Signal 91 percent of an expected 2.2 million marine species undescribed

Summary

The planetary boundaries framework does not yet include a comprehensive assessment of marine life. The genetic component of biosphere integrity is measured through extinction rates, but current estimates rest mainly on vertebrates and a few land invertebrate groups. In the ocean, invertebrates such as polychaetes, crustaceans and echinoderms are the most species-rich groups, so these estimates do not represent marine systems well. On top of that, 91 percent of the 2.2 million species expected in the ocean have yet to be described. Even as new data arrive, the lack of historical records makes precise extinction-rate estimates for marine biodiversity impossible. The report concludes that capturing marine biodiversity loss properly requires an alternative metric covering a wider range of taxa.