SEMINAR: The Influence of Mid-Ocean Ridges on Euphausiid and Pelagic Ecology

Mid-Ocean Ridges (MORs) are probably the most conspicuous underwater features of the World-Ocean. Forming a continuous mountain chain that runs around the globe like the seam of a baseball, ridges extends over 60000 km, transcending latitudes, biomes, and oceans. This study builds on the decadal efforts of the Census of Marine life, and presents new data on euphausiid distribution, in order to explore the influence of MORs on pelagic ecology. Generalized Additive Models of basin scale distribution patterns of euphausiids in the Atlantic and the Pacific suggests that species richness in the pelagic realm is driven primarily by variability in sea surface temperature and nutrient concentration, and that MORs have little influence on epipelagic diversity (0-200m). Analysis of horizontal and vertical mesoscale patterns of euphausiids and decapods over the northern Mid-Atlantic Ridge and the South West Indian Ocean Ridge suggests that MORs may structure vertical species richness patterns in the mesopelagic (200-1000m) and bathypelagic (1000-4000m). The influence of MORs at deeper depth horizons (> 200m) may be comparable to that of hedges in a farmland; whilst delimiting the extent of crops (or zooplankton assemblages), hedges serve as local hotspots of mammal and avian diversity.