CIHEAM Press Review

A recent study that found no general decline in the numbers of species in individual ecosystems has sparked controversy. Some scientists see it as evidence of how species adapt, while others see it as a sign that common invasive species, such as rats and mosquitoes, are the real winners.

An invasion of alien crayfish in Malta's natural freshwater streams is taking over the last haunts of some of the island's beloved species, a new study has found. 
Recently published in the Journal of Crustacean Biology, the study has revealed the extent of the invasion of freshwater valley systems in the Maltese islands by a number of introduced crayfish species. 

In a development that has important implications for conservation, scientists are increasingly focusing not just on what species are present in an ecosystem, but on the roles that certain key species play in shaping their environment.