With its ancient rainforests, rugged, granite-peaked mountains, idyllic lagoons and pristine beaches, Borneo is a wild place and perfect for a Nature lover like myself; I am fortunate enough to live and work in the Malaysian state of Sabah, which straddles the northern tip of this enormous island.

Sabah lies at the heart of the Coral Triangle and is home to some of the world’s greatest marine biodiversity; it is this hidden beauty below the surface of the sea that draws divers and snorkellers from around the world. One of the greatest attractions for these visitors and locals alike are the huge schools of fish that can be found at some of Sabah’s diving hotspots. However, this is not the same for me. During my dives, I usually adopt the position of a razorfish, hovering vertically with my nose an inch from the seabed looking for critters, oblivious to anything in mid-water.

Some of the highest marine biodiversity on the planet

The Coral Triangle is considered the global epicentre of marine biodiversity. The entire area represents one of the richest marine habitats in the world and an estimated 3,000 different species of fish, more than 600 reef-building coral species and more than 30 percent of the world’s coral reefs can be found here. Understandably, Sabah – lying at the heart of this extraordinary region – can claim to have some of the highest marine biodiversity on the planet. For a recent book project, myself and two other Scubazoo photographers travelled around the coast of Sabah documenting the highlights of the underwater world. It was during this trip that I began to leave my trusty macro set up on the boat and started to stare into the blue.

The first fish school that caught my attention was pretty tame – a small army of banded catfish stalking their away across the sand, devouring anything edible in their path in the local marine park near where I live in Kota Kinabalu. It was the way they moved as one in an ever-churning ball of stripes that got me though. How do they decide who goes in front and when to switch? Who gets the unlucky position at the edge of the pack where you could get picked off and how long do they have to stay there?

Blue-streak fusiliers swim close over the reef, with a whitetip reef shark, giant trevally swimming above.

Blue-streak fusiliers swim close over the reef, with a whitetip reef shark, giant trevally swimming above.

Home of the hammers

We travelled further up the coast to Malaysia’s only atoll, Layang Layang, or Swallow Reef, which rises 2,000 metres from the floor of the South China Sea approximately 300 kilometres northwest of Kota Kinabalu. The atoll’s almost total isolation means stunning visibility and pristine reefs, along with an abundance of pelagic marine life. In recent years, Layang Layang has been the site of many special encounters, including with whale sharks, orcas, melon-headed whales and even sperm whales.

Along with the huge schools of reef fish that thrive in these pristine waters, it is the hammerheads that people flock there for and huge schools can be seen in the blue. During the daylight hours, the schools of sharks, mostly females, are actively engaged in social interactions and jockey for prime social position in the centre of the school, before breaking up at night to hunt alone. Who knew that sharks were so sociable and how do they interact during this period when gathered together?

School of scalloped hammerhead sharks.

School of scalloped hammerhead sharks.

Because Sipadan is sensational

Continuing the journey along the coast, we eventually ended up on the western side of Sabah. Consistently voted one of the top dive destinations in the world, Pulau Sipadan is a must for any passionate diver. Sipadan is Malaysia’s only oceanic island. This tiny speck of land, located 40 kilometres south of Semporna, is in fact a needle-like pinnacle of rock and reef surrounded by 600-metre-deep water – a constant source of nutrientrich upwellings. These nutrients provide the basis for a remarkable food chain that culminates in the many large animals commonly encountered in Sipadan’s waters. In recognition of this unique and productive ecosystem, the area is now carefully protected, with limits on the number of divers that can visit every day and a ban on resorts on the island itself. Consequently, life there is flourishing.

Bumphead parrotfish swimming together as a school.

Bumphead parrotfish swimming together as a school.

As you descend into Sipadan’s clear waters, the first things that greet you are the sheer walls dropping down into the abyss; the pristine, colourful reefs; the green and hawksbill turtles, too numerous to count; and the dense schools of fusilier, batfish and anthias. Then you notice the intimidating mass of jacks and barracuda, the napoleon wrasse and whitetip and grey reef sharks, and your eyes are drawn out into the blue, as tales of whale sharks, mantas and hammerheads run through your mind.

Diving around Sipadan can be a dizzying experience as the variety of fish schools that encircle you is immense. It is hard to believe that when I first dived Sipadan many years ago, the most exciting find for me was a frogfish hidden in a channel. I now gazed in awe as barracuda, sharks and turtles cruised by. Why was I sticking my head in the sand all the time?

As soon as you exit the dive boat and start to dive at the famous Drop Off dive site of Sipadan, you are confronted by an immense school of jacks. The thousands of shimmering fish rotate like a massive glitter ball, and you notice the various sharks piercing in and out, and it is hard to drag yourself away and remember you have a dive to continue! It would be easy to spend the whole dive encircled by this mass of fish as they constantly shift and rotate as one.

Large school of chevron barracuda.

Large school of chevron barracuda.

A mention has to go to the number of turtles it is possible to see on a dive here. During the mating season, you can see a string of males, sometimes up to 10 in number, frantically chasing a female. Even without the clamour of the mating season, if you time the tide right then huge numbers of turtles can be seen as they head towards their feeding grounds.

Bumpheads at dawn and barracuda tornadoes

One of my favourite dives at Sipadan starts very early in the morning, which means you get to witness the sunrise on the journey out – a magical way to start the day. A truly impressive sight, if you can drag yourself out of bed in time, is the procession of bumphead parrotfish. They have strong beaks to feed on live corals and algae, and a single adult will ingest tons of coral each year, which is excreted as white sand. Their feeding activity is important for the production and distribution of coral sand within a reef, and to prevent growing algae from choking coral. In the early morning light, these huge fish make for a wonderful sight in the shallow water as they head out to deep water during the day.

In terms of shear numbers, it is hard to beat a massive school of barracuda, which can form a swirling “tornado” from the sea’s surface down to a depth of 30 metres. These spectacular schools, which may contain thousands of individuals, will break up at dusk as the barracuda head off to hunt for food, and convene again at dawn. Trying to get shots of this magnificent spectacle and control my mid-water buoyancy in a ripping current was one of the most challenging yet rewarding experiences of the whole trip.

I still love to hunt for critters and can’t resist a good muck dive, but it is never long before I take my eyes away from the sand to look up and have a good look around for what might be out there, schooling around in the blue.

Photography by Jason Isley/Scubazoo

This article featured in  SD OCEAN PLANET (Issue 4/2015)