Jean-Claude Quero

Les observations de poissons tropicaux et le réchauffement des eaux dans l'Atlantique européen

Abstract A recapitulation of the records of tropical fishes from European Atlantic waters shows that 67.6% were fishes caught from the upper slope, between approximately 200 and 600 m; 19.8% were fishes caught from the continental shelf; and 13.5% were specimens caught from the middle slope, between 700 and 1 300 m. Since 1963, the upper slope species have made regular northward range extensions off of south Portugal to north-western Ireland (about 55° 30′N), more and less rapidly, about 30 years for Cyttopsis roseus and only 6 years for Sphoeroides pachygaster. The continental shelf species, observed from 1969 but mostly from 1981, have a northward range to south-eastern Ireland (about 52° N), but 65.2% of them have been caught off the south of the Bay of Biscay. The middle slope species, recorded only from 1991 according to the development of the deep fishery, were caught between 48° N and 60° N. The northward range extension of upper slope species and the higher frequency of records of continental shelf species from the southern part of the Bay of Biscay coincide with the investigations on the warming of the south-north current in the upper slope of northern Spain and of the south French Atlantic continental shelf.

Changes in the Euro‐Atlantic fish species composition resulting from fishing and ocean warming

Abstract Studies of actual ichtyological biodiversity in the European Atlantic Ocean and estimation of changes in the relative abundance of fish species in catches off Arcachon, on the shelf and in the Bassin dArcachon, from 1727 to the present day are made. These show that some previously dominant species are now rare. Several disappeared to the south of the Bay of Biscay, such as the bottom‐living elasmobranchs with low reproduction rates (Echinorhinus brucus, Squatina squatina, Raja batis, R. brachyura, R. clavata, Dasyatis pastinaca, Myliobatis aquila, Galeorhinus galeus, Mustelus asterias), and teleostean fishes Trigla lyra and Eutrigla gurnardus. Overfishing with most fishing gears, but especially bottom trawls is responsible for their reduction. An additional study was made on tropical species which were not recorded before 1950 to the north of Portugal. The species include Zenopsis conchifer, Cyttopsis roseus, Chaunax spp., Sphoeroides pacbygaster. Tarpon atlanticus, Seriola rivoliana, S. dumeril...