fish assemblages of coralline and granitic habitats of Curieuse Marine National Park

Item Type Working Paper

Authors Pittman, S.J.

Download date 29/09/2021 03:20:04

Link to Item http://hdl.handle.net/1834/635 Draft Report, 1997

Coral reef fish assemblages of coralline and granitic habitats of Curieuse Marine National Park

Simon J. Pittman Seychelles Marine Conservation Expedition, Nov-Dec, 1996

Introduction

Curieuse Marine National Park encompasses a diverse range of shallow water marine and brackish habitats including coralline fringing reefs, granitic boulder reefs, deep patch reefs, algal flats, seagrass meadows, intertidal rocky shore, sandy beach and mangrove habitat. Many of these shallow water habitats support an abundance of varied marine life, which in turn supports a burgeoning interest from tourist divers and snorkellers.

Curieuse Marine National Park includes Curieuse Island and the surrounding waters including the channel between the island and the north-eastern coastline of Praslin. The designated boundary extends from Chevalier Point in the west to Pointe Zanguilles in the east up to high water mark, and includes the outlying islets of St. Pierre in the south-west.

In 1971 a government White Paper states ‘’ It is intended that the reefs lying between Curieuse Island and Praslin should form an area to be designated as a Special Reserve, the object of which will be to protect the rich and varied reef community. The Commission is satisfied that traditional methods of fishing will not interfere unduly with the efficient management of this Special Reserve, and it is accordingly intended to permit fishing by traditional methods to continue in the area’’.

Marine park designation began in 1979 when the area was declared a Marine National Park under the Curieuse Marine National Park (Designation) Order of 1979, S.I. 55, under the National Parks and Nature Conservancy Act, 1971. Additional areas, were designated shell reserves under Protection of shells regulations, S.I. 91, 1969 and The Conservation of Marine Shells Act,1981. Legislation permits no marine shell to be taken when such shells are on a reef, rock, bed of a lagoon or the sea or sea floor, within 400 m from the low water mark. There are a number of specifically exempted species, and the possession of explosives within such a reserve is prohibited. The total area is some 1370 ha including 283 ha of land (Curieuse) to 30 m below sea-level. The area is mostly government owned with some land areas such as the land around Anse Petit Cour privately owned.

Coralline and particularly granitic habitats are common around the inner Seychelles group, however, comparatively little is known of their ecology and biodiversity. Granitic habitats are usually the subtidal rock at the base of granite cliffs and extend to include fallen rock or fragmented boulders. These are characterised by carpets of low growing soft coral colonies and often a mosaic of encrusting sponges and hard coral. In more protected situations, complex hard coral colonies have established and in some areas even delicate branching and plate forms thrive. The hard coral communities can be regularly seen along a granitic transect but are usually isolated from each other, where the substrate is configured such that, platforms of complex coralline communities are unlikely to develop. Soft are the dominant growth form, better adapted for these more dynamic conditions, effective colonisers and characteristically a less palatable group than hard corals due to the presence of toxins.

The largest expanses of intact coralline reef appear to have developed in more sheltered locations within the marine park and lie between the land masses of Curieuse Island and Praslin. Storm damage is common in this area and the limited coralline reefs appear to have built and rebuilt over the years. The absence of physical protection through embayment along this stretch of coastline appears to be the predominant limiting factor to reef development.

In order to effectively manage these habitats it is essential to collect baseline data on habitat characteristics including species assemblages. This initial phase will also contribute information useful in the implementation of monitoring programs.

Aims

In addition to the aims outlined below, this study (TMRU) contributes to several of the projects within the EMPS, including the Coastal and Marine Environment Baseline Study (Project No. I1 and I2), the Review of Coastal Zone Management Plans (Project No. I4) and some contribution toward the longer term Marine Resources Management Plans (Project No. J3).

This study uses visual census and REEFWATCH site inspection techniques primarily to:

• Establish a quantitative characterisation of the fish community present in Curieuse Marine National Park

• Describe species distributions and habitat correlates within the marine park

• Record all fish species identified in the survey area and contribute to the existing and steadily growing list of marine fish of Seychelles

Methods

This study forms part of the larger habitat and species distribution surveys undertaken for the Curieuse National Marine Park. Nine sites within the boundary of the park were surveyed using transect-based visual census. Five of these were defined as coralline, due to the extent of their living hard coral cover and four were defined as granitic having communities living on or around granite boulders. Survey depth varied between sites with granitic sites generally shallower.

Sites were selected on a number of criteria:

• Easily accessible

• Suitability of site for laying transect line

• Represent important and definable habitat type

• Sites frequently used by local dive operators

At Curieuse MNP, the fish visual census covered a minimum total of 12,500m2 of carbonate reef including sand and rubble areas and 10,000m2 of colonised massive granite boulders, sand and rubble.

REEFWATCH methodology

General site inspections were recorded using the REEFWATCH methodology for site description. Information was recorded on the position of the site, the profile of the reef and a series of assessments concerning the aesthetic and recreational values of the site, the abundance and diversity of corals and fish and the extent and form of any impacts or pollution. To estimate substrate cover the observers assess by eye an overall estimate of the amount of hard and soft coral, sand, sediment, algae etc., within a 2 m band over a 20 m length of reef representative of the dive site within the depth range under study. Supplementary to this intensive survey a coral species list was recorded and note taken of species zonation.

Surveys usually commenced from 0900 hrs to 0930 hrs with second counts commencing between 1130 to 1200 hrs. At these times most survey species were more active and any crepuscular changeover was avoided.

At each site in the park, a 250 m weighted transect line was laid, the depth of which depended on the topography of the site. Efforts were made to lay the line in such a way as to limit large variations in depth along the line. Fish counts were recorded by swimming at constant speed at least 1 - 2 m above the substratum to minimize accidental contact and to fully incorporate the 5 m survey width, either side of the line, in the observers field of view. Due to the high abundance of some species, counts were restricted to one or possibly two fish groups per observer. This increases the observation time per group and therefore the accuracy of the census. Fish groups have characteristic behaviour and the observer is required to adjust their swimming behaviour accordingly so as not to overlook individuals. This is particularly important for the more recluse and cryptic species, such as some species of grouper and in some areas which support a large juvenile population.

At some sites, additional surveys were used to record invertebrate distributions.

Information was recorded directly onto illustrated waterproof sheets. After each dive, counts were compared and possible errors in identification corrected. Obvious erroneous data was excluded from the final analysis. Similar and more detailed methodology on underwater visual census can be found in The Reefwatch II Protocol for reef fish visual census, April, 1997 available from TMRU, University of York).

For this study separate counts were made of 6 reef-associated fish families including 33 species:

Family English name Local name No. of species counted

Chaetodontidae Butterflyfish Papillon 15 Pomacanthidae Angelfish Poisson ange 6 Balistidae Triggerfish Bourse 7 Tetraodontidae Pufferfish Piton 3 Diodontidae Porcupinefish Bouletange 2

All species of Chaetodontidae and Pomacanthidae were recorded. These families include many species which thrive in coral rich areas, some of which are obligate corallivores and their importance as indicators of coral health has been investigated. A recent resurgence in the use of Chaetodontidae as indicators of reef health and change has been stimulated by the on-line publication of A Manual for monitoring coral reefs with indicator species: Butterflyfishes as indicators of change on Indo-Pacific Reefs (http://coral.aoml.noaa.gov/themes/themes.html), 1996. In addition, these colourful, easily visible species are commonly found to be of aesthetic value to the tourist observer. Since the ban on spearfishing in the Seychelles, large Chaetodons Pomacanthids are probably rarely fished and although occasionally taken in fish traps, they are generally not of direct commercial value. However, in some parts of the world, species are extracted for the aquarium industry.

Balistidae, Tetraodontidae and Diodontidae are included as important predators of large invertebrates including hard-shelled molluscs and echinoderms (Echinoidea - sea urchins), including crown - of - thorns starfish (Acanthaster planci). In Kenya, triggerfish have been found to be particularly important predators of keystone reef grazing urchins, having profound implications for reef structural complexity.

Many of the commonest medium sized Tetraodontids are also considered important faculative corallivores, who frequently feed on branching corals. Species from these groups are easily identified by characteristic body-shape and swimming style. Some species are less active by day and often found resting in places within the survey area usually out of view from above.

In complement the quantitative data collected using the visual census, an inventory of fish species was compiled in order to assess the reef fish biodiversity of Curieuse MNP. At all sites visited and whenever practicable possible, fish were identified and recorded to species level. The list is inherently limited due to time restraints and many of the small less conspicuous or nocturnally active species were not included.

Key herbivorous families such as sp. and Scarus sp. were included in the species list but not in the visual census. However, notes on observations of key herbivorous and planktivorous fish have been included for each site.

Results

Chaetodontidae (Butterflyfish)

A total of 15 species of Chaetodontidae were recorded throughout the survey area. Most widely distributed species were C. trifasciatus, found at all 9 sites; C. auriga and C. guttatissimus (8 of 9); C. trifascialis and C. zanzibariensis (7 of 9). Least well distributed were C. falcula (2 of 9), F. flavissimus; Heniochus acuminatus and C. melannotus (3 of 9). Refer to fig. 1b.

Distinct differences were evident between Chaetodontid species diversity and abundance at granitic and coralline sites. At granitic sites a larger number of omnivores (faculative corallivores) than corallivores were recorded. Generally, lower abundance was recorded at granitic sites than coralline, except Curieuse Reef, which showed lowest overall abundance for all fish groups (refer to Fig. 1a).

Largest abundance of Chaetodontids was recorded at Anse Petit Cour with high counts of the obligate corallivore C. trifasciatus. Counts were primarily composed of juveniles, mostly recorded in the shallower branching coral rich areas of the transect band. This suggests that Anse Petit Cour has an important function as a nursery area for C. trifasciatus. No other areas surveyed showed significantly high numbers of juveniles.

Trophic preferences were investigated and distribution patterns could be seen to reflect prey abundance. Highest hard coral diversity and abundance was recorded at Coral Gardens 1 and 2 (minimum 12 sp.), Anse Petit Cour and Turtle Reef (minimum 10 sp.). Highest abundance of obligate corallivores (C. trifasciatus, C. trifascialis and C. meyeri) were recorded at these sites (refer to fig. 1c).

C. zanzibariensis is a faculative corallivore with a documented preference for hard coral polyps in some regions. This species shows highest abundance at coral rich sites at Curieuse MNP. However, other species identified as faculative corallivores were also well represented at most granitic sites. C. melannotus has a preference for soft coral polyps and this species was only found at granitic sites in low abundance. Although abundance is generally lower at granitic sites, diversity is comparatively high. This suggests that diversity of habitat provides for high fish diversity and that abundance is limited primarily by the extent of preferred substrate. It would appear that even at granitic sites hard coral cover and coral morphology (structural complexity) significantly determines Chaetodontid abundance and diversity. At the granitic side of St. Pierre, corals were seen to develop more extensively in protected flutes or gullies where even table and branching corals were seen in relatively dynamic conditions. These coral communities supported characteristic fish species seen elsewhere associated with these coral morphs.

Another study (Jennings, et al, 1996) in the inner islands showed that habitat variables accounted for 23-52% of the variance in biomass of Chaetodon species. Jennings et al (1996) also found a positive correlation between obligate corallivore biomass and coral cover.

In addition, C. lineolatus and C. falcula were found at coralline but not at granitic sites. C. zanthocephalus and C. auriga were more abundant at granitic sites.

At most transects within Curieuse MNP higher diversity was recorded per 2500 m2 than those at Baie Ternay and Baie Vallon in 1995, however, the total species including both deep and shallow sites at BT and BV shows higher diversity. Generally, lower abundance was recorded at Curieuse MNP sites and this reflects the more limited extent of coralline habitat at Curieuse MNP. C. unimaculatus and C. bennetti were not seen at any Curieuse sites. C. auriga was more ubiquitous at Curieuse than the Mahe sites (refer to TMRU, 1996). Jennings et al (1996) suggests that variation in C. auriga numbers may be attributed to a preference for sandy substrate or to human extraction through trapping, since this species is one of the largest of the Seychelles butterflyfish.

Trophic categories used in Fig. 1c.

Obligate corallivore Faculative corallivore (omnivore) Invertivore (inc. plankton)

C. trifascialis C. auriga F. flavissimus C. trifasciatus C. falcula H. monoceros C. meyeri C. guttatissimus H. acuminatus C. kleinii C. lunula C. lineolatus C. melannotus (soft coral) C. xanthocephalus C. zanzibariensis

Pomacanthidae including Centropyge multispinis

Large angelfish are conspicuously underrepresented at all sites in Curieuse MNP. In total 5 species were identified with 4 species recorded within the census area. These species feed primarily on sponges and tunicates, an apparently abundant prey item at all sites, particularly granitic sites. Pomacanthus semicirculatus was the most widespread species and occasionally seen with younger individual showing intermediate stage colouration. Highest abundance of large Pomacanthids was recorded at Roche Canon and St. Pierre. Lowest abundance was recorded at Anse Petit Cour. P. diacanthus was only recorded at Anse Petit Cour (refer to Figs. 3a and 3c).

The smaller, ubiquitous C. multispinis feeds primarily on filamentous algae. This species is common around oceanic islands in the western Indian Ocean and inhabits coral rubble and sandy areas with abundant crevices and holes. This species was recorded at all sites in high numbers. Highest abundance was recorded at Coral Gardens 1 and 2 (refer to Figs 3b and 3c). Of the granitic sites St. Pierre yielded highest numbers. In some areas, this species may provide an indicator of algal phase shifts or characterise areas of reef damage. Habitat type largely determines the distribution patterns of this species.

Balistidae, Tetraodontidae and Diodontidae

A total of 7 Balistids, 5 Tetraodontidae and 2 Diodontidae were recorded in Curieuse MNP. A total of 5 Balistids, 1 Tetraodontid and 2 Diodontids were counted within the survey band. Highest total abundance was recorded at granitic sites with equal mean diversity for both coralline and granitic sites.

Balistidae (Triggerfish)

Highest Balistid diversity was recorded for Coral Gardens 1 and highest abundance was recorded at Wolfgang Wall. Highest abundance for coralline sites was recorded for Curieuse Reef. Anse Petit Cour had the lowest abundance within the survey area (refer to Fig. 2a and 2b). Generally, this group has a preference for sand and rubble areas with high hard-shelled invertebrate and urchin abundance. This may account for higher diversity at Coral Gardens which showed the richest molluscan and echinoid populations.

Sufflamen chrysoptera was well distributed throughout the survey area, found at every site and had highest total mean abundance. Balistapus undulatus was also recorded at every site albeit in lower numbers. Large Balistids were only recorded at Coral Gardens 1, Turtle Reef and St. Pierre at very low abundance. Hard-shelled invertebrates such as some species of Gastropod have been describes as the preferred prey of some large Balistids. Counts of these were low at many of the sites and absent from some, however further studies would be necessary to determine any causal links between prey and predator population dynamics. Further protection of shell reserves may result in an increase in populations of some large prey species.

Overall, Balistids appeared underrepresented at Curieuse MNP compared with prey abundance. Similar observations were made at sites in Baie Ternay and Beau Vallon in 1995 with lower total abundance and diversity recorded over a larger census area. It is not known whether these species are particularly vulnerable and targeted by trap fisheries. Bait commonly used is plant material and normally targets herbivorous reef fish. In more intensively fished parts of the world, Balistid extraction is linked with release of prey populations, such as Diadema urchins and has implications for reef health. However, data collected at Curieuse MNP does not suggest fishing as a primary determinant of Balistidae distributions. Recruitment patterns, population ecology and habitat preference may need further study.

Tetraodontidae (Pufferfish)

Only Arothron stellatus was included in the census with sightings recorded at Coral Gardens 1 and St. Pierre. In addition several individuals of A. meleagris were recorded at coralline sites. Both these species include coral and other invertebrates in their diet.

Diodontidae (Porcupinefish)

Two species from this group were recorded in the survey area. D. hystrix was only recorded at St. Pierre. D. liturosus was recorded at St. Pierre and Anse Petit Cour. These species are recluse in daylight and were found sheltering under granite and coral overhangs. Nocturnal survey may yield higher numbers.

Summary

Highest overall fish abundance and diversity for all fish groups included in the census was recorded at Coralline sites, particularly Coral Gardens and Anse Petit Cour. Anse Petit Cour showed particularly high numbers of juveniles. Curieuse Reef showed lowest abundance and diversity which largely reflected the development of the reef and its unsheltered location seaward of Curieuse Island. Granitic habitats with generally lower habitat complexity and lower hard coral cover maintain relatively high diversity and abundance with healthy coral growth in sheltered positions. St. Pierre showed highest total abundance of the granitic sites, although a large proportion of this comprised high C. multispinis abundance. Most noticeably granitic sites supported diverse Chaetodontid populations (refer to Fig. 4)

Notes on observations of non-census species

Coralline sites

Coral Gardens 1 and 2 High hard coral cover and density with good complexity. Super-abundance of nocturnals above the reef (Priacanthus sp.). Moderate numbers of large herbivorous fish. High diversity of parrotfish. Some areas of algal encrusted branching corals with resident Pomacentrids. Pomacentrus sulfureus common over coral. Fewer planktivorous fish than Anse Petit Cour and Turtle Reef. Some large wrasse.

Anse Petit Cour - reef slope Sedimentation evident. Plankton rich water column. Complex reef structure. Abundant Pomacentrus sp. dominate assemblage. Aruanus dascylus common over branching coral. Large wrasse populations. Large tracts of sand with low fish abundance. Goatfish (Mullidae) common. Comparatively few herbivorous fish. Pomacentus sulfureus common. Shallower sections show smaller coral growth with areas of extensive thicket. Large numbers of corallivores. Super- abundance of planktivorous damselfish including Chromis sp. Low abundance of herbivorous fish over rubble areas.

Turtle Reef Less complex reef than Anse Petit Cour with larger tracts of sand. Pomacentrids abundant. Similar assemblages to neighbouring Anse Petit Cour but with lower abundance of juveniles. More goatfish and wrasses. Large mixed shoals of Fusiliers (Caesionidae). Four large Cheilinus fasciatus.

Curieuse Reef Low live coral cover and large areas of sand and rubble. Patches of soft coral cover. Remains of older more complex reef. Low fish abundance. Few herbivorous fish, mainly parrrotfish. Juvenile Goatfish and Wrasses foraging over rubble and sand. Low planktivorous damselfish abundance and few branching corals. Anthias sp. present in low abundance. Scolopsis frenatus common. Carnivorous on benthic invertebrates. Large schools of Fusiliers and Caranx sp. Occasional coral heads with diverse fish assemblages and cleaning stations. Some large Acanthids. Trunkfish - Ostracion trachys, previously only recorded from Mauritius.

Granitic sites

Wolfgang Wall High monospecific soft coral cover over granite. Mosaic of soft coral, encrusting hard coral and sponge on rocks. Some boulders uncolonised. Few carnivorous fish. Mixed assemblages of large herbivores common. Some branching coral colonies with damselfish. Large numbers of Abudefduf sexfasciatus in water column. Rabbitfish (Siganidae) abundant. Some large anemones with host fish (Heteractis magnifica with Amphiprion akallopsis). Lowest fish abundance over soft coral dominated granite and over sand.

Roche Canon Large monospecific soft coral covered granite. Only site with large Sinularia and Sarcophyton cover. Low live hard coral cover. Largest boulders support large branching corals. Large areas of rubble and sand. Many Rabbitfish (Siganidae). Abudefduf sexfasciatus common. Acropora sp. and small group of obligate acroporivores - Oxymonocanthus longirostris. Scolopsis frenatus common over rubble areas. common, grazing over granite rocks in the surge zone. Parrotfish, Scarus sordidus common over rubble.

Sainte Pierre Shallow granitic site, low soft coral cover, largely algal covered rocks. Unlike Curieuse Island granitic assemblages. Near extensive coralline reef. Fluted or gullied granite providing protected environment for hard coral growth. Corallivores common. Abedufduf sexfasciatus common. Herbivores very common. Parrotfish and large Acanthurus sp. Large number of highly territorial A. sexfasciatus (nesting?) in granite flutes.

References

Jennings, S., Boulle, D.P. and Polunin, N.V. (1996). Habitat correlates of the distribution and biomass of Seychelles reef fishes. Environmental Biology of Fishes, 45, 15-25.

Jennings, S., Marshall, S., and Polunin, N. V. (1996). Seychelles marine protected areas: Comparative structure and status of reef fish communities. Biological Conservation, 75, 201-209.

TMRU (1996) Habitats and species of Baie Ternay MNP and Baie Beau Vallon, Mahe. Tropical Marine Research Unit, University of York. Fish Species list for Curieuse Subfamily : Blenniinae

Marine National Park Plagiotremus rhinorhynchus

This species list was compiled using primarily, Subfamily : Salariinae Randall (1992) Reef Fishes; Lieske and Myers (1994) Fishes: Indo-Pacific and Exalias brevis and Debelius (1995) Indian Ocean Tropical Fish Guide. Video footage and photography were also used to aid identification. Family : CAESIONIDAE

[208 species from 44 families using Caesio caerulaurea C. lunaris visual census. Some very small and C. teres cryptic families are underrepresented C. xanthonota in this species list] Pterocaesio marri P. tile

Family : Family : CARCHARHINIDAE Subfamily : Acanthurinae Triaendon obesus A. leucocheilus Family : CARANGIDAE A. lineatus A. nigrocauda Carangoides ferdau A. nigrofuscus C. fulvoguttatus Acanthurus sp. Caranx melanpygus striatus Trachinotus blochii C. strigosus hepatus Family : CHAETODONTIDAE desjardinii Z. scopas Chaetodon auriga C. falcula Subfamily : Nasinae C. guttatissimus C. linealatus Naso brevirostris C. lunula C. meyeri Family : APOGONIDAE C. melannotus C. trifascialis C. trifasciatus Cheilodipterus macrodon C. xanthocephalus C. zanzibariensis Family : AULOSTOMIDAE Forcipiger flavissimus Heniochus acuminatus Aulostomus chinensis H. diphreutes H. monoceros Family : BALISTIDAE Family : CIRRHITIDAE Balistoides viridescens Balistapus undulatus Paracirrhites forsteri Melichthys indicus M. niger Family : CONGRIDAE Pseudobalistes flavimarginatus Sufflamen bursa Conger cinereus S. chrysopterus

Family : DACTYLOPTERIDAE

Family : BLENNIIDAE Dactyloptena orientalis Thalassoma sp. Family : DASYATIDAE Tribe : Labrichthyini Taeniura melanospilus Labrichthys unilineatus Family : DIODONTIDAE Labroides bicolor L. dimidiatus

Diodon hystrix Tribe : Novaculini D. liturosus

Novaculichthys taeniourus Family: EPHIPPIDAE

Subfamily : Pseudodacinae Platax teira

Family : HAEMULIDAE Pseudodax moluccanus

Family : LETHRINIDAE Plectorhincus flavomaculatus P. orientalis P. picus Gnathodentex aurolineatus P. schotaf Lethrinus enigmaticus L. harak Family : HOLOCENTRIDAE L. mahsena L. mahsenoides Subfamily : Holocentrinae L. microdon L. nebulosus Myripristis hexagona L. obsoletus M. melanosticta L. variegatus Sargocentron caudimaculatum Monotaxis grandoculis S. seychellense S. spiniferum Family : LUTJANIDAE

Family : LABRIDAE Aprion virescens Tribe : Hypseginyini Lutjanus bohar L. fulviflamma Bodianus axillaris L. gibbus B. diana L. kasmira L. sebae Tribe : Cheilinini Macolor niger

Cheilinus chlorourus? Family : MONOCANTHIDAE C. digrammus C. fasciatus Aluterus scriptus C. lunulatus Amanses scopas C. trilobatus Cantherhines fronticinctus Epibulus insidiator C. pardalis Oxycheilinus sp. Oxymonacanthus longirostris Pervagor aspricaudus Tribe : Julidini Family : MONODACTYLIDAE Anampses meleagrides Cheilio inermis Monodactylus argenteus Coris aygula C. frerei Family : MUGILIDAE Gomphosus caeruleus Halichoeres cosmetus Crenimugil crenilabis H. hortulanus Hemigymnus fasciatus H. melapterus Family : MULLIDAE Thalassoma hebraicum Mulloidichthys flavolineatus C. ternatensis Parupeneus barberinus C. viridis P. cyclostomus Dascyllus aruanus P. macronema Neoglyphidodon melas Parupeneus sp. Plectroglyphidodon lacrymatus Pomacentrus caeruleus Family : MURAENIDAE P. sulfureus

Gymnothorax flavimarginatus Subfamily : Amphiprioninae Siderea grisea Amphiprion akallopisos Family : MYLIOBATIDAE Family : PRIACANTHIDAE Aetobatus narinari Priacanthus blochii Family : NEMIPTERIDAE P. hamrur

Scolopsis frenatus Family : SCARIDAE

Family : OSTRACIIDAE Bolbometopon muricatum Cetoscarus bicolor Lactoria fornasini Calotomus carolinus Ostracion cubicus Hipposcarus harid O. meleagris Scarus caudofasciatus O. trachys? S. falcipinnis S. frenatus Family : PEMPHERIDAE S. ghobban S. niger Pempheris schwenkii S. psittacus P. vanicolensis S. rubroviolaceus S. scaber Family : PINGUIPEDIDAE S. sordidus S. strongylocephalus

S. viridifucatus Parapercis hexophtalma Scarus sp. P. xanthozona Family : SCORPAENIDAE Family : PLOTOSIDAE Pterios miles Plotosus lineatus P. radiata Scorpaenopsis diabolus Family : POMACANTHIDAE Family : SERRANIDAE Centropyge acanthops Tribe : Anthiinae Apolemichthys trimaculatus Centropyge multispinis Pseudoanthias squamipinnis Pomacanthus imperator P. semicirculatus Pygoplites diacanthus Tribe : Epinephelini

Family : POMACENTRIDAE Aethaloperca rogaa Anyperodon leucogrammicus Abudefduf sexfasciatus Cephalopholis argus A. sordidus C. miniata A. vaigiensis C. sexmaculata Chromis atripectoralis Epinephelus caeruleopunctatus C. dimidiata E. fasciatus C. opercularis E. fuscoguttatus E. hexagonatus E. merra E. polyphekadion E. tauvina Epinephelus sp. Plectropomus areolatus P. laevis P. punctatus

Family : SIGANIDAE

Siganus argenteus S.corallinus S. stellatus S. sutor

Family : SPHYRAENIDAE

Sphyraena sp.

Family : SYNGNATHIDAE

Corythoichthys flavofasciatus C. haematopterus ?

Family : SYNODONTIDAE

Saurida gracilis Synodus dermatogenys

Family : TETRAODONTIDAE Subfamily : Tetraodontidae

Arothron meleagris A. nigropunctatus A. stellatus Canthigaster solandri C. valentini

Family : TORPEDINIDAE

Torpedo fuscomaculata

Family : ZANCLIDAE

Zanclus cornutus Fish groups and associated substrate cover of coralline (C) and granitic (G) sites at Curieuse MNP

Chaetodontids Pomacanthids C. multispinis Lutj., Leth.,Aprion Serranids Balis.,Diod., Tetrao. 240

220 C 200 C 180 C 160 G C 140 G 120 G 100 per 2500 m2 G

Mean number of fish 80 C

60

40

20 0 123456789

100% Percentage substrate cover

0% rre CG1 CG2 St Pie Petit Cour Turtle Reef

Survey sites Point Rouge Roche Canon Curieuse Reef Wolfgang Wall Hard coral Soft coral Rubble Sand Rock Algae

Chaetodon trophic groups and associated substrate cover of coralline (C) and granitic (G) sites at Curieuse MNP

Obligate corallivore Faculative corallivore Invertivore 100 C 80 C C G 2 C 60 G G 40

per 2500 m G

Mean number of fish 20 C

0 123456789

100% Percentage substrate cover 0% rre CG1 CG2 Wall St Pie Wolfgang Petit Cour

Survey sites Turtle Reef Point Rouge Roche Canon Curieuse Reef Hard coral Soft coral Rubble Sand Rock Algae

Fig 1a. Chaetodontid abundance and species richness at Curieuse Marine National Park coralline granitic 100 10 90 80

sh 6 70 11 2

of fi 10 9 r 60 50 11 40 9 per 2500m n numbe a

e 30 8 M 20 3 10 0 tit rre e e P e Pi Reef Wall Cour St Curieuse Wolfgang

Sites Ans Turtle Reef Point Rouge Coral Gdns 1 Coral Gdns 2 Roche Canon Fig 1b. Chaetodontid abundance classes for Curieuse Marine National Park

Sites CG1 CG2 Point Curieuse Wolfgang Roche Anse Petit Turtle St. Pierre Rouge Reef Wall Cannon Cour Reef Species

C. auriga • • • • • o • • • C. bennetti o o o o o o o o o

C. falcula o o o o o o • • o

C. guttatissimus • • • • • o • • • C. kleinii • • • o • • o o • C. lunula • • o o • • • • • C. linealatus o o o o o o • o o

C. melannotus o o • o o • o o •

C. meyeri • • • o o o o o o

C. trifascialis • • • o • • • o • • • • C. trifasciatus • • • • •• • C. unimaculatus o o o o o o o o o

C. xanthocephalus o o • o • • • o •

C. zanzibariensis • • o • • o • • • F. flavissimus • • o o o o o o •

H. monoceros o o o o • o • • •

H. acuminatus • • o o o o o o •

o 0 • 1-5 • 6-10

• 11-20 Key for abundance classes (individual fish per 2500 m2 ) • 31-50 • 51-60

Fig 3a. Pomacanthid abundance and species richness at Curieuse Marine National coralline Park granitic 100 90 80 sh 70 2 of fi

r 60 50 40 per 2500m n numbe a

e 30 M 20 2 3 10 3 3 1 3 2 3 2 0 tit rre e e P e

Sites Pi Reef Wall Cour St Curieuse Wolfgang Ans Turtle Reef Point Rouge Coral Gdns 1 Coral Gdns 2 Roche Canon

Fig 3b. Centropyge multispinis abundance at Curieuse Marine National Park coralline granitic 100 90 80 sh 70 2 of fi

r 60 50 40 per 2500m n numbe a

e 30

M 20 10 0 tit rre e e P e Pi Reef Wall

Sites Cour St Curieuse Wolfgang Ans Turtle Reef Point Rouge Coral Gdns 1 Coral Gdns 2 Roche Canon

Fig 3c. Pomacanthid abundance classes for Curieuse Marine National Park

Sites CG1 CG2 Point Curieuse Wolfgang Roche Anse Petit Turtle St. Pierre Rouge Reef Wall Canon Cour Reef Species

A. trimaculatus • • o • • • o o •

C. multispinis • • • • • • •• •• • P. imperator • • • • • • o o • P. semicirculatus • • • • • • • • •

P. diacanthus o o o o o o • o o

o 0 • 1-5 • 6-10

• 11-20 Key for abundance classes (individual fish per 2500 m2 ) • 31-50 • 51-60

Fig 2a. Balistid, Diodontid and Tetraodontid abundance and species richness at Curieuse Marine National Park coralline granitic 100 90 80 sh 70 2 of fi

r 60 50 40 per 2500m n numbe

a 30 e 2

M 20 2 2 2 6 5 2 3 10 3 0 tit rre e e P e 1 2 Roche Pi Canon Reef Wall Sites Cour St Curieuse Wolfgang Ans Coral Gdns Coral Gdns Turtle Reef Point Rouge

Fig 2b. Balistid, Diodontid and Tetraodontid abundance classes for Curieuse Marine National Park

Sites CG1 CG2 Point Curieuse Wolfgang Roche Anse Petit Turtle St. Pierre Rouge Reef Wall Canon Cour Reef Species

Balistoides conspicillum o o o o o o o o o

B. viridescens o o o o o o o • •

Balistapus undulatus • • • • • • • • • Odonus niger o o o o o o o o o

Pseudobalistes flavimarginatus • o o o o o o o o

P. fuscus o o o o o o o o o

Rhinecanthus aculeatus o o o o o o o o o

Sufflamen bursa • o o o o o o o o

S. chrysopterus • • • • • • • • • Arothron. hispidus o o o o o o o o o

A. stellatus • o o o o o o o •

Diodon hystrix o o o o o o o o •

D. liturosus o o o o o o • o •

o 0 • 1-5 • 6-10 Key for abundance classes (individual fish per 2500 m2 ) • 11-20