Rivers, streams & waterfalls


Rivers and streams are vital to the islands ecosystem and are comparable to the arteries in the human body in terms of importance and function, performing crucial services such as nourishing habitats by transporting nutrients and flushing wastes from the landscape. The complex interactions between the water, soil, microorganisms, plants and animals creates a living network that connects the various habitats within the island ecosystem.

Waterfalls in some ways are keystone engineers in the way they enhance freshwater biodiversity by increasing the oxygen levels in the water allowing more complex plant life to establish in turn attracting more wildlife to the area as it is nutrient rich.

Freshwater systems are critical to both wildlife and humans through the various ecosystem services and processes they provide:

  • Water source for humans and animals
  • Critical habitats for wildlife (especially amphibians and freshwater species)
  • Natural source for hydro-electricity
  • Food source for the wildlife and humans
  • Natural water irrigation
  • Transportation for people, freshwater wildlife, sediment and nutrients
  • Recreation areas
  • Flood regulation
  • Important carbon sink (which combats against climate change)

Species such as the Asian Leaf Turtle (which are near threatened) can be found in this habitat along with many more amphibian species; Koh Chang frog, spotted tree frog and the green cascade frog (identification is still under debate) which after some research are unexpected to be found in Cambodia let alone on our island.


Rainforest / Jungle

poster background jungle

Rain forest ecosystem encompass almost 6% (and decreasing) of the earth land surface and supports more than half the worlds plants and animals, but more importantly converts 40% of the worlds oxygen. Samloem is mostly covered by dense rain forest, one of the world’s most biologically productive habitats on the planet. Forest habitats are the final stage of all ecosystems and as such they are a vital part of the island integrity by intensely binding the soil. Plants (especially large trees) retain most of the islands water filtering out the pollutants and maintaining the water table, whilst producing oxygen and facilitating the nutrient cycle.

Rain forests are made up of several different layers:

Emergent layer (at the top) which is exposed to sunlight and houses light weight animals

Canopy layer an umbrella like structure which blocks out most of the sunlight but retains the moisture and humidity. The wildlife here is very rich supporting a wider range of animals here.

Under-story layer here plant growth is limited to rather smaller trees, shrubs and climbing plants, however these are fast growing to reach adequate sunlight. The wildlife continues to increase in its diversity in this layer.

Forest floor hosts new growth but only fast growers or specialist plants can survive in such darkness. Nevertheless, the forest floor holds the key to the proper function of the rain forest ecosystem. Organic matter decays very quickly with the heat and humidity recycling nutrients back into the ecosystem through mutualism (a relationship where both species benefit each other) between plants and fungus.

All forest systems are the climax (final stage) of habitat succession and as such they are a vital part of the island integrity through its regulating, supporting, provisioning and cultural services provided such as:

  • Soil stabilization
  • Water filtration
  • Habitat for a wide range of species (mammals, insects, birds, amphibians, reptiles & micro-organisms)
  • Food source for wildlife and humans
  • Oxygen production
  • Nutrient recycling

The commonly sighted Long tail macaque can be found jumping through the canopy and resides in this habitat along with the more secretive asian palm civet and the slow loris. Song birds such as the white rump shama can be heard throughout the jungle and many different insects in all shapes and sizes including The nobles helen butterfly which is the first sighting in this country. We also have a species of mealy bug which has not yet been identified after investigation from several specialists.


Dunes & grassland


Dune grassland habitats are intertwined with beach systems as they are the transitional stage between beaches and forest. Dune systems support much of the beach ecosystem wildlife but the soil is more enriched making it more suitable to establish a nesting area for animals especially reptiles as the sandy-soil retains heat well. In most areas of the island dunes develop into Casaurina forests which climaxes into a highly diverse forests because Casuarina trees (along the beach and look like fir trees) stabilize the soil protecting the beach from erosion and assist succession along the dunes by fixing nutrients (nitrogen) into the soil changing the composition of the soil allowing less specialists vegetation to establish.

Due to previous logging on the island there is a grassland area along the trail to Lazy beach. Water Buffalo that were introduced have regulated the area through grazing creating dense grassland that improves soil stability and prevents against soil loss during the rainy season. Grassland soil contains many insects, fungi and mammals which ventilate the soil, consume vegetation and make burrows or nests below the surface.  This activity creates a natural nutrient cycle and waste treatment which is recycled in the ecosystem improving the habitat enabling it to support more specialist species; Sunda Pangolins a critically endangered and CITES protected species have been sighted in this habitat.

As a transition habitat sand dunes and grasslands support the island by:

  • Stabilizing the substrate
  • Habitat for larger specialist species
  • Habitat for sand dwelling insects
  • Coastal defense
  • Reservoir to replenish beaches
  • Water filtration or larger organic material

Grassland & dune habitat are more supportive of perennial plants species and herbs which attract more ground dwelling and pollinator species such as insects and small birds. The majestic oriental pied hornbill has been sighted resting in the outer edges of the forest  and the largest lizard we have on the island the malayan water monitor has been seen sunning themselves in the heat of the day.


Beaches & headlands


The islands coastal habitats (beaches, rock and cliffs) may not seem like the most diverse habitats but they are vital for the islands longevity.  Coastal habitats are influenced by their geography especially on islands, processes such as wave dissipation, sediment storage and transportation maintain the islands stability providing a defense against the open ocean. Within this buffer zone nutrients are recycled into the habitat whilst water is stored in grasses, algae and sand, filtering the water and retaining toxins.

This ecosystem is of huge scientific interest to understand the transition between land and marine habitats including the species adapted to both. Runner plants bind the sand above and below the ground to reinforce ground stability, but within the sand and shallow waters several ecosystems functions exist. The shallow waters along the beach provide a nursery for small animals like juvenile goat fish and needle fish which in turn becomes a feeding site for resident and migratory birds. This system maintains and improves biodiversity and the species gene pool of sand pipers, raptors, turtles, small fish, starfish, squid and other small vertebrates and invertebrates. Snakes have been observed anchoring themselves to rocks while they strike out at fish in the water for dinner.

Their are many different ecosystem benefit provided from these habitats due to the complex composition of land and sea:

  • Coastline protection
  • Sediment storage and transportation
  • Water filtration
  • Nutrient recycling
  • Recreational areas
  • Feeding grounds for birds
  • Increases genetic diversity

Besides the plants and animals here the beaches themselves differ from place to place. Saracen Bay’s white sandy beach comes from the digested coral consumed by parrot fish.  Sunset Beach is more yellow in color because of the oxidized iron in the sand and “have you heard the sand squeak beneath your feet as you walk through it”? Even silicone is found in the sand.

The one service this island provides that most appreciate and many people come to paradise island for is “the stunning views”.


Mangroves & Estuaries


Mangroves are halophyte (saline tolerant) plants that grow in estuarine areas buffering land habitats such as coastlines and wetland habitats where it provides an irreplaceable habitat and ecosystem for many species. You can find them on the southern side of saracen bay, near mad monkey and also in the bay of the fishing village (M’pai bai). It is the first marine habitat in a chain of habitats that facilitate each other and for this reason mangroves are a critical keystone habitat.

Mangroves – Sea grass beds – Coral reefs – Open ocean

Mangroves offer unique ecosystem services and processes because of their ability to filter harsh substances out of water. They can remove toxins from the water by retaining them in roots which in turn improves the water quality in the area, which contributes to coral reef health and their roots stabilize sediment and protect the shorelines from erosion. They also provide the foundations of the marine food web (fallen leaves) which propels the detritus cycle (detritus is plant matter that has decomposed into small pieces but they are vital food for filter feeding animals) which supports the higher trophic level species; Black nape terns, white bellied sea eagles and larger predatory fish.

Migratory and resident birds nest and feed here as it is supported by marine species that use the same habitat as a nursery and breeding site until they mature and migrate to coral reefs or sea grass beds. This process supports and stabilizes marine and terrestrial population growth while facilitating several processes from mangrove through sea grass beds, coral reefs until they reach the open ocean.

Mangroves and estuaries benefit the islands ecosystem through:

  • Sediment accumulation (coastline protection)
  • Habitat for many terrestrial & marine, vertebrates & invertebrates
  • Water filtration & removal of toxins
  • Carbon sink (combats climate change)
  • Feeding grounds for marine species, migratory and residents birds
  • Improves genetic diversity
  • Facilitates growth and health of other habitats


Sea grass beds

sea geass

Cambodia contains some of the world’s largest sea grass beds and around the island of Samloem you can find sea grasses inter-mixed with coral reefs at sites around Koh Koun. This ecosystem is hugely productive and diverse, rivaling the complexity and productivity of some rain forest systems. The presence of sea grasses indicate a healthy ecosystem as t is highly influenced by environmental change and facilitate the processes of most marine systems. As a habitat they support epiphytic (uses plants as a substrate) plants which establish on the grass and increase productivity by recycling nutrients into the food chain and increasing the food availability. Their presence protects fringing coral reefs from the impacts of sedimentation and protects coastlines from wave erosion. Their presence also provides additional fishing sites for fishermen; however these are vulnerable as they can be exploited when conditions restrict open water fishing.

Sea grass beds provide many ecosystem benefits for both the environment and the community:

  • Oxygenate the water
  • Increase productivity
  • Habitat for various species of marine vertebrates and invertebrates
  • Ecosystem indicator habitat
  • protects coastline through wave dissipation
  • Provides nursery habitat for fisheries commercial and exotic
  • Facilitates coral reef health
  • recycles nutrients

Commonly found between mangroves and coral reefs they play a similar role by providing a vital nursery and breeding ground for many commercial and exotic marine species. They directly provide fish, waterfowl and sea turtles with vast amounts of food establishing the first stage of the food web in this system. Within the sea grasses many species hide in their root system away from predators. Seahorses are commonly found here as sea grasses can support their whole life cycle, using the grasses to anchor themselves while they feed, breed and sleep all in one area.

Coral Reefs

coral reef

Coral reefs are one of the most diverse ecosystems on the planet, up to one third of marine fish species spend part of their life on coral reefs. Coral is an ancient living organism (more than 500 million years old) called a polyp which live in vast colonies with their symbiotic algae (supports the polyp by providing extra nutrients through photosynthesis) and create their own calcium carbonate coral exoskeleton to protect themselves. They feed on microorganisms called zoo plankton (some of these create the bioluminescence you see in the ocean at night) and other planktonic creatures.

They are an important spawning and hunting ground for both exotic and commercial marine species which supports tourism, recreation and coastal communities. Their presence dissipates waves and protects the coastline from erosion which in turn supports the recycling of chemicals and nutrients. The vast diversity of species present offers huge scientific research opportunities including medicinal benefits; some marine sponges are believed to combat carcinogens which cause cancers.

Being such a productive habitat corals reefs are vital for the facilitation of many marine processes and services:

  • Hunting grounds for various marine species and some birds
  • Breeding/ spawning grounds
  • facilitate wave dissipation
  • Support eco-tourism
  • recycle chemicals and nutrients
  • Medical and scientific research
  • facilitates the nutrient cycle


Open ocean (pelagic)


Open pelagic ecosystems are the largest ecosystems as they encompass the planet and connects the 5 oceans through the currents. Cambodia’s open waters are influenced by the Pacific (the largest ocean) currents and combined with warm temperatures and the gulf of Thailands morphology has created a highly diverse marine systems which provide the resources and complexity to support a variety from small commercial and exotic marine creatures and fish to large mammals and reptiles. The pelagic ocean is part of most marine fishes life cycle, usually spawning there which increases genetic diversity and establishes the foundations of most marine food webs (plankton).

The ecosystems main service is transportation of nutrients across the globe a bit like a mobile buffet, the smallest being phytoplankton which is microscopic algae that nourishes filter feeders and coral reefs. While zooplankton which are microscopic animals usually fish larvae carried by the current away from the spawning site to retain genetic diversity and supports the second stage of the food web. Constant water exchange through the currents regulates climate and the chemical components of the ocean maintaining seasonal change.

Through these processes we humans receive replenished fish stocks, food (fish, squid etc), research and knowledge that can facilitate medical research (studies on deep sea sponges indicate they may be used to combat cancerous cells in he body) as well as an understanding of how the planet has evolved.

Pelagic waters are vital systems and the benefits they provide and dispersed throughout the globe:

  • Transportation of nutrient globally
  • Increases genetic diversity
  • Regulate climate
  • Connects large migratory species to other areas across the globe
  • Scientific research site
  • Provides all stages of the food web
  • Supports commercial fisheries
  • Provide transportation for humans

In our pelagic waters around the island of Koh Rong Samloem many large migratory species have been recorded; Whale sharks, Spinner dolphins, False killer whales, Irrawaddy dolphin, Finless porpoise, Hawksbill and Green sea turtle to name a few.


This is a continual project so our website will be regularly updated with new information and species, so be patient as some areas of the website may be incomplete.

If you have any pictures or information from or about the island please help us to improve our database by sending your information through to us via our contact page