From MarineSpecies Introduced Traits Wiki
Definition of Biodiversity:
The variability among living organisms from all sources, including, 'inter alia', terrestrial, marine, and other aquatic ecosystems, and the ecological complexes of which they are part: this includes diversity within species, between species and of ecosystems.
This is the common definition for Biodiversity, other definitions can be discussed in the article
The term biodiversity is used by the Convention on Biological Diversity to refer to all aspects of variability evident within the living world, including diversity within and between individuals, populations, species, communities, and ecosystems. The term is commonly used loosely to refer to all species and habitats in some given area, or even on the Earth overall. In fact, it relates to environmental attributes, often species or species groups, which can be sampled and whose modification is supposed to reflect a change of biological diversity.