Abiotic and biotic dimensions of habitat for juvenile salmon and other fishes in the Skeena River estuary

Estuaries are increasingly degraded globally but provide nursery services for juvenile fishes through predator protection and increased food availability. This thesis examined the abiotic and biotic factors that contributed to abundance patterns of juvenile salmon and forage fish species in the Skeena River estuary, BC. I first showed that spatial abundance patterns were heterogeneous for salmon and that the combination of variables that predicted abundance differed between species. Inclusion of these dynamic abiotic and biotic variables increased predictive power over solely using static habitat descriptors for juvenile salmon. Next, I examined the association between fish and prey abundance for two forage fish and juvenile salmon species. Overall, fish abundance was not related to prey abundance, except for herring which co-varied with a highly consumed prey species. Understanding the factors influencing estuarine habitat use by economically-important juvenile salmon and forage fish can help inform risk assessment and guide environmental planning.