A humpback whale entangled in fishing gear off the coast of Truro this week was freed after a marine rescue team doing research in the area spotted the trapped animal.
The team, from the Center for Coastal Studies, was conducting a survey about two miles off Ballston Beach on Tuesday when they came across the whale.
“It was in a position where it was anchored by a long tether to the sea floor,” Marine Animal Entanglement Response director Scott Landry said by phone. The center reported that the whale had “two tight wraps of rope around the base of the tail heading to gear on the seafloor.”
The whale was still able to reach the surface to breathe.
Landry said it was lucky the team came across the whale, because it could have been stuck in place for far longer.
“What was remarkable about it is that the animal was not obvious,” Landry said of the chance discovery.
“Any passing mariner would probably not even notice it,” he said. “The reason we noticed it is because we were looking for humpbacks. We just barely noticed its head sticking out of the water.”
“Entanglements are very cryptic,” he said.
Based on the whale’s injuries, Landry said the team determined it had been entangled for one or two days. The humpback appeared to have dragged fishing gear snarled on its body into two more gear sets, which anchored the mammal to the sea floor.
After assessing the situation, the team contacted the National Oceanic and Atmospheric Administration for permission to begin disentangling the whale. All such activities need a NOAA permit because of the risks involved.
The team used a 30-foot pole equipped with a hook-shaped knife to cut the ropes wrapped around the humpback’s tail. Once free, the whale immediately swam off, the center said. It took about a half-hour to free the whale.
The center said the whale appeared to be in good condition. The team observed “rope cutting into the animal’s skin and blubber,” Landry said, but he expected the young whale would be fine. “Barring something that we don’t know about, the animal should make a full recovery,” he said.
Humpbacks are currently in the midst of an “unusual mortality event,” according to NOAA. The species has recently seen an increase in strandings from North Carolina to Maine, according to the agency, with 26 deaths recorded in 2016 and 24 so far in 2017 through Aug. 1. An average of 11 humpback whales died annually from 2011 to 2015.
Landry said recent documented humpback deaths can be attributed to a variety of causes, and researchers are still working to determine what is causing the ongoing mortality event.
“We’re finding a palette of reasons” for deaths, Landry said. “Some have been hit by boats, some have been entangled, some we don’t really know why.”
Landry also said he was concerned about the circumstances of this week’s incident. The animal was barely visible to the researchers, and he said there could be more whales trapped that won’t ever being found.
“It’s very unsettling,” he said. “One has to question how often this happens. There are probably a lot more whales out there entangled than are actually found.”Ben Thompson can be reached at email@example.com.