Salmon Watersheds Program

Review of Escapement Indicator Streams for the North and Central Coast Salmon Monitoring Program

Abstract

Annual estimates of returns of each salmon species to each Statistical Area and Conservation Unit (CU) on the North and Central Coast (NCC) of British Columbia are derived from data collected during spawning escapement surveys.  The 2006 Core Stock Assessment Program (CSAP) review identified escapement monitoring as a top priority within the CSAP for NCC salmon.  An initial set of escapement “indicator streams” was identified for each stock group based on historical time series, the reliability of escapement estimates, and the methods and costs of obtaining these data.  This information was used to prepare the 2006 escapement monitoring strategy for NCC salmon stocks.  However, the implementation of this strategy has fallen short of the goals in recent years.  The number of NCC streams with escapement estimates peaked in the mid-1980s at over 1500 streams, declined to less than 1000 streams in 1994, and reached an all-time low of 476 streams in 2014.  A set of streams referred to as “indicator streams” have been more consistently monitored over the years but coverage of these critical streams has also decline in recent years such that only 51% of the 679 indicator streams were surveyed in 2014. 

The decline in escapement monitoring effort and the importance of these data for annual assessment of stock status prompted this review of the escapement indicator streams and the discussions regarding survey priorities, methods, and costs with the groups that have been conducting these escapement surveys in recent years.