About 1 million species exist in ocean
The number of different marine eukaryote organisms could reach up to 972,000, according to researchers.
CSIC has participated in the international research, conducted by 270 taxonomists from 32 countries. The current number of marine species identified is roughly 230,000.
Every taxonomist has calculated the number of existing species within their specialty and estimated the number that remain to be discovered, both through statistical models as based on the experience of each expert.
According to Enrique Macpherson, researcher at the Center for Advanced Studies of Blanes (CEAB-CSIC, Spain), who has participated in the study: "Bringing together the leading taxonomists around the world to pool their information has been the great merit of this research."
The statistical prediction is based on the rate of description for new species in recent decades.
The results show that the total number of marine species would be about 540,000. However, this number ranges from 320,000 to 760,000.
Meanwhile, the experts have made another estimation based on their experience and on a projection of the number of species found in the sampled areas.
According to this prediction, the number of species ranges from 704,000 to 972,000.
All the information pooled by the experts show that just 230,000 species are correctly described.
In fact, researchers found about 170,000 cases of synonymy among previously known species. That is, one single species described under two (or more) different names.
Among the order, for instance, of cetaceans (Cetacea), researchers have found that there are 1,271 different names applied to just 87 species.
CSIC researcher Damia Jaume, from the Mediterranean Institute for Advanced Studies (IMEDEA, CSIC-UIB) and also involved in the study, states: "the best known is the species, and its greater size and commercial interest, the most common is synonymy."
Of the roughly 230,000 marine species known, about 200,000 belong to the kingdom Animalia; 7,600 to Plantae; 19,500 to Chromista; 550 to Protista; and 1,050 to Fungi.
The research has only counted with eukaryote organisms, i.e. those whose genetic information is enclosed in a cell nucleus, which has left out bacteria, viruses, and archaea.
The research data suggest that there are still about two-thirds of marine species to be described, most of which would already be inventoried.