Thailand: Acoustic tags to be used to monitor dugong behaviour

The Nation 22 Jun 14;

Japanese and Thai marine biology researchers plan to jointly monitor dugong behaviour via acoustic tags in Trang - home to Thailand's largest dugong population - in the hope of encouraging marine-life conservation.

Dr Kanjana Adulyanukosol, director of Marine and Coastal Resources Research and Development Centre (Upper Gulf of Thailand), and Kyoto University marine biologist Dr Kotaro Ichikawa went to Banbatuputeh School at Koh Libong, Trang on Tuesday to meet locals and prominent officials in order to explain the use of acoustic tags on dugongs.

Researchers have spent 10 years investigating the topic, with experiments set to start in November and implementation of the project set for the following February.

Researchers said the tags would not harm the dugongs as they would be tethered to the animals with a rubber rope with a built-in weak link.

The line, which is approximately 30 metres, can be broken to safeguard dugongs should the lines get tangled or they will eventually fall off in five days.

Capturing the dugongs to attach the tags will only take up to five minutes.

The Japanese team has used acoustic tags on over 1,000 dugongs in Sudan and Australia with great success. The work is divided into four procedures.

The acoustic tags will be attached to the dugong's tail and then an autonomous underwater sound-recorder will be placed on the seafloor or attached to a floating buoy.

The recorder will record sounds underwater and this is known as passive acoustic monitoring. The system will be equipped with built-in automatic detection software for dugong vocalisations.

A 60-metre-long hydrophone cable will then be towed behind a boat, with researchers monitoring the process from nearby Batuputae hill.

Five dugongs will be monitored over 14 days so that we have a better understanding of their habitat and daily routines. The information will be used to develop necessary measures for dugong conservation.

Trang has between 125-135 dugongs, with over 10 mother-child couplets.

Kanjana hopes that Koh Libong locals will help protect dugongs.

While she said she did not know why people killed the mammal, she reminded locals that Thailand had environmental protection laws covering dugongs.

Ichikawa declined to comment on the matter because he was aware that Thailand had laws to protect dugongs. He called on locals to stop smuggling the animal and preserve it instead.