Amira Ismail
Forget what you thought you knew about evolution; as climate change pushes marine life to the brink, it has no choice but to adapt or face extinction; and while some species are struggling to survive, others have managed to adapt and evolve under this environmental pressure in ways we’ve never seen before.
In this article, we will be exploring how marine organisms demonstrate resilience in response to warming waters and environmental degradation.
Adaptation strategies: the keys to survival
When discussing adaptation, the concept of plasticity inevitably arises, which refers to the organisms’ capacity to adjust their morphological, behavioral, or physiological traits depending on varying environmental conditions. In this context, it includes both phenotypic and genetic plasticity, crucial for enabling animals to respond effectively to ecological shifts. This is especially important when talking about climate change adaptation, pervasive particularly in marine organisms [1].
Behavioral changes
The ocean is a dynamic environment, and one of the most interesting aspects of marine life is how the organisms alter their behaviors to meet the challenges of changing conditions.
One notable area of their strategies is their reproductive and breeding methods, for instance, they may change their locations, times, and behaviors to ensure convenient conditions for their offspring [2].
Studies have revealed that Atlantic herring adjust their spawning locations and depths, seeking optimal thermal environments for their young to thrive [2].
Habitat shifts
As environmental conditions become less optimal due to global warming, species may relocate to more favorable habitats [2]; this can involve moving to deeper waters or adjusting their latitudinal ranges in response to thermal stress.
For example, some fish species instinctively migrate to the north or to deeper waters where temperatures are cooler and ideal for their living since warmer waters tend to hold less oxygen. As winter approaches, they typically return to their original habitats [3].
Physiological tolerance
Various aquatic animals have demonstrated physiological adaptations to cope with environmental stressors like ocean acidification and elevated temperatures [4].
In this case, many fascinating examples have been observed like marine calcifiers that have developed ways to counteract ocean acidification and to maintain or even accelerate their shell growth and strength through different mechanisms such as altering their mineral composition and crystallinity, fueled by metabolic energy [5].
Some research has shown that ocean warming or acidification in isolation leads to a positive energy budget, higher resource procurement, and physiological performance in marine animals such as bivalves and gastropods.
In this specific context, the effects of both of these stressors in isolation tend to pose less danger to crustaceans compared to when they’re combined since they can find ways to adapt and utilize food to fuel their energy and enhance their physiological mechanisms [5].
Genetic adaptation: the pathway to evolution
Populations of certain species may experience genetic changes over time, improving their resilience in novel ways.
Insights into this adaptive evolution have been gained through molecular-level comparisons, genome scans, and DNA sequence analysis to further explore and shed light on this concept; some interesting examples include species like red abalone and purple sea urchins that have shown genetic changes related to ocean acidification and different temperatures in environments. A particular study demonstrated how some alleles in sea urchin larvae changed due to increased CO2 percentage [6].
Conclusion: Cues for an immediate action
As we continue to study and understand these dynamic responses, it becomes increasingly clear that these marine species are finding ways to survive and thrive under these pressures, and these different adaptive strategies are a testament to their resilience but this doesn’t negate the negative impacts human actions have on them. Our climate is rapidly changing and oceans are getting warmer at unprecedented levels, challenging species that may not adapt fast enough to counteract their effects.
As we navigate the complexities of this ongoing change, it is crucial to improve conservation efforts and maintain the balance of the ecosystems in our oceans, as well as continue our research and studies on these species to foster their resilience and ensure the health of our planet.
Citations
[1] Padilla, D. K., & Savedo, M. M. (2013). A systematic review of phenotypic plasticity in marine invertebrate and plant systems. Advances in Marine Biology, 65, 67–94. https://doi.org/10.1016/B978-0-12-410498-3.00002-1
[2] Zhou, Y. (2024). Adaptation or Extinction: Survival Strategies of Marine Organisms under the Pressure of Climate Change. Int’l Journal of Marine Science. https://doi.org/10.5376/ijms.2024.14.0008
[3] US EPA, OA. (2018, January 4). Climate Change Indicators: Marine Species Distribution | US EPA. US EPA. https://www.epa.gov/climate-indicators/climate-change-indicators-marine-species-distribution
[4] Whiteley, N. M., & Mackenzie, C. L. (2016). Physiological responses of marine invertebrates to thermal stress. Stressors in the Marine Environment, 56–72. https://doi.org/10.1093/acprof:oso/9780198718826.003.0004
[5] Leung, J. Y. S., Russell, B. D., & Connell, S. D. (2020). Linking energy budget to physiological adaptation: How a calcifying gastropod adjusts or succumbs to ocean acidification and warming. Science of the Total Environment, 715, 136939. https://doi.org/10.1016/j.scitotenv.2020.136939
[6] Reusch, T. B. H. (2013). Climate change in the oceans: evolutionary versus phenotypically plastic responses of marine animals and plants. Evolutionary Applications, 7(1), 104–122. https://doi.org/10.1111/eva.12109
Opmerkingen