Cassidy Swanston

Cassidy Swanston is the Communications Director of the Pelling Lab, a curiosity-based laboratory that thrives on innovation and exploration. She is also the founder and executive director of Pulsar Collective, a nonprofit initiative with the mission to improve gender equality in science and technology. Her work is fueled by her belief in the power of storytelling and the importance of science literacy.

Do the sounds of ships scare Arctic sculpins?

August 21, 2018 | 2 minute read

Climate change is causing ice in the Arctic to quickly recede, opening the Northwest Passage to increased traffic of ships and boats. The frequency of sound that fish can hear is similar to the frequency of sounds made by typical sea vessels, and the noise and water disturbance that ships make can disrupt their biological patterns. An international research team set out to determine how vessels impact the movement of deep-water Shorthorn Sculpin in Resolute Bay, Nunavut. While the effect of vessels on how they moved was unclear, the presence of stationary vessels significantly affected where the Sculpins moved within the bay.

The study, published in the Canadian Journal of Fisheries and Aquatic Sciences, lasted from 2012 to 2015. The team collected data during each year’s summer and autumn when ice coverage is low. The researchers used satellite data along with a time-lapse camera to determine when there were no vessels, moving vessels (entering or exiting) or stationary vessels in the bay. Environmental factors like salinity and daylight hours were monitored as well.

The Sculpins’ movement was tracked using acoustic telemetry. This procedure involves surgically implanting electronic tags into a sample of caught fish and then releasing them back into the bay. The tags emit a unique sound signal which are picked up by a network of strategically-placed receivers (or listening stations). The difference in time it takes a sound signal to reach three or more receivers triangulates the position of the fish in three dimensions.

The data collected from the receivers revealed three “types” of sculpin movement based on rate, acceleration and linearity (how straight they swim): 1) feeding and hiding behaviour, 2) exploration of new environments, and 3) irregular movement typical during foraging. Analysis showed the number of daylight hours was the only variable to consistently affect movement type. For each year of the study, the response of sculpins to vessels was inconclusive, perhaps due to other environmental factors or because movement was tracked on a small number of fish.

However, the presence of stationary vessels did affect where the Sculpins moved within the bay. Although the data on their spatial use around moving vessels wasn’t sufficient for analysis, they consistently moved within a smaller range in the presence of stationary vessels. As well, they significantly shifted their core home ranges – the space they spend the most time in – when stationary vessels were present. As Arctic sea ice continues to recede and shipping policies evolve, these findings indicate a need for further study of how fish modify their movement in the presence of vessels. Knowing where fish go when ships are nearby can ensure conservation efforts are effectively directed towards maintaining a healthy Arctic ecosystem.

An Arctic Sculpin.

Read the full paper: Impact of vessel traffic on the home ranges and movement of Shorthorn Sculpin (Myoxocephalus scorpius) in the nearshore environment of the high Arctic in the Canadian Journal of Fisheries and Aquatic Sciences.

Cassidy Swanston

Cassidy Swanston is the Communications Director of the Pelling Lab, a curiosity-based laboratory that thrives on innovation and exploration. She is also the founder and executive director of Pulsar Collective, a nonprofit initiative with the mission to improve gender equality in science and technology. Her work is fueled by her belief in the power of storytelling and the importance of science literacy.