15 November 2012: According to a study published today and coordinated by the Intergovernmental Oceanographic Commission (IOC) of the UN Educational, Scientific and Cultural Organization (UNESCO), well-known marine animals, such as whales or dolphins, represent a tiny fraction of marine biodiversity. The 226,000 marine species identified so far are “but a small portion” of the estimated 700,000 to one million total.

This study draws its conclusions from the World Register of Marine Species (WoRMS), an open-access, online database created in 2007 with the participation of 146 institutions in 32 countries. Experts estimate that between two and eight new cetacean species, and almost ten marine reptile species, remain to be discovered. The unknown species are composed mostly of groups of macroinvertebrates, with tens of thousands of species of smaller crustaceans, molluscs worms and sponges awaiting discovery.

Ward Appeltans, coordinator of the Ocean Biogeographic Information System (OBIS) of IOC, noted that ocean life represents older evolutionary lineages than life found on land, and that evaluating the total number of species is important because it provides a idea of what is known and how much is not yet known of life in the ocean. [UNESCO Press Release]