Mother sperm whale and baby dead in fishing net in the Tyrrhenian Sea off Italy

A mother sperm whale and its baby have died after becoming tangled in a fishing net in the Tyrrhenian Sea off Italy's western coast, an Italian environmental group reported Thursday.

The Marevivo group said the Italian Coast Guard had responded to the sighting and surmised that the mother, which measured 6 meters (nearly 20 feet), died while trying to free its baby. They were found 8 miles off the coast of Palmarola Island in the Lazio region. It said part of the fishing net was found in the mother whale's mouth while the baby while was completely covered by it.

"The death of these two giants of the sea is a loss for our natural heritage, but knowing that what happened is our fault makes it even more tragic," said Marevivo President Rosalba Giugni. "Changing our behavior is not enough. We need to change our beliefs in order to understand and to actually feel that when we harm the environment, we do it to ourselves."

The deaths come after an 8-meter (26-foot) pregnant sperm whale was found dead on a Sardinian beach in March with 22 kilograms (48 1/2 pounds) of plastic in its belly.

Environmentalists say plastic is one of the greatest threats to marine life and has killed at least five other whales that had ingested large amounts of it over the last two years from Europe to Asia.