The most comprehensive assessment of ocean life has revealed that one third to two thirds of all species are still unknown to science.
The scientists published their findings in the journal Current Biology. There were fewer than 1 million marine species, including 226,000 species that had been described by science and 72,000 in collections awaiting description.
The rate of discovery is increasing, with an additional 20,000 new marine species described in the last decade, indicating that most marine species would be discovered in this century.
This is by far the most comprehensive assessment of how many marine species have been described to date, and how many undescribed species there could be, states Mark Costello, co-author. The study involved 120 of the world’s experts in taxonomy of marine species.
Many of the undiscovered species will come from smaller crustaceans, molluscs, algae, worms, and sponges. This is vital for conservation efforts since species are the most practical measure for distinguishing habitats and tracking progress in exploring the planet’s biodiversity. This also allows a more accurate estimate of extinction rates due to habitat loss.
The research will contribute to the World Register of Marine Species, an open-access, online database that has received contributions from 300 scientists from 32 countries.