Coral reefs are some of the most diverse ecosystems on the planet. In recent years, coral reefs have shown significant signs of stress as a result of increased anthropogenic (human) activity. The Roctopus ecoTrust monitor trends in the health and biodiversity of local reef ecosystems by gathering quantitative and qualitative information from a range of different organisms and abiotic (environmental) factors within a particular area. Information gathered from this project helps to identify factors associated with reef health, as well as the threats that coral reefs surrounding Koh Tao are subject to. This helps to inform effective management strategies in areas that require restoration, protection and conservation.
Across the globe, fish living on coral reefs have become increasingly more exposed to several threats including overfishing, pollution and habitat loss from climate change and ocean acidification. Significant damage caused to a reef often has serious consequences on the ability for many fish species to survive there. Biodiversity of reef fish is often a good measure of reef health and can be used to assess how the health of a reef is changing over time. The reef fish monitoring programme established by the Roctopus ecoTrust aims to provide information on the health status of reefs around Koh Tao by monitoring trends in the biodiversity of reef fish, as well as population trends for key reef species. This programme also aims to identify specific threats that local reefs are subject to, and the effect these are having on local reef fish communities.
Corals play an essential role in the providing of habitats to other marine organisms, protecting coastal communities from storms and coastal erosion, and facilitating microbial processes that regulate the enviornmental conditions of marine ecosystems. In the last 100 years, corals have been exposed to numerous threats, many of which have been associated with increased anthropogenic activity. As a result, areas all across the globe are seeing a mass reduction in coral cover. Coral nurseries established by the Roctopus ecoTrust are used for the active restoration of coral reefs. Fragments that are found living in hostile environments (most commonly when lying in the sand) are collected and transferred to artificial structures which are designed to provide an optimal environment for growth. Over time, these corals will completely cover the structures and become part of the natural reef.
Biodiversity is a defined as the number of different species in an area, and is a great measure of the health of any ecosystem from jungle to open ocean! We are incredible lucky to have an incredible diversity of reef building (scleractinian) and soft coral species in the Indo-Pacific, with Koh Tao showcasing lots of beautiful coral species of all shapes and colours. Unfortunatley, with historic bleaching and disturbance events, coral diversity in some areas has decreased, having a knock on effect on the diversity of other marine species found there. Our coral genera diversity research project aims to provide information on the relative abundance and diversity of different coral types around Koh Tao, forming links between stressors and the presence or absence of specific coral types.
Marine debris is often carried by winds and ocean currents to shallow bays and coves, where it commonly settles on nearby reefs. This can cause significant damage to coral structures and other reef associated organisms. The Roctopus ecoTrust organise weekly beach cleans in order to minimise levels of trash that may be carried onto local reefs. Roctopus contribute data to the Clean Swell project established by Ocean Conservancy, a science-based organisation that seeks solutions for a healthy ocean and wildlife that depends on it.
As well as organising regular dive clean-ups, Marine Biologist Jade has launched a monitoring program which targets the very specific problem of coral entanglement. Survey dives are conducted on all of the major dive sites of Koh Tao, as well as the less commonly visited areas. Reefs are systematically surveyed, with the frequency of entanglement events recorded, type of debris analysed and species most severely affected investigated. Of course, careful debris removal also forms an integral part of this program. Trainees at the ecoTrust can be expected to get hands-on with this project in all aspects, with survey dives conducted at least twice per month.
It is estimated that between 5-10 million tonnes of trash enter our oceans each year, the majority of which is plastic. Some types of plastic take hundreds of years to decompose. During this time, they have the potential to cause significant damage to coral reefs and the organisms that live there. The Roctopus ecoTrust conduct regular underwater reef cleans around the island, removing trash items that are likely to cause damage to local reef ecosystems. Roctopus are active members of the non-profit marine conservation organisation Project AWARE, and contribute data to their Dive Against Debris program. This program aims to prevent the accumulation of trash in marine environments by working with volunteer divers all across the world.
Fishing nets that are lost or discarded by fishing boats become a significant entanglement risk for reef fish living nearby. Nets that settle on reefs can also cause large scale damage to coral structures and other benthic organisms (organisms living on reef substrates). The Roctopus ecoTrust continuously monitor deeper areas around the perimeter of submerged pinnacles. These are areas where nets may have been trawled over reef substrates, causing nets to become entangled. Regular monitoring ensures the Roctopus ecoTrust team can deliver a rapid response in freeing entangled marine organisms and conducting net removals where required.
During their adult life stages, Crown of Thorns starfish (COTs) are corallivores and predate on the live polyps of hard corals. If the density of COTs increases within a particular area, the mortality of corals through COT predation may exceed the rate at which new corals are able to recruit in the same area. This may lead to a significant loss of hard corals within a reef ecosystem. In the last 100 years, COTs outbreaks have increased both in severity and frequency throughout the world and these outbreaks have commonly been associated with anthropogenic influences. Research projects established by the Roctopus ecoTrust aim to monitor the population density of COTs, and identify areas where outbreak populations may form. Research is also conducted on the habitat and dietary preferences of COTs in order to improve our understanding of the ecological effects of high COT densities around Koh Tao.