The world’s oceans remain largely unknown to science, with at least 1/3 of the total oceanic species in the world currently undiscovered, according to a new report.
And that is even with the dramatic increase in the number of new species discovered in the last decade compared to any previous ones.
By the researchers’ estimate there are likely as many one million species living in the world’s oceans in total, but probably not any more than that. So far, around 226,000 ocean living species have been described. And there are around another 65,000 species waiting to be described that are in specimen collections.
“For the first time, we can provide a very detailed overview of species richness, partitioned among all major marine groups. It is the state of the art of what we know — and perhaps do not know — about life in the ocean,” says Ward Appeltans of the Intergovernmental Oceanographic Commission (IOC) of UNESCO.
“The findings provide a reference point for conservation efforts and estimates of extinction rates, the researchers say. They expect that the vast majority of unknown species — composed disproportionately of smaller crustaceans, molluscs, worms, and sponges — will be found this century.”
“Earlier estimates of ocean diversity had relied on expert polls based on extrapolations from past rates of species descriptions and other measures. Those estimates varied widely, suffering because there was no global catalog of marine species.”
In response to this, such an inventory has now been created. “The World Register of Marine Species (WoRMS) is an open-access, online database (see http://www.marinespecies.org/) created by 270 experts representing 146 institutions and 32 countries. It is now 95% complete and is continually being updated as new species are discovered.”
“Building this was not as simple as it should be, because there has not been any formal way to register species,” Costello says.
“A particular problem is the occurrence of multiple descriptions and names for the same species — so called ‘synonyms,’ Costello says. For instance, each whale or dolphin has on average 14 different scientific names.”
“As those synonyms are discovered through careful examination of records and specimens, the researchers expect perhaps 40,000 ‘species’ to be struck from the list. But such losses will probably be made up as DNA evidence reveals overlooked ‘cryptic’ species.”
“While fewer species live in the ocean than on land, marine life represents much older evolutionary lineages that are fundamental to our understanding of life on Earth, Appeltans says. And, in some sense, WoRMS is only the start.”
“This database provides an example of how other biologists could similarly collaborate to collectively produce an inventory of all life on Earth,” Appeltans says.
The new report was just published online in the Cell Press publication Current Biology.
Source: Cell Press
Image Credits: Rachel Graham/Wildlife Conservation Society; Benthic via Wikimedia Commons