Unintended consequences of long-distance do-gooding?

It was believed by charitable do gooders  that buying insecticide-coated malarial nets for Africa ws an effective bit of altruism.

But a later development as noted in a report in the New York Times, that these nets were being modified and used for fishing in lakes such as Lake Tanganyika. 

The modified nets catch everything, leaving little breeding stock for future generations. Unintended consequences of long-distance do-gooding?