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
Ibrahim, N., et al., 2016, Status of Coral Bleaching in the Maldives in 2016, Marine Research Centre, Malé, Maldives
Species is a major factor in resistance (IUCN)
Acropora Porites
Ibrahim, N., et al., 2016, Status of Coral Bleaching in the Maldives in 2016, Marine Research Centre, Malé, Maldives
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
10
15
20
25
30
35
40
outer inner
me
an %
co
ver
+ SD
Inner atoll or outer rim reef
bleached
live hard coral
Solandt J-L, et al. (2016). Bleaching patterns and capacity building for Maldives conservationists during ReefCheck expeditions. Rufford conference proceedings, Sri Lanka
Why the difference? Aspect; adjacent deepwater; species?
Solandt J-L, et al. (2016). Bleaching patterns and capacity building for Maldives conservationists during ReefCheck expeditions. Rufford conference proceedings, Sri Lanka
ReefCheck surveys 2017:14 months: outer sites recovering, inner declining
0
5
10
15
20
25
30
35
40
45
50
HC SC RKC NIA SP RC RB SD SI OT
Bathalaa maagaa
0
10
20
30
40
50
HC SC RKC NIA SP RC RB SD SI OT
Rasdhoo
0
10
20
30
40
50
HC SC RKC NIA SP RC RB SD SI OT
Holiday thila
20172016
0
5
10
15
20
25
30
35
40
45
50
HC SC RKC NIA SP RC RB SD SI OT
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