Scientists studied species diversity and functional uniqueness of marine megafauna, and also determined the consequences of its partial extinction in the coming century. It turned out that the disappearance of species, already endangered, will lead to the loss of half of the functions carried out within the ecosystems of the oceans. In a study published in the journal Science Advances, the authors proposed a new index FUSE that will allow more precise calculation of ecological functions of marine species and to prioritize their protection.
For marine megafauna include organisms weighing more than 45 kilograms. These species play a critical role in ocean ecosystems: absorb huge masses of smaller organisms, transporterowych nutrients through excretion and create connections between distant ecosystems through migration over long distances.
Despite the overall value of marine megafauna, it is under threat of extinction due to uncontrolled exploitation by man, habitat loss, ocean pollution and increase water temperature. According to the International Union for conservation of nature (IUCN), a third of these species already on the brink of extinction due to small population numbers and fragmentation. Previously, scientists did not give clear predictions on how changes of global marine ecosystems through the loss of megafauna. In addition, many scientific studies are focused on species diversity, ignoring the functional diversity and the concept of ecological guilds. Functions of the megafauna in the ocean is unique and less mobile and small species of them not be able to perform.
Scientists led by Catalina Pimento (Pimiento Catalina) at Swansea University has developed a special index called FUSE (functionally unique, specialized and endangered), which allows to quantify the contribution of individual species to ecosystem functioning and to prioritize conservation.
The authors of the study created an extensive database that included all living marine megafauna (334 species). The researchers then modeled two scenarios of extinction at global and regional scales. The first of these (IUCN 100) based on estimated probability of extinction of each species in the next 100 years, taking into account their conservation status in the IUCN. The second scenario (AT IUCN) suggests the extinction of all threatened species.