Rockfish Species Trends in Puget Sound, Washington, USA, 2009–2023

Abstract

Rockfishes (Sebastes spp.) are a long-lived, understudied, multi-species fish assemblage in inland Washington (USA) waters. Driven by large-scale fishery removals in the 1970s, their numbers declined and have yet to recover, perhaps due to slow maturation and rare recruitment success. Since then, rockfish fishing restrictions have increased within Puget Sound, culminating in a 2010 total ban. Here, we analyze rockfish community trends (abundance and Shannon Diversity) within Puget Sound from 2009 to 2023. Our dataset includes 157 recorded dive transects from nine rocky or artificial reef habitats at depths 5–24 m throughout four Puget Sound basins: Admiralty Inlet (2 sites), Central Puget Sound (4 sites), Hood Canal (2 sites), and South Puget Sound (1 site). Significant differences in community species composition between basins were observed; we noted more Black (S. melanops), Yellowtail (S. flavidus), and Puget Sound (S. emphaeus) rockfish and fewer Brown rockfish (S. auriculatus) at sites in Admiralty Inlet vs. Central Puget Sound. Adult rockfish counts and Shannon Diversity varied seasonally, with higher rockfish counts and diversity indices in summer/autumn vs. winter/spring. Notably, we observed that total adult rockfish count per survey tended downward over time, driven partly by significant downward trends in Hood Canal Copper rockfish (S. caurinus) counts. We recommend continued monitoring and additional investigation into what factors besides fishing may be driving the trends reported here.