The World Beneath. Richard Smith
Caitlin’s dottyback, described in 2008. Cenderawasih Bay, West Papua, Indonesia.
One of the wildest locations on the planet that I have ever visited is unquestionably Cenderawasih Bay on the north coast of Indonesian Papua. Thickly forested mountains tumble into the expansive, still waters. Small villages dot the bay, and visitors must respect the local ownership of these untouched waters and receive permission from the villagers to dive the sites. On my first visit to the location, I was required to have a local national park ranger stay aboard my liveaboard vessel to aid in these exchanges. Whether it was an honest mistake, a village he should have been avoiding, or a miscommunication, I don’t know—but as we tucked into our lunch after the dive, we heard a ruckus outside. We dashed out to discover four bare-chested Papuans brandishing machetes, anger bursting from their eyes. They were livid that we hadn’t asked permission to dive the site; after all, as they saw it, we were effectively trespassing. It took some time to explain the misunderstanding and return calm. Thankfully a cold Coke isn’t easy to come by in these remote corners of the planet and they were somewhat placated by our supply. They had paddled several miles from their village, travelling in a dugout canoe, so we gave them some fuel to express our apologies, since their supply had long since run dry.
Maurine’s demoiselle, described in 2015. Cenderawasih Bay, West Papua, Indonesia.
Cenderawasih Bay is a marine biologist’s dream. It is a rare example of a location that illustrates evolution by isolation. Also known as “allopatric speciation,” Darwin saw this as the most common source of new species creation in terrestrial animals. In the same way that the Galápagos Islands are isolated from the mainland and species evolve there to suit the local conditions, Cenderawasih provides an almost self-contained ecosystem allowing for high levels of endemism. Endemism means that an organism is unique to a defined geographic region, in this case Cenderawasih Bay; although, it would also be true to say that these animals are endemic to Indonesia. The huge bay covering almost one and a half million hectares was isolated from the Pacific Ocean when large landmasses drifted across its mouth between two and five million years ago.37 These landmasses may not have created a complete physical barrier, but they were significant enough to alter currents in and out of the bay. Without this flow through, populations inside became separated from those outside the bay and over time adapted to the conditions they found themselves in within the bay.
Female ornate angelfish. Cenderawasih Bay, West Papua, Indonesia.
Diving in Cenderawasih Bay is a strange experience. While the reefs are ostensibly the same as many in Raja Ampat to the west, the inhabitants are largely alien. Bright blue and white Price’s damselfish, pink and yellow Caitlin’s dottybacks, and beige and yellow Maurine’s demoiselles are all ubiquitous here, but found nowhere else on Earth. Farther down the reef slope, the stunning Cenderawasih fairy wrasse inhabits rich coral areas at sixty feet below the surface. The shocking yellow streak and black blotches on the male’s side allow divers to spot the beauties from a fair distance away. It’s amazing that these fish remained in obscurity until 2006 when scientists first explored the bay. Previously, none of these fish were known to Western science. There are at least fourteen species of reef fishes known only from the bay, which is many more than you would expect from such a small area, with many sure to join them as it is explored further.
Male ornate angelfish. Cenderawasih Bay, West Papua, Indonesia.
While exploring the limits of recreational diving at around ninety feet, another quirk of the bay is revealed. The topographical structure of the bay means there are limited areas where the reef gently slopes into the abyss; instead, shallow slopes give way quickly to deeper drop-offs. Over the course of several ice ages, where the water level drops and subsequently rises thousands of years later, the shallow coral reef habitat was repeatedly lost and many species went locally extinct. When sea levels rose again, the lack of connectivity with areas outside the bay meant that the vacant niches couldn’t be filled by migrants. It seems that deepwater species instead seized the opportunity to fill some of these niches and moved up into the shallows. As a result, while diving in Cenderawasih it is possible to see fishes such as the alluring ornate angelfish, Randall’s anthias, and the Burgess butterflyfish in water much shallower than they are found in elsewhere in the world.
Male Randall’s anthias. Cenderawasih Bay, West Papua, Indonesia
Burgess butterflyfish. Cenderawasih Bay, West Papua, Indonesia.
The final area of the Bird’s Head trio is Triton Bay. Located southeast of Raja Ampat on the south coast of Papua, this area has been revealed as another region rich in endemic species. In 2006 scientists mounted an exploratory expedition and found many new and indigenous species, such as Jamal’s dottyback, Nursalim flasher wrasses, and a unique walking shark. The leading theory that most likely explains the high levels of endemism around Triton Bay relates to the two large freshwater rivers that flow into the ocean to the north and south of the bay. In a similar way to the landmass-blocked mouth of Cenderawasih, the freshwater from the rivers acts as a barrier to the marine organisms in the bay. Trapped within by these walls of unsuitable habitat, the animals within evolved to suit local conditions.
Jamal’s dottyback, described in 2007. Triton Bay, West Papua, Indonesia.
The walking sharks, or epaulette sharks, are an intriguing group found around the coast of New Guinea and northern Australia. As their common name suggests, their preferred method of locomotion is walking rather than swimming. They use adapted pectoral fins to crawl around in the reef shallows to hunt for their prey. As they live in shallow water and won’t swim across deep water or unsuitable habitat, they can easily become cut off. As a result, at least six species of walking shark have evolved around the coastline of New Guinea.38 Each of the three areas of the Bird’s Head has a unique species of walking shark and there are another three in Papua New Guinea to the east. It is not beyond the realms of possibility that more species may be discovered along the New Guinean coast as scientists explore it further.
Raja Ampat walking shark. Raja Ampat, West Papua, Indonesia.
Milne Bay walking shark, described in 2010. Milne Bay, Papua New Guinea.
I have made some of my most unexpected discoveries and observations in the Bird’s Head region and experienced the bounty of the coral reef in its full splendor. I have been surrounded by such thick schools of fish that I could not even glimpse my dive buddy a few feet away. I have seen the biggest fish in the sea, the enormous whale shark, in both Cenderawasih and Triton Bays and one of the world’s smallest fish, Satomi’s pygmy seahorse, in Raja Ampat. This is truly a special corner of the world.
Male Galapagos pike blenny displaying. San Cristobal, Galapagos Islands.
Outside the Coral Triangle
Travelling outside the Coral Triangle, and to the periphery of the ocean’s coral realm, reveals reefs with their own special assemblages of creatures. When compared to the Coral Triangle these reefs can seem relatively poor in terms of species richness, but