It’s a familiar ecology story: human dam-building activities in the 1980s wiped out a species of prawn in the Senegal River by blocking its migration routes. But this tale takes an unexpected turn into human health. A pilot study suggests that reintroducing the prawns to the river wouldn’t be good just for biodiversity—it could also help to control a parasite that causes disease in humans.
The research, published today in PNAS, found that when river prawns were reintroduced to a village’s water supply, the number of parasite-carrying water snails dropped substantially compared to a village with no prawns. This drop had a significant impact on the disease levels of the villagers.
This reads like a poorly constructed experiment. The “control” village really wasn’t. There should have been a third village with a net, and no prawns or medication if they were going to do it correctly. Or at the very least set up a third net in a similar setting and conduct snail counts in all three. But I could understand the reluctance to withhold medication just for the study, assuming there was enough to go around outside the study area already.
The article didn’t mention if the prawns were edible, but I’d take prawns over snails any day.