Environmental controls of phenology of high-latitude Chinook salmon populations of the Yukon River, North America, with application to fishery management

Mundy, P. R., and Evenson, D. F. 2011. Environmental controls of phenology of high-latitude Chinook salmon populations of the Yukon River, North America, with application to fishery management. – ICES Journal of Marine Science, 68: 1155–1164.Phenologies of a number of anadromous fish species have been demonstrated to vary in concert with environmental factors that change with global warming, such as water and air temperatures. Anadromous fishery managers will need advice from models of phenology, or migratory timing, as functions of environmental factors in those harvest areas where annual migratory timing can vary sharply. Such models are also necessary to advise fishery managers on how and when global warming projections of the IPCC model ensemble should be factored into regulatory decisions. Specifically, we demonstrate that the annual timing of marine exit of Yukon River Chinook salmon (Oncorhynchus tshawytscha) at 63°N 165°W for 1961–2009 varied in close concert with modelled sea surface temperature, air temperature, and sea ice cover. The best linear model for 1961–2009 combines sea surface and air temperatures to explain 59% of the annual variability in migratory timing (ice cover is available only for 1970–2009). Changes in phenology of high-latitude Chinook salmon are expected in response to global warming. As average temperatures increase, the frequency of earlier migrations is expected to increase, making management of the fishery more challenging.