Marine researchers are working to better understand the health of baleen whales, commonly seen off of the Big Island, and how they respond to environmental stress.
A December 2020 study published in Conservation Physiology analyzed steroid and hormone metabolites in baleen whale fecal matter to find trends in hormone and steroid levels associated with environmental stress, nutrition, reproductive states, age and sex.
"This was the first effort to try identifying baseline vs. abnormal hormone concentrations in gray whales, as nobody has done that before in this species," the study's lead author, Leila Lemos of Florida International University, said in an interview with Current Science Daily. "It is important to first understand the range of common levels to later identify what is out of this range and why."
The study found trends in post-weaning and pregnant females for the highest progestin metabolite concentration, and the highest androgen, glucocorticoid and thyroid metabolite concentrations in mature males. All the hormone levels except androgen varied significantly each year.
Monitoring baleen whales has been historically tricky, and this study has made significant strides in understanding whale physiology and establishing more beneficial indicators for conservation efforts.
Lemos noted that studying steroid and hormone levels in response to stress can help researchers understand changes in whale communication, the ability to find food, immune systems and reproduction trends. The next steps for marine researchers include more monitoring and sample collecting.