Monitoring long term changes in coral and fish communities in the central South Pacific [email protected] CRIOBE (Centre de Recherches Insulaires.

Monitoring long term changes in coral and fish communities in the central South Pacific

[email protected]

CRIOBE(Centre de Recherches Insulaires Observatoire de

l'Environnement)UMS 3278 CNRS - EPHE - Université de Perpignan

IRCP (Institut des Récifs Coralliens du Pacifique)Moorea - French Polynesia

T. LISON DE LOMA, Y. CHANCERELLE, S. PLANES

Tiahura area

• 3 areas - Fringing reef 3 areas - Fringing reef

- Barrier reef- Barrier reef

- Outer slope- Outer slope

• Twice a year (Spring and Fall)Twice a year (Spring and Fall)

• Number of speciesNumber of species

• Number of individualsNumber of individuals

100 m 2

• % of substrate cover% of substrate cover

• Water temperature recordsWater temperature records

• Catastrophic events: Catastrophic events:

- Acanthaster- Acanthaster

- Hurricane- Hurricane

- Bleaching- Bleaching

• Human impactsHuman impacts

•Reef scape/remote sensing mapping Reef scape/remote sensing mapping

Fish communities

Other data /

Moorea/Tiahura Data records : 1987 to 2010 (23 years)Moorea/Tiahura Data records : 1987 to 2010 (23 years)

Temporal increase in total density and SR, BUT…Temporal increase in total density and SR, BUT…decrease in density of commercial fishes in all habitats.decrease in density of commercial fishes in all habitats.

Polynesia Mana Network

Coral surveys at different scales:Coral surveys at different scales:-permanent 1 m2 quadrats-permanent 1 m2 quadrats

-landscape photography (> 10 m)-landscape photography (> 10 m)-manta tow (> 100 m)-manta tow (> 100 m)

Fish surveys: Fish surveys: - 200 m2 transects- 200 m2 transects-total fish faunatotal fish fauna

-densitydensity-size estimatessize estimates

Polynesia Mana Network

Tahiti pass, Tetiaroa Tahiti pass, Tetiaroa Tahiti jetty, Tahiti Faaa, Marutea, Rangiroa Tahiti jetty, Tahiti Faaa, Marutea, Rangiroa

Tikehau, Mataiva, Aratika Tikehau, Mataiva, Aratika Bora Bora, Takapoto, Nengo Nengo, TubuaiBora Bora, Takapoto, Nengo Nengo, Tubuai

Monitoring coral reef fish in MPAsMonitoring coral reef fish in MPAs

Other confounding effects: habitat disturbancesOther confounding effects: habitat disturbances

Monitoring inside MPAs eliminates confounding effects due to fishing Monitoring inside MPAs eliminates confounding effects due to fishing only after stabilization of fish density/biomassonly after stabilization of fish density/biomass

A. planciA. planci outbreaks in French Polynesia outbreaks in French Polynesia

- minor coral loss and community change with climate-induced disturbances- 96.1 ± 2.0 % decrease in coral cover due to COTS outbreak ‘natural’ predation far more devastating than climate-induced recurrent bleaching… so far.

- habitat structure intact