West Papua’s Raja Ampat is one of the most biodiverse places on the planet. While increasing numbers of tourists explore the remote location, parts of the region have seen mild coral bleaching in recent months. Is the paradise suffering from its own success?
I’m floating motionless amidst brilliantly hued soft corals. Different species, shapes, sizes, and colours as far as the eye can see. I float past a wide toadstool leather coral, a pulsating xenid mesmerises me with its pink tentacles that rhythmically dance in the water column, endless shoals of tiny fish swirl around this fascinating coral garden laden with sponges, sea fans, tunicates, hard corals and crinoids, while a peculiar-looking school of razorfish moves from coral to coral, resembling a grazing herd of cows. In the shallower end of the reef, long mangrove roots extend into the coral garden and high above my head, two eagles are circling.
Here in Raja Ampat, at the heart of the coral triangle, biodiversity is booming. An incredible 36% of the world’s reef fishes and 76% of the world’s known coral species can be found here. Manta rays, numerous shark species, whales and other megafauna are frequent visitors to the 1,500-island, 4,000km2 archipelago off the coast of Indonesia’s West Papua. A single reef in Raja Ampat is said to contain more species than the entire Caribbean. The reasons for the region’s high biodiversity are complex. Its remoteness has kept development at bay, while its sheltered location within the path of the Indonesian Throughflow, a strong current that flows from the Pacific through to the Indian Ocean, brings nutrients, eggs and larvae to the region. According to research conducted by the non-profit Conservation International, another reason for its biodiversity are temperature fluctuations in the water due to currents. As reefs in Raja Ampat are exposed to a wide variation in temperatures – some reefs experience a 6 to 12 degrees Celsius variation within 24 hours – they are believed to be better equipped to deal with fluctuating temperatures and climate change.
Despite this positive outlook, the more time I spend in Raja Ampat, the more signs of human-induced pressures I come across. Brooke Pyke, an underwater photographer, and expedition leader who travelled to Raja Ampat at the beginning of 2023, remembers: “I visited Raja Ampat in both 2019 and 2020. I have vivid memories of the reefs being beautiful and abundant. I went back this year, post-Covid, and I was shocked to see how things had changed. Shallow reef sections at some of the dive sites I visited were showing signs of bleaching and many anemones were completely white. Some of the large sea fans in certain areas had algal growth on them.” On social media and numerous dive blogs, I come across the same story: certain dive sites across Raja Ampat have experienced bleaching events in recent months.
To find out more about these events, I speak to Vincent Chalias, founder of Ocean Gardener, an Indonesia-based NGO that is dedicated to coral reef education and coral restoration. He explains that recent bleachings can be attributed, for the most part, to this year’s La Niña climate phenomenon, a natural weather pattern that transports warm water at the ocean surface from South America to Indonesia. While it does so, it swirls up cold water from the deep near South America’s coast and brings warmer-than-normal sea surface temperatures to the southern Pacific Ocean around northern Australia, New Guinea, and Indonesia. “Through this year’s La Niña event, we experienced particularly bad weather, all due to warm water surfaces. We had dry weather on South America’s west coast and extremely warm and wet weather on this side of the Pacific,” says Chalias. “Luckily, this event was not a major one. While the water temperature wasn’t over 32 degrees Celsius for a long time, which is considered extremely high for Indonesia, it was in the 29-30 degrees Celsius range for a very long time. That explains the mild bleaching event. Coral bleaching is all about the combination of high temperature and the time frame.”
Shawn Heinrichs, founder of Only One and an underwater filmmaker and photographer who has worked on projects in Raja Ampat for many years, agrees that the bleaching events have been transient, for the most part: “There seems to be a resilience within the corals in Raja Ampat that aren’t necessarily witnessed in other corals. I’ve seen entire reefs white and thought it’s over. Then I return a year or two later and the coral coverage is beautiful. I don’t think it’s an ‘alarm bell situation’ yet. If we see multi-year bleaching, if we see entire large structures collapsing, then we might have something on our hands.”
Other, more pressing threats facing Raja Ampat should be taken more seriously, urges Heinrichs: “I think a greater threat is coral disease. It is having a significant impact on certain sites that used to be pristine.” The issue is not entirely separate from bleaching; bleached corals are stressed which makes them more vulnerable to allergies and diseases. According to the study The abundance of coral diseases and compromise health in marine protected areas on Dampier waters, Raja Ampat, published in IOP Conference Series: Earth and Environmental Science in January 2023, coral diseases currently present in Raja Ampat are black band disease, which is caused by a blue-green algae, dark spots disease, as well as skeleton-eroding band disease. Chalias points out that these diseases could well be related to the influx of tourists to the region in recent years: “Hundreds of liveaboards, with an undetermined number releasing their sewage tanks into the water currently tour the region, while numerous resorts and homestays don’t have proper sewage treatment facilities.” Heinrichs agrees: “There are other concerns around the corals that we need to have a serious look at: the runoff from boats, the runoff from land, sewage, and other types of nitrates – all the other things that are being dropped into the water.”
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