What Structures Marine Biodiversity and why does it vary?

Abstract

Marine ecological biodiversity research is a scientific field with few observational data to support a weak theory largely borrowed from terrestrial ecology and lacking in experimental verification. The relative lack of scientific interest and effort until recently was a consequence of the general feeling that marine biodiversity is far less threatened than terrestrial biodiversity. This view is not sustainable. There is now ample evidence of widespread changes in most coastal habitats in populated areas around the world (coral reefs, mangroves, seagrass fields, intertidal rocky shores and subtidal sediments on the continental shelf and margin) due to exploitation of marine resources, introduction of exotic species and the increased pressure from mariculture and fisheries. The sustainable exploitation of the seas requires development of a sound theoretical framework for marine biodiversity, including genetic, species and habitat diversity and especially the relationships between them. At the present state of knowledge such a general theory is still far from being reality. In this paper an overview is given of the main elements that an ecological theory of species diversity should include and what aspects of human pressure on the biodiversity of marine ecosystems should be given priority attention.