Similan Science

Similan Science

With the huge changes to the Similan Islands national park this year, and the seemingly last minute implementation of new rules, it became very clear to us that our communication with the Thai authorities was not enough as it should be. So were overjoyed when we were kindly invited to join the ‘Phuket Marine National Park Operation Center 2′ and a group of Thai university students, to help carry out a series of ongoing scientific studies at the Similan Islands.

Similan islands scientific research experiments scuba diving

Introducing the Scientists

At the start of the season we wrote a blog about a collapsed sea fan at Similan Island #9. This was the first time we met Nok and her team from the MNPOC. They helped us fix the broken coral and informed us of their ongoing studies. What we didn’t expect was to then be invited out on a 3 day scientific expedition onboard the Peter Pan Similan liveaboard. I would like to take this opportunity to thank Mr Prarop, the organiser of these studies, for inviting us onboard. It was great to meet you and find out about all the excellent work you are doing.

Group photo on Peter Pan Similan Liveaboard

The Experiments

There were a variety of projects and teams on board. Some of the experiments have been going on for as long as 7 years under Mr Prarop’s supervision. Here is a quick breakdown of some of those studies and the implications they might have on the Similan national park.

Sediment Sampling

One of the main studies focused on the impact of speedboats on the shallower reefs next to the beaches. These studies were carried out at Similan’s busiest areas; Donald duck bay (Island #8) and Princess Bay (Island #4). A third control study was done on the east of Island 8# where speedboats are not allowed. This project was split into 2 parts. Firstly, sand samples were collected at various depths/distances from the beach. These samples will be taken back to the lab where they will be analysed. The will check grain size of the sediment and check for foreign chemicals and pollutants that should not naturally be occurring there naturally.

In the same locations, they attached small trays with 3 cups inside each tray, a few inches above the sand. These cups will be left for 1 month before they are collected. The hypothesis is that in the areas with lots of speedboat traffic, the sand will be disturbed much more, and there should be a higher volume of sand in the cups. If the sand is constantly being disturbed and settles on the corals, then the coral will not be able to grow. The results of this experiment could have a large impact on any future decisions to restrict speedboats accessing the Similan Islands.

Coral Regrowth

If you have ever dived at West of Eden on Similan Island #7, you will probably have already seen this experiment in action. The equipment consists of a large metal frame with slots to insert tiles at various different angles.

These tiles are left down for one year and are then taken back to the lab to see what has grown on them. This study has already been going on for years and they discovered that different corals grow at different angles. Some grow best on a flat surface, some horizontal, some at an angle and others underneath. DNA samples are recorded of each type of organism growing on the tiles.

Once the tiles have been removed, the old metal frames are left on the dive site. Long term they will also be studying which corals eat away at the metal. So next time you are diving at West of Eden, take a closer look to see what is growing on the tiles. However, you may need to wait a while. These slates were just put in place on 15th December.

We were shown the growth on one of the tiles when we returned to the boat. To see that a new coral had grown about 1-2cm in an entire year highlighted how important it is to take care of our reefs. Attempting to help repair coral reefs is a very long term process.

Electro Magnetic Current Reading

Some of the experiments involved using highly specialised equipment. One of the university students was studying the currents inside the bays. The electromagnetic current reader is a small metal device suspended just above the sea bed. It measures the direction and intensity of the currents over a 25 hour period.

The results of studies on currents in the area is potentially a useful one for us divers. At dive sites with tidal currents, predicting the intensity and direction of water movement is relatively simple with the use of accurate tide charts. However, due to the location and shape of the Similan Islands, we get more Dynamic currents. These are not so easy to predict and require research like this to have a better understanding of how the water moves around the islands.

Reef Surveys and Other Experiments

At most dive sites the university students assisted Nok and her team with general reef surveys. Firstly, one team member attaches a tape measure to the reef and reels it out 100 meters across the reef. Then a larger team follow the tape measure taking photos and notes of the various coral and fish species. These studies are compared with previous years to see if there is any imporvement in the overall health and diversity of the reef.

Other experiments included various techniques for planting new corals. These are being carried out around the Similan and Surin national parks. Next time you dive at Richelieu Rock, look in the shallow areas of the bay and you can keep an eye on the growth of new stag horn corals cable tied to the reef.

Thinking of the Future

It was a privilege to be invited on the trip and great to see all the excellent work being carried out. To Mr Prarop and the ‘Phuket Marine National Park Operation Center 2′, we are always more than happy to have you or your team on the MV Hallelujah and will offer any assistance you require.

Hopefully the results of these experiemnts can help to better protect the underwater locations we love so much. Let us know your opinions of the studies in the comments section below. And let us know if you would be interested in finding out more about how to get involved.