Another Fine Mess 'Biocontrol' Got Us Into

There are many examples of problematic attempts at biocontrol. Notable cases include the introduction of the Cane toad to Australia and the Indian mongoose to Hawaii. A less well-known example resulted in the wiping out of the unique Partula 'tree snails' in French Polynesia (https://www.theguardian.com/environment/2023/apr/27/polynesian-partula-snails-extinct-in-the-wild-species). Problems were caused in Polynesia, by the accidental introduction of the alien African giant land snail (kept, today, as a non-demanding 'pet' by some folk). Attempts were made to wipe out this alien by loosing another 'outsider'. The predatory Rosy wolf snail was the designated killer and consequently released. Unfortunately, the Rosy wolf snails found the small endemic (local) Partula snails easier prey. The wolf snails 'sped' along the slime scent trails of the Partula to make their kills. Partula became extinct on all the islands of French Polynesia. Now, more than 5000 Partula (of 11 different species) have been reared in English, Scotish and US zoos. These snails will be released on the islands of Mo'orea and Tahiti. The snails will be marked with a dot of paint that emits UV when specially illuminated. This will help scientist to track the populations, as they (hopefully) re-establish themselves.