Dear MARMAM community, On behalf of my coauthors, I am pleased to share our recent publication in Scientific Reports:
Barlow, D.R., Strong, C.S. & Torres, L.G. Three decades of nearshore surveys reveal long-term patterns in gray whale habitat use, distribution, and abundance in the Northern California Current. Sci Rep 14, 9352 (2024). https://doi.org/10.1038/s41598-024-59552-z ABSTRACT: The nearshore waters of the Northern California Current support an important seasonal foraging ground for Pacific Coast Feeding Group (PCFG) gray whales. We examine gray whale distribution, habitat use, and abundance over 31 years (1992–2022) using standardized nearshore (< 5 km from shore) surveys spanning a large swath of the PCFG foraging range. Specifically, we generated density surface models, which incorporate detection probability into generalized additive models to assess environmental correlates of gray whale distribution and predict abundance over time. We illustrate the importance of coastal upwelling dynamics, whereby increased upwelling only yields higher gray whale density if interspersed with relaxation events, likely because this combination optimizes influx and retention of nutrients to support recruitment and aggregation of gray whale prey. Several habitat features influence gray whale distribution, including substrate, shelf width, prominent capes, and river estuaries. However, the influence of these features differs between regions, revealing heterogeneity in habitat preferences throughout the PCFG foraging range. Predicted gray whale abundance fluctuated throughout our study period, but without clear directional trends, unlike previous abundance estimates based on mark-recapture models. This study highlights the value of long-term monitoring, shedding light on the impacts of variable environmental conditions on an iconic nearshore marine predator. The full article is open access, and available online: https://www.nature.com/articles/s41598-024-59552-z Please do not hesitate to reach out with any questions or to request a PDF copy. Cheers, Dawn Dawn Barlow, PhD (she/her) Postdoctoral Scholar Marine Mammal Institute | Department of Fisheries, Wildlife, and Conservation Sciences Oregon State University | Hatfield Marine Science Center Geospatial Ecology of Marine Megafauna Lab<https://mmi.oregonstate.edu/gemm-lab> dawn.bar...@oregonstate.edu
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