Every Friday, the Roctopus ecoTrust meets up at Victor’s Bar on Sairee Beach at 5:45 pm for a weekly beach clean‑up. Every Saturday, the team heads out for clean‑up dives around the island, pulling up debris that could otherwise damage the reefs you come here to dive on. Led by marine biologist Matt Knott, dive masters in training (DMTs) and volunteers join in – not just to clean up the ocean, but also to collect important long‑term data that gets sent to global projects like Clean Swell. The numbers show far more than ‘we cleaned a lot this week’; they reveal where Koh Tao’s pollution really comes from and how it changes once you move from the beach down to the reef.

Hi, I’m Jess.

Not long ago, I walked away from a six-figure professional career — the kind of job you’re “supposed” to hold onto — to follow a calling that’s been tugging at me for years. Turning my lifelong love for the ocean into something more than just a vacation hobby. I’m new to this experience of the ocean, having only completed my open and advanced certifications in 2023. Now, only two years later, I have completed my ECO divemaster training. 

I’m in my early 40s, and I’ll admit — I’m older than most of the people taking this path. But if there’s one thing I’ve learned, it’s that timing is personal. Life is a journey of a thousand choices that lead you exactly where you need to be. Every closed door is simply an opening to another — sometimes one that smells like salt air and feels like freedom.

I’ve always been drawn to the ocean — its power, its mystery, its fragile beauty. Pair that with a deep respect for the environment, starting this new journey feels less like a career shift and more like a homecoming. This chapter isn’t about escape; it’s about alignment. It’s about choosing purpose over comfort and curiosity over convention.

If you’ve ever felt the pull to change direction — especially when the world thinks you shouldn’t — you’re in the right place.

In SCUBA diving we like to keep our hand signals clear and simple. Therefore, anything looking remotely like a sea slug or flatworm gets referred to as “nudis”. This leads to a bit of confusion when I claim that the adorable sea slugs commonly known as Shaun the Sheep are in fact not nudibranchs but sacoglossans.

Now you’re probably wondering why differentiate them – what could possibly be so special about the order Sacoglossa? The biggest answer is kleptoplasty - and this is where things get weird. These tiny sea slugs are some of the only Metazoans that are able to not only sequester but also functionally retain chloroplasts from the algae they feed on – this means they can use foreign chloroplasts to actually photosynthesise themselves. Why they do it is still a mystery in the scientific community, and though there are quite a few theories, none have explained how they’re able to in the first place.

Figure 1 Butterflyfish pair swimming by their coral reef ecosystem.

In coral reef ecosystems everythingis interconnected, from the individual corals themselves to all the reef dependant and associated organisms. This includes your Koh Tao locals: Butterflyfish, Bannerfish, Angelfish, Rabbitfish, Damselfish… the list goes on. The balance in this ecosystem is quite delicate; therefore, one’s vulnerability to a changing climate will ultimately affect the other. As a result of coral bleaching alone, coral reef fishes are facing changes in population and recruitment dynamics, connectivity, and overall loss of abundance, diversity, and changes in community composition (Koester et al., 2023). Declines in coral health alter reef food webs, reducing availability of coral associated prey and shifts toward algae dominated reefs.

The Green Turtle, Chelonia mydas, has officially been moved from Endangered to Least Concern on the IUCN Red List, the world's largest list of globally threatened species. This is the first time since their initial assessment in 1982⁶, and is a huge achievement for global conservation efforts. But what does this mean for Turtle Island exactly?   

Hi everyone, My name is Vincent, I'm 28 years old and from Germany.

I arrived on Koh Tao on the 9th of March 2025 to start my Eco-Divemaster Training with Roctopus on the 15th of March. I just want to tell you a little something about Ko Tao and my 3 1/2 months here, that are coming to an end in 11 days. Arriving on the island, I already felt like this was going to be a great 3 1/2 months here. The first few days I went on fun dives to get back into diving, as my last dives were in january of this year. Meeting the rocto staff, being on the boat, and just spending a few days there before really confirmed that I made the right decision coming to Roctopus for that.

Coral reefs, often referred to as the rainforests of the sea, are some of the most diverse and productive ecosystems on the planet. However, these vibrant underwater ecosystems are facing unprecedented threats due to climate change, pollution, overfishing, and coastal development. Coral restoration has emerged as a critical tool in the fight against coral reef degradation. In this blog post, we'll delve into various active coral restoration methods and discuss why coral restoration is so crucial for the health of our oceans.

A juvenile starry pufferfish (Arothron stellatus) displays vibrant aposematic colouration, warning predators of its toxicity.

A school of bigeye snappers (Lutjanus lutjanus) create a unique formation at Chumphon Pinnacle, Koh Tao with the help of a delicate sensory system.

A malabar grouper (Epinephelus malabaricus) perches at the reef edge following a busy night launching stealthy ambush attacks on unsuspecting prey. Traps are commonly used around the world to catch large groupers resting near the reef edge – often a much easier target that other high value fish swimming mid-water. 

Two juvenile longfin batfish (Platax teira) peform a drifting swimming behaviour close to the surface, where their behaviour and morphological features which closely mimic floating debris keeps them out of danger from predators lurking beneath.

A comb jelly lures in prey with a dazzling light show of vibrant colours pulsing rhythmically down its entire body.

A prawn goby (Cryptocentrus cinctus) peers out of its hole, acting as a sentinel for its mutualistic partner, an Alpheid shimp 

 A Box jellyfish (Tamoya spp..) migrates from the deep ocean to feed on zooplankton living at shallower depths.

Hermit crabs are decapod crustaceans found all over the world in a diverse range of marine ecosystems. In coral reef ecosystems, these crabs are often found on sandy sea beds or rocky surfaces, and are occasionally found living on coral branches. They are omnivores with a diet mainly consisting of detritus.

A pickhandle barracuda (Sphyraena jello) swims in the open ocean where it can single out its prey and engage in a high-speed chase.

A Blue Spotted Ribbontail Ray (Taeniura lymma) resting under a reef overhang, waiting for the sun to set before beginning a hunt. During high tide, these rays are often seen to migrate inshore to sand flats where they feed on invertebrates and bottom dwelling fish that inhabit these shallower sandy areas.

A Lagoon Damselfish (Hemiglyphidodon plagiometopon) living amongst an arborescent branching coral.

Sea anemones (Heteractis magnifica) competing for habitable space on the reef.

A variety of hard corals providing important habitats for several reef fish and invertebrates, creating a biodiversity like nowhere else on the planet.

Damselfish, alongside clownfish, are both members of the family Pomacentridae, and are two of the most abundant reef-dwelling fish. They often live in and around coral reefs or sheltered sandy lagoons; however, some species have been recorded to live up to depths exceeding 100m. Primarily herbivores known for cultivating algae ‘gardens’, they may eat some small invertebrates and anemones, but these typically form a small part of their diet. These fish are most well known for their territorial nature and nesting behaviours; unlike most families of pelagic fish, the damsel fish lay their eggs attached to a substrate (a solid object such as coral, rock, and other debris).

Question: Does frequency of divers on dive site locations alter the response and recovery time of gobies to perceived threats?

Throughout the Indian, Pacific, and Atlantic Oceans, species of Goby fish (Gobiidae) form a mutualistic symbiotic relationship with species of alpheid shrimps, commonly known as pistol or snapping shrimp (belonging to the family Alpheidae). Interactions between species lead to different advantages and benefices for all the concerned individuals, for instance protection against predators, food supplies or a safe place for breeding (Karplus and Thompson, 2011; Karplus, 1974).

I was curious and fascinated by this buddy team since my first time in the ocean, practising my skills over the sand. Witnessing these sentinel gobies guarding their little shared kingdom with their powerhouse shrimp, rearranging the furniture. With Koh Tao being one of most popular places to dive, I wanted to find out if higher diver traffic on dive sites affected these species, and in what way. So, I embarked on a 2-week research project to find this out.

As Marine Ecology Interns, we have spent the last few weeks alternating between the classroom and the ocean, learning about fish and coral identification, their importance in ecosystems, and how we can protect and preserve our incredible reefs. We have participated in many clean-up dives, biodiversity assessments, and removal of certain species threatening coral health and growth, such as drupella snails and the crown of thorns starfish. 

 As part of my 4-week eco-internship at Roctopus, I assisted in a variety of ongoing research projects such as biodiversity surveying and artificial reef construction and maintenance. In addition to this, I had the opportunity to conduct my own personal research project. I wanted my project to focus on the impacts of the recreational SCUBA industry on coral health.