Entanglements, Entanglements

WDC has always realized and celebrated the importance of responsible whale watching. One of the essential conservation outcomes of whale watching in the Gulf of Maine is the ability for whale watch companies to spot, report and stand by entangled whales until the Provincetown Center for Coastal Studies (PCCS) disentanglement teamcan respond. In fact, we ended our whale watching season with an entangled whale: Tornado’s 2012 calf. One of our fall interns, Evan Henerberry, is going to tell the rest of the story.

Tornado, a well-known mother and grandmother, returned this year with her seventh documented calf. We began seeing this mother/calf pair in late May, but on October 23rd the calf was reported entangled by a whale watch boat off Gloucester. The calf was reportedly towing over 500 feet of line with buoys attached from the left fluke and damage was clearly visible. The rescue team quickly responded to the whale watcher’s call; however, they were unable to relocate Tornado and her calf once they were on the scene, once again highlighting the importance of standing by an entangled whale until the rescue team is on-sight.

Plans were made for an aerial survey of the region and thankfully the pair was found and another rescue attempt was mounted on the 25th. After hours of arduous and dangerous work, Tornado’s calf was freed. We were fortunate enough to be arriving on scene on our last trip of the season as the disentanglement team had just freed the calf. We carefully documented the pair and thankfully the calf was last seen swimming calmly with it’s mother, scarred but alive.

Tornado and her calf’s ordeal and ultimate rescue, both the result of interactions with humans, paint an interesting picture. It was a bittersweet end to the whale watching season, particularly because on this trip we also saw harbor porpoises, which are struggling with their own entanglement issues.

This drawing by Scott Landry of PCCS shows just how dangerous entanglements can be, they are one of the primary dangers impacting whales. It’s made even more dangerous because we do not know the extent to which it is injuring and killing whales, and thus is underestimated. There is an abundance of fishing gear in the ocean and plenty of evidence that whales interact with it, including cases like this as well as entanglement scars left on whale from unwitnessed interactions.

Scientific awareness of entanglement can be traced as far back as the late 1950’s when the Journal for Deep-Sea research reported on 14 incidents of large whales becoming entangled in submarine cables while foraging. Since this time, more effort has been put into actively assessing the extent of whale interactions with marine debris, including actively fished gear.

A 30 year study by the New England Aquarium determined that out of 626 individual North Atlantic right whales photographed from 1980-2009, over 80% showed signs of previous entanglement. The plight of the North Atlantic right whale, a critically endangered species, puts a fresh urgency on these efforts, both to prevent entanglements and respond effectively to those that occur. As great as it is that whales can be disentangled, everyone agrees that disentanglement is not the solution. Work is being done to decrease the risk of entanglement in the first place.

Through the years there have been many strategies tested to reduce the threat of entanglement, some of which could be viewed as long shots. For example, studies have tested the effectiveness of glow-in-the dark fishing lines and lines of various colors to make them obvious to whales. Computer models have reconstructed entanglement interactions and mathematical models have estimated where the risk is the highest based upon the overlap of whales and gear – all in hopes of figuring out ways to reduce risk.

There have been gear modifications that help prevent and reduce the severity of entanglements, such as: acoustic alarms to warn harbor porpoises of gill nets, weak links on the vertical lines attaching gear to surface buoys which will break under a certain amount of pressure to prevent a whale becoming anchored to gear, and replacing floating line in-between lobster traps with sinking line to reduce the amount of line in the water column. But clearly more needs to be done. Disentangling whales is like putting a band aid on a cut- it will help to improve the condition but not prevent it from happening. The disentanglement teams all agree that the world would be a better place if there were no need for them to intervene at all and hope for the day when they can hang up their helmets for good.

In fact, just this week a fisherman reported an entangled whale outside of Cape Cod Bay. Again, the disentanglement team sprang into action and discovered a dangerously imperiled young humpback, which has yet to be identified. According to Scott Landry of PCCS,  “The whale was so injured and unhealthy that it couldn’t raise its flukes.” Heavy and durable synthetic fishing line was wound tightly around the whale’s tail and the team believed it had been towing the line for some time. Thankfully they were able to cut the gear off this humpback.

We are very thankful to the PCCS rescue team for their efforts and the fisherman who reported the entangled whale. This latest incident demonstrates the need for everyone to take part in conservation. There are simple choices you can make to help whales in your everyday life. For example, choose seafood that is sustainably caught and reduce the use of plastics, another threat to whales.Also, be sure to report any entanglements you may observe to the Coast Guard or your local disentanglement hotline (1-800-900-3622).