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Feature » Environment
Pink Dolphins an indicator of marine fertility
* Published: 21/03/2010 at 12:00 AM
* Newspaper section: Brunch Bangkok Post
Each morning, a group of two-metre long pink creatures gather around Thong Nian Bay, off Khanom district in Nakhon Si Thammarat, where their favourite food - fish fry - is abundant. They swim alongside fishing boats, waiting for the small fish to come their way. These Indo-Pacific humpback dolphins, or pink dolphins, are fiercely domestic creatures; they live in the same habitat throughout their lives.
But their home is no longer safe. Man-made threats, particularly from fishing and tourism and rising pollution, make them vulnurable to extinction. Their population in the area has declined to only 49, compared with several hundred in the past. Such a drastic reduction prompted local people, authorities and the private sector to join forces to protect them.
According to the Marine and Coastal Resources Department Region 4, 11 humpback dolphins off Khanom died between 2006 and 2008. The major causes of their deaths were being trapped in fishing nets or the effects of large fishing boats and tour boats.
"Once, two dolphins were surrounded by dozens of tour boats. They panicked. Big fishing boats with push and pull nets also come here and stay for three to four months. This year, two dolphins were found dead with wounds clearly caused by fishing nets.
"If two of them die each year, there will be none left here 20 years from now," said Suvat Juthapruek, a Walailak University researcher who conducted research on humpback dolphins off Khanom.
His one-year research project, sponsored by the Biodiversity Research and Training Programme (BRT) and completed late last year, estimates the present and future numbers of humpback dolphins off Khanom. It confirms that major threats are sightseeing tours and large fishing trawlers equipped with push and pull nets.
Suggested solutions are limiting the number of dolphin sightseeing tour boats to five for every 30-minute round instead of 20 all at once, promoting the use of suitable fishing nets, supporting in-depth research on the impact of tourism, educating the villagers about sustainable conservation and raising public awareness.
According to the research, 49 humpback dolphins are usually spotted in an area covering 73km2 from Racha ferry pier in Don Sak, Surat Thani, to Khanom, Nakhon Si Thammarat. The best spots are Nang Kam Bay, Thong Ching Bay and Nong Nok Bay, which are remote and free of resorts.
Humpback dolphins, or Sousa chinensis, are 2.2 to 2.3m long when fully grown. They live about 20m to 1km off the coast. The older they are, the more their skin colour fades from grey to white and then pink. They start mating at age 10. Their lifespan is 60 years. Each female adult gives birth to one cub at a time after nearly two years of pregnancy, and can have only a few offspring in her entire life.
Humpback dolphins are listed by the International Union for Conservation of Nature (IUCN) as an endangered species under Appendix I of the Convention on International Trade in Endangered Species of Wild Fauna and Flora (Cites), which bans trading. Their existence is an indicator of the quality of the marine ecology.
The sea off Khanom is a habitat for four types of dolphins - Indo-Pacific humpback dolphins, bottlenose dolphins, Irrawaddy dolphins and finless porpoises. However, humpback dolphins are local animals. They live near the coastline and never migrate elsewhere.
"Dolphins are an indicator of the fertility of this area, which is well known as a nursery for baby marine animals and sea grass," noted Pimpaporn Thongsaem, secretary of the Society for the Protection of Marine and Coastal Resources in Khanom, which has some 1,000 members from all walks of life.
She said humpback dolphins have been living in the area for at least 80 years. However, the number of dolphins per pod declined to five or six from 20 to 30. Since the arrival of tour boats, more dolphins have stayed away. Local fishermen at Laem Prathab in Khanom district have earned extra income from taking tourists to watch the dolphins in the area.
"Our greatest concern is the increasing death rate of the dolphins. In November, three of them were found dead due to fishing nets and natural causes. We encourage the villagers to keep an eye on these dolphins," she said.
For about six years, local communities in Khanom have been collaborating well with the public sector to protect the dolphins through educational programmes, walk rallies and beach cleaning.
Concerned agencies and the BRT have educated local villagers about the nature and protection of humpback dolphins, especially how to observe their life without annoying or harming them.
Recently the BRT, the Marine and Coastal Resources Department, Total E&P Thailand and the Total Foundation of France launched a community-based programme for local villagers at Tambon Thong Nian in Khanom to look after 30 buoys surrounding the 12km stretch of the sea inhabited by the dolphins, from Phi Island to Thong Nod Bay.
The buoys, donated by Total, are for marking the humpback dolphins' living and feeding areas and warding off large tour boats and fishing trawlers with push and pull nets that mainly cause death to the dolphins and rapidly damage marine biodiversity.
Prof Visut Baimai, director of the BRT, said the buoy installation was a good start for the planning of natural resources conservation, which needs the active participation of local people, officials, educational institutes and organisations. "This pilot project will serve as a role model for other areas if it gets a positive response from local communities," he said.
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