PARENT SESSION
Contributed Oral Session 131: Biogeography: Ranges; Species Area; Populations
Thursday, August 11, 1:30 PM - 5:00 PM, Meeting Room 515 A, Level 5, Palais des congrès de Montréal

Global biodiversity patterns of benthic marine algae.

Kerswell, Ailsa^*,1, ¹ School of Marine Biology and Aquaculture, Townsville, Qld, Australia

ABSTRACT- Species richness patterns are remarkably similar across many marine taxa, yet explanations of how such patterns are generated and maintained are conflicting. We use published occurrence data to produce comprehensive diversity maps for all benthic marine algal genera and for species in the Order Bryopsidales. These results explicitly document distinct latitudinal and longitudinal diversity gradients and we consider how the size and location of algal geographic ranges combine to generate the patterns. Algal genera have biodiversity hotspots located in temperate regions, while bryopsidalean species reach peak diversity in the tropics. For both groups, hotspots are generated by the accumulation of small to medium ranging taxa in a common location in addition to a base of diversity created by wide ranging species. Endemic taxa contribute only modestly to the diversity of hotspots. Differences between Indo-Pacific and Atlantic Ocean algal diversity are identified and used to understand the processes underlying the observed patterns. We also observe striking similarities in the diversity patterns of benthic marine algae and other marine taxa, which allows us to further speculate on the mechanisms underlying global marine diversity patterns. We suggest that warm-water ocean currents feed areas of significant suitable habitat to create diversity hotspots for a suite of marine taxa.

Key words: macroalgae, diversity, range