment of Changes in Chinook Salmon Fisheries in Lakes Michigan and Huron from 1986 to 2011

AbstractWe produced a spatially explicit assessment of the changes in stocking, catch, fishing effort, and catch per effort (CPE) for Chinook Salmon Oncorhynchus tshawytscha in Lakes Michigan and Huron from 1986 to 2011. We focused on describing spatial differences in the changes that occurred during three well-known episodes of rapid change: (1) a decline in abundance during 1986–1994 in Lake Michigan, (2) a recovery in abundance during 1994–2006 in Lake Michigan, and (3) a decline in abundance during 2002–2010 in Lake Huron. We used a spatial grid system to describe and contrast trends in fishing effort and CPE among the main lake basins (Michigan, Huron, and Georgian) and subregions within those basins. We applied linear regressions, ANCOVAs, and Tukey’s tests to assess differences. We found that trends differed among and within basins during all three episodes, which resulted in changes in the distribution of fishing effort and CPE. Fishing effort generally decreased in all basins and subregions over ...