Shifting Baselines

For a baseline to shift, there must be an element of amnesia. To be forgotten, you must first be acknowledged as existing. What of the unlucky mollusks then? Few people know much about these slimy, slow movers. A new article discusses the vertebrate bias in conservation and the grim future for mollusks, particularly terrestrial species.

The decline and loss of mammals, birds, and other vertebrate species is well documented and often brought to public attention as a consequence of recent human impact on environment. It is indeed alarming to realize that we have lost 135 bird species, 70 mammal species3, and that so many more are under threat because of human activities. However, as guilty we should feel for their loss, vertebrates represent less than half of the documented extinctions. Comparatively, invertebrate species (without a backbone) receive much less media attention, even though they comprise nearly 99% of all animal diversity4 and occupy a central role in the survival or maintenance of most ecosystems.

There are an estimated 80,000 to 150,000 described molluscan species and they are the 2nd most diverse animal group (after arthropods), thus representing a large part of evolutionary history that happened on our planet. But their extinction rates are not widely known mostly because if you don't know a mollusk population exists, it's even more difficult to know when it has declined or perished.

Luckily, there are several mollusk maniacs here at ScienceBlogs. Check out more about mollusks and the threats to their survival (such as invasive species) here.