Life under the sea is filled with simple pleasures, free from the hustle and bustle of human life. In the midst of the stress of the COVID-19 pandemic, who would have thought there would be a reversal of closures for humpback whales?
A team from the University of Queensland, led by Dr. Inquisitive Jake Linsky made a fascinating discovery: the calming effect on migrating humpback whales off the east coast of Australia.
Dr. Linsky, part of UQ’s School of the Environment, has been studying the health of this species from the Moreton Bay Research Station. When he’s not in a lab, he’s out taking drone photos and collecting bulb samples to assess the health of these free-wheeling cetaceans.
“Controlling” whales
With their remarkable recovery from historic whaling, the health of these Australian humpback whales has been a topic of great interest. The team has been eager to use modern tools to monitor their well-being.
“We used drone photography and sediment samples to assess the health of eastern Australian 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 keep a check on their health.”
Decoding the stress levels of humpback whales
“We also used small boats to approach the whales and collect small samples of skin and blubber from the whales’ flanks,” added Dr. Linsky.
Once collected, these t-shirt samples were examined for hormones and gene expressions related to stress, energy stores and immune health. A striking finding was the significantly lower concentration of cortisol – a stress hormone – in 2021 compared to 2020.
Reduction of environmental stressors
This decrease in cortisol levels indicates a reduction in environmental stressors during the year. How did this happen?
Dr. Linsky attributes the change to several factors, including a change in climate and the drastic change in human activity during the pandemic.
“Several things happened during this period that likely contributed to our findings, including a La Niña climate shift and dramatic changes in human activity during the pandemic.”
“Our gene expression results also raise a further hypothesis that the whales may have responded to a decline 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 occurred throughout the Southern Ocean.”
Implications for conservation policies
Findings from the study of Dr. Linsky have critical implications for conservation policies aimed at protecting humpback whales and other marine species.
The observed decline in cortisol levels during periods of reduced human activity supports the argument for establishing marine protected areas and enforcing stricter regulations on marine traffic and pollution.
By minimizing human-induced stressors, we can create safer and more conducive environments for these magnificent creatures.
Furthermore, the study highlights the importance of international cooperation in marine conservation, as migratory species such as humpback whales travel great oceanic distances.
Joint efforts are essential to ensure that these animals face safe shelters. This is essential to increase their chances of survival in a constantly changing global environment.
The big picture
What does this mean for the future? These findings shed light on the role of migratory whales as health indicators of Antarctic marine ecosystems.
“Eastern Australian humpback whales have demonstrated 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 also providing valuable insights into how other whale populations in distress can be conserved.”
The study is published in the journal Marine Environmental Research.
—–
Do you like what you read? Subscribe to our newsletter for engaging articles, exclusive content and the latest updates.
Check us out at EarthSnap, a free app brought to you by Eric Ralls and Earth.com.
—–