Our coast is about to get a lot more noisy.
On Wednesday, British Columbia granted environmental approval of Kinder Morgan's Trans Mountain pipeline project, following a federal green light in late 2016. Both governments believe this project can simultaneously achieve economic gain and environmental safety, with BC adding 37 new conditions (including stronger protections for wetlands, caribou and grizzlies) to the National Energy Board's 157.
The pipeline will augment transport of diluted bitumen from Alberta to BC for export. It will also lead to greatly increased tanker traffic on the coast—and a profound change in local underwater soundscapes.
The potential damage of this project to endangered whale populations has incited environmental groups to challenge the federal approval in court. Canada has put forward an Ocean Protection Plan in part to address this, although it's yet to be tested. The plan aims partly to reduce noise that could harm marine mammals, chiefly whales.
While scientists have long described the acoustic world of cetaceans, it is only recently that we've begun to acknowledge the importance of sound to other marine life. As a marine biologist based in BC, this has been a focus of my work.
Take the lesser-known plainfin midshipman, which gets its name from the spectacular pattern of silver light-emitting organs called photophores that run the length of its belly and are likened to the buttons of a naval uniform. In the summer months, these brilliant fish flood the intertidal zones from Alaska to Mexico, bringing a tremendous surge of nutrients to a host of predators, including mink, seals, crabs, and starfish.
But the most phenomenal thing about this fish? It sings.
Also known as the canary fish or talking fish, the male plainfin midshipman sings to attract females to his nest. (After she lays her golden, M&M-sized eggs, childrearing is left completely to the alpha male.) His hum is a low frequency 100 Hz, and one drone can go on for over an hour. Standing by the water's edge on summer nights, when many males chorus together, the sound resonates clearly out of the ocean and into the air; the result is a zen-like, uninterrupted 'ommmmm' like a roomful of yogis. It's hypnotic.
Imagine living in a construction site, 24/7: these organisms are stuck and forced to endure
To some, it can be annoying. In the 1980s, an unidentified hum woke up houseboat tenants in San Francisco Bay. Beginning in the summer months just after dark and continuing until just before dawn, the sound drove residents crazy. They accused everyone and everything from the US Army Corps of Engineers to the local sewage plant for being responsible for the buzz. When a neighboring biologist suggested the source was the plainfin midshipman, everyone scoffed. A fish produce that much noise? Impossible. But they were wrong.
Fish are acoustic creatures. Of the 30,000 known species of fish, all those studied can hear. Further, at least 800 can make sound. Many fish depend on sound to communicate, detect prey and avoid predators.
But it's not just fish. Snapping shrimp and sea urchin can produce an enormous racket, while many other forms of sea life—from crustaceans to bivalves to coral—rely on sound to orient themselves and find habitat. In some places, noise produced by fish and invertebrates is the dominant sound in the ocean, and can be a proxy for ecosystem health.
Life inside the ocean has adapted to a diversity of natural sounds relating to animals, climate, and geologic activity. But a different type of noise introduced by humans (termed "anthropogenic noise") is causing problems today.
Imagine living in a construction site, 24/7: while you and I can plug our ears or walk away, many of these organisms are stuck and forced to endure. As a result, many face harm. Whale and dolphin strandings and deaths have been recorded near Navy test sites for decades. Pile driving—the process of hammering infrastructure into the ground to support anything from offshore gas platforms, wind farms to bridges—can damage fish, causing inner bleeding or injury to swim bladders.
Seismic noise has been shown to cause internal bruising in crab, and malformations and developmental delays in scallops. Even octopus and squid can suffer massive acoustic trauma from low frequency noise.
In their review of Kinder Morgan's application to the National Energy Board regarding the pipeline expansion project, the Department of Fisheries and Oceans addresses impacts of pile driving on fish and invertebrates, and discusses recommendations to decrease them. But when it comes to tanker traffic, DFO concludes that the impact of increased noise on fish is "likely to be of low risk." The rationale appears to be a lack of data. The words 'precautionary approach' are not found in the review.
This is troubling. Ship noise, which tends to be chronic, low frequency, and far longer-reaching than high frequency noise, could be the most damaging form of global noise pollution, given its current scale and predicted growth.
Further, noise emitted from ships has a frequency that commonly overlaps with those produced by marine animals, and can mask communication; how can these organisms talk to each other over all that racket?
While it's true we can't say exactly how sea life will respond to increased shipping noise off our coast, research is showing that fish, crabs, and even sea slugs can suffer in multiple ways from boat noise exposure. We should at the very least act with caution.
There is a silver lining to this problem, if we're prepared to accept it. Unlike many global ocean threats (ocean acidification, warming waters, overfishing, marine pollution), noise has a comparatively simple solution: quieter props. Most of a ship's noise comes from propeller cavitation, when bubbles are formed and then pop. New, more efficient propellers and even retrofitted old ones can cut down on noise dramatically. Another way to limit noise is to decrease ship speed, which also saves on fuel: a win-win.
Updating our propeller technology and reducing ship speed will be an important part of quieting our oceans. But it won't address the host of other problems increased tanker traffic will bring about, including ship strikes and oil spills.
When we talk about oceans, we must address what's upstream.
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