Counting Starfish

cots blog1Last November Udo Engelhardt, an expert on the management of crown-of-thorns starfish (COTS), visited Seychelles to provide training to local stakeholders after concerns of an outbreak (a sudden increase in the population of COTS) in the northwest of Mahe. The training session took place over a couple of days and involved a classroom theory session and then in-water practical surveys and starfish collection. We were taught about the biology of the animal, possible causes of outbreaks, the survey method, and the easiest ways to find and, if necessary, to remove the starfish. Not easy for the extremely cryptic juvenile COTS!

In light of the COTS problem being experienced in the northwest, we have designed a project to conduct in the southwest; Petite Anse is the home of Four Seasons Resort Seychelles and a WiseOceans team, and we want to assess the population status of these coral-eating predators here, and to set up a long term monitoring programme to determine a sustainable level. The results of the project, as with all of our marine and coastal research data, will be presented to the Seychelles Ministry of Environment, Energy and Climate Change.

cots blog6Crown-of-thorns starfish are naturally found on coral reefs throughout the Indo-Pacific. Their preferred diet is coral polyps of the fast-growing branching varieties. At a sustainable level COTS can increase coral diversity by feeding on the faster-growing species and so creating space for the slower-growing corals to settle and grow. However at an unsustainable level, problems arise… The starfish are capable of destroying coral reefs by consuming the coral faster than it can grow, resulting in a dead, barren reef.

Crown-of-thorns starfish can eat their diameter in coral everyday, and can reach up to 1 metre in size!

So far excellent progress within the project has been made. The full WiseOceans team at the resort have undergone the theory training on detailed crown-of-thorns biology and ecology, and on the survey method that is used. The first underwater transects have been laid and successfully surveyed by the Marine Educators, Jo and Charlotte (the results are top secret – for now!). Next up will be the second round of surveys, and additional reef monitoring surveys for information on factors such as coral cover and diversity. Finally the data will be compiled and the report written up, and decisions regarding the long-term management of crown-of-thorns starfish in Petite Anse will be made. So we’ll be pretty busy over the coming months!
Being under the water as part of your job is great, although as with any job, distractions can be a challenge… the friendly turtle, tiny white tip reef shark and rare coral species certainly were for us!

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The crown-of-thorns population assessment project is a great addition to the Marine Educator role. Delving deep into a topic, enhancing my knowledge on the creature and contributing to scientific research from Seychelles is incredibly exciting and we look forward to seeing the outcome.

Don’t forget to check back in 6 months to see how it all went!

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