Phenology and Fraser River sockeye salmon marine survival. (September 2021)

• Record Type: Journal Article
• Authors: McKinnell, Skip; Irvine, James R.
• Is Part Of: Progress in oceanography. Volume 197(2021)
• Publication Date: 2021-09
• Subjects: Chlorophyll -- Queen Charlotte Sound -- Ocean productivity -- Smolt migration timing -- Pulse model -- Sockeye salmon; Oceanography -- Periodicals; 551.4605
• DOI: 10.1016/j.pocean.2021.102632
• Languages: English
• ISSNs: 0079-6611

Abstract

Abstract: Inspired by the pioneering work of Dr. Bill Peterson who demonstrated the utility of ocean indicators at predicting survival of coho and chinook salmon in the Columbia River, we investigated whether the phenology of primary productivity could explain variable marine survival of Fraser River sockeye salmon. Building on a study that had found a strong correlation between satellite-derived spring chlorophyll concentrations in Queen Charlotte Sound (British Columbia) and smolt survival, we hypothesized that smolt migration phenology could help to explain interannual survival differences among years. Applying a new migration model to 18 years of smolt migration data from Chilko Lake demonstrated that interannual differences in smolt migration timing were organized in up to 3 pulses of abundance with a general trend by the largest peak toward earlier peak migration dates over the time series (1998–2016). Analysis of satellite-derived fluorescence line height data within Queen Charlotte Sound identified 4 productivity domains through which most young sockeye salmon would migrate. Each domain had distinct seasonal productivity patterns. With these data, we were unable to demonstrate significant correlations between spring bloom dates in these domains and smolt marine survival, or between smolt migration timing and marine survival. Having separate survival estimates for each pulse and phenological indicators of the sockeye salmon prey base might improve our ability to test the hypothesis that phenology matters to sockeye salmon in the Queen Charlotte Sound region.