Skip to content

Global ocean conveyor lowers extinction risk in the deep sea

April 1, 2014

General paradigms of species extinction risk are urgently needed as global habitat loss and rapid climate change threaten Earth with what could be its sixth mass extinction. Using the stony coral Lophelia pertusaas a model organism with the potential for wide larval dispersal, we investigated how the global ocean conveyor drove an unprecedented post-glacial range expansion in Earth’s largest biome, the deep sea. We compiled a unique ocean-scale dataset of published radiocarbon and uranium-series dates of fossil corals, the sedimentary protactinium-thorium record of Atlantic meridional overturning circulation (AMOC) strength, authigenic neodymium and lead isotopic ratios of circulation pathways, and coral biogeography, and integrated new Bayesian estimates of historic gene flow. Our compilation shows how export of Southern Ocean and Mediterranean waters after the Younger Dryas 11.6 kyr ago simultaneously triggered two dispersal events in the western and eastern Atlantic respectively. Each pathway injected larvae from refugia into ocean currents powered by a re-invigorated AMOC that led to the fastest postglacial range expansion ever recorded, covering 7500 km in under 400 years. In addition to its role in modulating global climate, our study illuminates how the ocean conveyor creates broad geographic ranges that lower extinction risk in the deep sea.

Henry L-A, Frank N, Hebbeln D, Wienberg C, Robinson L, van de Flierdt T, Dahl M, Douarin M, Morrison CL, López Correa M, Rogers AD, Ruckelshausen M, Roberts JM, in press: Global ocean conveyor lowers extinction risk in the deep sea, Deep Sea Research Part I: Oceanographic Research Papers, doi:10.1016/j.dsr.2014.03.004. Article (subscription required).

 

Advertisements

Comments are closed.

%d bloggers like this: