Area off Vancouver Island is a high-risk zone for ship-whale collisions: study

A new study has identified several previously unknown high-risk zones for ship-whale collisions, including a large zone off the southwest coast of Vancouver Island.

Study results published in the journal Science this week, for the first time, anyone estimated the global risk of whale-ship collisions for blue, finned, humpback and sperm whales.

“This helps us identify where whales are most vulnerable,” said Chloe Robinson, an ecologist and director of Ocean Wise’s Whales Initiative, who co-authored the study. “There has never been anything this comprehensive before.”

The study found that global shipping lanes overlap 92% with the migration routes of four species of whales that inhabit the world.

Global databases show high risk of deadly ‘gambling’

The research team spanned five continents and used 435,000 unique whale sightings – from government surveys to citizen observations, animal-borne GPS tags and even whaling records dating back to 1960.

They then compared this data with the movement of 176,000 cargo ships between 2017 and 2022. The vessels were tracked using an automatic identification system and compared to the whales’ areas to determine where they were likely to encounter each other.

“We’re talking about five billion ship positions,” said Robinson, who noted that a recent study estimates that up to 20,000 whales are killed annually by ship strikes. “It’s a bit of a game of chance. The more whales and ships overlap, the greater the likelihood that one of these encounters will result in a ship strike.

In addition to entanglement in fishing gear, ship strikes pose a major threat to large migrating whales.

However, lead author Anna Nisi, a postdoctoral researcher at the University of Washington’s Ecosystem Guardian Center, said that studying ship-whale collisions can be extremely difficult because in most cases the ship will hit the whale and sink without anyone noticing.

“Sometimes they come into port with the whale hanging over the bow of the ship and then they realize they hit something,” Nisi said.

Ship-strike hot spots around the world have been identified

In the Americas, the highest risk areas for whaling ship collisions were found along the Pacific coast of North America, as well as off the coasts of Panama, Brazil, Chile, Peru and Ecuador.

Robinson said scientists have a fairly good understanding of where ship and whale paths overlap in Canadian coastal waters. However, if you sail further from shore, the risk of whale ship collisions becomes much less obvious – until now.

The study found that near the southwestern tip of Vancouver Island, a large concentration of ships passes through the same waters used by humpback whales and fin whales to migrate and feed.

The hottest spot for ship-whale collisions is just outside the existing management zone for southern resident killer whales Swiftsure Bank. The area – which includes seasonal speed restrictions and fishing closures – stretches for approximately 40 kilometers along the west coast of Vancouver Island, between Port Renfrew and Bamfield.

A little further west, the study found what Robinson described as a stop on the whaling highway, where humpback and fin whales feed and rest before entering the Salish Sea or continuing north and south.

“This is a place where if there are strikes, they go unreported,” she said.

Ship attacks are becoming more frequent in BC waters

The study was carried out due to the growth of the humpback whale population and the increase in maritime traffic. According to Robinson, this combination increased the risk of collision.

Between 2022 and 2024, Ocean Wise tracked at least 15 whale attacks in British Columbia waters. Robinson says another recent impact is still being investigated and the actual total is much higher because most collisions go undetected.

“We see it more and more every year,” Robinson said. “Across the coast of British Columbia, at least 10 humpback whales were struck on 10 separate occasions last summer alone. And that’s what we know.”

Humpback whales are born during migration season, passing between northern and southern feeding and breeding grounds each year. During migration, whales usually sleep on the surface, which puts them at high risk of being struck.

Robinson, the number of ships has also increased by 300 percent in the last 30 years. “So it’s a real concern for these species.”

The greatest risk of strikes occurs in territorial waters

The study found that more than 95 percent of whaling ship collision hot spots are near the coast, where countries can protect marine life in their exclusive economic zones.

However, only seven percent of areas with the highest collision risk were found to have any whale protection measures in place.

The study found that installing management systems in just another 2.6% of the ocean would protect whales in all of the highest risk locations.

“It’s a small percentage, but obviously a very large area,” Nisi said. “This means there is a big need and a lot of opportunity to expand whale protection measures.”

Long-term coexistence requires cooperation with industry, says the ecologist

Efforts to slow and reroute ships passing through whale areas have improved in recent years. Robinson said that in Sri Lankan waters, the Swiss-Italian Mediterranean Shipping Company had voluntarily redirected its vessels towards important whale habitat areas.

“Striking whales is harmful not only to their image, but also to the environment. They support these measures because they care about long-term coexistence,” she said.

Closer to home, a system of hydrophones, infrared devices and human reports now provide information to coastal whale warning systems from Washington to BC and Alaska.

Then, Robinson said, the system should be expanded to previously unknown hot spots further from the coast, such as the area identified west of Swiftsure Bank.

This could mean extending Swiftsure Bank’s management area by just a few kilometers to help humpback whales and fin whales – two species that cannot echolocate objects like their toothed killer whale cousins.

Infrared cameras can help detect whales

Robinson said one measure she thought could have a big impact would be to equip ships with infrared cameras capable of detecting whales within a radius of several kilometers. “Maybe some sailors… respond better knowing that there is a whale 100 percent in front of your ship, 200 percent, rather than saying, ‘slow down, there might be a whale here.’ ”

Robinson said such cameras can cost between $50,000 and $75,000, but could be an opportunity for companies to promote themselves as having a more whale-friendly business.

“I know people who had to go to therapy after killing a humpback whale at the controls,” she added.

Robinson said that without protections, Arctic waters could become another high-risk hotspot as sea ice melts due to climate change, opening up shipping lanes.

“Knowing there are plans to expand shipping lanes into these areas to reduce navigation times and speed things up through prime whale habitat, I think this is a really good opportunity to get ahead of the problem before it becomes a problem.”

​ — With files from Brenna Owen, Canadian Press