Using Infrared Thermography to Assess Welfare in Free-Ranging Rorqual Whales

by Anik Boileau and Jamie Ahloy Dallaire, Sept-Iles Education and Research Center

In recent years, anthropogenic disturbances such as maritime traffic, pollution, and fishing have had a negative impact on the welfare of great whales around the world. The town of Sept-Iles, Québec, located on the Gulf of St. Lawrence, hosts the largest mineral port in North America, with an average 500 cargo ships docking annually. This area is also an important feeding ground for many marine mammals, notably blue and fin whales, prompting concern for their welfare. Traditionally, health assessments of great whales employed invasive tools such as biopsies and satellite tagging. A new approach is needed to assess overall welfare in a noninvasive way.

With the support of a Christine Stevens Wildlife Award, the Sept-Iles Education and Research Center developed and validated a noninvasive welfare assessment protocol using infrared thermography to measure stress. Infrared thermography uses a thermal camera to create images of an object from the infrared radiation it emits. In this study, we used this technique to collect data related to behavioral indicators such as reactions to boat approaches and physiological indicators such as respiratory rates, body temperature, and body condition for 10 fin whales found within 20 nautical miles of the Port of Sept-Iles.

We analyzed the videos and images with thermal imaging software, focusing on extracting temperature values from the dorsal fin and the blowholes at different angles. We also tested different parameters so we could identify which one should be used specifically for fin whales (as baseline values).

The preliminary results show that the baseline mean temperature of blowholes at the moment of inhalation was 14.76°C (SD=0.73) and the baseline mean temperature of dorsal fins was 7.13°C (SD=0.65). While the core body temperature in fin whales is unknown, we assume it falls within the mammalian range of 31–41°C, as measured using a standard thermometer. Since we can’t use this method on a free-ranging cetacean, infrared temperature measurement is the best alternative. For instance, now that we have a baseline normal blowhole infrared temperature of 14.76°C, we expect that this temperature will increase in an emaciated or chronically stressed individual, making it possible to use this method to correlate with other indices when assessing the welfare of cetaceans.

This pilot project demonstrates that using infrared thermography can be a valid tool to integrate into a free-ranging whale welfare assessment protocol. Continuing research into validating all animal-based welfare indicators (physical, behavioral, and physiological) and environmental disturbances (ships’ presence in the area and distance from the whale, sea temperature, salinity, etc.) can now include correlations with infrared thermography values as a valid, noninvasive welfare measure for fin whales. As we gather more data, we hope our research will support legislative changes concerning whale welfare and best practices in intensive industrial settings and high maritime traffic areas that overlap with cetacean habitat. 

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This study was funded by the Christine Stevens Wildlife Awards program. To learn more about this program or to view additional studies, click here.

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Program Terms: Marine Wildlife

AWI Quarterly Terms: Feature Article