Journal
ICES JOURNAL OF MARINE SCIENCE
Volume 79, Issue 4, Pages 1063-1074Publisher
OXFORD UNIV PRESS
DOI: 10.1093/icesjms/fsac046
Keywords
Bering Sea; bottom-trawl; catchability; cold pool index; model-based index; VAST
Categories
Funding
- North Pacific Research Board grant [1805]
Ask authors/readers for more resources
As oceans warm, the distribution of groundfish species shifts, which can complicate management efforts. This study developed model-based biomass estimates for three Bering Sea groundfish species by combining data from the US and Russia. The results show that groundfish densities have shifted northward and high-density areas now span across the international border.
Shifts in the distribution of groundfish species as oceans warm can complicate management efforts if species distributions expand beyond the extent of existing scientific surveys, changing the proportion of groundfish available to any one survey each year. We developed the first-ever model-based biomass estimates for three Bering Sea groundfishes (walleye pollock (Gadus chalcogrammus), Pacific cod (Gadus macrocephalus), and Alaska plaice (Pleuronectes quadrituberculatus)) by combining fishery-independent bottom trawl data from the U.S. and Russia in a spatiotemporal framework using Vector Autoregressive Spatio-Temporal (VAST) models. We estimated a fishing-power correction to calibrate disparate data sets and the effect of an annual oceanographic index to explain variation in groundfish spatiotemporal density. Groundfish densities shifted northward relative to historical densities, and high-density areas spanned the international border, particularly in years warmer than the long-term average. In the final year of comprehensive survey data (2017), 49%, 65%, 47% of biomass was in the western and northern Bering Sea for pollock, cod, and plaice, respectively, suggesting that availability of groundfish to the more regular eastern Bering Sea survey is declining. We conclude that international partnerships to combine past data and coordinate future data collection are necessary to track fish as they shift beyond historical survey areas.
Authors
I am an author on this paper
Click your name to claim this paper and add it to your profile.
Reviews
Recommended
No Data Available