2025/07/23 by Charlotte Gauthier, Patrick Reis‐Santos, Bronwyn M. Gillanders +3 · 1 voice
Environmental Science · #Marine and fisheries research #Fish Ecology and Management Studies #Marine Bivalve and Aquaculture Studies
paper · pdf · doi:10.1093/icesjms/fsaf132
openalex publication_date 2025/07/23 · openalex created_date 2025/10/10 · openalex updated_date 2026/07/29
Abstract Partial migration is a common strategy in marine fishes, enhancing resilience through diversified movement patterns that buffer the effects of environmental changes. A key ecological outcome of migration behaviour is growth variability, which provides insights into the adaptive value of different migratory strategies. Using otolith back-calculation, we investigated how growth patterns of Atlantic halibut (Hippoglossus hippoglossus) in the Gulf St. Lawrence (Canada) varied among resident and migratory individuals whose migration histories were determined previously via otolith chemistry. Von Bertalanffy growth models fitted with nonlinear mixed-effects models revealed that migrants exhibited faster growth rates and greater theoretical maximum lengths compared to residents of both sexes, with significant differences in length-at-age emerging from the age of six. However, both contingents showed good condition, with no differences in relative condition. Overall, growth differences likely reflect the benefits of warmer temperatures and increased prey abundance or quality in shallow summer habitats for migrants, contrasted with potential increased competition in denser halibut populations in deeper channels. Overall, this observed difference in growth suggests that increased habitat quality in shallow areas can overcompensate for energy costs associated with an annual migration, which can exceed 1000 km. The complex growth dynamics between migratory and resident contingents highlight the challenges of managing species with partial migration, where specific components may disproportionately contribute to stock biomass, particularly in the context of changing environmental conditions.