Fringing Reefs of Reunion Island and Eutrophication Effects - Part 3: Long-Term Monitoring of Living Corals

Abstract

No . 5 9 6 P AR T 1 : L o n g -T e r m Mo n i t o r i n g o f T wo S h a l l o w Co r a l Re e f Co mmu n i t i e s C a t h e r i n e T o u r r a n d , Od i l e N a i m, L i o n e l B i g o t , C h r i s t o p h e C a d e t , B r u c e C a u v i n , S t u a r t S e mp l e , L u c i e n F . Mo n t a g g i o n i , P a s c a l e C h a b a n e t a n d He n r i c h B r u g g e ma n nNo . 5 9 7 No . 5 9 7 P AR T 2 : L o n g -T e r m Mo n i t o r i n g o f P r i ma r y P r o d u c e r s Od i l e N a i m, C a t h e r i n e T o u r r a n d , E n r i c B a l l e s t e r o s , S t u a r t S e mp l e , L i o n e l B i g o t , B r u c e C a u v i n , P a s c a l e C u e t , a n d L u c i e n F . Mo n t a g g i o n i No . 5 9 8 P AR T 3 : L o n g -T e r m Mo n i t o r i n g o f L i v i n g Co r a l s Od i l e N a i m, C a t h e r i n e T o u r r a n d , Ge r a r d F . F a u r e , L i o n e l B i g o t , B r u c e C a u v i n , S t u a r t S e mp l e a n d L u c i e n F . Mo n t a g g i o n iA T OL L R E S E AR C H B UL L E T I N NOS . 5 9 6 -5 9 8 FRINGING REEFS OF REUNION ISLAND AND EUTROPHICATION EFFECTS ABSTRACTSpatio-temporal variations of living coral coverage, species richness and diversity were studied on two fringing reef sites at Saint-Gilles La Saline on Reunion Island from 1987 to 2009. The Site-Toboggan (T) was characterized by oligotrophy, Acropora corals, abundant sea urchins and few primary producers. The SitePlanch'Alizés (P), was characterized by heterotrophy, massive corals, abundant primary producers and rare sea urchins. From the shore to the outer reef slope, both reef flats comprise the back reef at around 1.5m deep ('B'), coral zone 'L' with large shore-normal strips of coral 0.8m deep, coral zone 'N' with narrow shore-normal strips of corals at around 0.4m deep, and an outer reef flat (<0.4m deep, with breaking surf -not studied). In the period 1993 to 2002, a total of 36 coral species was recorded (31 species at T, 19 at P). In 1993, after a 1992-bleaching event, Acropora coverage was low and only 3 species were recorded (A. muricata, A. cytherea, A. abrotanoides). By contrast, in 2002, when Acropora cover was much higher, there were 11 species, but only two at P in the 1993-2002 interval. The highest coral diversity (Shannon index, H') occurred on the N coral zone at T in 1996, following an increase from 1993, and after which it declined, as the staghorn coral A. muricata strongly increased its cover. By comparison, non-Acropora coverage remained relatively stable at T. At P, coral coverage increased from 1993 to 2002 in both coral zones but only the increase of Porites (Synaraea) rus was statistically significant. Overall, trends in coral cover and diversity indicate both sites were in better health in . Between 1987 The number of coral species on the reef flats may have slightly decreased in the last 40 years. Faure ( , 2009) recorded 74 species in the1970s and 71 species in 2009, of which 36 species were recorded on inner reef flats and 62 species on outer reef flats. The number of species reco...

Fringing Reefs of Reunion Island and Eutrophication Effects - Part 1: Long-Term Monitoring of Two Shallow Coral Reef Communities

“…Moreover, P waters have slower flow rates, higher mean and more variable sea surface temperature (Denis et al, 2009). Thus, physico-chemical parameters of waters at Site-P greatly differ from those measured at Site-T (see discussions in parts II and III, Naim et al, 2013aNaim et al, , 2013b.…”

“…Species richness and diversity of corals is treated in part 3 of the paper (Naim et al, 2013b). At Site-T, 11 Acropora species formed 68.4% of the coral coverage, while at Site-P, only two species of Acropora accounted for 12.6% of cover.…”

“…The species composition, diversity and biomass of primary producers will be also analyzed at the two sites; (3) Part 3 (Naim et al, 2013b) focuses on the temporal variation in coral abundance, diversity and coral species as bioindicators.…”