Dead Coral - Hin Daeng and Ko Ha

[DontLieToMe]

I just returned from a trip that included diving at Ko Ha and Hin Daeng. Another thread reported coral death at Hin Moung and Hin Daeng. This same type of coral death is taking place at depths of 45+ feet at Ko Ha. The corals appear to fall off and litter the sea bed and then are washed to sea. I have included two pictures showing several corals of this type scattered on the sea bed as well as a close up of the coral anchoring point. The extent of coral death at Hin Daeng was very extensive.

 

[patamus]

I am sorry to hear about that. I just got back from my trip yesterday and enjoyed it very much. However, because most of the Dive Company on Phi Phi advised against going out to Hin Daeng I didn't go but I enjoyed the diving on PHI PHI Ley and the other smaller islands south of PHi PHI Ley. Did you dive there?

 

[DontLieToMe]

We also dived areas around Phi Phi such as Hin Bida, Bida Nai, and Bida Nok. I did not observe the coral issues at those sites.

 

[MoonWrasse]

Bida Nok and Bida Nai - the other 2 smaller islands just south of Phi Phi Ley - are just fine as far as I can tell. However the waters seem much cloudier there this year than in the past.

Similans are just fine, excellent visibility, fewer boats there right now.

 

[DontLieToMe]

Visibility throughout November of last year was very good. Since December there has been great variability in visibility from the south up to and including the Mergui Archipelago. As far as Hin Daeng - there was large amounts of green "matter" floating in the water. Other areas such as Phi Phi, Shark Point, and Ko Doc Mai were very green. Visibility on the west side of Ko Doc Mai was down to 3 feet (1 meter). The change at Hin Daeng is very dramatic since last November. My perception is that with the loss of the soft corals the growth of Corallimorpharians is occuring very rapidly.

 

[Christian]

...and the worst hit site according to reports is not Hin Daeng, it's Hin Mouang.
Have they cancelled all diving there..?

 

[Bowmouth]

Thai marine biologists have recently dived Hin Daeng/Hin Muang and taken samples to study and find the cause of the dying reef. Appearantly not only soft corals are dying at these sites but also sea stars and (hinchbeak) shrimps.
If I hear any news/updates on the research I'll post it immediately.

 

[drbill]

Very sorry to hear this. I spent a month in Thailand back in 2001 enjoying the diving and the people (Land of Smiles... at least outside of Bangkok!). Please post whatever the scientists find after they've conducted their tests.

 

[Diver_City Boys]

what a pity , any new update on this?

 

[ianto200]

Here is a copy of the interim report compiled by Reefatch worldwide

Dear All

As you know there have been some strange events happening in the seas near lanta, in particular surrounding the sites of hin deng and hin muang and more recently Koh ha. As you are also aware many of you have been making and recording our observations, collecting samples and shooting video clips of various sites around the region. In the first instance I would just like to congratulate you all on a marvelous effort and also to reassure you that we have some of the planets finest scientists looking at the data and samples you have collected. The scientists are in no particular order outlined below.

K. Nippon PMBC
K. Apple Chulalongkorn University and Reefcheck
K. Wilkinson Reef and rain research centre, Australia
K.Thaithawarn Chulalongkorn university
K. Henoc CHARM
K. Visser CHARM
K. Garner Reefwatch worldwide

In addition many thanks to CHARM for their support and weight in getting attention on the situation

They are currently collating data and discussing the issue at length they will be giving an opinion soon but I thought I would drop you all a note with an explanation as to what has been discounted so far.
If you can remember the initial causes being suggested were cyanide or other poisoning, leaking toxic waste from an unknown source, algae bloom (sometimes called a red tide) fishing boats with powerful electric devices capable of trawling and electrocuting any organism caught and perhaps the least fashionable was cold water coming from the Antarctic or other location.

1 cyanide or poison.

K. Thaithawarn from Chulalongkorn and K.Nippon from PMBC both did tests on water samples and organisms and could find no traces of cyanide or any other commonly used chemical associated with fishing using this method. It was also concluded that as the areas affected covered a great many square kilometers this was unlikely to have been the cause of outbreak.

2 Electrocution by nets.

K. Apple from Chulalongkorn noted that this theory fails to hold water again on a geographical basis and also you would expect to see evidence showing many fish or organisms with exploded abdomens caused by contact with the electrical nets. K. garner from Reefwatch worldwide also found the theory unlikely as the cost of this technology not to mention the high risk to the fishermen made it unlikely.

3 Leaking toxic waste

K. Garner researched the Lloyds of London insurance data base for any reports of vessels being lost in the area. He found no such reports and also commented again on the wide spread area that had been affected noting that similar incidents had been observed as far south as taratoo and as far north as the similan islands. I (Ian) did hear of a report that a vessel ad gone down but this was never confirmed.

4 Algae bloom

Some of you might recall that this was my (Ian) personal favorite and I even sent you all a fact sheet on the subject. Wrong! K. Thaithawarn fromChulalongkorn analyzed the samples of organisms and water and his findings were that there was no bloom. The phytoplankton found in the water samples are typical species found in the ocean and the densities were low. Samples taken from deeper depths showed no signs of phytoplankton so a plankton bloom is probably not the cause of death to the organisms.

5 Cold water currents

Now you might have noticed how scientists never actually say that this is or isn’t the reason for any particular phenomena (note the frequent use of probably or maybe or perhaps) however the cold water theory has not been discounted by any of the scientists above. In fact this is the theory that has them all talking at the moment the debate centers around whether the cold water is from a colder region like antartica or perhaps due to seismic activity in the very deep parts of the Indian Ocean where the water is also extremely cold.


In conclusion at the moment it seems probable that the cold water theory is favorite, you can however be sure that as soon as I know you will!


Best Regards

Ian Shaw

Reefwatch Worldwide and Reefcheck


PS If you haven’t done so already please go to www.reefcheck.org and sign the coral reef petition of existence. Over one million signatures required.