26 Jan 2015

Climate change redistributes fish species at high latitudes

One of our experts co-led a study on Arctic warming and the interchange of fishes between the North Atlantic and North Pacific Oceans.

Throughout much of the Quaternary Period, the marine biotas of the North Atlantic and North Pacific have been separated by harsh climate conditions in the Arctic. A new study published in the journal Nature Climate Change highlights that climate change has begun to weaken this natural barrier – promoting the interchange of fishes between the two seas and bringing ecological and economic consequences.

Dr. Mary S. Wisz (Senior Ecosystem Scientist, DHI Denmark) co-led the study as part of an international research team. The team represented diverse fields, including fish taxonomy, trophic ecology, fisheries science, climatology, oceanography, and ecological modelling. 

The team’s predictive ecological modelling showed that as sea temperatures and productivity increase at high latitudes, Arctic warming promotes the interchange of fishes between the North Atlantic and North Pacific Oceans via the Northwest and Northeast Passages. Redistribution of species and interchange will cause a tremendous increase in fish biodiversity in coastal areas around Greenland and Svalbard, for example, resulting in dramatic changes to interactions between species. 

Such biotic interchange can cause severe ecological consequences. The construction of the Suez Canal in 1869, for example, resulted in the invasion of Red Sea marine fauna into the Mediterranean Sea. Now, Red Sea fishes dominate the Mediterranean fish community. This has had harmful ecological and economic consequences for the Mediterranean’s biodiversity and its fishing industry. 

The newly published work foresees that some commercial species will extend their range at higher latitudes as increased productivity and sea temperatures improve fish yields. However, these fish populations will also encounter new ecological contexts with climate change, such as competition between existing and invading species. The coming decades will therefore present new challenges and opportunities for North Atlantic and North Pacific fisheries, which globally contribute almost 40% to commercial fish landings.