Feral fish

No, not the long-haired hippy type, I mean those that are not indigenous to a habitat.  USGS and NOAA just co-published a pictorial guide to the non-native fishes of Florida.  This is doubtless part of the heightened awareness of this problem in US waters and, indeed, worldwide.  Lord Robert May recently cited invasive alien species - along with climate change, over-exploitation, and habitat destruction - as the most important causes is species extinctions in the biodiversity crisis.  It seems marine species are not immune to this effect; even though the diversity-stability hypothesis predicts that reefs ought to resist invasions.

My PhD thesis was about what happens to the parasite fauna when a fish gets introduced to a new habitat, so this subject is close to my heart.  To learn more, read about the subject as reviewed by my colleague Mark Torchin here: