8 June - World Oceans Day

Thematic Areas: Marine and Coastal Resources

When talking about islands, some people think of white sandy beaches, clear sea water, nature, and vacations spent visiting islands. However, today, millions of islands in seas and oceans are being affected by climate change.
 
How do islands form?
 
Scientists classify islands into two major groups. The first group, Continental Islands, consists of islands located on continental shelves, not far from the mainland. Most of these islands are formed by the movement of tectonic plates, such as Phuket Island, Taiwan, and other commonly known islands. The second group, Oceanic Islands, consists of islands found in oceanic regions, most of which are formed by underwater volcanic eruptions, such as the Hawaiian Islands.
 
In Thailand, islands fall into the first group. According to the Department of Marine and Coastal Resources' database, there are 936 islands: 374 in the Gulf of Thailand and 562 in the Andaman Sea. Most of these are small islands with an area of less than 10 square kilometers. There are 28 medium-sized islands. Additionally, there are six large islands, each with an area of more than 100 square kilometers, which include Phuket Island, Samui Island, Chang Island, Tarutao Island, Phangan Island, and Kood Island.



Ecological Value of Islands
 
Most islands are sources of biodiversity, home to rare species of plants and animals. Some islands that have been isolated from the mainland for a long time exhibit the evolution of organisms with unique, endemic characteristics.
 
According to the National State of Biodiversity Report, the Surin Islands are home to a variety of bird species, including the rare Nicobar pigeon. On Samae San Island, the Ang Thong lady's slipper orchid, an endemic plant, can be found. This island also provides habitat for hornbills, green-legged partridges, and pied imperial pigeons, all of which are threatened and endangered species. Koh Chang serves as a habitat for both resident and migratory birds and is home to the Koh Chang frog, an endemic species. The area around Libong Island has seagrass beds and serves as a habitat for dugongs.
 
Several islands are nesting sites for sea turtles, which are rare marine animals. They often choose to lay their eggs in tranquil and safe beach areas, such as Kra Island, Kram Island, Surin Islands, Phuket Island, and Koh Khao Island. Therefore, various activities must be carried out with caution to protect these delicate ecosystems.



Certainly, many islands boast beautiful natural landscapes, with colorful coral reefs and unique shapes, making them popular destinations for nature lovers and divers. Examples include Koh Chang, Koh Talu, Turtle Island, Similan Islands, Surin Islands, Phi Phi Islands, and Lanta Island, among others.

Climate Change Threatens Islands
 
Islands are classified as one of the most vulnerable groups to climate change, stemming from alterations in atmospheric temperature, sea temperature, rainfall patterns, storm intensity, and sea level rise. Varen's article specifies that islands at risk from climate change can be found across all latitudes, such as in Australia, Indonesia, the Caribbean, and Pacific Ocean nations.
 
According to NASA's sea level rise data, global sea levels have been rising by an average of 3.4 millimeters per year between the years 2536-2564 B.E. This trend inevitably affects various islands. The impacts not only result in the loss of residential areas and affect fishing and coastal tourism, but also in biodiversity loss, affecting marine animals, seabirds, sea turtles, and coral reef ecosystems. The phenomenon of coral bleaching has been increasingly observed in many areas over time.
 
According to New Scientist report, the Solomon Islands, a country in the southern Pacific Ocean, have experienced significant impacts from rising sea levels.  Between the years 1957-2014, six islands have disappeared entirely, while another six have shrunk by 20-62%. Rising waves have engulfed some island settlements, leading to their complete submersion.



Island Communities Awaken
 
Leaders of various island nations have become increasingly aware of the issue of climate change. They addressed the impacts on small island developing states at the 27th Conference of the Parties (COP27) to the United Nations Framework Convention on Climate Change in 2023. They called for global awareness and serious action to address climate change, emphasizing that its causes and effects cannot be managed by any single country alone.
 
With the rising trend of sea level and the impacts of climate change, some countries are closely monitoring and preparing for the situation. Apart from organizations like NOAA and NASA in the United States, Singapore has established the Centre for Climate Research Singapore (CCRS) to study the specific impacts on the country and to develop measures for mitigation and adaptation to the impending changes.
 
In Thailand, we currently lack comprehensive data to clearly reflect the situation of sea level changes.  It is crucial to continue data collection efforts. There should be an accelerated investment in developing modern and advanced sea level monitoring stations by various agencies. Meanwhile, various islands can easily collaborate to monitor changes in the area for a clearer understanding of the situation.


Complied by Tanirat Tanawat, Thailand Environment Institute (TEI)
Source of information:
  • Department of Marine and Coastal Resources. 2024. Marine and Coastal Resource Database.
  • Thailand Environmental Institute. 2566. 12 Islands, 12 Best Practices.
  • Office of Natural Resources and Environmental Policy and Planning. 2020. Thailand's Biodiversity Status Report.
  • New Scientist Website
  • NOAA: National Oceanic and Atmospheric Administration Website
  • Veron, S., et al. 2019. Vulnerability to climate change of islands worldwide and its impact on the tree of life. Sci Rep 9, 14471.
  • UN World Oceans Day 2024 Website