Throughout the summers of 2012 and 2013, the dogs were trained to keep the gulls from landing on the beach while researchers tested water and sand samples for E. coli. The team found that bacterial counts were significantly lower on the beaches where the dogs were working. They also learned that timing is crucial. Dr. Alm found that if the dogs didn't curb the seagulls in the beginning of the season, E. coli would establish and could not be reduced.
It sounds like there's a lot more research to be done, but the Border Collies seem to be a humane solution for keeping beaches open and people healthy.