The population of critically endangered North Atlantic right whales numbers just 500.
The whales’ population has grown in recent decades, but its growth rate appears to be declining due to a combination of human-caused deaths and a drop in calving, researchers say.
The recent spate of deaths and entanglements, combined with the flagging population, an unexplained shift in habitat, and the poor health of many whales spotted this summer has researchers concerned for the future of the species.
Bad news came in three for critically endangered North Atlantic right whales (Eubalaena glacialis) in late September.
On Thursday, September 22, an 8-year-old female whale tangled up in hundreds of feet of fishing lines and buoys turned up off the coast of Massachusetts. By sundown, a rescue team was able to cut away much of the trailing line and the whale swam off. Her fate remains unknown, but rescuers were hopeful she might free herself from the remaining line.
Then the next day, Friday, a whale watch boat reported a dead right whale off the coast of Maine. The U.S. Coast Guard towed the carcass 20 miles to port — no small feat as the whale measured in at 43 feet long and 45 tons. A team of 20 performed a necropsy the following day. “The whale had rope entangled around her head, in her mouth, and around both flippers,” stated a press release from the Fisheries Service of the National Oceanic and Atmospheric Administration (NOAA). The team identified the whale as an 11-year old female. Her thin blubber, injuries, and other characteristics led them to conclude that chronic entanglement is what did her in.
Finally on Saturday another dead right whale turned up off the Maine coast, this one without any entanglement but so badly decomposed that researchers have not yet been able to determine a cause of death.
North Atlantic right whales are arguably the world’s most imperiled whale species. Their population of around 500 has made gains in recent decades that now appear to be floundering due to a combination of human-caused deaths and a mysteriously declining birth rate. The latest incidents bring to eight the number of entanglements and deaths since the beginning of 2016.
On a September 27 press call, scientists, rescuers, NOAA officials, and others involved in the three recent incidents lamented the loss of the two whales and the injury to the third as a significant blow to the right whales’ small population — particularly the death of the 11-year old female.
“For a population that is recovering, these females that have lived to ten years and have just started now entering the reproductive pool of these animals, it’s a loss,” said William McLellan, director of the Marine Mammal Stranding Program at the University of North Carolina Wilmington, on the call. “She would be expected to have five or six calves in next 25 or 30 years. So it’s just a loss to the population.”
Failure to thrive
North Atlantic right whales range mainly off the busy eastern coast of North America, earning the species its nickname, the urban whale. Just a handful of animals remained when hunting them was banned in 1935. By 1992, the population hovered around 295 individuals, and it did pretty well in the 1990s and 2000s, growing to around 500 by 2015.
Those gains were hard won. In the U.S. starting in the late 1990s, NOAA officials, scientists, conservationists, and fishers came together to designate fishing closures, make changes to fishing gear, and reduce shipping speeds in the vicinity of right whales. Canada moved some shipping lanes out of right whale thoroughfares.
Together entanglements in fishing gear and collisions with ships have accounted for about half of all documented right whale deaths since 1980. The efforts to reduce ship collisions seem to be paying off, with the number right whales killed by ships declining.
But that’s not the case with fishing-gear entanglement. If anything, despite two decades of effort and difficult-to-negotiate gear changes, the problem appears to be getting worse. That’s according to six right whale researchers, including McLellan and another on the press call, who penned a commentary in the journal Frontiers in Marine Science this August.
“[O]ur review of the recent science suggests that fishing gear entanglements are increasing in number and severity, and that this source of injury and mortalities may be overwhelming recovery efforts,” the authors write in the paper.
They point to research showing that between 2010 and 2015, 85 percent of diagnosed right whale deaths were due entanglements. (Fifteen percent were due to ship kills.) And to a 2015 analysis showing that 83 percent of living North Atlantic right whales bear scars from entanglement with fishing gear.
The commentary also pointed out that the right whale population’s growth rate appears to be declining as a result of these human-caused deaths and a drop-off in calving.
“[R]ight whales are not yet a conservation success story. Right whales need immediate and significant management intervention to reduce mortalities and injuries from fishing gear, and managers need a better understanding about the causes of reduced calving rates before this species can be considered on the road to recovery,” the authors conclude.
The paper took NOAA to task for sunnily stating in a January 2016 press release announcing the expansion of designated critical habitat for right whales, “We’re making significant progress in reversing the population decline of the species, and are seeing signs of recovery.” Similarly, other researchers have described to Mongabay a concern that the agency may be positioning the species as a success as a prelude to shifting resources to other priorities.
“NOAA Fisheries’ whale specialists and our leadership share the concerns these researchers have raised. We look forward to working with them and others to better understand right whale status and the factors that may be holding back recovery,” Teri Frady, spokesperson for NOAA’s Northeast Fisheries Science Center, told Mongabay when asked for a response to the paper.
More trouble for right whales
Last week’s entanglements and deaths weren’t the only recent bad news for North Atlantic right whales.
Philip Hamilton, a research scientist at the New England Aquarium in Boston who has been studying right whales for decades, told Mongabay that including those incidents, six right whales have been found entangled so far this year (two died) and a total of four have been found dead. All but one of the incidents happened within a 38-day period in August and September.
“Unfortunately, this is pretty much par for the course for us” for right whale entanglements, David Gouveia, Marine Mammal and Sea Turtle Program Coordinator for NOAA Fisheries Greater Atlantic Region said on the press call. “We’re generally right now on par with our averages per year. However it’s still early in the year so it’s a concern for us.“
Over the summer, Hamilton participated in the aquarium’s annual field survey to the right whales’ summertime feeding grounds in Canadian waters. In recent years, the whales have been strangely absent from areas in and around the Bay of Fundy, between the Canadian provinces of Nova Scotia and New Brunswick, where the team had consistently found them during the 30-odd preceding summers they had gone looking. The reason for the deviation remains unknown, but researchers suspect it indicates a shift in their zooplankton prey base that has left many somewhere on the continuum from puzzled to concerned.
This year, the team also searched for the whales 200-plus miles to the northeast, in the Gulf of St. Lawrence. To everyone’s surprise, they found right whales in both places.
While Hamilton said the crew was happy to have found the missing whales, there were fewer than in years past and some unsettling entanglements. Research by colleagues at the aquarium has shown that the breaking strength of rope used in fishing gear has increased, leading to worse entanglement injuries.
“This year we saw a number of whales that all the skin was removed from the leading edge of their flukes. Parts of them are just getting flayed by the recent entanglements,” Hamilton said. “It’s really discouraging, depressing, and heartbreaking.”
Moreover, the crew was dismayed to find many whales were in bad condition, often with striking white lesions on their heads and bodies.
“We had about four or five whales in the Bay of Fundy that looked just horrible,” with huge lesions, Hamilton said. It’s unclear whether the lesions are a sign of disease, food scarcity, stress, or some other factor, but they definitely indicate poor health and don’t bode well.
“The last time the whales looked so poorly it was reflected in the calving,” Hamilton added, recalling a period in the late 1990s, when the number of calves born tanked and around 35 percent of the whales showing up in the Bay of Fundy had skin lesions.
One side effect of the whales’ puzzling habitat shift is that it complicates efforts to protect them, Hamilton said. For instance, Canada moved shipping lanes in the Bay of Fundy, but now the whales seem to be spending more time in the Gulf of St. Lawrence — and several were spotted in a shipping lane there this summer. Last summer three right whales were killed in the area, possibly as a result of ship collisions.
As for the recent deaths and entanglements, NOAA is currently analyzing gear removed from the entangled whales to see where it came from, with an eye to both potentially holding the responsible fishers accountable if they violated any regulations and learning more about how whales get entangled in the first place.
NOAA Fisheries Service spokesperson Jennifer Goebel told Mongabay last week that the agency is in a monitoring phase to see whether existing rules are doing enough to reduce entanglements, and that a committee dedicated to reducing human-caused deaths among the region’s large whales would be reviewing all the data at a meeting in November. “But, obviously, events over the past week give us reason for concern,” she added.
- Kraus, S.D., Kenney, R.D., Mayo, C.A., McLellan, W.A., Moore, M.J., Nowacek, D.P. (2016). Recent Scientific Publications Cast Doubt on North Atlantic Right Whale Future. Frontiers in Marine Science 3:137. doi: 10.3389/fmars.2016.00137.