Impact of shark-feeding tourism on surrounding fish populations off Moorea Island (French Polynesia)
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CSIRO PUBLISHING
www.publish.csiro.au/journals/mfr Marine and Freshwater Research, 2010, 61, 163–169
Impact of shark-feeding tourism on surrounding fish
populations off Moorea Island (French Polynesia)
Matthias VignonA,B,E , Pierre SasalA,B , Ryan L. JohnsonC,D and René GalzinA,B
A UMR 5244 CNRS EPHE UPVD, Biologie et Écologie Tropicale et Méditerranéenne,
Université de Perpignan Via Domitia, 66860 Perpignan cedex, France.
B USR 3278 CNRS-EPHE, Centre de Recherches Insulaires et Observatoire
de l’Environnement (CRIOBE), BP 1013, Papetoai Moorea, French Polynesia.
C Mammal Research Institute, University of Pretoria, Pretoria, 0002, Republic of South Africa.
D Oceans Research, PO Box 1767, Mossel Bay, 6500, Republic of South Africa.
E Corresponding author. Email: matthias.vignon@univ-perp.fr
Abstract. Shark feeding is widespread throughout tropical, subtropical and temperate marine ecosystems and gives rise to
controversy because there is little consensus regarding its management. There are few comprehensive reports that consider
how shark feeding with bait might impact local fishes, despite the development of this practice during the last few decades.
Although shark feeding might theoretically have parasitological effects on local non-target fish species in the vicinity of
feeding areas, this aspect has never been investigated. During an extensive parasitological survey conducted between 2005
and 2007, a total of 1117 fish belonging to six common grouper and snapper species were sampled throughout the entire
north coast of Moorea Island (French Polynesia), encompassing three localities where feeding has occurred frequently
since the 1990s. Parasites exhibited no spatial patterns except for the infections on the blacktip grouper (Epinephelus
fasciatus). On this species, the prevalence of larval cestodes that parasitise sharks as adults and the intensity of their
infestation were significantly higher around shark-feeding localities compared with non-shark-feeding localities. Our
results suggest for the first time that although long-term shark feeding has parasitological implications, the impacts appear
limited, only involve cestode larvae from one host species and do not seem to affect the health of the fish we studied.
Additional keywords: cestode, fish health, hepatosomatic index, Lutjanidae, Pacific, parasites, Serranidae.
Introduction facilitate close observation and predictable interactions with fish
Marine and coastal tourism is one of the fastest growing indus- species (including elusive predators). Shark feeding is probably
tries (Miller 1993), with most of the associated underwater one of the most impressive activities that tourists can experience
activity concentrated around the world’s reefs where leisure underwater, and yet it is a controversial issue with little consen-
tourism primarily comprises fishing and diving (Hall 2001). sus regarding its management, because feeding is suspected to
Yet, despite an increased awareness of the economic and envi- impact local ecosystems. Although some studies conclude that
ronmental significance of tourism, data on the environmental moderate levels of shark feeding have only a minor impact on
impact of tourism remain scarce in the majority of coastal regions the behaviour of sharks (Laroche et al. 2007), deliberate and
of the world. Adverse effects that have been reported include long-term shark feeding is suspected to alter natural behaviour
damage from small boat anchors, boat groundings and the activ- patterns and populations, engender dependency and habituation
ities of snorkellers and SCUBA divers, who cause deliberate and increase aggression towards humans (Orams 2002). Yet tour
and accidental reef damage by souvenir taking, divers’ fins and operators defend the practice as a means to spread awareness,
reef walking (Tratalos and Austin 2001; Zakai and Chadwick- promote conservation and generate economic benefits for the
Furman 2002). This is especially relevant in the Pacific Islands non-consumptive utilisation of wildlife (Kiss 2004; Topelko and
(Harrison 2004). Dearden 2005). Despite this controversy, there are few stud-
Wildlife interaction occurs in a wide variety of settings ies that consider the impact of shark feeding, even though the
throughout the world and has become increasingly popular dur- practice is widespread and growing.
ing recent years (Duffus and Dearden 1990; Orams 2002). This Ecological studies on shark feeding have focussed primarily
is especially true in reefs where the diversity of fishes in shallow on how provisionisation directly affects the behaviour patterns
waters is very high. The dive industry, as a whole, recognises of sharks (Johnson and Kock 2006; Laroche et al. 2007). In con-
the significant value of such interactive marine experiences. The trast, little is known about the indirect effects of shark feeding,
practice of fish feeding (provisionisation) has recently become including how parasites may increase in abundance, affecting
a popular means by which tourists and tourism operators can non-target species in the vicinity of shark-feeding areas. Fish
© CSIRO 2010 10.1071/MF09079 1323-1650/10/020163164 Marine and Freshwater Research M. Vignon et al.
aggregations (larger shoal size and density) caused by artifi- were collected in two successive years: February–April 2006
cial provisionisation have been recorded in the Mediterranean and February–July 2007. Supplementary samples of C. argus
Sea (Milazzo et al. 2005), Atlantic Ocean (Ilarri et al. 2008) were caught in March 2005. All fish were speared on the out-
and Pacific Ocean (Cole 1994; Sweatman 1996), suggesting side slope of the barrier reef at a depth ranging between 5 and
that long-term feeding might indeed affect the natural com- 40 m. To prevent any loss of ectoparasites, particularly those
munities and behavioural dynamics of fish populations. Such not permanently attached (Grutter 1995), each fish was imme-
high host densities generally favour transmission efficiency of diately enclosed within an individual plastic bag, underwater at
directly transmitted parasites (Arneberg et al. 1998; Sasal 2003). the point of capture, until dissection. To evaluate the effect of
Moreover, several studies report that fish fed with inappropriate spatial distribution and number of sampled fish, the north coast
food, such as that typically provided by tourists, can result in an was arbitrarily subdivided into 16 localities (Fig. 1) ranging in
increase in fat deposits in the liver and a modification of several length from 100 m to 2 km, with narrower localities around the
physiological indices (GBRMPA 1993; Luo et al. 2005; Jamil two main shark-feeding areas (localities 9 and 12).
et al. 2007). Such physiological alterations may favour infection
by parasites by increasing host susceptibility (Barber 2005). Ulti- Parasite collection
mately, sharks are definitive hosts for several parasite species
For each individual, standard length (SL) and total length (TL)
and therefore a source of parasites that can spread their eggs
were measured to the nearest millimetre. Both total (W) and
and/or larvae in the surrounding areas, affecting a wide variety
eviscerated weight (We ) were measured to the nearest gram.
of local organisms as intermediate hosts and compromising their
Fulton’s condition index (K) is believed to be a good indica-
health (Caira and Reyda 2005), altering their behaviour (Barber
tor of a fish’s general well being (Bolger and Connolly 1989),
et al. 2000; Thomas et al. 2005) and significantly reducing their
and was calculated as: K = We /SL3 . In addition, the hepatoso-
marketability (Caira and Reyda 2005).
matic index (HSI ) was calculated as an indirect index of energy:
Although feeding might have ecological effects on local
HSI = Wi /We , where Wi is the liver weight. All of the parts of the
non-target species in the vicinity of shark-feeding areas, the par-
fish (including the gut cavity, internal organs, tissue, gills, oral
asitological aspects of this practice have never been investigated.
cavity and fins) were examined for parasites under a binocular
Thus, we specifically studied the effects of shark feeding at three
microscope. Parasites were counted and fixed for identification.
localities around Moorea Island, where shark feeding has been
Individual cestodes were moderately flattened by coverslip pres-
occurring since the 1990s. The two main shark-feeding localities
sure and fixed with a drop of Bouin’s solution, stained with
are popular and receive divers twice a day, almost 365 days per
alcoholic chlorhydric carmine and then mounted in Canada bal-
year. The remaining locality is less visited. The aim of the study
sam. Cestode larvae were undifferentiated and thus possessed
was to test if shark attraction due to feeding is correlated with
none of the morphological features of adults, on which tax-
parasite distribution in six local non-target species of common
onomy is usually based, making species, genus or family-level
grouper and snapper along the north coast of Moorea Island.
identification difficult or impossible. Epidemiological indices
On the basis of published studies, we tested for a local increase
(prevalence, abundance and intensity) were used according to
of parasites in the vicinity of shark-feeding areas. Moreover,
Bush et al. (1997). Prevalence is the number of hosts infected
we tested if provisionisation alters the health (characterised by
with one or more individuals of a particular parasite species.
decreases in Fulton’s condition index and hepatosomatic index)
Abundance is the number of individuals of a particular parasite
of six common species in the vicinity of shark-feeding areas.
in a single host regardless of whether or not the host is infected.
Intensity (of infection) is the number of individuals of a par-
Materials and methods ticular parasite species in a single infected host. Cestode larval
Site and host collection terminology used by Chervy (2002) was followed here.
During an extensive parasitological survey, 1117 fish were
sampled on the outer slope along the entire north coast Data analyses
of Moorea Island (17◦ 30 S, 149◦ 50W, Society Archipelago, Multivariate regression trees (MRT; De’ath 2002) were pro-
French Polynesia), encompassing three shark-feeding local- duced for each fish species. Six factors were included as potential
ities (17◦ 29 56 S 149◦ 55 38W; 17◦ 29 08 S 149◦ 51 32W; explanatory variables of individual parasite loads: individual fish
and 17◦ 28 36 S 149◦ 50 41W) (Fig. 1) and involving several length (SL, cm), sampling depth (m), sampling month, sam-
shark species: mainly the blacktip reef shark (Carcharhinus pling year, distance from shark-feeding area (m) and distance
melanopterus), the grey reef shark (C. amblyrhynchos), the sil- from closest channel (m). This multivariate discrimination tech-
vertip shark (C. albimarginatus), the lemon shark (Negaprion nique constructs a hierarchical tree by repeatedly partitioning
acutidens) and, occasionally, the whitetip reef shark (Triaenodon the dataset into two mutually exclusive groups, each of which
obesus). Six abundant long-lived fish-predator species found in has similar values to the multiple response variables. Each split
the shallow waters were selected: four groupers (Cephalopho- is defined by a simple rule, based on a single explanatory vari-
lis argus n = 195, C. urodeta n = 249, Epinephelus fasciatus able minimising the sum of squares of the multivariate mean
n = 213 and E. hexagonatus n = 122) and two snappers (Lut- within each group. The splitting procedure is then pruned back
janus fulvus n = 193 and L. kasmira n = 145) with contrast- to the desired size by cross-validation using the minimum rule of
ing ecological habits (i.e. feeding habits, territorial and social Breiman et al. (1984). The MRT technique does not require any
behaviour between families as well as between species within assumptions about the form of the relationships between obser-
each family; Allen 1985; Heemstra and Randall 1993). Samples vations and explanatory variables and is robust to collinearityImpact of shark-feeding tourism Marine and Freshwater Research 165
(a)
1000
800
Abundance
600
400
200
(b)
14
12
10
Abundance
8
6
4
2
149°54W 149°46W
17°30S
5 km
1 km
17°35S
N
Fig. 1. Mean abundance (±s.d.) of (a) tetraphyllideans and (b) trypanorhynchs found throughout the north coast of Moorea
in the blacktip grouper (Epinephelus fasciatus). Data are provided by locality (number of sampled hosts per locality: 10, 10, 10,
10, 10, 10, 10, 13, 25, 20, 20, 20, 15, 10, 10, 10 from west to east); the pictograms correspond to shark-feeding areas.
of explanatory variables (De’ath 2002). These analyses were sampling month, sampling year, distance from shark-feeding
performed using the mvpart package in R statistical software area and distance from closest channel) plus parasite intensity,
(Therneau et al. 2004). as explanatory variables of individual Fulton’s condition indexes
MRTs with distance from shark-feeding area explaining and HSI.
more than 5% of the variability in individual parasite loads A Mann–Whitney U-test was performed to compare the mean
were selected and the Dufrêne–Legendre index (Dufrêne and Fulton’s condition index between potentially impacted individ-
Legendre 1997) was used to identify the parasites that were char- uals (hosts collected within 100 m from the point directly below
acteristic of clusters involving distance from shark-feeding area. the feeding buoy) and non-impacted individuals (using the aver-
The statistical significance of the index was assessed using a ran- age for the three feeding areas). In addition, ANCOVAs using
domised permutation procedure (Dufrêne and Legendre 1997). fish length as a covariate were used to test for the differences in
Those parasites characteristic of clusters involving distance from HSI between impacted and non-impacted locations. Fish length
shark-feeding area were analysed by a second MRT using the was selected because HSI was correlated with host size. Data
same six factors to assess their specific effect. The arbitrary sub- were log10 (x + 1) transformed to satisfy the assumptions of the
division of the north coast was not taken into account during the ANCOVA.
statistical analysis using MRT but was used to display spatial
distribution of parasites (abundance, Fig. 1).
To test the potential effect of the parasites characteristic of Results
shark-feeding areas on the health of the fishes, we performed a Sampled fish were infected with highly diverse parasite com-
final MRT using the same six factors (length, sampling depth, munities: cestodes, copepods, isopods, leeches, monogeneans166 Marine and Freshwater Research M. Vignon et al.
and nematodes belonging to a minimum of 19 families and that host individuals collected within 108 m of the point directly
mainly parasitising the mouth, gills, stomach, intestine and mus- below the feeding buoy had higher HSI compared with the previ-
cle. Owing to a lack of description of parasites from French ous arbitrary expectation (used in the ANCOVA) that individuals
Polynesia, species-level identification was not possible. In total, collected within 100 m of the feeding buoy might be potentially
45 parasite taxa were identified (see Accessory publication, impacted by shark feeding.
available on the Marine and Freshwater Research website, for
global summary statistics of epidemiological data). All but one
Discussion
of the MRTs revealed that distance from shark feeding explained
less than 5% of the variability in individual parasite loads. Only Local parasitological effects
the pruned tree performed for Epinephelus fasciatus used the dis- The life cycle of cestodes lacks free-living stages and relies on
tance from shark-feeding area as an important factor (49% of the the direct ‘food web’ transfer between hosts, parasitising sharks
total variability for the overall parasite community) and discrim- as adults. Their life cycles typically involve two to three inter-
inated parasite assemblages characterised by tetraphyllidean mediate hosts in which larval stages develop (Caira and Reyda
plerocercoids and trypanorhynch plerocerci. Both groups are 2005) plus several paratenic hosts (i.e. hosts with no effect on
larval cestodes. Trypanorhynch plerocerci were found encysted the completion of the life cycle). Thus, there are several non-
in muscle or mesentery surrounding the posterior part of the exclusive ways that shark feeding can locally increase prevalence
intestine. Tetraphyllidean plerocercoids were found free in the and/or intensity of cestode larvae, and these may vary between
caecum, intestine and occasionally in the stomach. These para- trypanorhynchs and tetraphyllideans.
sites also occurred in other host species (C. argus, C. urodeta, First, deliberate and long-term feeding is suspected to alter
E. hexagonatus, L. fulvus and L. kasmira) but parasitological natural behaviour, engendering conditioning, dependency and
indices were not explained by distance from shark-feeding area. habituation of animals (Orams 2002). Although natural aggre-
In those fish, trypanorhynch plerocerci were occasionally found gations have been reported for numerous elasmobranchs (i.e.
but none of them had an overall prevalence greater than a few sharks and rays), acoustic telemetry studies suggest a higher
per cent and infections usually consisted of a single individual. degree of residency in the area where sharks gain a noticeable
In contrast, tetraphyllidean plerocercoids were frequently found amount of food rewards over months or years (Shackley 1998;
in all sampled species with a high overall prevalence (between Johnson and Kock 2006; Laroche et al. 2007). In Moorea, shark
60 and 90%) and a basal individual intensity ranging from 5 to feeding has occurred at three localities on the outer slope off the
100. north coast since the 1990s. The two main shark-feeding local-
Among the six factors included in the second MRT (using ces- ities receive divers twice a day, almost 365 days per year. The
tode larvae exclusively), only the distance from shark-feeding remaining locality is less visited. Therefore, sharks in Moorea
area and fish length were relevant and explained 90% of total are probably conditioned to artificial provisionisation and may
variance of cestodes between individuals throughout the entire spend a substantial amount of time at feeding localities (Johnson
north coast of Moorea Island, with only five splits (Fig. 2). The and Kock 2006).
prevalence and intensity of trypanorhynchs increased with host Because adult cestodes parasitise the spiral intestine of almost
size and decreased with distance from shark-feeding localities. all orders of elasmobranchs, artificial aggregation and increased
Indeed, in parts of the reef distant from shark-feeding localities, site fidelity may result in a local facilitation of the life cycle
trypanorhynchs were absent from samples. In contrast, tetraphyl- of natural cestodes; eggs are locally released in faeces and then
lideans are ubiquitous throughout the north coast (100% mean infect nearby intermediate hosts with low mobility. Groupers are
prevalence in all parts of the outer slope) and their intensity locally infected by cestode larvae as paratenic hosts via feeding,
increased about four to 6-fold at shark-feeding localities. requiring that intermediate invertebrate hosts should also have
None of the sampled host species exhibited significantly low mobility. This hypothesis could explain the local increase
different Fulton’s condition indexes (Mann–Whitney U-test, of ubiquitous tetraphyllideans, which remain present even far
P > 0.1) for those collected near the feeding buoy. Four species from feeding areas with a low basal intensity. This hypothesis
(C. argus, C. urodeta, L. fulvus and L. kasmira) exhibited no could also explain the local presence of trypanorhynchs, whose
differences in HSI near the buoys (ANCOVA, P > 0.1). Only intensity is reduced 2-fold over 100–200 m and which remain
E. fasciatus and E. hexagonatus exhibited slight, but significantly absent or are not found far from feeding areas (Fig. 1).
higher HSI when collected near the feeding buoy (ANCOVA, The second hypothesis differs from the first by the origin of
F1,210 = 94.85, P = 0.00001 and F1,119 = 12.89, P = 0.0004 cestode larvae. During each feeding session, massive baits of
respectively). local pelagic fish (i.e. dolphinfish, jacks and tuna) are used. Typ-
Ultimately, none of the pruned trees performed on individ- ically, the occurrence of cestodes is more pronounced in benthic
ual Fulton’s condition indexes and HSI used cestode intensity species than in mesopelagic or bathypelagic species (Campbell
as an important explanatory factor. When using total cestode et al. 1980; Caira and Reyda 2005); however, bait species can
intensity (all larval stages together) as well as tetraphyllidean ple- be infected by cestode larvae (Williams and Bunkley-Williams
rocercoids and trypanorhynch plerocerci independently, only the 1996). These larvae are naturally transmitted to pelagic sharks
distance from shark-feeding area and fish length were relevant and may not occur in reef-associated shark species, such as those
and explained 38% of total variance of individual Fulton’s con- attracted to baiting in Moorea. Thus, feeding of reef-associated
dition indexes and HSI between individuals, with only three sharks with unusual or only occasional natural food may lead to
splits. HSI decreased with host size and increased with distance the local food-borne infection observed around Moorea. Once
from shark-feeding localities. Splits in the pruned tree revealed sharks are infected, the remaining parts of the parasitic life cycleImpact of shark-feeding tourism Marine and Freshwater Research 167
FD 660.5 m FD 660.5 m
1
SL 24.5 cm SL 24.5 cm
n 115 2
14 1400
10 1000
6 600
2 200
SL 21.5 cm SL 21.5 cm FD 199 m FD 199 m
5 3
n 16 n 31 SL 28.5 cm SL 28.5 cm
14 1400 14 1400 n 27 4
n 16 n8
10 1000 10 1000 14 1400
6 600 6 600 10 1000 14 1400 14 1400
2 200 2 200 6 600 10 1000 10 1000
2 200 6 600 6 600
2 200 2 200
Fig. 2. Multivariate regression tree based on cestode intensities of 213 blacktip groupers
(Epinephelus fasciatus). The overall tree explained 90% of total variance of cestode intensity
between individuals: trypanorhynchs shaded and tetraphyllideans unshaded. Branch lengths
are proportional to percentage of explained variance and splits are numbered in descending
order of importance. Among the six factors included in the analysis, only fish length (SL,
cm) and distance from feeding area (FD, m) were statistically significant.
can readily occur. Moreover, it is likely that long-term territo- Non-target fish aggregations (caused by artificial provisionisa-
rial E. fasciatus individuals act as opportunistic scavengers on tion) may favour transmission efficiency of parasites with direct
bait scraps that typically fall to the bottom during a feeding ses- life cycles, and inappropriate food supply may favour infection
sion, and therefore become infected. In addition, this unusual by parasites with either direct or indirect life cycles. Moreover,
food supply may explain the significantly higher HSI of E. fas- sharks are definitive hosts for several parasite species and are
ciatus and E. hexagonatus in the immediate vicinity of feeding therefore a potential source of larval parasites for other fishes.
areas. This hypothesis could explain the local increase of try- However, collected data suggest specific and limited impact on
panorhynchs, which are almost absent in groupers more than a local non-target fish species with no evidence that artificial pro-
few dozen metres from the feeding area because groupers hunt visionisation affects physiological health of surrounding hosts
and feed on live prey. Even though we found numerous ces- (except HSI for E. fasciatus and E. hexagonatus within 100 m
tode larval stages in baits commonly used to attract and feed of the feeding buoy) or their susceptibility to parasites (except
sharks, we recognise that evidence that these stages are viable and parasites with indirect life cycles parasitising sharks as adults
can infect groupers remains to be collected. One of the remain- for E. fasciatus).
ing questions is to know whether and how frequently sharks Through their indirect life cycles, parasites are functionally
eat infected groupers and thus complete a cestode’s life cycle. coupled with the surrounding free-living diversity, providing
Otherwise, groupers may just accumulate larvae as a develop- potential bioindicators of diversity and abundance of animal
mental dead-end. communities (Hechinger et al. 2007). Manipulating the spa-
tial distribution of one upstream host in a complex life cycle
Specific and limited impact may alter the distribution of parasites in downstream hosts
Theoretically, shark feeding might have parasitological effects (which carry the subsequent stages of parasites) (Hechinger and
involving both parasites with direct and indirect life cycles. Lafferty 2005). In one study, more shark tapeworms on paratenic168 Marine and Freshwater Research M. Vignon et al.
fish hosts were found at an island with lots of sharks compared Although shark feeding might theoretically have parasitolog-
with another island with few sharks (Lafferty et al. 2008). In that ical effects on local non-target fish species in the vicinity of
study, shark depletion was due to extensive fishing, emphasising feeding areas, this aspect has never been investigated. For the
that the natural (not due to shark feeding) occurrence of sharks first time, here we suggest that deliberate and long-term shark-
can affect parasites in local fish populations. However, it remains feeding has very limited and focussed impacts. Fortunately,
possible that other environmental differences between islands parasitological effects of shark feeding in Moorea Island appear
could also affect parasite communities. In the present study, the very localised (within a few hundreds of metres), only con-
occurrence of shark feeding in three distinct localities throughout cern cestode larvae from one host species and do not noticeably
the north coast of Moorea Island provides a convenient and pow- impact the health of intermediate hosts.
erful means to replicate local effects of shark feeding using local Both tourists and management agencies have an obligation to
gradients in distance from shark-feeding areas and minimising carefully consider the impact of tourism on wildlife (Duffus and
other environmental effects. As a consequence, abundance of Dearden 1990; Orams 1995). For the responsible management of
cestode larval stages in suitable teleost fish might be a conve- shark-feeding operations, any potential direct or indirect impact
nient method for assessing spatial variation in shark abundance needs to be considered. Further research is required to determine
(reviewed in Lafferty et al. 2008). This is especially relevant whether the results of the present study were an isolated case and
as reef shark populations are already heavily depleted (Robbins to what extent they apply to other localities (both tropical and
et al. 2006), most sharks remain elusive and their abundance is temperate) and other taxa (e.g. ray feeding is especially popular
difficult to quantify. with snorkellers and provisionisation frequently alters their nat-
Among all host species investigated, only parasites from the ural behaviour) (Shackley 1998; Newsome et al. 2004; Gaspar
blacktip grouper (E. fasciatus) exhibited an obvious spatial struc- et al. 2008).
ture. In either hypothesis, differences between hosts may involve
specific host ecology: territoriality, microhabitat, feeding habits,
Acknowledgements
etc. Although snapper (Lutjanus spp.) can temporarily aggregate
We would like to thank K. Lafferty for revising this manuscript as well as
in shark-feeding areas, it is unlikely that they exhibit spatial
other anonymous reviewer, who made valuable suggestions to improve the
fidelity because they freely move throughout the outer slope
manuscript. Financial support for this research was provided by CNRS (UMR
of Moorea Island. The use of highly vagile (and thus tempo- 5244). CRIOBE facilities (UMR2978 CNRS EPHE) were used during this
rally variable) hosts in a given locality is not representative and field expedition. Sampling was carried out according to Polynesian guide-
does not provide a suitable basis for use as local bioindicators lines and policies of PGEM (Marine Space Management Plan) of Moorea.
(Hechinger et al. 2007). In contrast, groupers, including E. fas-
ciatus, are long-lived and territorial within a restricted area of
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