Impacts of climate change on fish

The shelf seas surrounding the British Isles have warmed four times faster than the global average over the last 30 years. Recent warm conditions are unlike anything in the last 20,000 years, and warming is highly likely due to human activities linked to the global carbon cycle. Recent warming has caused some cold-water demersal (bottom-dwelling) species to move northwards and into deeper water (e.g. cod, whiting, monkfish), and has caused some warm-water demersal species to become more common or “invade” new areas (e.g. John dory, red mullet). Pelagic (blue-water) species are showing distributional shifts, with mackerel now extending into Icelandic and Faroe Island waters (with consequences for management), sardines and anchovies invading Irish and North Sea environments, and anchovies establishing breeding populations in the southern North Sea. Teasing apart the relative influences of the North Atlantic Oscillation, the Atlantic Multidecadal Oscillation and Global Warming as drivers for these changes is an important challenge.