With vessel strikes to right whales on the decline since numerous mitigation measures were put into place, the current number one threat to right whales is entanglement in fishing gear. The majority of the entangling fishing gear involves pot or trap gear (for bottom dwellers like lobster and crab, or certain fish species) and gillnet (for groundfish like cod and haddock, and other fish species). Nearly 83% of the North Atlantic right whale population shows evidence of having been entangled in fishing gear at least once, with 59% being entangled more than once (some whales have experienced over five entanglement events!). Entanglement impacts cover a wide range: from residual scarring only (typically minor), to moderate and severe levels, the latter of which includes individuals with attached gear that can lead to reduced health, infection, severing of body parts, starvation... along with what must be an incredible amount of suffering. Unfortunately, in recent years entanglement cases categorized as severe have become more frequent.

Right whale "Bridle" (Catalog #3311) suffered a severe entanglement during which this line sliced through and under the callosity. Despite disentanglement attempts, Bridle most likely died from causes related to his injuries. Photo: Florida Fish and Wildlife Conservation Commission under NOAA Permit # 932-1905/MA 009526.

Steps have been taken to address this chronic problem, such as the creation of seasonal fishing closures, reduction of the number of vertical lines in the water and use of sinking groundline, but it's still too early to determine how these measures have helped. Researchers from the New England Aquarium (Amy Knowlton, Scott Kraus, Tim Werner) and Center for Coastal Studies (Jooke Robbins, Scott Landry), and rope engineer Henry McKenna turned to examining the ropes recovered from disentangled whales or from those found dead and entangled to see if trends would emerge to shape the story of why these entanglements have increased. That's right- the National Marine Fisheries Service maintains a storage facility that houses the ropes pulled off of entangled whales! This is just one of the reasons why disentanglement by professional teams is so important- they know they need to recover the gear to help advance our knowledge and understanding of the entanglement issue.

"Ruffian" (Catalog #3530), photographed with numerous raw wounds all over his body after a severe entanglement. Photo: Florida Fish and Wildlife Conservation Commission, taken under NOAA Permit #932-1489-09.

Amy Knowlton and her colleagues took these recovered ropes (132 different ropes from 70 entanglements of humpback, right, fin and minke whales) and analyzed them to determine polymer type, diameter, and breaking strength. They then combined this information with whatever was known about the individual whales with regards to entanglement configuration, severity of the injury, and life history to get a bigger picture of what is going on. Their newly published paper "Effects of fishing rope strength on the severity of large whale entanglements" thoroughly explains all of this (and includes a download of supporting information such as an example of a case study and how these ropes were analyzed), but in a nutshell here's what they found:

• Injury severity has increased over the years, and is related to rope strength.
• Weaker species (e.g.: minke) and younger whales are less likely to successfully break free of stronger rope, resulting in complex and potentially lethal entanglements.
• Reduced breaking strength rope (breaks at 1700 pounds or 7.56 kN) could reduce the probability of mortality by 72%.
• Forces applied during normal fishing operations in many areas are lower than 1700 lbs, so presently used fishing line is stronger than what the majority of fisheries need.

The tight line on this whale (Catalog #3279) cuts through the blowholes and into the head, while likely also wrapping through the mouth as the line is seen exiting the top of the lip. The whale's ability to breathe was clearly inhibited. Photo: Canadian Whale Institute/ New England Aquarium.

Our 35th field season in the Bay of Fundy will get underway next week and extend until the end of September. As you can imagine, it is a busy time as we are getting field supplies all pulled together- cameras, computers, satellite phones, data forms, and various other items. We've also spent the past couple of months securing research permits, sorting out our field team personnel and coordinating with other field teams who will be joining us.

The Nereid crew, working mom #3513 and her calf as they swam unusually close to shore.  Photo: Moira Brown, Canadian Whale Institute.

In addition to our Bay of Fundy surveys conducted on our 29 foot vessel Nereid, the Aquarium is collaborating with Canadian Whale Institute and will be conducting two offshore surveys on Roseway Basin, south of Nova Scotia. Each of these surveys will be two weeks long, and conducted on the 46 foot R/V Shelagh with a team of six persons who will live aboard the boat.

Observing right whales aboard the Shelagh during our first offshore trip last season.  Photo: Marianna Hagbloom, New England Aquarium

Joining us in the Bay this season will be another Aquarium team who will be collecting right whale respiration samples from the R/V Callisto, as well as a team from NOAA and Syracuse University who will be collecting acoustic recordings from mother/calf pairs off the R/V Selkie.

Now we are keeping our fingers crossed that the right whales show up this year! There have already been a few sightings reported by the local whale watch boats, so hopefully this bodes well for a stronger right whale presence than last season!

Stay tuned for the latest updates via our Facebook Group Page, and our Twitter @rightwhalescoop.

-Amy

-Amy Knowlton

Over the past two days we have had both the R/V Nereid and R/V Callisto offshore surveying the Bay of Fundy for the elusive right whales. On Sunday, teams from both boats saw a couple of right whales but again they were very difficult to work -- single animals staying at the surface only briefly and traveling long distances between each surfacing. Neither boat was able to collect any photos for our right whale identification catalog. Our impression was that the right whales were searching for food but weren't finding anything. But at the end of the day on Sunday, our colleagues working out of the Grand Manan Research Station called to report they had found a mother/calf pair in the Grand Manan basin (where right whales are typically found) which was exciting news. Maybe this was a sign that things were shifting.

On Monday when the Nereid crew got back out to the basin, it felt like the Bay had come alive! We began to see right whale flukes in all directions and the bird life was incredibly active: storm petrels, shearwaters and gannets were there in droves! There were also many fin whales, minke whales, basking sharks and harbor porpoise in a very small area perhaps just a few square miles in size. It seemed to be a feeding frenzy! Over the course of the day the Nereid crew photographed seven individual right whales including #3390 and her calf, one of only seven calves documented this past winter calving season off the southeast U.S. coast. The Nereid crew is out again today and hopefully will be out over the next few days as the fog has finally lifted and the winds are calm.

Stay tuned for videos and updates from the Nereid crew!

Entanglements in fixed fishing gear continues to be a serious concern for this small, endangered right whale population.


Scientists from NOAA Fisheries Service approaching a young North Atlantic right whale they disentangled on January 15 off the coast of Cape Canaveral, FL. Photo via NOAA, credit: With permission from EcoHealth Alliance.

Over the course of the past five months, three right whales have been seen carrying gear: Catalog #1503, a reproductive female who was seen one day in September on Jeffreys Ledge with rope entangling her head; Catalog #3120, a male born in 2001 who was also seen on Jeffreys Ledge in October entangled in gillnetting either in mouth or around flippers (this animal also suffered a serious entanglement in 2002) and the most recent case, a two year old female, the 2009 calf of Catalog #2611.

She was sighted on Christmas Day down in the southeast U.S. severely entangled with gear through her mouth and around her flippers and trailing behind the body. The first animal has not been resighted and the second animal has only been sighted far from shore so no disentanglement attempts could be mounted and their fate is uncertain.


Scientists from NOAA Fisheries Service and its state and nonprofit partners successfully used at-sea chemical sedation to help cut the remaining ropes from a young North Atlantic right whale on January 15 off the coast of Cape Canaveral, Fla. The sedative given to the whale allowed the disentanglement team to safely approach the animal and remove 50 feet of rope which was wrapped through its mouth and around its flippers. Photo via NOAA, credit: with permission from Florida Fish and Wildlife Conservation Commission

The third animal was recently the focus of a complex sedation and disentanglement effort detailed in this press release from NOAA.


Disentangled right whale off the coast of Cape Canaveral, Fla. on January 15. Photo via NOAA, credit: with permission from EcoHealth Alliance

We don't yet know if this two year old will survive. She is very thin and sustained injuries from her entanglement and may have gear still remaining on her flippers. But the monumental efforts taken to free her using all tools available underscores the need to first, try to save all right whales in imminent danger of dying from human activities, and second, to quickly and effectively put changes in place that will eliminate these dangers. Both of these are challenging to accomplish but there is a concerted effort on several fronts to do so.

Here is a short video of those monumental disentanglement efforts on the open seas.
Scientists from NOAA Fisheries Service and its state and nonprofit partners successfully used a long pole with attached knife and buoy to help cut the remaining ropes from a young sedated North Atlantic right whale on January 15 off the coast of Cape Canaveral, Fla.Video via NOAA, credit: with permission from Georgia Department of Natural Resource

As two previous posts (here and here) by Marianna shared, we were involved in the necropsy of the latest dead right whale found on August 13 in Nova Scotia. Sadly, this was the third right whale mortality in the past two months.


Right whale necropsy on August 15

On June 27, 2010 a right whale carcass was found floating 50 nm east of Cape May, New Jersey and towed to shore for a full necropsy under the direction of Dr. Michael Moore from Woods Hole Oceanographic Institution. This adult male had suffered a chronic entanglement around the head and flippers which led to its demise. Unfortunately, this particular entangled animal was not known to us when it was alive and we have not been able to ID the carcass as it was too decomposed. We hope to get an identification through genetic analysis.

The second carcass was found floating on July 2, 2010 off the coast of Jonesport, Maine. It had two propeller cuts on the side of the body. Samples taken of the lacerations were taken at sea by a team from Allied Whale at the College of the Atlantic but the carcass was too decomposed to learn anything about the timing of the vessel strike (i.e. if it occurred before or after death). The animal was a sub-adult female. Again, individual ID is not known but may be determined from genetics.

And now, this third carcass - determining the cause of death is still underway but there are indications of blunt impact at the skull region from a vessel strike.



We are very concerned about this latest rash of right whale deaths, perhaps all the result of human activities. Though the right whale community has made great strides in implementing protective measures for right whales, this job is certainly not yet complete.

- Amy