Author: Obaaku Amponsah Aning
Date: August 26, 2026
Article Title:
Spatial Ecology of Atlantic Halibut across the Northwest Atlantic: A Recovering Species in an Era of Climate Change
Article Affiliation:
Fisheries and Oceans Canada
Memorial University of Newfoundland
University of Alaska Fairbanks
Université du Québec à Rimousk
University of Massachusetts
University of Connecticut.
Article Citation:
Shackell, N. L., Fisher, J. A. D., den Heyer, C. E., Hennen, D. R., Seitz, A. C., Le Bris, A., Robert, D., Kersula, M. E., Cadrin, S. X., McBride, R. S., McGuire, C. H., Kess, T., Ransier, K. T., Liu, C., Czich, A., & Frank, K. T. (2022). Spatial Ecology of Atlantic Halibut across the Northwest Atlantic: A Recovering Species in an Era of Climate Change. Reviews in Fisheries Science & Aquaculture, 30(3), 281–305. https://doi.org/10.1080/23308249.2021.1948502
INTRODUCTION
The recovery of Atlantic halibut (Hippoglossus hippoglossus) represents a rare success story in modern fisheries science. Once considered nearly collapsed in the 19th century due to overfishing, halibut stocks in Canadian waters have rebounded since the early 2000s. This rebound coincides with stricter management practices and an expansion of thermal habitat under climate change.
The authors of this review examined the spatial ecology of halibut across the Northwest Atlantic to better understand their stock structure, movement, and recovery potential. They asked: how do halibut populations organize across space and time? What drives their recovery in Canadian waters? How might climate change influence their future distribution?
To address these questions, the study synthesized genetic data, conventional and electronic tagging, fishery surveys, and habitat modelling.
RESULTS AND DISCUSSION
Halibut in the Northwest Atlantic are managed as four stocks, but genetic evidence supports two main populations: one in the Gulf of St. Lawrence and another on the Scotian Shelf–Grand Banks. Within these, there are subpopulations structured by juvenile “hotspots” and diverse migratory contingents.
Tagging studies revealed that most halibut remain relatively close to their release sites (3–90 km), though some migrate seasonally to deep continental slopes to spawn. Migration patterns vary widely; even halibut tagged at the same location can show very different routes, highlighting a contingent-based structure.
Climate-driven warming has increased the availability of suitable habitat, especially around southern Newfoundland and the Scotian Shelf. This expansion may have supported the recent increase in halibut abundance and fishery landings. Still, contrasting trends remain: Canadian stocks are healthy enough to be Marine Stewardship Council–certified as sustainable, while U.S. populations are still listed as a “Species of Concern.”
This study underscores the importance of spatial structure in fisheries management. Recognizing halibut as a “stock complex” of multiple subpopulations is essential, since overfishing even one subgroup could undermine recovery.
For Atlantic Canada, the implications are particularly strong. Halibut are now the second most valuable ground-fish in the region, with fishery revenues increasing sevenfold since the early 2000s. At the same time, warming waters and shifting currents introduce uncertainty about the species’ long-term stability.
Understanding where halibut spawn, how juveniles settle, and how migration patterns may shift with climate change will be critical for adaptive management.
CONCLUSION
The Atlantic halibut’s recovery demonstrates how effective management, combined with ecological change, can reverse the decline of a once-collapsed species. Yet the complexity of halibut’s spatial ecology, multiple populations, diverse migratory contingents, and climate-driven habitat shifts means continued monitoring and research are vital. For fisheries managers, scientists, and Atlantic communities alike, the halibut is both a conservation success and a reminder of the challenges climate change poses for marine ecosystems.
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