Researchers have recently learned that bottlenose dolphins, far from being the pacifists of the Pacific, are ferocious killers of a related species, the harbor porpoise.
Other marine mammals in the same stretch of the St. Lawrence, including harbor porpoises and seals, had been found to have high levels of contaminants in their tissue.
Some species, like the harbor porpoise, have been depleted to a point where their replenishment is in doubt.
Others say it might deter harbor porpoises, but be a dinner bell for seals.
An intensive survey to estimate the abundance of harbor porpoise in the Gulf of Maine began in 1991.
Visitors to Alder Creek or the Garcia River within Manchester can enjoy pods of harbor porpoises at play, spawning steelhead, and wintering waterfowl.
He was invited to review the biological acoustics laboratories for the Danish National Research Foundation and has been collaborating on the echolocation of harbor porpoises in the Netherlands.
A promising gillnet that is effective in reducing bycatch for harbor porpoises contains barium sulfate.
They focused on harbor porpoises, marine mammals up to five feet long, that were turning up dead with a strange mix of injuries, including multiple skeletal fractures and damaged internal organs.
In 1999 the aquarium opened a new rehabilitation center for harbor porpoises in Duxbury, Massachusetts.