Warming and exponential abundance increase of the subtropical fish Capros aper in the Bay of Biscay (1973-2002)

The exponential abundance increase of a sub-tropical species, boarfish (Capros aper), as well as the sea bottom temperature increase in the continental shelf of the Bay of Biscay (France) over the three last decades are reported. This species was rare in the seventies and is now a dominant one. This is a small bathy-demersal, probably short-lived species with few predators (probably because of the presence of strong spines) and not exploited by fisheries. In the same time, a significant temperature increase in the bottom waters is observed during the breeding season of this population. The boarfish abundance increase is related to the warming, its ability to invade and the absence of predators as well as the absence of fishing.