July 20, 2016 at 04:56PM on Facebook

RIP to Robert Treat Paine, the ecologist who discovered the central, regulatory role of top predators in ecosystems. “Paine demonstrated conclusively that, at least on one rocky shore, the top predator both controlled its prey and affected most of the other species in the community (R. T. Paine Am. Nat. 100, 65–75; 1966). The ochre starfish is a generalist predator, consuming barnacles, snails, limpets and more. Its favourite food is the California mussel — the dominant competitor for space on the rocks. By controlling mussel numbers, starfish enable a wide diversity of species to co-exist, including other prey species, and an array of seaweeds, sponges and anemones that the starfish do not consume. When Paine removed the stars from the system, mussels quickly crowded out other species. Comparable dynamics were later demonstrated for keystone species in other marine, terrestrial and freshwater ecosystems.”