If you haven’t heard of George Monbiot, you should have! He is a gifted story-teller and environmental activist, and I love reading his articles, which are diverse and well-thought out. His credentials are excellent (read his bio for some interesting history of his exploits when he was young), his knowledge and interests broad, and his writings impressive and inspiring. He writes for the Guardian and his articles are on his website.
I was especially taken by his recent article entitled Everything is Connected, and reminded me of the wonderful video and story associated with the reintroduction of wolves to Yellowstone National Park 20 years ago (that he narrated). He and others at the Sustainable Human organisation have produced another video on the theme of whales and whale poo. It is well worth a look. It is called How Whales Change Climate.
Both stories are based on the concept of trophic cascades. In trophic cascades, the effects of predators ‘cascades’ down through the trophic (feeding) levels, to their prey, their prey’s prey and so on, in sometimes counter-intuitive ways. A big fish, for example, eats a smaller fish, which in turn eats zooplankton, which grazes on phytoplankton. These ‘top-down’ effects can be substantial and have been considered important for maintaining biodiversity in a number of ecosystems. See, for example, Fabrizio Sergio‘s work on raptors and Julia Baum‘s and Boris Worm‘s work in oceans. I will post a blog devoted to trophic cascades and rivers in the near future.
Of course, there are many more interactions in nature besides trophic cascades that structure ecosystems. But the appeal for me as an ecologist and as a teacher of ecology is that stories involving trophic cascades show really nicely the interconnectedness of components of ecosystems that we might not, at first or even second and third glance, think are connected. Trophic cascades also warn against complacency: that if we affect one component of an ecosystem, we are most likely creating a ripple effect that can carry far beyond the original disturbance.
I hope you enjoy George Monbiot’s writing.