ANCHORAGE, Alaska— The Center for Biological Diversity today urged Royal Caribbean to adopt a policy of slowing its cruise ships to 10 knots or less when traveling through important whale habitat.

Today’s letter to the company follows a June 19 incident where a Royal Caribbean mega-cruise ship arrived at port in Seward, Alaska, with a dead endangered fin whale on the bow. Federal officials determined that the whale was pregnant and had suffered blunt force trauma to the spine, ribs and jaw — consistent with a ship strike.

“I’m infuriated that this supersized cruise ship hit an endangered whale in such a horrific way,” said Cooper Freeman, Alaska director at the Center for Biological Diversity. “The death of this mother and baby fin whale sets back the entire population. Royal Caribbean must be held accountable for this gruesome death and take immediate action to avoid this happening again.”

Vessel strikes are a leading cause of death for large whales, with hundreds of whales killed in U.S. waters every year by ship strikes. Scientists regard documented cases as an undercount, because most whales struck by ships sink to the bottom of the ocean, going unnoticed or unreported.

Except for Alaska Native subsistence harvest, killing a whale, even accidentally, is illegal under the Marine Mammal Protection Act and the Endangered Species Act for listed species such as the fin whale. The June 19 incident is under investigation by federal authorities.

“People deserve to know how this happened, including whether the crew knew there were whales in the ship’s way and how fast the ship was traveling,” said Freeman. “For years we’ve been calling on the federal government to implement mandatory vessel speed reductions in whale hot spots, but Royal Caribbean can take immediate action to avoid hitting more whales with its ships. It’s so frustrating that government and industry fail to enact common-sense solutions to this problem while our endangered whales suffer deadly consequences.”

The Center’s letter urges Royal Caribbean to “adopt a policy requiring your cruise ships to slow to 10 knots or less when traversing through important whale habitat areas.” Studies show that slowing ships to 10 knots or less can prevent deadly ship strikes.

The Center also has a lawsuit pending against the U.S. Coast Guard over the agency’s failure to protect whales in designated shipping lanes off the West Coast of the United States.