Humpback whales were happier during the pandemic hiatus, research found

Research led by the University of Queensland found that migrating humpback whales off Australia’s east coast were less stressed during the first year of the COVID-19 pandemic. The research report is published in Marine environment research.

Dr. Jake Linsky from UQ’s School of the Environment led the study from Moreton Bay Research Station to measure the health of the species at a time of unprecedented changes in human activity.

“We used drone photography and blubber samples to assess the health of eastern humpback whales in the waters off Minjerribah – North Stradbroke Island – during their migration in 2020 and 2021,” said Dr. Linsky.

“This population has made one of the most successful recoveries from historic whaling, so we wanted to use the latest tools at our disposal to ensure their health is in check.”

Scientists used drone images to measure the whales’ size and body condition.

“These are basic indicators of the energy reserves used during their long annual migration and intensive breeding season,” said Dr. Linsky.

“We also used small boats to get close to the whales and collect small samples of skin and blubber from the sides of the whales.

“These fat samples were analyzed for hormones and gene expression related to stress, energy reserves and immune health.”

Laboratory results revealed significantly lower cortisol concentrations in whales in 2021 compared to 2020.

“This change in their physiology suggests a decrease in environmental stressors between the two years,” said Dr. Linsky.

“Several things happened during this period that likely contributed to our findings, including a shift in climate to La Niña and dramatic changes in human activity during the pandemic.

“Our gene expression results also raise the additional hypothesis that whales may have responded to a decrease in pollutants in their distant feeding waters.

“Previous studies have found similar changes in stress hormones in whales on the opposite side of the Antarctic continent – our findings support the idea that these changes have occurred throughout the Southern Ocean.”

The researchers said the results highlight the role of migratory whales as indicators of the health of Antarctic marine ecosystems.

“Eastern Australian humpback whales have shown a remarkable ability to adapt to changes in their environment, but our study highlights the importance of mitigating human impacts so they can continue to thrive in our rapidly changing oceans,” said Dr. Linsky.

“By continuing to monitor and protect humpback whales off Australia’s east coast, we can ensure their health and stability while offering valuable insights into how other struggling whale populations might be conserved.”