Scientists estimate that there are more than 1 million marine species but only about 250,000 have been formally described in scientific literature over the centuries. Those figures exclude microbes -- of which the census estimate there are up to 1 billion kinds.
Myriam Sibuet, vice-chair of the Scientific Steering Committee on the mammoth study, said: "The census enlarged the known world. Life astonished us everywhere we looked. In the deep sea we found luxuriant communities despite extreme conditions."
The census also collated information on the 16,764 species of fish that have ever been described -- but estimates that a further 5,000 have yet to be discovered.
The short version is that nobody knows how many species are out there and if they do not know that, then then there is no real way to know whether the number of species is increasing or decreasing. Thus, the warmista claims of a great modern mass extinction driven by global warming are without scientific foundation!