The understanding of the North Atlantic ecosystems dynamics, connectivity and biodiversity requires an integrated knowledge of its present and past connection with the Mediterranean Sea. Many deep-sea species, including structural engineers such as cold-water corals and a wide variety of gorgonians and sponges, as well as several species of fish and other invertebrates are distributed in both the Atlantic and the Mediterranean basins. Indeed, it seems that some species (e.g. L. pertusa) recolonised the Atlantic from the Mediterranean after the last glacial episodes.

The present day interconnection and possible interdependency of deep-sea populations occurring at each side of the Strait of Gibraltar are presently unknown, although the strong influence of both the Mediterranean Outflow water (MOW) and the Atlantic Meridional Overturning Circulation (AMOC) may result in convergence at least in the Northern Atlantic. In this context, the Mediterranean Sea is highly relevant due to its influence on the thermohaline circulation that is originated in the Polar convective cells in the North Atlantic and in the Greenland and Labrador seas, where the “North Atlantic Deep Water” (NADW) originates.

This case study focuses on understanding the Atlantic-Mediterranean biodiversity and connectivity and will address the role of the Mediterranean waters regarding those aspects. The area supports intensive anthropogenic activity, including tourism, fisheries, aquaculture, oil and gas exploitation, bioactives, wind energy and it is an important area for maritime traffic.

Blue Growth Sectors: Biotechnology, Fisheries, Oil and Gas

Gorgonian (Callogorgia sp.) at the Gazul summit. © Instituto Español de Oceanografia (IEO), Medwaves Expedition (2016).