MEPS 749:141-158 (2024)  -  DOI: https://doi.org/10.3354/meps14720

ABSTRACT: Rapid climate change in high-latitude ecosystems presents a challenge to fisheries management, as ecosystems are exposed to novel climate conditions that might expose non-stationary climate-biology relationships. Recently, the eastern Bering Sea has experienced a series of warm years outside the range of previous observations, resulting in shifting species distributions. We tested whether exceptionally warm temperatures from 2014-2019 revealed temporal non-stationarity in the relationship between temperature and the local abundances of walleye pollock Gadus chalcogrammus, an ecologically and commercially important species. Using survey catch per unit effort (CPUE) as a local abundance proxy, we detected a gradual shift through time in the local abundance-bottom temperature relationship, but little evidence for a sharp transition associated with marine heatwave conditions. Because pollock have expanded their range into novel habitats in the northeast Bering Sea (NEBS), we tested whether our models, parameterized for the southeast Bering Sea (SEBS), had predictive skill in the northeast. Our models were generally able to identify areas of high and low CPUE, though they under-predicted the magnitude of abundance observed in the northeast during the warm years. Spatial associations between pollock and other species differed between the warm period (2014-2019) and previous decades (1982-2013) for 3 of 9 species, providing mixed evidence for non-stationarity. These findings contrast with results showing sharp rather than gradual changes in climate-biology relationships associated with climate transitions in nearby ecosystems. The same processes that govern walleye pollock abundance and distribution appear to apply to both the SEBS, historically the core of their distribution, and the NEBS.

KEY WORDS: Bering Sea · Pollock · Non-stationarity · Rapid warming

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Cite this article as: Oke KB, Litzow MA, Mueter F (2024) Shifting temperature-abundance relationship for Bering Sea walleye pollock consistent with northward expansion during exceptionally warm conditions. Mar Ecol Prog Ser 749:141-158. https://doi.org/10.3354/meps14720 Export citation Share:    Facebook - - linkedIn