Northeastern Atlantic cold-water coral reefs and climate

Abstract

U-series age patterns obtained on reef framework-forming cold-water corals collected over a nearly 6000-km-long continental margin sector, extending from off Mauritania (17N; northwest Africa) to the southwestern Barents Sea (70N; northeastern Europe), reveal strong climate infl uences on the geographical distribution and sustained development of these ecosystems. Over the past three glacial-interglacial cycles, framework-forming cold-water corals (Lophelia pertusa and Madrepora oculata) seem to have predominantly populated reefs, canyons, and patches in the temperate East Atlantic and the Mediterranean Sea. Above 50N corals colonize reefs in the northern East Atlantic primarily during warm climate periods with the biogeographic limit advancing from ~50N to ~70N. We propose that north-south oscillations of the biogeographic limit of reef developments are paced by ice ages and may occur synchronously with north-south displacement of cold nutrient-rich intermediate waters and surface productivity related to changes of the polar front.