Multi-disciplinary approaches for coral reef management in Eparses islands (SW Indian Ocean)
P. Chabanet (1), L. Bigot (2), J-B Nicet (3), S. Andrefouët (1), C. Bourmaud (2), C. Conand C. (2), P. Durville P. (4), Fricke (5), Gravier-Bonnet (2), Grellier M. (6), Mattio L. (7), Le Pape O. (8), H. Magalon (2), T. Mulochau (4), D. Obura (9), J. Poupin (10), Quod J-P. (3), E. Tessier (11) & M. Zubia (3)
(1) Institut de Recherche pour le Développement (IRD) - France
(2) Université de La Réunion - ECOMAR - Reunion Island
(3) ARVAM / Pareto - Reunion Island
(4) Aquarium de La Reunion - Reunion Island
(5) MNH Stuttgart - Germany
(6) Museum Histoire Naturelle / TAAF - France
(7) University of Cape Town - South Africa
(8) Agrocampus Ouest - France
(9) CORDIO East Africa – Kenya, (10) IRENAV - France
(11) Reserve Naturelle Marine - Reunion Island
Context & Objectives
Materials & Methods
Results & Discussion
Conclusion
•
Demographic growth => degradation of coral reefs Human perturbation makes coral reefs more susceptible to global change
•
Areas with low human impact are rare ó study the impact of climate change / Eparses Islands
•
They should be classified as MPAs to reinforce their protection But knowledge of coral reefs is very low
Programme BioReCIE (2011-2013)
Management
(Biodiversity, Resources and Conservation of coral reefs at Eparses Is.)
1) Complete inventories associated with DB and base GIS
2) Establish a baseline study of fish communities
3) Look for potential indicators of disturbance for optimised
monitoring over the long-term
Context & Objectives
Materials & Methods
Study area
Eparses Islands
Results & Discussion
Conclusion
SW Indian Ocean
(Emerged land / coral reef surface)
Glorieuses
9 km2 / 201 km2
Tromelin
Juan de Nova
5
km2
/ 212
2 km2 / 7 km2
km2
Bassas da India
April 2011
0 / 96 km2
Europa
35
km2
/ 18
km2
Nov. 2011
Context & Objectives
Materials & Methods
Results & Discussion
Conclusion
Remote sensing
Underwater Visual Census
Standardized methodology consistent with GCRMN method at highest taxonomy level
GCRMN Station!
UVC - Reef flat and slope (10-15 m)
45 stations
"
BENTHOS transect LIT (20 m) x 3 – benthic categories & coral species
"
FISH belt transect (50 x 5 m) x 3 – species, abundance & size
"
Resilience analysis belt transects (20 x 1 m) –
" "
coral sizes and site resilience indicators (coral communities, management regime, turbidity,..)
Biodiversity inventory - Random path 50 min
Habitat classification mapping
Materials & Methods
Context & Objectives
Results & Discussion
Conclusion
Glorieuses
1,8 18,3
26,4
Benthic communities
53,6
Tromelin
9,8%
3,2% 32,9%
Juan de Nova
16,2 38,9
13,9
54,2% 31,0 7,7% 3,3%
48,3 %
40,7 %
Bassas
14,4% 2,6%
82,7%
Europa
Gradient along the Mozambic channel Coral cover Glorieuses - à + Europa
Algae cover Glorieuses + à - Europa
Differences could be due to their geomorphology, isolation and thermal stress Good recovery at Juan de Nova (2004-2011)
Materials & Methods
Context & Objectives
Results & Discussion
Conclusion
SR theoretical (Allen & Werner, 2002) ó Coral Fish Diversity Index (CFDI) Chaetodontidae, Pomacanthidae, Pomacentridae, Labridae, Acanthuridae and Scaridae
Comoros 507
Mozambique 10
Glorieuses 1
468
Madagascar 3,4
576
613
Juan Nova 5
423
443
Bassas 6
305
Europa 7
390
1
2
Rodrigues 9
410
Reunion 8
565
Durville & Chabanet, 2009 - 2 Samoilys, 2010 - 3 Allen, 2005 - 4 Samoilys & Randriamanantso, 2011 - 5 Chabanet & Durville, 2005 6 Van der Elst & Chater, 2001 - 7 Chabanet et al., 2011- 8 Fricke et al., 2009 - 9 Heemstra et al., 2004 - 10 Samoilys, 2010
Context & Objectives
Materials & Methods
Results & Discussion
Conclusion
ALL ISLANDS
Coral communities
Gobiidae undet.
Specific communities for each island with “crossing over” for Europa/Bassas
Europa Montipora / Porites spp , Bassas mixed hard / soft corals, Juan de Nova Pocilloporidae & mixed algal (CA /AA), Glorieuses algal assemblages dominated by Halimeda spp, Tromelin Faviidae (Favia, Favites spp)
Good recovery from 1998 bleaching events
Fish communities
Density dominated by plancton. > 59%
Biomass dominated by piscivores > 77%
RS dominated by carnivores > 57% (11% Piscivores)
High biomass 195 g/m2 (> 950 g/m2) except for Glorieuses 84 g/m2 ó illegal fishing?
Presence of large piscivores / herbivores and low fleshy algae
ó health of
coral reefs
Materials & Methods
Context & Objectives
Results & Discussion
Conclusion
FOCUS EUROPA
Biodiversity
Gobiidae undet.
Inventory in progress (some sp new for Europa, not for science)
(algae, cnidarians, crustaceans, echinoderms, fish)
Scleractinian corals
128 sp
Hydroids
Echinoderms
77 sp
37 sp (36 new)
Algae
Crustaceans
Fish
134 sp (all new, 10% N)
175 sp (61 new)
390 sp (92 new)
Materials & Methods
Context & Objectives
Results & Discussion
Conclusion
FOCUS EUROPA
Europa 7
100 80 60 40 20 0
ü High coral cover
S fish S cor
Europa 6
ü Low fleshy Europa 2 100 80 60 40 20 0
algae cover / high coralline algae
100 80 60
ü Clear spatial
40 20 S fish S cor
0 S fish
S cor
pattern between North /South
Europa 3
ü High fish and
100
coral species richness
80 60 40 20 0 S fish S cor
Europa 4
Context & Objectives
Materials & Methods
Results & Discussion
Conclusion
EUROPA Island - Habitat mapping
European Nature Information System (EUNIS)
50 differents types of habitat
Identify priority conservation areas for managers
Context & Objectives
Materials & Methods
Results & Discussion
Conclusion
Marion Dufresnes expedition
✓ get synoptic measurements on all islands
(GCRMN in SW Indian Ocean)
✓ establish baseline of benthic and fish communities of Eparses Islands
Europa
✗ biodiversity inventories /DB
(algae, cnidarians, crustaceans, echinoderms, fish)
✗ marine habitat mapping (geomorpho, communities, pressures, …)
Identify priority areas for conservation and management
Next steps Glorieuses (2012) et Juan de Nova (2013)
Thank you for your attention!
Acknowledgements Terres Australes & Antarctiques Françaises (TAAF) INEE/CNRS INSU IRD AAMP FRB ANR Interface Veolia Environment Foundation Initiative Française pour les Récifs Coralliens IFRECOR Forces Armées Zone SO Océan Indien (FAZSOI)
