Deep sea creatures are contaminated with man-made pollutants

By Beth Daley, Globe Staff

Man-made chemicals are contaminating squids and octopuses in the deep sea, according to a new study published in the journal Marine Pollution Bulletin.

Scientists already know that whales and other marine mammals’ blubber and tissues contain a variety of chemicals known as persistent organic pollutants because they don’t degrade over time.

Close-up of eyes of Teuthowenia megalops, a cockatoo squid. Although not very muscular, the species is quite common in the deep waters off New England. (Michael Vecchione, NOAA)

Researchers have speculated that the pollutants accumulate in the whales because they feed on contaminated squids. The study, by the National Marine Fisheries Service and the Virginia Institute of Marine Science of The College of William and Mary set out to discover if whales have some unique ability to accumulate pollutants or if they were the top predator in a contaminated deep-sea food web.

The researchers collected 22 specimens in the western North Atlantic from depths of 3,300 to 6,600 feet, including vampire squids, short-finned squid, and large jelly-like octopuses. The researchers detected polychlorinated biphenyls, or PCBS, a banned probable human carcinogen; DDT, the controversial U.S. banned pesticide that is still used in some parts of the world to control diseases like malaria;

Tributyltin, used in antifouling paints for boats that is being phased out worldwide because of it toxicity to some marine organisms; and other chemicals.

“It was surprising to find measurable and sometimes high amounts of toxic pollutants in such a deep and remote environment,’’ said Michael Vecchione of the National Systematics Laboratory for the National Marine Fisheries Service.

The deep sea squids and octopuses are the primary food for some marine mammals that have teeth that include beaked, sperm, killer and beluga whales and dolphins and porpoises.