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252 JARDEWESKI.cdr
Journal of Coastal Research
1210 - 1214
SI 39
ICS 2004 (Proceedings)
Brazil
ISSN 0749-0208
Fish Assemblage on Artificial Reefs in South Brazilian Coast
C. L.F. Jardeweski† and T. C. M. de Almeida‡
Laboratório de Ecologia de Comunidades
Universidade do Vale do Itajaí Centro de Ciências
Tecnológicas da Terra e do Mar, Itajaí, 88330 002, Brazil.
† [email protected][email protected]
ABSTRACT
JARDEWESKI, C. L. F. and ALMEIDA, T. C. M., 2006. Fish assemblage on artificial reefs in south brazilian coast.
Journal of Coastal Research, SI 39 (Proccendigs of the 8th International Coastal Symposium), 1210 - 1214. Itajaí,
SC, Brazil, ISSN 0749-0208.
The introduction of artificial reefs in coastal environments has been widely used with diverse objectives, such as:
fisheries and marine habitat enhancement, protection of shorelines, delimitation and protection of marine areas of
ecological relevance. The present study has as main objective the comparison of the structure and composition of
associated ictiofauna in artificial reefs, introduced in two distinct places: close and distant from the rocky shore. Two
groups of three structures (Reef BallÔ) were disposed in the Island João da Cunha/SC, a group located near the
rocky shore and the other with a distance of 50 meters. The strategy of visual census was used in the accompaniment
of ictiofauna, done by linear transects in the mentioned areas. The fishes were counted and identified to the lesser
possible taxon. A total of 19 species were identified, Stegastes fuscus was the most abundant in the area close to the
rocky shore and Haemulon sp for the distant points. The diversity was larger in the reefs near to the rockyshore
(0,693 1,925 nats) then in the distant points (0,60 1,332 nats). The total abundance also presented a similar standard
pattern to the diversity, being higher near the rockyshore. Two distinct species associations were identified, one in
distant reef points composed by Batigobius soporator, Haemulon sp and Anisotremus virginicus; and another
association near the rockyshore, composed by Sparissoma sp, Epinephelus marginatus, Sphoeroides testudineus,
Eucinostomus sp, Stegastes fuscus, Diplopodus argenteus, Pareques acuminatus and Epinephelus morio. The
presence and the distance of the rocky shore, was shown as an important factor, in the colonization of artificial reefs.
However, it must be considered, that the available time for the colonization also must interveine in this process.
ADDITIONAL INDEX WORDS: Artificial reef, assemblage, reef fishes.
INTRODUCTION
Artificial Reefs (AR) are characterized as structures
manufactured in concrete, wood, pneumatics and rocks, placed
in the aquatic environment. They can have diverse functions,
serving as tools of great utility, when their placement in the
environment is planned and well sized.
These structures provide new niches for marine life,
attracting many species of invertebrates and fishes (CAR and
HIXON, 1997). Many species use them for shelter from currents
and predators, as well as utilizing the fouling fauna and flora as
a food source (SPANIER, 1994; SAUL and CUNNINGHAM, 1997;
GODOY et al., 2002; RILOV and BENAYAHU, 1998).
The most notable alteration following the implantation of
these structures is the increase in fish catches, this being one of
the principal reasons for the utilization of artificial reefs
(PHONGSUWAN et al., 1994; ZALMON et al., 2002). The
observation that fish are attracted to objects placed in water thigmotrophism (OREN, 1968), such as the tuna catches near
floating objects in the open ocean (FAD Fish-Attracting
Devices) and prosperous fishing near shipwrecks
(SUMMERHAYES and THORPE, 1996; BOHNSACK et al, 1997) is
among the principal factors which encouraged the utilization of
AR (SVANE and PETERSEN, 2001).
In Brazil, BRANDINI (1998) and ATHIÊ (1997) carried out
revisions regarding the registration and the utilization of
artificial reefs. The utilization of AR was registered back in the
17th century by the Tupi and Tamoio Indian Nations and since
the 1970s structures constructed with rocks, mangrove tree
branches and concrete have been utilized by small fishing
communities in the northeast of Brazil (CONCEIÇ Ã O, 1998). In
recent years, many research groups have concentrated their
studies on the effects of these structures in the marine
environment (ATHIÊ , 1999), a program for the application of
these structure along the entire coast of the state of Parana
(southern Brazil) appearing at the end of the last century
(BRANDINI, 199). However, little is known regarding those
aspects related to the structure of the fish communities and the
associated species in this new substrate, when compared with
natural substrates, such as a rocky shore.
The objective of the present study is to describe and compare
the structure and composition of the fish communities of
artificial reefs and a nearby rocky shores, located on an island
off the southern coast of Brazil.
METHODS
StudyArea
The structures were placed near the João da Cunha Island
(Porto Belo Island) at coordinates 27°08'S and 48°32'W (Figure
1). The region is characterized as a stable and well sheltered
bay. The island, together with the continent, form a channel
influenced principally by tides.
In the bay, there are some areas of mollusk cultivation which
favor a reduction in hydrodynamism, which increases the
sedimentation rate and reduces the visibility of the water. The
sediments in the region, in general terms, is characterized by a
mixture of sand and mud, which also contributes to the
reduction in visibility.
The shallow sheltered bays, in the state of Santa Catarina, are
little affected by the seasonal intrusion of subtropical waters of
the south and provide a habitat for around half of the known reef
fish species of the Brazilian continental platform (FLOETER et
al., 2001). The coast of Santa Catarina is the southern limit of
the reef fishes distribution in the Brazilian province, with the
occurrence of rocky shores inhabited by algae and sponges
(FLOETER, op cit).
Three areas were monitored during the experiment, a rocky
shore (CN), considered as the control, near the area where the
reefs were placed and with similar characteristics; reefs,
positioned at two distinct sites: one near the island rocky shore
(RD) and another placed further from the island (RF). In each
of the areas where the artificial reefs were sunk, 3 Reef BallÔ
structures were placed.
Census Technique
The monitoring of the fish community was effected by way
Journal of Coastal Research, Special Issue 39, 2006
1211
Fish Assemblage on Artificial Reefs
BRAZIL
Figure 1. Localization of Porto Belo Island.
of visual censuses carried out along linear transects (WATSON
and QUINN II, 1997; Ferreira et al., 1993), of dimensions 20m x
2m, randomly placed at the above locations, in a 10 minute
period. The censuses were carried out monthly from March to
August 2003, by means of SCUBA diving. In each census, all
fishes were counted along the transects, and the identifications
were carried out during the census up to the lowest possible
taxon. The three areas were monitored on the same day to avoid
great variation in the environmental conditions.
DataAnalysis
The data were organized in the form of a matrix, in which the
columns represented the different censuses in each month and at
each place, and the lines represented the species. For the
characterization of the fish community structure, the ShannonWeaver (Ln) diversity index, the equitability and the total
abundance of fishes, were utilized (PIELOU, 1984). The
community structure was compared by means of analysis of
variance considering the locations as the source of variation
(UNDERWOOD, 1994).
The species composition at the three areas was compared
through the analysis of similarities applied over a matrix of
dissimilarity. The faunistic similarity was calculated from the
Bray-Curtis coefficient (ANOSIM). The correspondence
analysis was applied to the identification of the fish species
associations (LEGENDRE and LEGENDRE, 1998).
Table 1. Percent frequency of species occurrence in censuses carried out at the rocky shore (CN), the Artificial Reefs near the
rocky shore (RD) and the Artificial Reefs distant from the rocky shore (RF).
Family
Carangidae
Bleniidae
Diodontidae
Gerreidae
Gobiidae
Haemulidae
Ostraciidae
Pomacentridae
Scaridae
Scianidae
Scorpaenidae
Serranidae
Sparidae
Tetraodontidae
Total Species
Species
Caranx sp
Ophioblennius atlanticus
Diodon sp
Eucinostomus sp
Batigobius soporator
Anisotremus virginicus
Haemulon sp
Acanthostracion quadricornis
Stegastes fuscus
Abudefduf saxatilis
Sparisoma sp
Pareques acuminatus
Scorpaena sp
Epinephelus marginatus
Epinephelus niveatus
Myctiroperca acutirostris
Diplectrum sp
Diplopodus argenteus
Sphoeroides testudineus
CN
--16.7
16.7
--16.7
16.7
83.3
--83.3
33.3
--33.3
------100
50.0
83.3
100
12
Journal of Coastal Research, Special Issue 39, 2006
RD
16.7
------16.7
16.7
50.0
16.7
100
--33.3
--16.7
50
16.7
100
66.7
100
16.7
14
RF
------33.3
50.0
33.3
33.3
--16.7
------16.7
----83.3
50.0
----8
1212
Jardeweski and Almeida
35
Abundância Total
Diversidade (Ln)
2
1,5
1
0,5
0
30
25
20
15
10
5
0
RD
RF
RD
CN
RF
0,95
8
7
6
5
4
3
2
1
0
Equitabilidade
Número de Espécies
CN
Locais
Locais
0,9
0,85
0,8
0,75
0,7
RD
RF
RD
CN
RF
CN
Locais
Locais
Figure 2. Community structure parameters obtained for the three study locations.
RESULTS
A total of 19 species distributed among 14 different families,
were identified. The most abundant species were Sparidae
Diplodus argenteus, Serranidae Myctiroperca acutirostris,
Haemulidae Haemulon sp and Pomacentridae Stegastes fuscus,
with these species totaling 78% of the total fishes registered in
the censuses.
The fish diversity showed significant differences between
the 3 locations (F=8.858; p= 0.0029) with the lowest being
found for the furthest reefs. The same pattern was obtained for
the total abundance of fishes (F=6.646; p= 0.0086) and for the
equitability were differences between the 3 locations not
detected (Figure 2).
The species composition differed for the 3 locations
(RGlobal=0.451; p=0.1%), (Table 2).
The highest diversity, abundance of fishes and number of
species were found for RD and CN and the lowest values for
these community structure parameters were obtained for RF
(Figure 2).
The correspondence analysis permitted the extraction and
interpretation of two factorial axes, which explained a total of
46% of the specific abundance variation for the sites and the
sample months. It is worth noting that the aspects related to the
Fish Assemblage on Artificial Reefs in South Brazilian Coast
temporal variations are considered in this analysis.
Axis 1, responsible for 24% of the variation, was formed by
positive coordinates of the censuses carried out at RF in the
months of July and August, and by the negative coordinates of
the censuses carried out at the same location in the months of
March, April and May. Axis 2, responsible for 22% of the
variation, was formed principally by the negative coordinates of
CN in the months of March, April, May, July and August
(Figure 3). Axis 1 showed a seasonal variation in RF, while axis
2 showed the different species associations found between RF
and, CN and RD.
Table 2. Significance level of groups.
Number >=
Observed
R Statistic
5.2
4.2
Scorpaena sp
3.1
2.1
The occurrence of species which form small shoals such as
Diplodus argenteus at RD and CN, and Haemulon sp at all
Groups
Eucinostomus sp
Axis 2
DISCUSSIONS
locations may have influenced the density results, generally in
the visual census the most abundant species are overestimated
(WATSON and QUINN II, 2001; FERREIRA et al., 1993).
In the species association, the highest number found at RD,
was due to the proximity to the rocky shore (CN), which may be
functioning as a source area for new organisms. It is worth
mentioning that the inner reef area (RD) is a sheltered location
with greater stability in relation to the hydrological aspects of
the environment, providing a direct migration of new
individuals.
The location where the ReefBallsÔ were positioned at RD
would be at the interface of the consolidated substrate of the
rocky shore with the muddy-sand of the infralitoral zone, where
we can verify a greater variety of habitats and niches available.
Along with this high heterogeneity found, the artificial reefs
increase the habitat complexity, allowing greater chances of
finding abundances and diversities higher than those verified at
other locations.
As in the case of SANTOS and MONTEIRO (1997), a higher
similarity in the fish assemblage of the artificial reefs was
expected as a consequence of the insertion of reefs on
unconsolidated sea bottoms. In fact, the reefs fixed to soft
substrates created a discontinuity in the bottom biocenose
promoting the appearance of new communities of benthic
organism, which favor the enrichment and diversification of the
original fish community.
It is worth mentioning that RF is found near a tidal canal with
little protection against the action of local currents, this directly
influencing the offering and migration of new individuals. The
Diploplectrum sp
fuscus Sparisoma sp
-2.1Stegastes-1.04
Significance Possible
Level %
Permut.
Actual
Permut.
Batigobius soporator
1.1
Mictiroperca acutirostrix
Diplopodus argenteus
Anisotremus virginicus
1.1
2.1
3.1
Epinephelus marginatus Haemulon aurolineatum
Abudefduf saxatilis
Sphoeroides testudineus
-1.04
Equetus acuminatus
RD RF
1
0,559
0,2
462
462
RD CN
7
0,239
1,5
462
462
RF CN
1
0,587
0,2
462
462
-2.1
Axis 1
Figure 3a. Diagram of correspondence analysis.
Journal of Coastal Research, Special Issue 39, 2006
4.2
5.2
Fish Assemblage on Artificial Reefs
RF Ago
2.4
RF Jul
1.9
1.4
Axis 2
1.0
0.5
RF Jun
RD Mar
RD AgoRD Mai
CN Ago
CN Jun
-0.5 RD Jul
-1.0
0.5
RD Jun CN Abr
RD Abr CN Jul
1.0
1.4
1.9
2.4
CN Mai -0.5
CN Mar
-1.0
Axis 1
Figure 3b. Diagram of correspondence analysis.
instability of the hydrological aspects, combined with
endogenic and biological aspects (e.g. greater availability of
food and more shelter) may control the distribution of local
fauna of reef fishes (GODOY, 2002).
As BELLAN and BELLAN SANTINI (1991) and BOMBACE (et
al, 1994) have shown, the attraction capacity of reefs is
regulated by their size and density in the environment, and
greater diversities are found in artificial reefs near natural reefs,
as in the case of RD when compared to RF. The distance of the
natural reefs probably represent an important role in the
recruitment of the artificial reefs, since the natural substrate
may constitute an important source of juvenile migration,
settling of larvae and spores.
On the other hand MACARTHUR and WILSON (1967) noted
that despite the number of colonizing species being limited by
the size of the reef and its distance from the source of new
individuals, estimates regarding the number of species do not
indicate anything regarding the composition of the established
assemblages. Therefore we may state that the reduced number
of species found at RF was influenced mainly by the distance
from a source of new individuals and its exposure to the actions
of local currents.
Another important aspect to be mentioned is that RF is still in
the initial process of succession, which directly reflects in the
behavior of the community structure, since from March to
August the number of species found increased from 4 to 8,
doubling the parameters found, and in the same way diversity
and density were also influenced by the same inherent process
of succession.
For RF we may verify seasonability which was shown by the
species association found in the fall for Anisotremus virginicus,
and in the winter for Eucinostomus sp. The other species
Batigobius soporator and Scorpaena sp identified in the species
association for RF (Figure X) are classified as cryptic, and may
have been underestimated in the visual census (WILLIS, 2001;
FERREIRA et al., 1993), and they can therefore not be considered
as strong indicators of seasonability.
ACKNOWLEDGEMENTS
This work is part of a graduation work concluded thanks to
CTTMAR, UNIVALI and INSTITUTO ECOPLAN. We also
would like to thank Dr. Tito Almeida for their valuable critical
analisys, contributions and suggestions.
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Journal of Coastal Research, Special Issue 39, 2006

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