Abstract
Groundfish morphometric condition indicators, derived from length‐weight relationships, offer insights into fish population health and productivity. This study explores how groundfish conditions vary across the Aleutian Islands, a 1700‐km‐long region that separates the Bering Sea from the North Pacific Ocean, creating distinct ecological zones due to differences in oceanography. We assessed the condition of the six most abundant groundfish species by using length–weight residuals collected in biennial Aleutian bottom trawl surveys conducted by the Groundfish Assessment Program National Marine Fisheries Service, Alaska Fisheries Science Center, from 1986 to 2022. We analyzed covariates such as latitude, longitude, sex, bottom depth, surface and bottom temperatures, average annual biomass, and the day of the year to understand their influence on fish condition. Results indicate that while fish north of the passes were statistically heavier for their length, the overall effect sizes were small. Significant predictors of groundfish weight included sex, latitudinal and longitudinal position, surface and bottom temperatures, and depth. The study highlights the importance of understanding spatial heterogeneity in the Aleutian Islands, as it informs fisheries management practices. The findings suggest that factors such as water mixing, nutrient availability, and prey concentration may drive observed spatial patterns in fish condition. These insights contribute to targeted management strategies for sustaining fisheries and conserving marine ecosystems in this ecologically significant region.