Captive whales, dolphins and epigenetics

What is epigenetics?

Epigenetics is a field of study that investigates how gene expression is controlled and how environmental factors can influence gene activity. Changes to an animal’s genes due to epigenetic modifications can affect their overall health, behavior, and susceptibility to disease. For example, stress can cause epigenetic modifications that may weaken an animal’s immune system or alter their behavior. Exposure to toxins, diet, and other environmental factors can also modify gene expression.

To sum it all up, epigenetics is the study of how genes are regulated and how environmental exposures can modify gene expression. By understanding the mechanisms that control gene expression, researchers can uncover the factors that contribute to an organism’s overall health and behavior.

Stressors and their effects on captive whales

Captive whales, including killer whales and dolphins, are often subjected to a range of stressors such as limited space, lack of social interactions, noise pollution, and changes in diet and temperature, McCaw et al. (2020). Stressors like these can lead to chronic stress which can have long-term impacts on the physical and mental health of these animals. Hence, modifications to their DNA markers. You can read more about chronic stress on whales in captivity in this article by Marino et al. (2018) titled “The harmful effects of captivity and chronic stress on the well-being of orcas (Orcinus orca)”.

We believe that studies should be done on potential epigenetic changes in captive marine mammal populations. We know these marine mammals undergo a great deal of stress which increases stress hormones which may impact the genes regulating the stress response. Additionally, epigenetic changes may also affect the whales’ behavior, as changes in gene expression could alter the animals’ stress response and social behavior. These changes could be responsible for orcas killing and injuring their human trainers as well as their ability to interact with each other. Stress can also lead to bacterial, viral and fungal infections seriously comprising the physical health of the mammal. 

Introducing Lolita to a Sea pen

We suspect that Lolita’s DNA has undergone modification as a result of being in captivity and if moved to a sea pen that will create additional stressors from the new environment which include but are not limited to change in sunlight, water quality and temperature, underwater acoustics and noises from vessel traffic, organic and inorganic organisms in the seawater. We are not saying she should not be moved, we are expressing concern about the complexity of managing her care and the changes she will experience moving from a captive pool to a sea pen.  A pool in Miami and a sea pen in the Pacific Northwest are vastly different environments and  we are concerned about her physical and mental health as she transitions from a concrete pool in Miami to a different climate environment in Washington. Since this blog article is about epigenetics, we are wondering if the new sea pen climate and location would further modify gene expression and what would the consequences be to Lolita if that were to happen.