Wriftten by Margaux Hein and Fanny Couture
Fanny and I have just spent 7 weeks with the NHRCP team to conduct the research part of our master’s thesis. The aim of our thesis is to investigate the effect of the marine protected areas (MPAs) on the marine life around Koh Tao. Fanny focuses on fish while I am looking at coral health and diversity. Yet other than the protected area component, we also wanted to understand how other activities within the sites might affect the marine life. One of them is the impact of boats. Surveying the boats at each of our study sites gave us an idea of the relative boat traffic, as well as the diving and snorkelling pressure around the island. Boat traffic may impact the marine life through noise and sediment re-suspension. Diving and snorkeling boats are also associated with impacts such as noise, fish feeding, coral breakage, and eventual anchor damage. We differentiated 3 types of boats:
– Passing boats: boats that passed within our sampling area but did not stop.
– Snorkeling boats: snorkeling boats that stopped at the sites. We differentiated the small long tails carrying a few passengers and the big snorkeling boats carrying between 50+ people.
– Diving boats: Diving boats that stopped at the sites.
Altogether, we surveyed 6 sites around the Island. 3 within the new MPA framework: Twins, Sairee, and Shark Island; and 3 outside the MPA: Sai Nuan, Ao Leuk, and Hin Wong bay. The surveys were conducted at peak hour for 4 hours (10am-2pm). We went to each site twice giving us a total of 8 hours of survey per site.
To be honest and confirm our teammates suspicions, these surveys mostly involved working on our tan and drinking shakes. This said, while the data hasn’t been properly analyzed yet, we already found big differences among the sites. Sairee and Sai Nuan had very little to no diving or snorkeling activity but huge boat traffic. On the other hand, Hin Wong Bay and Ao Leuk were hubs of diving and snorkeling. At some points, we could easily estimate that 200+ people were frolicking around at these sites. Twins was mostly characterized with a high diving pressure, while Shark Island was the quietest site for all 3 categories of boats. We also noticed differences in the boat visitation depending on the weather. For example, very few boats were present at twins under the stormy weather. Conversely, very few boats visited Shark Island under beautiful conditions. All sites have different expositions, and more surveys may be needed at different time of the year.
The next step is to analyze the data and cross it with the fish and corals survey we have been conducting in the last 7 weeks. This will help getting a better understanding of how the boat traffic around the island may influence the coral and fish assemblages. Hopefully, these surveys will also help the Save Koh Tao Marine Branch in estimating and regulating the traffic around the island.