How this kind of pollution is harming killer whales

Almost all of the world’s shipping is conducted traversing the oceans. That’s not just by volume either, where it accounts for approximately 80%, but also in terms of value, with around 60% carried by boat. It’s fair to say that maritime shipping is a primary engine of the global trade economy.

With that scale of operation there are a variety of costs, one of which is a well-documented negative impact on the environment. The majority of that effect is accounted for with carbon and particulate emissions, but there’s another, less immediate issue humming just below the surface.

Cargo ships are loud.

The whole maritime shipping industry is so loud that ambient underwater noise has more than doubled in decibels since the 1950s. When noise levels disrupt environments and the species that live in them — humans included — it’s called “noise pollution.”

For underwater creatures, louder background noises can, at best, be disruptive and, at worst, deadly. That’s because many of those species experience noise like land dwellers experience sight. According to marine biologists, sound is the primary sense for many sea creatures.

The killer whale population in the Pacific Northwest — federally recognized as an endangered species — lives in an area of high shipping traffic. Seattle, Tacoma, Vancouver Island and the 20 or so other ports in the Strait of Juan de Fuca are major hubs for trade. That’s between the United States and China, as well as the mainland and Alaska.

Like most whales, orcas use their sense of hearing to communicate, socialize and hunt and have been competing with the din from the many boats traversing the region for decades.

After years of research, a demonstrable link between underwater noise pollution from nearby shipping lanes and increased mortality and lower birth rates among killer whale pods of the region was found.

A study published in September by the Property and Environment Research Center (PERC), an organization dedicated to market solutions for conservation efforts, used the robust record keeping on the whales of the region to, not only show the connection, but also propose a market ready solution.

“The overall findings — which I was not expecting and was equally surprised by — is that noise pollution does have a negative effect that is discernible, observable and changes the whale population,” said Scott Taylor, the author of the study and a professor of economics at the University of Calgary.

“We knew that whales were adjusting and were impacted by vessels, but no one had been able to find a link between vessel noise and — what we would say, as a population level event — the probability of births or the probability of deaths. And that’s the big thing that this paper does," he said.

Taylor borrowed from other proven environmental economics policies to find a solution, too. He’s also a research associate at the National Bureau of Economic Research and was the Canada research chair in International, Energy and Environmental Economics and has vast experience with such programs to draw on.

He determined that a variation of pollution permits based on vessel noise assessments — quieter ships exist — sold by governmental agencies to private companies was the best place to start.

There are variables, but ultimately the goal would be to ensure that — at a policy level — shipping companies know that there are costs below the surface for doing business.

“The idea that underwater shipping noise may adversely affect whales may seem somewhat incredible,” Taylor wrote in the paper.

But, “by pricing vessel noise, we can align conservation with commerce — protecting one of the ocean’s most iconic species without sacrificing the global flow of goods."

How does noise affect the whales?

While the oceans are vast, and the suggestion that noise from boats would have such an impact on dispersed mammals may seem improbable, it overlooks how the issue arises in specific locations.

“Neither whales nor ships are spread evenly across the globe, and the same nutrient-rich coastal waters favored by whales are also home to many of the world’s busiest shipping lanes,” Taylor wrote in the study. “Consequently, ship-to-whale interference is common. Whales cannot easily avoid vessel noise without abandoning prime feeding and calving grounds.”

To emphasize the point — and as an immense stroke of luck in understanding the relationship between whales and noise pollution — there’s a population of orcas living in the Pacific Northwest that’s among the most heavily studied whales in the world. Researchers have kept detailed records of the “Southern Resident killer whales,” including data on their health and genealogy, accurately recording births and deaths since the 1970s.

Despite a concerted effort to protect that population of whales, their numbers have been declining for decades, according to Taylor’s paper.

Their habitat is the area near the Strait of Juan de Fuca, which is where the Pacific Ocean flows past Vancouver Island into the greater Seattle region. Since the 2000s, when trade with China rapidly expanded, those waters have seen a demonstrable increase in shipping traffic.

By comparing the data from the studies of the killer whales with shipping records and other macro economic data from the past 25 years, Taylor was able to see a substantial impact on the whale populations depending on the relative shipping activity.

For example, the recessions of 1981-1982, 1990-1991, the dot-com bubble and the 2008 financial crisis all showed significant slowdowns in shipping traffic through the strait, which resulted in much quieter waters.

During those periods (representing years’ worth of data), Taylor found that whales “likelihood of death is considerably higher in noisy years,” and that “in years of peak fertility (for the orca females), noisy years lower the probability of a subsequent successful birth by over 25%.”

During the same period, a closely related pod of whales that is also heavily studied, The “Northern Resident killer whales,” have seen a steady increase in population. The primary difference between the two groups is that the northern neighbors do not have major shipping ports traversing their home territories.

What’s the economic solution?

Taylor said that if the pollution in question was something other than noise, then the solution would be obvious. “Put a price on the pollution,” he wrote.

His suggestion is that governing agencies of the regional shipping lanes — state, federal or international, depending on the waters in question — would determine how much noise an environment could withstand and stay healthy. Afterward, they’d create permits based on their allowable decibels.

In turn, shipping companies would have to measure the noise each of their ships produce as it varies greatly based on age and model, and purchase permits to allow for that much noise to traverse a specific port.

Those costs would then influence how the shipping companies make logistical decisions. For example, younger, quieter ships could traverse whale sensitive routes.

“I think that just the realignment of your fleet, in many cases, might have a large effect,” Taylor said.

As for whether it is an issue that governments or shipping companies would be willing to face, Taylor pointed out that the whales are an endangered species and the impact of noise is destructive to them.

“I’m well aware that shutting it down is not the right thing to do, but we are going to address it,” Taylor said. “It may not be in the next three-and-a-half years, but at some point in time, this is going to become an issue.

“The idea could be dead on arrival, but the truth is that both the Canadian and U.S. governments have experimented with other policies to reduce noise pollution underwater and it’s typically been things like slowdowns or there are suggestions that the ships be held up and then all go on convoys,” he said. “These are things that people actually have been doing. Some of them have been voluntary. People are spending real money on trying to reduce noise pollution.”

Taylor believes his solution could address the problem before it eventually comes up. The endangered species designation requires a review of all policies that might have an impact on the whales.

“If we had a more proactive, positive way to deal with it, maybe some of those costs would go away,” Taylor said. “This might be a way to get ahead of that litigation and to offer a win-win solution.”