Rising sea temperatures have prompted many Atlantic groundfish species to migrate north and west around Iceland. In contrast, Arctic species have either declined or remained stable, according to new research from the Marine and Freshwater Research Institute (Hafrannsóknastofnun) and the University of Akureyri.
Atlantic opportunists expand as Arctic fish decline
The institute stated that the multidecadal analysis, published in Scientific Reports, drew on annual surveys dating back to 1987 and grouped fish by life-history strategy and geographic range.
“The changes are significant,” the summary noted, with Atlantic ‘opportunistic’ species expanding and shifting into the Northwest grounds as waters warmed, while Arctic opportunists shrank.
Life-history strategies reveal winners and losers
Researchers classified species as opportunistic, periodic, or equilibrium, and also categorised them by whether they were Arctic, Atlantic, or broadly distributed.
Examples include capelin and sandeel (opportunistic), cod and plaice (periodic), and skates and spurdog (equilibrium). Widely distributed species such as cod, haddock and saithe have generally benefited from warmer conditions.
The institute’s release, dated 29 August 2025, emphasised that the most pronounced changes occurred from 2000 to 2010, following a temperature rise that began in 1996.
Echoes of past climate cycles
The authors — Jón Sólmundsson, Ólafur Á. Sigurðsson, Ingibjörg G. Jónsdóttir, and Steingrímur Jónsson — add that the past 15–20 years have shown greater stability in groundfish communities, consistent with longer-term Multidecadal Oscillation patterns observed in the early to mid-20th century. “Recent shifts may echo past periods,” the institute’s summary said.
The study, titled ‘How different life‑history strategies respond to changing environmental multidecadal study of groundfish communities’, situates today’s trends in a historical context first observed by Icelandic research pioneers Bjarni Sæmundsson and Árni Friðriksson between 1925 and 1945, underscoring the role of natural climate variability alongside ongoing warming.