Vessels a risk to whales: research
“If the fishing industry can do that and have been asked to do that, the multinational large shipping traffic should be asked to do the same.” Gretchen Fitzgerald National program director, Sierra Club Canada
Vessels, large or small, and moving at different speeds can be fatal to right whales, a Dalhousie University researcher's study shows.
“What this work showed is that if you are on a vessel on the ocean, a large or fast- or slow-moving vessel or even a seemingly small lobster boat, you can be a risk to right whales,” said Sean Brilliant, one of the research team leads on a study published recently in Marine Mammal Science.
“Nobody can assume that they are not a threat to the whales,” said Brilliant, a senior conservation biologist with the Canadian Wildlife Federation and an adjunct at the university.
“We point out that these lobster vessels at full speed could be lethal if they run into a whale. There is no free pass there, they can't just assume that they are OK. Similarly, we showed that large vessels are much less safe, even at speeds that we thought would be safer speeds (10 knots). The problem with killing whales by running ships into them is not going to be solved by slowing ships down. We need to find ways to separate ships from whales.”
Any vessel greater than 13 metres, including crab boats, are considered larger vessels while most lobster boats fall in the small vessel category, Brilliant said.
BIOPHYSICAL MODELS
The research team from the university's Oceanography department, including co-lead Dan Kelley, a physical oceanography at Dalhousie, used information about right whale anatomy and Newtonian mechanics to construct biophysical models that predict the stresses whales experience during collisions.
The study focused particularly on North Atlantic right whales. Researchers looked at 40 ship strikes in which they knew the speed and size of the vessel and found that many of the whales did not have broken bones.
Instead, they suffered internal hemorrhaging, supporting the contention that collisions can be fatal because they disrupt the blood system on the whale's back.
Brilliant said if a smaller fishing boat strikes a whale, the skipper will probably know it because the whale will be approximately the same weight and size as the boat.
“The thing with smaller fishing boats, too, is they are much more dynamic and capable of slowing down more quickly, the skipper is a few metres above the water's surface, compared with the captain of a cargo vessel who might be 15 storeys above the surface of the water and has no ability to either stop or turn,” Brilliant said.
LARGE VESSEL FACTOR
“The finding on the large vessels is quite important,” said Gretchen Fitzgerald, national program director for Sierra Club Canada, which has been pressuring the federal government to update its right whale action plan.
“Avoidance essentially is the only mitigation and that is something that will have to be taken very seriously by the federal government, especially in the Gulf of St. Lawrence,” Fitzgerald said.
A recent U.S. National Oceanic and Atmospheric Administration (NOAA) study shows only 366 North Atlantic right whales exist on the planet. Of the surviving whales, only 94 are females.
“Stop hitting them and get better at knowing where they are, which I think they have gotten a little bit better at this year,” Fitzgerald said of saving the species. “You could say, we know the whales are coming in through the Cabot Strait, we can hear them, we can see them. Avoidance right now is what is going to have to happen to save the species. That will have to take pretty big leadership on behalf of the transport minister and the federal government.”
EXCLUSION ZONES
The researchers concluded that establishing exclusion areas for vessels, altering shipping lanes and revising traffic separation schemes would be necessary to totally avoid collisions from large ships.
The team established that there may be more opportunities available for small vessels to mitigate their risk of causing a lethal ship strike.
Fitzgerald said a lot of the small vessel traffic is curbed by closing the fishery when it is known that the whales are nearby.
“If the fishing industry can do that and have been asked to do that, the multinational large shipping traffic should be asked to do the same,” Fitzgerald said. “I think we just have to get a lot better at detecting because that is an alarming trend that even a lot of mitigation that we've been supporting and promoting for many years on the Bay of Fundy and on the Gulf of St. Lawrence may not have been as effective as we had hoped.”
FISHERY CLOSURE
The Canadian government on Monday ordered for the second time this month a temporary fishery closure in the Roseway Basin off southern Nova Scotia after multiple detections of North Atlantic right whales in the area.
The order closes several fisheries until further notice and could affect the lucrative southwestern Nova Scotia commercial lobster fishery when the season opens next week.
The Roseway Basin is about 35 kilometres south of Cape
Sable Island and has been designated a critical habitat for the whales.
If no right whales are spotted during the aerial surveys, the area will reopen for the start of the lobster fishery, said Burns.
Sightings have become rarer in the area in recent years as right whales moved north into the Gulf of St. Lawrence. Since 2017, 20 right whales have died in the gulf, some caused by vessel strikes, but there have been no deaths reported in 2020.
Chief Mike Sack of the Sipekne'katik First Nation said in release Wednesday that the band has approved a temporary two-week closure of their Treaty Fishery.
“We have and will continue to operate with conservation as our foremost concern, the presence of the endangered North Atlantic Right Whale in the region has resulted in the immediate decision to suspend our fishery activities in the Roseway Basin critical habitat area, as identified by DFO'S grid system,” Sack said.