Arctic Warming and the Atlantic-Pacific Fish Interchange

by Kyle Jensen

For most of the Quaternary Period the inhospitable environment north of the Arctic Circle has served as a biotic barrier between Northern portions of the Atlantic and Pacific oceans. Through it is known that interchange across the Northwest and Northeast passages has occurred, currently only 135 of over 800 fish species found above 50° of latitude are found in both oceans. Continued warming may result in the reopening of these passages resulting an accelerated interchange of species between the Atlantic and Pacific as species follow favorable conditions into higher latitudes. This may also lead to increased movement of fishing and shipping vessels through these channels, which could facilitate further interchange. This has the potential to impact the food webs and biodiversity of systems in both of these oceans, the consequences of which would affect ecosystems currently comprising 39% of global marine fish landings. To analyze potential impacts of future species interchange, Wisz et al (2015) has made forecasts of potential distributions for 515 fish species. Continue reading