"Crown-of-thorns" starfish genetics may help protect reefs

Posted by Quality Marine Staff on May 16, 2024

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The Great Barrier Reef, a stunning marine ecosystem, faces a serious threat from the crown-of-thorns starfish (COTS), which feed on coral polyps, leading to widespread coral degradation. This predation diminishes coral cover, disrupting the entire marine ecosystem and causing a decline in biodiversity. However, research on the starfish's genes offers hope for combating this ecological menace.

The impact of crown-of-thorns starfish (COTS) on coral reefs is worsened by the slow growth and recovery rates of coral ecosystems. Coral regeneration takes decades, and frequent or severe COTS outbreaks can significantly delay reef recovery efforts. Moreover, reefs weakened by COTS predation are more vulnerable to other environmental stressors like climate change, pollution, and overfishing, further impeding their ability to bounce back. Therefore, controlling COTS populations is crucial for safeguarding the health and resilience of coral reefs, which play vital roles in marine biodiversity, coastal protection, and supporting local economies reliant on tourism and fishing.

University of Queensland researchers Marie Morin and Mathias Jönsson conducted a study to uncover the genetic mechanisms behind the destructive behaviors of crown-of-thorns starfish (COTS), particularly their prolific reproduction. They focused on gene expression, identifying over 2,000 protein-coding genes that exhibit significant seasonal changes. This sheds light on the seasonal rhythms and behaviors of COTS, offering insights into their biology and potential vulnerabilities. By understanding these patterns, scientists can target efforts to control the starfish population and protect coral reefs. The study's major discovery was the identification of specific genes crucial to COTS reproductive processes, aiding in understanding spawning timing and reproductive organ development.

The discovery of specific genes crucial to the reproductive processes of crown-of-thorns starfish (COTS) marks a significant advancement, offering the potential for targeted genetic interventions. These interventions could involve manipulating the identified genes to disrupt the starfish's reproductive cycle, potentially by preventing fertilization, inhibiting the development of reproductive cells, or altering the timing of spawning. By disrupting the reproductive cycle, scientists aim to control the population growth of these starfish and mitigate their destructive impact on coral reefs, thereby allowing the reefs to recover and thrive. Marie Morin emphasizes the promise of this approach, stating that finding ways to disrupt this communication genetically could halt the starfish from reproducing.

Unlike previous studies that relied on captive starfish, the research delved into the heart of the Great Barrier Reef to analyze wild populations. Professor Bernard Degnan underscores the importance of this approach, noting that studying marine animals in a lab can lead to changes in their behavior and functional genetics. By capturing crown-of-thorns starfish in their natural habitat in the deep heart of the Great Barrier Reef, researchers were able to gain insights into the true genetic makeup and behaviors of these creatures. This field research provides valuable data for understanding the dynamics of wild populations and informing conservation efforts aimed at preserving coral reef ecosystems.

The research on the genetics of crown-of-thorns starfish (COTS) is hailed as a game-changer in reef protection by Dr. Mary Bonin, GBR Foundation COTS Control Innovation Program Director. The study's findings open avenues for developing new control tools to combat the threat COTS pose to the Great Barrier Reef's delicate ecosystem. By understanding and manipulating COTS genetics, scientists aim to devise targeted, environmentally friendly solutions to control their population outbreaks and safeguard the reef's future.

The next phase of research will involve further genetic analysis and exploration of natural pest control measures. The ultimate goal is to develop innovative strategies deployable on the Great Barrier Reef to mitigate COTS damage and restore its vitality. Given the urgent need to save coral reefs from the impacts of climate change, pollution, and other stressors, this research offers hope for their preservation. Despite the challenges posed by COTS, scientists are optimistic about forging a brighter future for coral reefs and the myriad marine species that depend on them, thanks to the insights gained from unraveling the secrets hidden within COTS genes. To learn more head to Sanjana Gajbhiye’s article at Earth.com https://www.earth.com/news/crown-of-thorns-starfish-gene-expression-may-help-protect-reefs/