Ship noise now dominates the soundscape of the world’s oceans, and the Salish Sea is no exception. Ocean noise can mask signals that fish, marine mammals, and even invertebrates use to communicate, navigate, find mates, and search for food. There has been so much amazing work done by many scientists and researchers to measure noise in the Salish Sea and to understand the impact of that noise on Southern resident killer whales (SRKWs). But how much noise is too much? How much mitigation is enough? And how will we know?
We are pleased to share this paper written by Oceans Initiative’s Chief Scientist Dr. Rob Williams along with Dr. Cindy Elliser and Ginny Broadhurst from the Salish Sea Institute, Western Washington University. This paper focuses on the critical question: How much is too much noise for Southern resident killer whales?
The Salish Sea Institute is publishing a series of white papers intended to stimulate discussion around urgent questions and transboundary cooperation of our shared Salish Sea. Together, Oceans Initiative and Salish Sea Institute hope to convince funders and managers of the urgent need for a carrying capacity study to try to estimate how much vessel noise is acceptable to SRKWs, and how much mitigation it will take to help the whales recover. If we don’t have a shared vision of our target destination for sound seas, we’ll never get there.
Endangered species legislation in the U.S. and Canada aims to prevent extinction of species, in part by designating and protecting critical habitats essential to ensure survival and recovery. These strict laws prohibit adverse modification or destruction of critical habitat. The population dynamics of SRKWs are now driven largely by the cumulative effects of prey limitation, anthropogenic noise and disturbance, and toxic contaminants, which are all forms of habitat degradation.
It is difficult to define a single threshold beyond which permissible habitat degradation becomes unlawful destruction. In a recent paper in BioScience, with lawyers, scientists, and policy experts from Natural Resources Defense Council, Ecojustice, and the US Marine Mammal Commission, we present evidence suggesting that line may have already been crossed.
This summer, from mid-July to the end of September, we studied southern resident killer whale behavior under varying levels of boat and ship traffic. (This is an extension of our 2017 field season with OrcaSound). The Port of Vancouver has asked ships to slow down to less than 11 knots as they transit Haro Strait. Reducing ship speed can reduce shipping noise underwater, but slower speeds mean those ships take longer to transit the area. Working with Port of Vancouver and SMRU Consulting, we are exploring how whales navigate that trade-off between noise level and duration of exposure.
Do the whales find more salmon if they are exposed to a little bit of noise for long periods of time? Or is it better to get the noise over with quickly?
Reducing noise is especially important because endangered southern resident killer whales (SRKW) feed in Haro Strait in the summer, and our work has shown that vessel noise disrupts killer whale foraging. While missing one meal might not seem like it would have long-lasting or population-level effects, Haro Strait is a noisy place, which may result cumulatively in many lost meals for the killer whales. We had our team on the western hillsides of San Juan Island all summer to track killer whales in an effort to find out if and how their behavior changes with the slower, quieter ships.
A ship transits Haro Strait by a family of southern resident killer whales. (PC Toby Hall). The theodolite crosshairs allow us to convert horizontal and vertical angles to estimates of latitude and longitude, knowing the cliff height.
To track these whales, we used an instrument called a theodolite. You may have seen them on construction sites or traffic surveys. A theodolite has a telescopic lens that we use to track killer whale movement. After setting a constant reference point, the theodolite can determine the angle between the reference point and the whale we’re looking at. It gets the vertical angle from a gravity-referenced level vector. A computer connected to the theodolite can use those two angles (along with the precise location and elevation of the theodolite) to estimate distances and fixed positions of objects on the ocean’s surface (whales, ships, etc). Your geometry teacher was right—this math does have real-world applications. And we can get all of this fine-scale information noninvasively, without another research boat confounding the effect we are trying to measure. This year, the developer of Pythagoras software generously shared code to let us integrate extremely high-resolution AIS data on the movement of ships, so we could automagically collect precise and accurate data on the ships, while having our expert observers concentrate on measuring the whales’ behavior.
In 2017, the killer whales were worryingly absent from the islands much of the summer, which left us with a small sample size. In fact, for the month of August 2017, the SRKWs were nowhere to be found. This year’s longer field season produced much more data. There were 29 days with whales present around San Juan Island. We had tracking stations set up in three locations along the west side of San Juan Island: County Park, Hannah Heights, and Cattle Point, which allowed us to get close to continuous tracks along Haro Strait. We are excited to analyze the data, which should allow us to determine more about killer whale behavior in the presence of these slower ships.
Video credit: Toby Hall
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This work felt profoundly important this year, in a season riddled with heartbreaking news about the endangered southern residents. J35’s calf died shortly after being born, and the mother mourned the loss of her offspring by pushing around the carcass for 17 days. J50, the youngest individual in the southern resident population, was found to be critically malnourished. NOAA launched the first attempt to supplement a southern resident killer whale’s diet with additional fish. Unfortunately she has not been seen since September 7 and is presumed dead. It is abundantly clear than additional conservation effort is needed, and our team worked hard to make this field season count, both in the field and on the Southern Resident Killer Whale Task Force.
This work wouldn’t have been possible without a super pod of a team. The Oceans Initiative team was led by Erin and Rob, and consisted of our employees Laurel Yruretagoyena, Natalie Mastick, and Laura Bogaard, as well as Toby Hall, Sarah Colosimo, Jess and Chris Newley, and Elizabeth Robinson, who provided additional field support.
Thank you, as always, for supporting our efforts to keep orca habitat clean, quiet, and full of salmon.
Southern resident killer whales in Haro Strait. Photo by Toby Hall
Southern resident killer whales are in decline. Our recent population viability analysis on southern resident killer whales predicted that, if threats remained constant, it should take several decades for the population to decline from 80 to 75 whales. In fact, that decline took only three years. We fear that the decline is accelerating, and we may be reaching a tipping point.
By studying killer whales from land, we can measure their responses to noise without adding the noise of a research boat to the equation. We use noninvasive techniques to measure swimming speeds, breathing rates, and other behavior. Our work on both northern and southern resident orca has shown us that the whales spend 18-25% less time feeding in the presence of boats than in their absence.
We recently joined an international, interdisciplinary study to understand the relative importance of the three main threats to recovery in the endangered killer whale population. The whales are facing a perfect storm of threats–not enough salmon, too much noise, and too many toxic chemicals in their bodies–but lack of prey is at the eye of the storm. This research shows it will take 30% more big, fatty, Chinook salmon than we’ve seen on average over the last 40 years for the population to reach our recovery goals. That will take time, but we have to start now. Meanwhile, reducing noise and disturbance can help make it a little bit easier for whales to find the salmon we have now. In the coming months, we will be revisiting our study on identifying critical foraging areas in the Salish Sea and strengthening their protection.
Today, 22 April 2017, marks the 48th time that people around the world celebrate Earth Day. Since 1970, the effects of climate change have become undeniable, but the environmental news is not all bad. The voices of 1970s environmental grassroots movement were heard, and that public pressure led the USA to pass some of the most powerful legislation anywhere to protect endangered species and their habitat. Given our focus, it’s not surprising that we see the Marine Mammal Protection Act as one of the best examples of grassroots movements leading to real-world conservation gains. Over the last few decades, consumer demand has shifted fisheries practices to the extent that “dolphin-safe tuna” is now the industry standard in North America and Europe. Similar efforts drove the Save the Whales movement, which led to a moratorium on commercial whaling in 1986. We’re not naive, but we are inspired by #OceanOptimism.
After every public lecture we give, people ask how they can help.
People often share feelings of hopelessness and powerlessness in the face of global losses of biodiversity and wilderness. The paradox is that collectively, we hold the power to influence policy, and with every purchase we make, we have the power to influence markets and industrial practices. We cast a vote every time we buy – or choose not to buy – a product. And we are struck by the energy in today’s March For Science events around the world. The people have spoken, and they want policy to be based on reliable evidence. Our tagline, Science for the Sea, tells you that we share that view.
Here are some examples of the power of consumer choice that have inspired us lately. This is not an exhaustive list, and it draws heavily from personal experience. When have you “voted” or made a sustainable choice with your dollar? We’d love to hear from you in the comments.
Don’t buy what you don’t need. Our friends at Patagonia blew us away in 2011 with their New York Times ad asking people not to buy their products. Prevention is far better than a cure.
Reuse and upcycle. Last year, Patagonia donated their entire Black Friday sales to environmental programs like ours. Reusing or repurposing products is far more resource-efficient than recycling.
Buy locally. As Rose George wrote in her gorgeous book, 90% of all the goods we purchase were shipped overseas. Support local businesses and reduce your environmental footprint. Our friend, Alexandria Rossoff, has run a thriving jewelry business in Seattle for 38 years that seamlessly integrates sustainability by reusing estate jewelry and catering to a local market. As she launches an online business model to spend more of her time on her conservation mission, we were touched that Alexandria has decided to donate a portion of her last month’s in-store sales to our nonprofit. Thank you!
