A discussion on the global disparity in the resilience of coral reefs by Shweta Sharma.

1. Global disparity in the resilience of
coral reef

2. Author
George Roff and Peter J. Mumby
Presented by
Shweta Sharma

3. Introdution
 What is resilience ?
 Why coral reef is one of the most intensively studied system
in context of resilience ?
 Coral reef resilience and geographic bias.
 The two major biogeographic provinces of coral reef
1. The caribbean
2. Indo-Pacific

4. Great caribbean coral reef
Deep water coral

5. Great caribbean coral reef
5 Meter Reef Coral

6. Indo-Pacific Corals

7. Indo-Pacific Coral

8. Differences in the recovery and state of
Caribbean versus Indo-Pacific reefs



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Indo-Pacific and Caribbean reefs differ in many ways.
1) Faunal composition, Grazing pressure
2) Greater niche partitioning of herbivore in the Indo-Pacific
while herbivore biomass in the Caribbean lies below
potential carrying capacity.
3) Species richness(Acanthudidae), Coral reproductive trait
4) Ecological resilience capacity
5) Greater proportion of macroalgal dominance and a
higher severity of phase shift in the caribbean than in the
Indo- Pacific.

9. Differences in the recovery and state of
Caribbean versus Indo-Pacific reefs


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Indo-Pacific and Caribbean differ in many ways.
Caribbean reef shows decline of trajectories, with no
observation of recovery following disturbance .
46% of reef in Indo-Pacific have showed evidence of recovery
following disturbance.
83% of Caribbean reefs exhibited either no recovery(47%)
or no decline 36%.
39% of Indo-Pacific reef exhibited either no recovery(24%)
or no decline(15%).

10. Bar Graph showing Recovery, No decline, No
recovery of coral reef

11. Graph showing macroalgal dominance

12. Biodiversity-based hypotheses
 Hypotheses 1
 Loss of fast-growing Acropora corals in the Caribbean
are responsible for low resilience of coral in this region.
 1) Two categories of corals
I) Fast-growing branching corals from families Acroporidae
and Pocilloporidae capable of extending > 100 mm per
year.
 II) Slow-growing corals capable of extending<50 mm per
year.

13. Biodiversity-based hypotheses
 Hypothesis 2
Higher diversity and greater functional redundancy of
herbivores in the Indo-Pacific than in caribbean.
 1) Elevated herbivore diversity can increase reef resilience
by providing greater niche diversification and creating
functional redundancy.
 2) Burkepile and Hay found that two complementary
herbivore species were more effective in mitigating algal
bloom than was a single species

14. Biodiversity-based hypotheses
 3) There is striking difference in the species and generic
richness in Caribbean and Indo-Pacific.
 a) Of the 88 species and six genera of Acanthuridae that
inhabit in the Indo-Pacific and Caribbean regions,
 Caribbean have only four species represented by a single
genus(Acanthurus).
 b) Caribbean lacks acanthurids of the genus Naso, some of
which consume the largest of reef macrophyte
sargassum spp.

15. Bottom-up hypotheses
Macroalgae bloom faster in the Caribbean

16. Bottom-up hypothesis

17. Bottom-up hypotheses
 Hypothesis 3

Higher adult stock of macro algae on Caribbean reefs
imply higher rate of algal recruitment in this region.
 1) Speed of algal bloom is high where herbivory is intense so this
finding leads to fourth hypothesis.

Hypothesis 4
 Various anthropogenic activity like land cultivation, deforestation,
producing nutrients, and nutrient supply from terrestrial sources
might be higher in Caribbean leading to Coral algal phase shift.

18. Bottom-up hypotheses
 Hypothesis 5

Nutrient nitrogen and phosphorus helps in algal growth but
it growth is limited by various metals e.g iron. Algal growth is
less limited in the Caribbean due to increase in Aeolian dust a
good source of iron , resulting increase in algal bloom when
other enabling condition are met.

19. Top-down hypotheses
Hypothesis 6
 Herbivore biomass is greater in Indo-Pacific than in Caribbean
creating higher absolute grazing pressure in Indo- Pacific
1)Total herbivores fish biomass in the Indo-Pacific averaged
29.0gm-2 while Caribbean have 9.25gm-2.
2) Parrotfish biomass in the Indo-Pacific was nearly twice that
of the Caribbean. (13.12gm-2 VS 6.7 gm-2)
3) Biomass of surgeonfish is more than fourfold higher in the
Indo-Pacific than in the Caribbean( 11.61gm-2VS2.56gm-2) and
maximum biomass found 12 fold higher in the Indo-Pacific
than in the Caribbean.

20. Conclusion
 Indo-Pacific reef have greater capacity of resilience than
the Caribbean.
 Algal bloom occur more readily in the Caribbean .
 Disease that resulted in loss of both fast growing coral, are
responsible for present state of the caribbean.
 Referances:- Roff, G., & Mumby, P. J. (2012). Global disparity
in the resilience of coral reefs.Trends in ecology &
evolution, 27(7), 404-413.

21. Thanks