It is an event so rare that no one can remember it happening in Boston Harbor, and no one can predict what is about to unfold.
A dead finback whale, which could be as long as 70 feet, was spotted early Sunday morning floating near Black Falcon Cruise Terminal in South Boston, drifting with the currents like a message in a bottle.
But it won’t drift forever. It will eventually wash ashore. And when it does, it will present a whale-sized logistical challenge for the scientists looking to cut it apart to figure out what killed it, and law enforcement officials who may have to deal with thousands of onlookers who could come to look at it if it lands in an accessible area, such as a beach in South Boston.
Then there are issues involving land owners who are often shocked to hear they must dispose of it. Federal law says that if it lands on your beach, it’s your problem.
The finback whale was spotted off Long Island Sunday afternoon, and near Boston Light Monday. But its final resting spot is still anyone’s guess and will largely determine just how big of a problem it creates, said Tony LaCasse, a spokesman for the New England Aquarium.
“We have islands with piers and islands without piers,’’ LaCasse said. “We have islands with bridge access, and islands with no bridge access. If it comes up on Carson Beach in South Boston, that could make access easy, but then you’ll have to deal with restricting the access of thousands of onlookers.”
When it does come ashore, the shallow slope of Boston Harbor could make it difficult to pull the whale above the high-tide line without tearing it apart, leaving just 6 to 8 hours between tides for the necropsy and removal to take place.
Towing a whale to shore is very rare, LaCasse said, because it is expensive and requires approval of the National Oceanic and Atmospheric Administration, which usually only grants such permission if the whale is a critically endangered species, the carcass is fresh, and a suitable landing spot can be found. Understandably, it’s tough to find a land owner willing to host a “big, dead smelly whale,” LaCasse said.
So its final resting place will be left to chance and currents.
“I often call it a negative lottery,” said LaCasse, noting that there is sticker shock when a landowner is informed of the $15,000 to $20,000 cost of removal.
There are towns on the South Shore and Cape Cod that know the drill, but for others, “It’s almost like the stages of grief. Denial. Anger. Then acceptance,” LaCasse said.
LaCasse said aquarium officials have never had to work with Boston on such an issue, because whales are rare in the harbor — just three to four are spotted each year – and no one in the marine rescue community can remember seeing or hearing of one being found dead in the harbor., where beaches are under jurisdiction of the state Department of Conservation and Recreation.
Removing a whale involves huge equipment demands. A finback could weigh close to 100,000 pounds, and its blubber alone could fill up several construction dumpsters, according to LaCasse. Another option is to bury the soft tissue at the site, but that requires a confluence of many good circumstances.
For a necropsy, cutting through the tough hide and nine inches of blubber to get to the internal organs is a major ordeal, requiring a dozen trained staff and a truckload of whale-flenching tools that must be constantly resharpened. If they can get front-end loaders onto the site, they will often use two to pull back the blubber once the cuts are made.
If the whale comes ashore in an area where people will probably gather, LaCasse said, the aquarium will typically send a team of educators to answer questions and help keep people away from the animal. With the huge curiosity comes health risks.
“There’s always a health concern with species that don’t have regular contact with each other,” LaCasse said. “We can get things that are unfamiliar to our systems.”
Dogs are a particular concern. They are often the first to find a beached whale on early-morning beach walks, and they famously go nuts over the smell of rotting whale.
“Then Fido comes back to you and rubs his nose in your face, and all of a sudden we’ve had this opportunity to transfer pathogens from an animal to a human very quickly,” he said.
Once the whale has been successfully parsed, the skeleton may be preserved for display in a museum or educational institution by allowing the flesh to rot away in a special landfill or dropping it into lobster trap-like structures to the ocean floor to let crabs and worms and small fish pick the bones clean,’’ LaCasse said. “Each process takes about a year.’’
At the moment, the cause of death remains a mystery. Aquarium scientists have examined the floating corpse and noticed an unusual amount of blood around it, but LaCasse said that until the necropsy is complete, it’s impossible to tell whether it died due to natural causes, impact with a vessel, or entanglement in a fishing net.
Finback whales are common in this area but are listed as endangered, with an estimated 10,000 remaining in US waters, according to NOAA.