Koh Haa

Koh Haa. Koh Haa is a small island group in the Andaman Sea off the coast of southern Thailand, noted for clear waters, submerged lagoons, and coral reefs. The islets lie within a maritime region frequented by scuba diving operators, protected-area authorities, and scientific survey teams from institutions such as Chulalongkorn University, Prince of Songkla University, and NGOs like World Wide Fund for Nature and Conservation International. The area is often accessed from nearby hubs including Phuket, Krabi, Koh Lanta, and Trang Province ports.

Geography and geology

The islands are a compact cluster of limestone and karst outcrops rising from the Andaman Sea continental shelf near the Malay Peninsula coast, sharing geomorphological features with formations in Phang Nga Bay, Surin Islands, and Phi Phi Islands. Geological surveys reference regional tectonics related to the Indian Plate–Eurasian Plate interactions and Quaternary sea-level changes recorded in Sunda Shelf sediments. Bathymetric maps used by marine biologists and hydrographers show steep drop-offs, submerged caverns, and a central sunken lagoon that creates distinct hydrodynamic conditions similar to features around Similan Islands and Koh Rok. Navigation charts employed by the Royal Thai Navy and commercial operators mark shoals, pinnacles, and channels used by liveaboard vessels and day-boat services from Ao Nang and Krabi Town.

History and etymology

Human use of the islets has included episodic visitation by Moken sea nomads, fishing communities from Trang Province and Krabi Province, and maritime traders traversing the Andaman Sea routes between Penang, Langkawi, and Surat Thani. Colonial-era charts produced during the era of the British Empire and regional mapping by the Royal Thai Survey Department note the islets as waypoints for local fisheries and monsoon navigation. The name used locally derives from Thai and regional Malay toponyms, and historical accounts in travelogues by Prince Chula Chakrabongse-era explorers and 20th-century naturalists reference the archipelago’s notable lagoons and reef systems. Scientific expeditions by institutions such as Mahidol University and international teams from University of Oxford and Smithsonian Institution have documented the islands’ natural history in surveys and monographs.

Marine environment and biodiversity

The surrounding reefs host hard and soft corals, sponges, and benthic assemblages characteristic of the Indo-Pacific biogeographic province, with species lists overlapping those recorded at Similan Islands, Surin Islands, and Koh Phi Phi. Ichthyofauna include reef-associated species observed in surveys by UNEP partners and regional research groups: groupers referenced in studies by IUCN, wrasses catalogued in taxonomic work associated with Natural History Museum, London, and pelagic visitors recorded by Australian Institute of Marine Science comparative research. Megafauna such as green sea turtles, hawksbill sea turtles, and occasional sightings of whale sharks and manta rays have been reported in collaborative monitoring by WWF-Thailand and university dive-research programs. Benthic surveys identify coral genera common to Coral Triangle fringe zones, and algal communities supporting local herbivores mirror records from Southeast Asian coral reef studies.

Tourism and diving

The islets are a popular destination for day-trip diving and snorkeling excursions run by operators based in Phuket, Koh Lanta, Krabi, and Ao Nang, and listed by international guidebooks referencing Lonely Planet and diving directories associated with PADI and SSI. Dive sites around the islands are known for swim-throughs, a submerged central lagoon, and wall dives comparable to sites in the Similan Islands. Local tourism enterprises, regional tourism authorities such as the Tourism Authority of Thailand, and liveaboard companies from Phuket and Koh Phi Phi include the islets on itineraries that attract international divers from markets like Germany, United Kingdom, Australia, and China. Seasonal patterns tied to the Northeast Monsoon and Southwest Monsoon influence access windows, while adventure travel writers and magazines have featured the sites in destination roundups.

Conservation and management

Management responsibilities involve coordination among provincial marine authorities, national agencies such as the Department of Marine and Coastal Resources and the Royal Forest Department, and conservation NGOs including WWF and The Nature Conservancy that have worked regionally on coral reef protection. Zoning, visitor limits, and mooring-buoy programs are among strategies promoted by international partners like UNEP and IUCN to reduce anchor damage and diver impacts, following protocols similar to those at Similan Islands National Park and Mu Ko Surin National Park. Research collaborations with universities and citizen-science initiatives coordinated through networks such as Reefbase and regional dive centers contribute monitoring data used in adaptive management and restoration trials employing coral gardening techniques developed in projects with Coral Restoration Foundation-style methodologies.

Category:Islands of Thailand