Image: Dr Maria Byrne, CC by 4.0

Sea urchins can pass heatwave resistance on to the next generation, according to a recently published study.

Global ocean temperatures are increasing, exposing ecosystems to marine heatwaves which can increase the temperature of marine waters by 5°C higher than normal in summer. These can last several months and cause devastating effects on marine life.

Dr Bayden D. Russell from The Swire Institute of Marine Science and The School of Biological Sciences at The University of Hong Kong, along with his research group, in collaboration with Dr Maria Byrne, from the University of Sydney, experimentally assessed whether adult sea urchins (Heliocidaris erythrogramma) that are exposed to marine heatwaves could pass beneficial protective mechanisms onto their offspring, thus ensuring the survival of the next generation. Although they found that they could,these carryover effects may not remain effective throughout the development and growth of juvenile urchins. 

Sea urchins are both economically and ecologically valuable. They maintain the structure and function of benthic marine ecosystems by eating algae that would otherwise take over these systems in the absence of urchins, making the ecosystem simpler and less biodiverse. This role is particularly important in ecosystems stressed by human activities like nutrient pollution or marine heatwaves, which benefit fast-growing algae that replace critical habitats like coral reefs or larger seaweed forests such as kelp forests.

When exposed to thermal stress, some urchin species have the ability to pass on protective mechanisms to their offspring as a means of defence should the offspring come up against the same type of stress as their parents. 

If a marine heatwave occurs at any time during the spawning period of the urchins, these carryover effects could lead to increased survival of the juveniles under what would normally be stressful temperatures. But, if the heatwave continues throughout the larval development, these short-term physiological responses may lead to higher mortality and ultimately reduce the survival of the next generation,” said Dr Jay Minuti, lead author

Jay J. Minuti, Maria Byrne, Hamish Campbell, Deevesh A. Hemraj, Bayden D. Russell, 2022. Live-fast-die-young: Carryover effects of heatwave-exposed adult urchins on the development of the next generation, Global Change Biology

CC BY 4.0


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