Why does biodiversity matter?
Why does it matter if we are losing species at an alarming rate?
There are many reasons, not least because the variety of life on earth directly benefits mankind in simple, practical ways. And besides these benefits, there's the inherent beauty we recognise in species such as the tiger, which make them worth saving for their own sake – our planet is a richer, more interesting place for species like this, and for rainforests, coral reefs and savannahs. Many people argue (including us) that we have a moral duty to preserve as much of life on earth as possible, and that we are guardians of the planet and all its life.
But beyond that, the natural world consists of so many complicated relationships between species that removing just one can sometimes have catastrophic effects beyond what we might expect. Sea otters, for example, are what is referred to as a 'keystone species' in the coastal waters of the North Pacific. They feed on sea urchins and other invertebrates, which in turn feed on kelp (a kind of sea weed).