I've been looking at ocean biodiversity that's the diversity of species that live in the world's oceans. Biologists still don't know how serious a threat to their survival is for each individual species. So a body called the global marine species assessment is now creating a list of endangered species on land so they consider things like the size of the population. How many members of one species are in a particular place and then they look at their distribution in geographical terms. Although this is quite difficult when you look at fish because they are so mobile and then they calculate the rate at which the decline of the species is happening. So far only 1500 species have assessed but they want to increase this figure to 20000 for each one. They assess they used the data they collect on that species to produce a map showing its distribution. So finally what can be done to retain the diversity of species in the world's oceans. Firstly, we need to set up more reserves in our oceans places where marine species are protected.
We have some but not enough in addition to preserve species such as leather-back turtles. We need to create corridors for migration so they can get from one area to another safely.