 Biodiversity however, is not a concept but an umbrella term (Haila and Kouki 1994); the content of which is quite diverse as can be inferred by definitions provided in many different texts (Wilson 1988, Reid and Miller 1989, CBD 1992, Margalef 1997).The distinction between and biodiversity is also fairly unclear in many studies in biology.As with most other issues in Ecology and Evolution, paradigms dominating the study of biodiversity on both global and regional scales come mainly from the terrestrial environment despite the marked distinctive features of marine biodiversity and the fact that the aquatic (freshwater & marine) environment occupies more than two thirds of the Earth’s surface (Vanaverbeke et al.