This is an article on rising cyanobacteria levels in Raja Ampat, (Indonesia), following the monitoring work done by the Barefoot Conservation team on Arborek island.

Trouble in paradise: In the biodiversity oasis of Raja Ampat, cyanobacteria poses a serious threat to the region's abundant coral reefs. Is tourism to be blamed?

https://oceanographicmagazine.com/features/cyanobacteria-in-raja-ampat/

Extracts:

Together with Dr Josie Chandler, the head of science at the NGO I manage, we started monitoring the presence of the microorganisms. Chandler is a marine biologist who specialises in coral reef ecology, with her most recent research focused on crown-of-thorns starfish populations in Australia. “I had not heard of cyanobacteria covering coral reefs to this extent before, so as soon as Erika mentioned the issue I jumped into a rabbit hole of papers and studies to learn as much as possible about what is happening. Turns out, this is serious.”

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“The problem is not sunscreen or breakage of corals by irresponsible divers, but without question the major issue is the increase in human sewage. Sanitation systems here are basic pit toilets, which meet the needs of small local populations without harming groundwater or marine ecosystems. However, the surge in tourism has overwhelmed these systems. The issue is accelerated by new beachside toilets near the shore, reducing the longer travel through soil before reaching the reef – the biological breakdown. The discharge of untreated sewage from liveaboard boats intensifies the challenge,”

“Liveaboard operators have a lot to answer for, because their solutions for this problem are much more straightforward than island-based operations. Of course, this would come at a cost, but ultimately the cost of losing Raja Ampat reefs would be a lot more expensive. The livelihoods of local communities depend upon these reefs. Strict regulations need to be put in place,” says Chandler. She manages the team of on-site scientists remotely but has come to Raja Ampat to see what is happening with her own eyes. Under her leadership, cyanobacteria blooms have been monitored around Arborek Island for almost two years, and various photogrammetry projects 3D-map nearby reefs to observe bleaching in collaboration with the National Oceanic and Atmospheric Administration, an American scientific and regulatory agency.

“The problem with cyanobacteria is that stopping the blooms is a huge task. It demands all stakeholders – villagers, resorts, liveaboards, and homestays – to come together, as new ways to offload sewage need to be put in place. But it has to be done if we want to keep the coral reefs alive,” says Chandler. “The real worry lies with the fact that bleached reefs’ chances to recover are minimal once smothered by cyanobacteria, and the cyanobacterial blooms are only getting bigger and more frequent.”

Installing bio tanks – wastewater treatment systems that use microorganisms to break down sewage  – across Raja Ampat and on liveaboards could be a critical first step. However, Arborek’s low-lying geography presents a challenge: high tides cause septic tanks to float up, complicating their installation. But the stakes are high. “It would be heartbreaking to see the most biodiverse reefs in the world succumb under the weight of preventable anthropological stressors like wastewater and overtourism,” says Chandler. Since 2022, Gress and Chandler have sent multiple alerts to the government and BLUD, accompanied by data collected over many months clearly showing the increase and impact of cyanobacteria. Their appeals have been rebuffed.

Edited April 30Apr 30 by bghazzal

On a related note:

Deep Sea Reporter

Tourism Threatens to Destroy Coral Reefs in Raja Ampat -...

In the heart of Raja Ampat is the small island village of Arborek, home to the NGO Barefoot Conservation. The team at Barefoot Conservation has been monitoring the reefs around the island, collecti...

https://waterpixels.net/forums/topic/2180-raja-ampat-coral-bleaching-2024-caught-in-the-confluence-video-by-dr-phil-dustan/

https://waterpixels.net/forums/topic/2335-article-more-than-80-of-the-worlds-reefs-hit-by-bleaching-after-worst-global-event-on-record/

Edited April 30Apr 30 by bghazzal

I was discussing these articles and videos with an Italian marine biologist, and he was pointing out that unfortunately the phenomenon has been known for years among those in the field, and he turned over to me one of his scientific papers on the same topic, here in the Mediterranean in 2007

Climate change is affecting marine environments all over the world but scientists' attention is mainly devoted to tropical areas. In the Mediterranean Sea, species with a cold affinity are decreasing very fast from 0 to 40 m depth, while warm water species increase. From 2000, several populations of the zoanthid Parazoanthus axinellae (Schmidt 1882) have been showing signs of suffering along the Ligurian coast. Here we report a three‐year monitoring, from June 2001 to September 2003, of a population of P. axinellae on the rocky cliff of the Portofino Promontory (Ligurian Sea). During this span of time the population, which covered an area of several square metres with a density of about 1 polyp cm⁻², was severely reduced. In the meanwhile an encrusting sponge, Crambe crambe, rapidly colonized the free substrates abandoned by the zoanthid. Warm water and the massive proliferation of a cyanobacterium attributed to the genus Porphyrosiphon are hypothesized to be the main causes of this disease.

https://www.tandfonline.com/doi/full/10.1080/11250000600911675#d1e357