Majority of Marine Species Still Remain Unknown to Scientists

While more new marine species were identified over the last 10 years than during any previous decade, as many as two-thirds of the plant and animal species living in the oceans may still be unknown to scientists, a new study says. Writing in the journal Current Biology, a team of international scientists estimates that there are
Marbled swimming crab
Hans Hillewaert/Flickr
The marbled swimming crab
likely 700,000 to 1 million species in the oceans, of which only 226,000 species have so far been identified. Another 65,000 are sitting in scientific collections awaiting identification, according to the study. The study, which was produced by 270 experts from 32 countries, represents the most comprehensive inventory of marine life, and notes that the majority of unknown species are composed of crustaceans, mollusks, worms, and sponges. “For the first time, we can provide a very detailed overview of species richness, partitioned among all the marine groups,” said Ward Appeltans, a biologist at UNESCO’s International Oceanographic Commission and one of the study’s authors. The complete inventory can be viewed online at