The loss of one species from an ecosystem can have unpredictable — and on occasion catastrophic — cascading effects. A modelling study suggests a strategy for rescuing a troubled ecosystem: selectively remove one or more additional species.

Sagar Sahasrabudhe and Adilson Motter of Northwestern University in Evanston, Illinois, showed that removing or partially suppressing one or more species in a food web at key time points after one member has become extinct saves other members of the web from the same fate. The duo used several model food webs, as well as two webs modelled with data derived from real ecosystems — the Chesapeake Bay off Maryland and Virginia, and the Coachella Valley in Southern California.

The idea — a controversial one that may not sit well with some conservationists — relies on the fact that ecosystem networks tend to shift to a different stable arrangement after losing members.

Nature Commun. doi:10.1038/ncomms1163 (2011)