Krista Trounce, krista.trounce@portvancouver.com
Vancouver Fraser Port Authority
999 Canada Place, Vancouver, British Columbia, V6C 3T4

Popular version of 4aAB7 – Managing vessel-generated underwater noise to reduce acoustic impacts to killer whales
Presented at the 181st Acoustical Society of America Meeting at 10:40 AM PST on Thursday, December 2, 2021
Click here to read the abstract

Every year, thousands of ships en route to Canada’s largest port, the Port of Vancouver, transit through the Pacific Ocean’s richly biodiverse Salish Sea, home to a vast array of marine life including the endangered Southern Resident killer whale.

As Southern Resident killer whales rely on sound to survive, underwater noise from commercial ships can interfere with their ability to hunt, navigate, and communicate, which is why both the Canadian and U.S. governments recognize “acoustic disturbance” as one of the key threats to the species’ recovery.
To better understand and reduce the effects of vessel-generated noise on local whale populations, the Vancouver Fraser Port Authority launched the Enhancing Cetacean Habitat and Observation (ECHO) Program in 2014. The ECHO Program coordinates research projects to advance our understanding of underwater vessel noise and since 2017, has led seasonal initiatives encouraging ships to slow down or stay distanced to reduce underwater vessel noise while transiting through Southern Resident killer whale foraging areas.

To achieve high levels of participation in its voluntary initiatives, the ECHO Program works closely with both Canadian and US marine transportation industry, vessel traffic management agencies and pilots and captains aboard commercial vessels. During the last two seasonal slowdowns, over 90% of piloted commercial vessels voluntarily reduced speed in Haro Strait and Boundary Pass, key areas of Southern Resident killer whale critical habitat. In-water measurements collected on behalf of the ECHO Program and the Government of Canada have shown that for the vast majority of ships plying the waters of the Salish Sea, reduced speeds result in measurable reductions in underwater noise generated both at the ship source, and in nearby whale habitats.
Hear the difference: Underwater sound from the same container ship operating at regular and reduced speeds

MP3: Container ship at regular speed (19.4 knots)*

MP3: Container ¬¬¬ship at reduced speed (10.6 knots)*

To date, more than 6,000 ships have participated in the ECHO Program’s voluntary underwater noise reduction initiatives, by either slowing down, or moving away from key areas, across 74 nautical miles of shipping routes in the Salish Sea. During the summer of 2020, these initiatives helped achieve a nearly 50% reduction in underwater sound intensity from commercial shipping, in key Southern Resident killer whale foraging areas.
The endangered Southern Resident killer whales face many challenges to their recovery, and underwater noise from vessel traffic is just one of these challenges. Through science-based decisions and regional collaboration, the ECHO Program partners are proving that voluntary efforts can help make a difference.

A killer whale (orcinus orca) nearby a commercial ship transiting through the Salish Sea, off British Columbia’s southern coast. (Photo credit: Joan Lopez)

A pod of killer whales (orcinus orca) travel nearby a commercial ship in pod formation. The southern resident killer population is made up of three matrilineal pods (J, K, L), which are led by the eldest female. (Photo credit: Joan Lopez)

Andrea M. Simmons, andrea_simmons@brown.edu
Charlotte R. Thorson, charlotte_thorson@alumni.brown.edu
Madeline McLaughlin, madeline_mclaughlin1@brown.edu
Pedro Polanco, pedro_polanco@alumni.brown.edu
Amaro Tuninetti, amaro_tuninetti@brown.edu
James A. Simmons, james_simmons@brown.edu
Brown University
Providence RI 02912

Popular version of 2pPPa1 – Echolocating bats modify biosonar emissions when avoiding obstacles during difficult navigation tasks
Presented Tuesday afternoon, December 2, 2021
181th ASA Meeting, Seattle WA
Click here to read the abstract

Bats use echolocation, an active biological sonar, to find their way in the dark. By broadcasting trains of intense ultrasonic sounds and listening to returning echoes, they can locate and identify obstacles to their flight (vegetation, buildings) and capture small insect prey. Bats often fly and forage in groups. When other flying bats are present, they face the added challenge of separating out the echoes from their own broadcasts from the broadcasts and echoes created by these other bats, while still maintaining their flight path. To assess how bats address these challenges, we flew individual and then pairs of big brown bats (Eptesicus fuscus) through a curved flight corridor bounded by rows of closely spaced vertical hanging plastic chains that produced echoes mimicking those produced by dense vegetation. When flying alone, each bat broadcasts sonar sounds containing frequencies from 100-25 kHz in a characteristic pattern of alternating long and short time intervals. These short time intervals allow fast reactions to immediate collision hazards, while the long intervals allow the bat to peer deep into its surroundings to plan its upcoming flight path. When two bats fly towards each other from opposite ends of the curved corridor, they maneuver to avoid colliding. There are three distinctive biosonar reactions tied to these maneuvers. First, both bats increase the strength of their broadcasts (Lombard effect) during the brief time they are in close proximity. Second, they produce more short time intervals, speeding up their broadcast rate. Third, at the point where they are in closest proximity and the need for each bat to avoid being interfered with by the other bat is most acute, one of them sharply decreases the low-frequency end of its broadcasts to about 15 kHz. This unusual, asymmetric response allows this bat to distinguish echoes of its own broadcasts from those of the other bat, even though the total range of frequencies remains large. Bats place particular priority on the lowest frequencies in echoes, and having different lowest frequencies lets them separate out each other’s biosonar broadcasts and prevent mutual interference when close together.

Rivera-Parra, JL, jose.riverap@epn.edu.ec
De la Cruz, I.
Viscarra, S.
Vasconez, C.
Dueñas, A.
Xulvi, R.
Sorriso-Valvo, L.

Popular version of 5aABb2 – A tale of two singers: how do bats and bird mixed-flocks respond to petroleum industry noise in the Ecuadorian Amazon
Presented Friday morning, December 3, 2021
181st ASA Meeting, Seattle, WA
Click here to read the abstract

Industrial noise can have a significant impact on animal groups that rely on acoustic communication for fundamental survival activities. Our research focuses on two of these groups: insectivorous bats, which use ultrasound to navigate and find food; and mixed flocks of insectivorous birds, that rely on vocalizations to communicate about foraging direction and potential threats. The Yasuni Bio-sphere Reserve in the Ecuadorian Amazon is one of the most biodiverse spots in the world, but it is also a place with thriving oil exploitation activities.

It is well known that some disturbance, such as roads, or industrial noise, can be related to biodiversity loss, however, how much of these effects can be attributable to the noise caused by the oil exploitation have never been measured, nor has it been characterized. Furthermore, characterization of noise is usually done only in the audible spectrum, meaning the frequencies that us as hu-mans can hear, but is not done taking into account ultrasound.

To characterize the noise caused by oil exploitation we selected three different places, based on the potential source related to the oil industry, plus a control point: 1) drilling site, 2) processing facilities, 3) a control site, a forest with no disturbance. For all three sites recordings of both audible and ultrasonic sound were made in a transect from the border of the source of industrial noise to-wards the forest. To further analyze the effects of the noise, biological surveys were made both in birds and bats. We characterized bats and birds vocalizations, and the industrial noise profile, both in ultrasound and audible frequencies.

Our results suggest, in both groups, the immediate response is avoidance; this results, in the short and long term, in a biodiversity loss. These effects are proportional to how much noise the habitat itself absorbs, the complexity of the habitat, the complexity of the noise, and the distance from the source. In the long term the effects seem to include a change on habitat use, and modification on community composition. Thus is possible it can cause a disruption of ecosystem services by bats and birds, such as natural pest control, polinization, and seed dispersal, which can lead to a broader change in forest dynamic.