State of knowledge of coastal and marine biodiversity of Indian Ocean countries – An article from the Public Library of Science

The Indian Ocean extends over 30 per cent of the global ocean area and is rimmed by 36 littoral and 11 hinterland nations sustaining about 30 per cent of the world’s population. The landlocked character of the ocean along its northern boundary and the resultant seasonally reversing wind and sea surface circulation patterns are features unique to the Indian Ocean.

The Indian Ocean also accounts for 30 per cent of the global coral reef cover, 40,000 sq kms of mangroves, some of the world’s largest estuaries, and 9 large marine ecosystems. Numerous expeditions and institutional efforts in the last two centuries have contributed greatly to our knowledge of coastal and marine biodiversity within the Indian Ocean. The current inventory, as seen from the Ocean Biogeographic Information System, stands at 34,989 species, but the status of knowledge is not uniform among countries.

Lack of human, institutional, and technical capabilities in some Indian Ocean countries is the main cause for the heterogeneous level of growth in our understanding of the biodiversity of the Indian Ocean. The gaps in knowledge extend to several smaller taxa and to large parts of the shelf and deep-sea ecosystems, including seamounts. Habitat loss, uncontrolled developmental activities in the coastal zone, over extraction of resources, and coastal pollution are serious constraints on maintenance of highly diverse biota, especially in countries like those of the Indian Ocean, where environmental regulations are weak.

The article notes that the foremost issue in improving the state of knowledge of coastal and marine biodiversity in Indian Ocean countries is strengthening the taxonomic capacity base throughout the region. It has been variously hypothesized, from comparisons of the known diversity of a certain group in a region to the total number known in that group from other intensively studied regions or its global abundance, or from projections of the abundance of number of species in a smaller sampled area to the total area of the habitat in the region, that described biodiversity is only a fraction of what remains to be discovered. In light of the dwindling population of taxonomists, however, the magnitude of the task ahead is obvious.

The second issue of concern is the existence of gaps in the spatial and temporal coverage of CMB inventories. Given the vast difference between the number of species known now and those waiting to be discovered, increased spatial coverage is critical. Some obvious areas where gaps exist are continental shelves and deep seas, including seamounts. Even along the 60,000 km coastline of Indian Ocean countries, there are vast stretches that have never been sampled.

In this context, it is crucial to increase awareness among governmental funding agencies, international organizations, and donor agencies of the need to support biodiversity research.