On Scotland’s northwest coast, windswept emerald headlands, crescent white sand beaches, and aquamarine fjords form a patchwork of islands called the Hebrides. The area is rich in marine life, home to over 24 species of whale, dolphin, and porpoise, thanks to a confluence of warm and cool currents and a unique underwater topography. But if the Hebridean Whale and Dolphin Trust (HWTD) has anything to say about it, visitors will be spotting these creatures from the shoreline along the new Hebridean Whale Trail they’ve developed.
The trail promotes low-impact wildlife viewing from land, where marine animals will be less impacted by boat noise disturbance, and visitors will be encouraged to take a slow approach to travel. Similar trails are carved along coastlines around the world, from South Africa to Canada.
Anthropogenic noise in the ocean is rising, negatively impacting wildlife that lives there, according to a comprehensive new review that draws on noise pollution studies from across different marine science disciplines. The negative effects of human-caused noise include limiting marine animals’ ability to hunt and find food, disrupting social behaviors, producing an acute stress response that can cause physiological changes, like hearing loss, and in extreme cases, death.
Marine wildlife has taken advantage of the fact that sound travels much further and faster in the water than in air by developing their capacity for hearing and acoustic communication. When their ability to navigate the dark ocean depths by echolocation is masked by noise, the effects can be profound. A recent study published in Frontiers in Marine Science shows female orcas stop foraging when vessels come closer than 400 yards, which raises reproduction concerns. In the Pacific Northwest, where the endangered killer whale population is nearing a historic low, noise disturbance can’t be discounted as a contributing factor.
“The discourse on ocean health has almost entirely ignored noise pollution,” says Carlos Duarte, a marine ecologist at King Abdullah University of Science and Technology in Saudi Arabia and lead author on the paper. “The impact of noise might be far higher than the impact of marine plastics because it’s pervasive and affects every organism, from jellyfish to whales.”
While large shipping vessels and seismic surveys (acoustic shock waves used to identify oil and natural gas reserves below the ocean floor) are the worst offenders, the sound caused by small commercial boats can’t be discounted. “Small boats are not as loud as large ships but they’re highly concentrated in coastal waters, which is home to much of the biodiversity in the marine environment,” says Lucille Chapuis, an aquatic bioacoustician at The University of Exeter in England and an author on the paper. “Small boat noise has indeed been shown to disrupt marine fauna.” A Danish study published in Scientific Reports showed that recreational vessels actually dominate human-caused noise in coastal waters.
The maelstrom of warming waters and non-acoustic pollutants in our oceans have already resulted in exponential biodiversity loss, reducing the natural soundscape that all marine life depends on for survival. “Now we’re creating an acoustic fog of human sounds that masks the remaining natural sound, so it becomes increasingly harder for animals to communicate,” says Duarte.
Rather than call for a moratorium on whale watching expeditions, wildlife conservationists like the HWTD are advocating for a reduction in the number of boats on the water through the development of land-based viewing. “In the Hebrides, harbor porpoises are echolocating almost constantly to find their prey and see underground,” says Siobhan Moran, community outreach manager at The Hebridean Whale Trail. “Increased boat traffic and increased industry here on the West Coast of Scotland is really increasing the underwater background noise. If you're on the land, you're not causing any kind of intrusion into their world.”
The organization also aims to help make marine operations more aware of good practices. “Part of what we do is work with whale watching boat operators to train them in more sustainable practices like letting them know what the proper distance is to keep from the animals,” says Moran. The trail engages travelers through citizen science too, encouraging them to use an app called Whale Track to report whale, dolphin, and porpoise sightings and share photos. The data is then collected, analyzed, and used to support the HWTD’s research and campaigns that inform government policy aimed at protecting the Hebridean waterways.
The 33 sites that make up the Hebridean Whale Trail offer day hikes that range from a short walk out to the water, where visitors are greeted by an interpretive sign, to wilderness sites patrolled by rangers who share their local knowledge and whale-watching tips. Most of these places are close to the small towns that dot the islands, where travelers can warm up with a cup of tea after, or stay for the night. Whether travelers are scanning the horizon over a thundering waterfall on the Isle of Skye or strolling on the sand along gentle turquoise waves on the Isle of Iona, they’re often guaranteed a private audience with the marine animals that call these coastal waters home.
In developing tourism in this remote part of western Scotland, the Hebridean Whale Trail hopes to keep this serene environment intact. “If we just expand without limits and have a million boats in the water then that will take away from what's special here,” says Moran. Developing the trail was part of a plan to encourage people to take a slow approach to travel in the region, taking time to explore the area on foot and engage with the surrounding community. “Increasingly, we’re seeing people want more meaningful holidays,” says Moran.
Scotland isn’t the only country that’s developed a land-based approach to whale watching. In South Africa, a 6-day trek takes hikers along 35 miles of coastline in the De Hoop Nature Reserve. A similar long-distance hiking and cycling route in New Zealand is currently being developed, which will connect coastal communities on the country’s South Island from Picton to Kaikōura, one of the best places in the world for spotting sperm whales. Multiple shore-based whale watching trails exist in Australia, from New South Wales to South Australia. And in Vancouver, Canada, Lighthouse Park marks one of the northernmost sites along The Whale Trail, which stretches from Dana Point in southern California up the coast to Prince Rupert in British Columbia.
There in the temperate rainforest, an ochre earth pathway meanders under a canopy of old-growth western hemlock and Douglas fir, leading down to the Burrard Inlet. A briny breeze mingles with the spray of waves striking ancient, barnacle-encrusted granite. An interpretive sign at the water’s edge guides visitors in spotting the marine life that this Whale Trail site was chosen for, including harbour porpoises and Pacific white-sided dolphins as well as grey, humpback, and killer whale species.
The North American Whale Trail’s 130 sites are incredibly diverse, and although travelers have the chance to spot an array of marine wildlife along the trail, it was created with one particular animal in mind: the endangered Southern Resident orca, or killer whale. The population has plummeted in the last few decades, with only 73 left.
“My original impetus for creating the trail was to let people know where the orcas live,” says founder Donna Sandstrom from her home in Seattle, Washington. “It's in that golden moment of awareness that you get people curious and caring, and that's where conservation starts.”
The non-profit worked closely with marine biologists, community members, and partners including NOAA Fisheries, National Marine Sanctuaries, and the BC Cetacean Sighting Network, to establish the trail, many of whom Sandstrom met when they partnered to return Springer, an orphaned orca, to her pod in 2002. The decline in the orca population is a three-pronged problem, a result of a dearth of chinook salmon caused by overfishing and climate change, chemical pollutants, and vessel noise.
“We support boat-based whale watching as long as it’s sustainable for the species being watched, and it’s not for the Southern Residents,” says Sandstrom. “Commercial whale-watching here grew exponentially during the same period the orcas declined,” adds Sandstrom. The fleet followed the orcas year round, and stayed with them up to twelve hours a day during the peak season. “Essentially the whales didn't take a breath when they weren't followed by whale watching boats.”
In Washington State and Canada, the law dictates that boats stay approximately 400 yards away from killer whales and 100 yards away from other marine mammals. But this was only put into effect in 2019, isn’t always adhered to, and should be 1000 yards, according to advocacy organizations like The Whale Trail. To that end, Sandstrom worked as part of a state-wide orca recovery task force that succeeded in requiring commercial whale watching operations to complete a licensing program aimed at reducing noise and disturbance for the animals. When the orcas return this spring, they’ll have a better chance at finding food and acoustically communicating with one another.
Plus, protecting the killer whales and other marine wildlife through shore-based watching can be just as moving an experience as seeing them out on the water. “In Seattle, there’s a lighthouse at Alki Point and I've seen whales come so close you can hear their breath,” says Sandstrom. And unlike some coastal safari expeditions, shore-based watching is free and accessible to everyone.
If travelers are set on viewing non-endangered whale species and other marine wildlife from a boat, Be Whale Wise is a good place to start their research into what makes an operation sustainable. Marine wildlife activists are also calling for changes to be made to commercial vessels, including modifying hull shape, propellers, and onboard machinery to make them less noisy. Similarly, offshore construction sites are encouraged to use acoustic barriers like bubble curtains. Compared to other environmental stressors marine ecosystems face, such as microplastics and chemical runoff, noise pollution is easier to control. “Once noise pollution is gone, the impacts are immediately removed,” says Duarte.
The melancholic song of orcas. The sizzle and pop of a coral reef. A bell-like trill made by a photosynthesizing seagrass meadow. A healthy ocean has a natural symphony of its own. One that marine life from killer whales to small fish depend on hearing for their survival. In a world where ocean health and human health is inextricably linked, our own survival also hangs in the balance. “This is a water planet,” says Sandstrom. “The whole world is a whale trail.”
