Through all the gloom, signs of resilience in Maldives reefs · Most disappointing part of Maldives holidays 1998 Recovery? –from an affected baseline Pisapia, C. et al. Coral recovery

Through all the gloom, signs of resilience in Maldives reefs

Jean-Luc Solandt, Gabriel Grimsditch, Nizam Ibrahim, Matthias Hammer, Benjamin Cowburn, Bryce Stewart, Katrina Mcpherson, Rafil

Mohammed, Ibrahim Shameel, Gregor Hodgson

Outline

• Wider socio-economic considerations

• Bleaching 1998

• Time for recovery?

• Bleaching 2016

• Bleaching impact during the event

• Short-term recovery (2 – 12mnths)

• Phase shifts?

• Areas of hope (or Hope spots)?

An affected baseline…..even in 1997

• 1994 –commercial grouper cages and export

• 2011 – 17 ‘cage’ facilities 78 dedicated fishing vessels in 3 atolls.

Sattar et al., (2011) Review of Maldives Grouper Fishery. MRC

Resorts / construction adds pressure

China is the biggest visitor nation – 198,655 visitors in 2011.Visitors in 2011 were 930,000Plans to open 27 new resort islands in 2017 alone, increasing visitor numbers to 7million

Bleaching 1998

Cesar et al, 2000 Assessing the impacts of the 1998 coral bleaching on tourism in the Maldives and Sri Lanka, CORDIO.

Figure 7. Most disappointing part of Maldives holidays 1998

Recovery? – from an affected baseline

Pisapia, C. et al. Coral recovery in the central Maldives archipelago since the last major mass-bleaching, in 1998. Sci. Rep. 6, 34720; doi: 10.1038/srep34720 (2016).

COT outbreak

Bleaching event

Tsunami

32 degrees for 3 weeks

27.5

28

28.5

29

29.5

30

30.5

31

31.5

32

32.5

01-Apr 08-Apr 15-Apr 22-Apr 29-Apr 06-May 13-May 20-May

seaw

ate

r te

mp

era

ture

(C

elc

ius)

5m 10m

IUCN data – during the bleaching event

Ibrahim, N., et al., 2016, Status of Coral Bleaching in the Maldives in 2016, Marine Research Centre, Malé, Maldives

IUCN sites


Species is a major factor in resistance (IUCN)

Acropora Porites


ReefCheck sites: 34% (2015 data) to 12% 2 months after bleaching

Solandt J-L, et al. (2016). Bleaching patterns and capacity building for Maldives conservationists during ReefCheck expeditions. Rufford conference proceedings, Sri Lanka

ReefCheck surveys - outer reefs/channels fare better 2 months after heating event

0

5

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30

35

40

outer inner

me

an %

co

ver

+ SD

Inner atoll or outer rim reef

bleached

live hard coral


Why the difference? Aspect; adjacent deepwater; species?


ReefCheck surveys 2017:14 months: outer sites recovering, inner declining

0

5

10

15

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30

35

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45

50

HC SC RKC NIA SP RC RB SD SI OT

Bathalaa maagaa

0

10

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50


Rasdhoo

0

10

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30

40

50


Holiday thila

20172016

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5

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45

50


Kudafalhu

Phase shift starting at inner atoll sites?

…to…carpet anenomes

Kudafalhu

…to algae (similar to Jamaica, circa 1995)

Bleaching

+

Crown of Thorns.

Density of 14.3/100m2

Conclusions• Baseline condition of reefs is affected due to disease, COTs, Drupella, previous

bleaching, overfishing, run-off, construction.

• Inner reefs undergoing phase shifts: Some inner reefs now dominated by Discosoma corallimorphs, others by algae.

• Outer reefs faring better due to more resilient coral life forms / proximity of deeper water and steeper ‘drop-off’ aspect.

• Previous bleaching episode required 10 years recovery time.

• Will 2026 show a recovered coral community, BOTH for r- and k-strategist species?

• Maldives government and international community are ineffective at dealing with the scale of the issue.

• Citizen science illustrates the issue – development of local groups such as ‘reef checkmaldives’.

ThanksJean-Luc Solandt, Gabriel Grimsditch, Nizam

Ibrahim, Matthias Hammer, Benjamin Cowburn, Bryce Stewart, Katrina Mcpherson, Rafil

Mohammed, Ibrahim Shameel, Gregor Hodgson

Documents

Through all the gloom, signs of resilience in Maldives reefs · Most disappointing part of Maldives holidays 1998 Recovery? –from an affected baseline Pisapia, C. et al. Coral recovery