Truthfully, I have never personally witnessed the spectacle of a major Crown-of-Thorns Starfish (COTS) outbreak in the sea. My colleague from the Headquarters (Extension 1816), who saw the scene again this year outside the southern side of Dongsha Atoll, said he almost cried upon seeing it and has been urging me to go help with the removal efforts.
As for why COTS outbreaks occur, although scientists propose various reasons, such as high nutrient levels in the sea, rising seawater temperatures, or a decline in the number of COTS predators, there is actually no consensus. We can only quietly track the frequency of outbreaks and do our best to remove them when they happen to minimize damage to the coral reefs.
Looking at the photos brought back by my colleague (Extension 1816), I couldn't help but think: if we call coral reefs the rainforests of the sea, are COTS outbreaks like the wildfires in Sequoia National Park, periodically burning through our coral reef rainforest? Many research reports observe that COTS preferentially feed on Acropora, which are among the faster-growing types in the corals. This observation, combined with my analogy of COTS as wildfire, brings Aldo Leopold's "A Sand County Almanac" to mind.
In "A Sand County Almanac," Leopold regarded fire as a significant ecological force, discussing its dynamic role in forest regeneration, maintaining biodiversity, and shaping landscapes. He implicitly criticized simplistic forest management approaches that aimed to completely suppress natural fire. His understanding of fire embodies his "land ethic" – the concept of understanding and respecting the natural processes of ecosystems.
If, like wildfire, COTS outbreaks burn down the marine forest built by Acropora, could this also be seen as a way to suppress fast-growing coral species, thereby helping other types of corals with different growth patterns establish themselves in the habitat? Of course, we cannot confirm this. Internationally, it is generally accepted that COTS are part of the coral reef ecosystem, and their predation is a natural phenomenon. Under ideal natural conditions, small-scale or infrequent outbreaks might be considered natural disturbances that trigger local successional processes and could even play a role in maintaining long-term diversity. However, the frequent and large-scale COTS outbreaks currently experienced in many regions worldwide are largely exacerbated by human factors. The destruction they inflict on coral reefs far outweighs any potential "natural succession" role COTS might play. This intensity of disturbance, especially when compounded with other environmental stresses, often hinders the healthy succession and recovery of coral reefs. It more readily leads to ecosystem collapse or phase shifts towards unfavorable states, where other organisms, such as algae, replace corals.
However, in the waters surrounding Dongsha Atoll, we benefit from relatively less human disturbance and a healthier coral reef environment. Therefore, perhaps within the tragedy of this COTS outbreak, we can introduce a different rhythm. Through long-term, fixed-point monitoring and investigation, we can continuously document the changes in the coral reef community following the COTS outbreak. Simultaneously, we can investigate the populations and feeding behaviors of various COTS predators, and even work towards restoring different natural enemies that prey on COTS during various stages of their life cycle. Perhaps, one day, we can unravel the mystery behind these outbreaks.
The Crown-of-Thorns Starfish Outbreak
Crown-of-thorns starfish eating coral