Maldives: Addendum

Update from our Maldives coral reef and whale shark expedition

Here’s an e-mail by our scientist Jean-Luc to Reef Check Italy, who are working with us on a scientific paper. We thought you might like to see this as it contains a nice summary of what we found.

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We visited North and South Ari reefs, last visited in 2018. I was so depressed by the inner reefs then that we moved operations in 2019 and 2022 (post Covid) to South Male’ and Vaavu atoll reefs, that appear healthier.

Conclusions from this year

Outer reefs of Ari haven’t changed much – just accumulated slightly more of the same coral cover since 2018 (Rasdhoo, Bathalaa and Dhigurah wall).

Inner reefs are showing three post-bleaching trajectories:

Trajectory 1

Acropora coral (previously dominant in Maldives reefs over geological time in shallow water environments) recolonise and dominate the shallowest reefs (to 5 m max), where bleaching had damaged them and where grazing is extensive (example site: Kuda falhu). We think (re)growth of any coral below 5 m is difficult in many central atoll reefs, because of extensive rubble fields of unconsolidated material drifting down the slope from previous bleaching, then storm events.

Trajectory 2

A shift to Porites rus (that can be branching and plating and massive in life-form) and Porites cylindrica and Pocillopora (probably P. verrucosa) in (mostly) shallow reefs. These three lifeforms are prevalent in Baros House reef (from a snorkel to the south of the resort), and from surveys in previous years in South Male’ inner reefs – at Beybe’s and Guraidhoo inner (see photos from previous reports of surveys in 2019 and 2022).

Trajectory 3

A phase shift in reefs from coral-dominated to Corallimorph-dominated (worrying). This is the case at Dega thilla. I have recorded in all my time in the Maldives two other reefs entirely dominated by this blanketing lifeform – one was Adhureys Rock way back in 2005. You have the data from that site I think. I think the other one was about 2011 or 2012 (from North Male’ I think – I’ll have to look these up).

So there is little variation in outer reefs, drops-offs, near channel reefs, but the above three trajectories in inner reefs does show this tremendous variation. I suppose there is another where things remain pretty much dead – with low coral cover, and not much else in terms of dominance. That would be expressed by Oshigali finolhu that we visited as our last site (an inner reef near to Dangheti Island, South Ari on the last day).

I hope these observations, and data are useful. As I said in the Wetransfer, we also have photo quadrats at all sites if your students want to analyse these in more detail.

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Other achievements of the expedition include:

Since its inception in 2011, this expedition has thus far trained over 100 people in Reef Check surveying, including over 30 local Maldivians in techniques on how to monitor their reefs and set up community-based monitoring schemes. As a direct result of this, local NGO Reef Check Maldives was formed in 2017 and is now active in community-based reef conservation work and advocacy. Some of these community surveyors are now teaching Reef Check themselves, and are employed by government agencies and private consultancies to undertake management and surveillance. A colouring and educational booklet for local schools has also been produced and distributed around the country with the help of the local Ministry of Education. The expedition has also surveyed reefs that were impacted by the coral bleaching event of 1998, and identified recovery in most reefs prior to the 2016 bleaching event. Data on reefs and whale sharks are given to local and international NGOs, government and other decision-makers, who are planning on increasing the number and area of Maldives marine protected area (MPA)s. Our Reef Check data will form part of that picture when the government considers new MPA areas. Other achievements include: Post-bleaching assessment and scientific paper, assessment of fish populations inside and outside ‘MPAs’, two masters theses with University of York, conference presentations (IMCC, Washington 2009 & ECRS, 2017), four resorts trained in Reef Check, one of which is now undertaking its own Reef Check and hosting coral rehab work, two dive centres (Vaavu atoll, Fulidhu and Baros) trained in Reef Check, award-winning Maldivian expedition placement (Shaha Hashim) now employed by Blue Marine Foundation grouper project at Addhu atoll, national Reef Check Coordinator (Hassan Baybe) at ‘Save the Beach’, Vilingili.

Update from our Maldives volunteer expedition encompassing volunteer scuba diving, marine biology volunteering and marine volunteering