Big Blue Conservation had a day to remember when we were invited by local fishermen to watch how they fish, what they catch and to teach them how to identify species to through back and those they can eat. This trip is all part of the new Koh Tao Shark Project, aimed at learning about our shark populations on Koh Tao.
We were very lucky to be invited by P'Mat, a local fishermen, to join him on one of his fishing trips. We watched him fish with 7 other men off a longtail boat, deploying 7 nets in total, each about 100m long but only 3m high. With these nets, they hoped to catch Pink whiprays, a species of ray with a large distribution and currently has a conservation status of "least concern". Other than rays, they catch other small fish like fusilier, but in 16 hours of work with 7 nets, they caught only 10 different fish. Not species, 10 individual fish. We did a dive next to the net as it was being raised from the bottom, and we witnessed how careful they were, and no substrate was disturbed or broken from these nets - great news!!
Of the total catch, 7 were what they wanted to keep and 2 they successfully released back into the water. One trumpet fish died unnecessarily, but in the bigger picture, they were very responsible with the fish they caught and how they did it. They showed substantial understanding of the fish they collected, including being able to identify male rays versus females, and if the females were smaller then a hand, they put them back. We asked them why, and they replied "for next time". This is a wonderful thing to see, not only are the nets they are using are non-destructive, but the fishermen themselves are thinking in sustainable terms.
So what next? Well as part of the Koh Tao Shark Project, the fishermen have agreed to give us, for free, any sharks or rays that they catch accidentally (other than pink whiprays), so that we can survey and tag our populations. With the Pink whiprays, they will report to us how many they catch each trip, including male to female ratio, so we can help them monitor their fishing populations. This trip has shown us how our local fishermen are just as dedicated to keeping our oceans healthy and profitable for everyone. Thanks to P'Mat and his team for allowing us to come along - see you next time!
A big happy Earth Day for yesterday people of Earth! We celebrate Earth Day to help remind us of how beautiful and fragile our world is and that it is mainly our responsibility to ensure it stays that way. With this in mind we had a crew of 17 people clean up North Sairee yesterday, and collected almost half a tonne (462 kgs) in rubbish!! It was insane to see how much trash we could find at the side of the roads and in waterways. Most upsetting was the amount of beach rubbish, as the majority of this will end up in our ocean, contributing to the substantial amount of plastics and garbage in our water.
In the afternoon we had 36 people join us for the underwater section of our clean up (after a fantastic dive at Chumphon pinnacle), and we managed to collect around 17 kgs of rubbish, including 8 eroding batteries - lovely.
Celebrations didn't stop there! The Save Koh Tao Office hosted a Film festival where local contributed a short film about island life or a topic they feel especially passionate about and we all voted which was the best one. The winner was a fantastic film about one of Koh Tao's artificial reef deployment, by Simon Dowling. Well Done Simon! We all had a great day raising money and awareness about our Earth and celebrating everything is does for us. Thanks to everyone that helped out or contributed to the day. Go forth and be ECO!
Drupella Snails can be responsible for extensive coral reef damage, once an outbreak occurs removal must take place for the balance to be restored. On Koh Tao in 2010 following a bleaching event we lost a significant amount of the Drupellas favourite dish - Acropora (staghorn) coral. As a result, the Drupella population well exceeds the Acropora cover, meaning goodbye to even more acropora colonies as they eat the remainders. Drupella snails use a special mouth 'radula' and feed off of living coral tissue, particular favourites being stag horn and plate coral colonies here on Koh Tao. The snails leave white tissue scars on affected coral and can usually be found congregated at the base or deep down in-between the coral branches. Adults have a robust looking shell, 2 to 3cm long, are covered in small cones/ spikes and are deep purple in colour due to their shells being cover in calcereous algae. Juveniles are usually 0.5 to 1cm long and are white in colour.
In an attempt to reestablish the balance between durpella and Ancropora populations, we must remove excess Drupella snails from the reef. It is important to make sure removal is of the snail's only and not the common hermit crab which also takes up residence in an empty Drupella snail's shell, some easy clues for checking are waving the shell (if they drop off immediately, they are hermit crabs), and also the hermit crab will re-emerge from its shell relatively quickly once removed and in your hand.
On our last trip we collected 313 snails! We saw 31 aggregations, and then the odd snail or two on its own. All in all a good trip (well...maybe not for the Drupella victims...).
If you are planning your own collection, be careful not to damage the coral colony you are collecting them from; there's no point 'helping the coral' by removing snails if you break the coral in order to do so.... we only remove the most easily accessible Drupella snails. Once we've removed what we can from a dive we place the snails in fresh water for 24hrs before then replacing the shells back onto the coral reef so the shell can then bio-degrade, this then enriches the water with calcium carbonate which other organisms will intern use to build their own exoskeleton (anything from coral, octopus, all marine shell's, cuttlefish, clams..etc).
A very heart felt congratulations to our recent Eco internship graduates! You spent the last month learning all about marine systems, understanding the underwater world and the problems it faces, and practising skills in how to help it. It is thanks to the dedication of eco-minded divers like you that mean we can generate research and gather information in an effort to look after our reefs on Koh Tao and on larger scales too, so THANK YOU!
Our class of March 2013 consisted of team Italy - Ettore Baratta, who became an expert in fish identification, Carola Buscemi who is so passionate about recyling she made her own signs, and Aris Thomasberger who we just can't (and never want to!) get rid of. Alissa Muench from Canada was survey queen on every dive she did, Kate Jenkins from the UK helped to set up the Koh Tao Shark Survey, and Joe Morgan helped us reach more people than ever before with our online campaigns. Thanks Eco-people!
So AJ and Tina from Scotland who are starting the internship just now, I expect great things from you guys to keep our eco team as fantastic as ever!!
The Koh Tao Shark Survey enjoyed it's first nursery success today - we were so excited to receive a call from the local fishermen we are working with early this morning telling us they had accidentally caught 3 blue spotted rays last night. We went over there to collect them and brought them back to our nursery tanks. Next, we made sure they were healthy and not damaged from the fishing nets, then we took measurements and data from the rays (2 males and one very small female!) and took photographs of the spot pattern on their upper body, which is specific to each individual ray and can be used to identify them. We can now use this data to track the ray populations, especially if they are re-sighted. A few hours after they were originally caught, they were released back into the water, where they happily swam straight under some rocks.
Just when we thought the day couldn't have been better, late on during a dive at our adopted reef, we saw the small female hiding underneath our coral nursery!
The sharks had been caught by the fishermen and would have suffer a BBQ death if it had not been this project and the fishermen who support it. It's great to see the project working, with locals getting involved and some happy rays as a result. Stay tuned for more updates on our Koh Tao Shark Survey efforts.