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Chapter 1:  Quantifying habitat use and preferences of spawning sockeye salmon (Oncorhynchus nerka) using individual movement data: a case study in Bristol Bay, Alaska

Map of the study sites located on Little Togiak Lake within the Wood River System in Southwest Alaska.

Alaska’s Bristol Bay salmon fisheries control many ecological processes that support the livelihoods and economies with which they are connected. Yet the impact of changing climate threatens the sustainability of this area’s fisheries management. Researching the mechanisms behind how individual salmon chooses a habitat under different environmental conditions and levels of population density has been relatively understudied. It is critical to understand the nature and extent of salmon movement, habitat selection, and preference on which reproductive success and population productivity rely. Applying a discrete choice model to twenty years of annual fish tagging data of two spawning sockeye salmon populations at A and C creeks on Little Togiak Lake, we: (1) identify stream habitat features (e.g., slope) that influence the spatial distribution and population densities of spawning sockeye salmon; and (2) share results on how salmon select a habitat among varying degrees of reproductive habitat and protection from predators. These preliminary findings have implications for fisheries management, including predicting population abundance and occupancy of spawning habitat; and establishing effective habitat restoration goals and strategies. These results also have the potential to inform management of a range of systems prior to initiation of proposed human development (e.g., mining) which causes a major threat to the world’s freshwater habitats.