One in six species in "Finding Nemo" is threatened by extinction say scientists

The ocean faces a biodiversity crisis. Scientists wanted to know whether notoriety of the characters in "Finding Nemo" helped with better protection. Helas, of the 1568 species represented and analysed for their conservation status, some 16% are threatened by extinction, e.g. half of the 8 species of Hammerhead sharks (Anchor).

Except for marine turtles, many species are not well studied for their conservation status. So there is some uncertainty about the degree of threat. Invertebrates, such as sea stars, crabs, bivalves and gastropods are particularly poorly studied.

But where studies are available, they are often point to rather high levels of extinction threat. For example, all six species of turtles (Squirt, Crush) are in that category.

Despite the immensity of the ocean, quite a number of fish species are also threatened, particularly Geat whites and mako sharks (Bruce, Chum), but also eagle rays (Mr. Ray). Clownfish Nemo himself is suffering from those threats.

When analysing the reasons for poor conservation status of species, fisheries turn out to be the single most important, followed by climate change and habitat destruction. Sharks and rays decline as dramatically as they do almost exclusively because of fishing. The warming of surface waters  affects e.g. coral leading to bleaching and thus destruction of habitat of reef associated fish and invertebrate species. Pollution and development also affects these nearshore species.

Species carrying out wide-ranging migrations like turtles and marine birds face a much broader range of threats. Not only do they drown in fishing nets, but their nest are being robbed, they may starve to death from ingesting plastic they mistake for food or their habitat during other stages of the life cycle may be affected by changes in the land and the oceanic environments.

In summary, comparatively poor knowledge about the conservation status of marine animals translates into hazards for even prominent species. It is a confirmation of the trend that we don't protect what we don't know and a good reason to spend more time and resources on studying the ocean and its wonderful creatures to avoid losing them.

To read the scientific article click here. Food for thought not only for World Oceans Day (8 June). The reference is

Loren McClenachan, Andrew B. Cooper, Kent E. Carpenter, & Nicholas K. Dulvy. Extinction risk and bottlenecks in the conservation of charismatic marine species. Conservation Letters 5 (2012) 73–80.