Ghost Runs: Management and Status Assessment of Pacific Salmon (Oncorhynchus spp.) Returning to British Columbia's Central and North coasts
The management of Pacific salmon (Oncorhynchus spp.) populations, which are spatially distributed across thousands of waterways in coastal British Columbia, Canada, presents considerable challenges to resource managers. We evaluated the efficacy of salmon management by Fisheries and Oceans Canada (DFO) over the past 55 years in two key areas: (i) the achievement of internally generated target escapement levels and (ii) escapement monitoring. We show that less than 4% of monitored streams (n = 7 of 215), which represent a small fraction of all salmon-bearing waterways (n = 2592), have consistently met escapement targets since 1950. During this same period, the number of streams monitored by DFO has simultaneously decreased. Further, current monitoring efforts fall short of encompassing the range of salmon diversity identified within recently designated conservation units. Importantly, we found that this erosion of monitoring effort has been biased towards dropping smaller runs that failed to meet target escapements in the previous decade. We suggest that such increasingly selective monitoring is presenting a progressively more biased evaluation of population health. In addition to fostering a “shifting baseline” syndrome, we conclude that these changes to monitoring can not provide data required for precautionary harvest management under the high exploitation levels that these runs experience.
Price, M. H., Darimont, C. T., Temple, N. F., & MacDuffee, S. M. (2008). Ghost runs: management and status assessment of Pacific salmon (Oncorhynchus spp.) returning to British Columbia’s central and north coasts. Canadian Journal of Fisheries and Aquatic Sciences, 65(12), 2712-2718.