Reef Fish Communities RESULT AND DISCUSSION
with coral reefs health, and fish that commonly called major fish that mainly utilized as an ornamental fish.
Based on census result in conservation area of Siompu Island, Kadatua Island and Liwutongkidi Island, reef fish can be grouped according to family,
species and number of individuals. From the total number of fish observed at all observing stations were showed that the fish are derived from 436 family, from
1.081 species with total of 5.871 individuals Appendix 3, 4, 5 and 6. Observation by visual census of reef fish in Siompu coastal waters was
performed at 5 points stations that showed the number of fish obtained for all stations were 1.433 individuals from 44 family of 137 species. Based on
classification according to the group, the group of major fish that many encountered at all stations are the family of Pomacentridae as many as 380
individuals, from 30 species. Species that mainly found at all stations are the species of Dascyllus reticullates, Dascyllus trimaculatus, Dascyllus aruanus and
Chromis ternatensis . Indicator fish group is the most powerful species that
associated with coral reef. Generally, this type of fish called butterfly fish that comes from Chaetodontidae family. Family Chaetodontidae was found numerous
in all stations by the number of 60 individuals from the species of Chaetodon kleinii
, Chaetodon lunula, Chaetodon ephippium and Forcipiger flavissimus. While target fish that encountered at all stations were from 15 families, consist of
119 species and 380 individuals. Often found at all stations were the family of Acanthuridae, Caesionidae, Siganidae, and Lethrinidae.
From observations of reef fish communities around Liwutongkidi Island at 10 points of observing station, found a number of 2.800 individuals from 40
families of 145 species. This amount consisted of groups of target fish, schools of indicator fish, and major fish groups. Group of target fish in Liwutongkidi coastal
water was obtained as many as 16 families from 46 species as many as 803 individuals. The type of fish that often found around the station are the family of
Acanthuridae with 9 species, Caesionidae with 2 species, and Lutjanidae with 5 species.
Major fish group was consisted of 23 families from 84 species with amount of 1.825 individuals. Major fish group that often found at the observation
station werw the family Pomacentridae 28 species, 14 species of Labridae, Balistidae 4 species, 3 species of Scaridae, Anthiinae two species, and two species
of Apogonidae. Group of fish indicators that found at all stations are Chaetodontidae family from 15 species with amount of 172 individuals. This
group of fish generally have a beautiful color patterns and movements so it looks very attractive. The type of indicator fish that often found at the research station
are the type of Chaetodon trifascialis, Chaetodon lunulatus, Chaetodon kleinii, Forcipiger flavissimus
and Heniochus varius. Observations based on the type of reef fish done by visual census method
in the waters of the Kadatua Island. From 5 points of observation station, we found 37 families from 157 species and as many as 1.638 individuals. Number of
individuals that grouped according to the type of fish were showed a number of major fish with abundance of 21 families, 95 species and 1.081 individuals.
Largest number of species was from Pomacentridae family consists of 32 species and 602 individuals. The types that found at all stations were Dascyllus
reticulates, Dascyllus
trimaculatus, Dascyllus
aruanus, Pomacentrus
muluccensis , and Chromis retrofasciata.
Figure 13. Abundance of target fish group according to Family in Siompu, Liwutongkidi and Kadatua Islands.
50 100
150 200
250 300
350 400
A c
a n
th u
rid a
e S
er ra
n id
a e
C a
e sio
n id
a e
H o
lo c
e n
tr id
a e
M u
lli d
a e
H a
e m
u lid
a e
S c
a rid
a e
L u
tja n
id a
e S
ig a
n id
a e
S p
h y
ra e
n id
a e
C a
ra n
g id
a e
S y
n o
d o
n tid
a e
L e
th ri
n id
a e
S c
o m
b rid
a e
N e
m ip
te rid
a e
D e
sy a
tid a
e
P la
ty c
e p
h a
lid a
e
J u
m la
h i
n d
iv id
u
Family
Siompu Kadatua
Liwutongk idi
Target fish abundance as many as 442 individuals with the largest fish species was Pterocaesio tile from the family of Caesionidae, while indicator fish
as many as 115 individuals with the largest number from the species of Chaetodon kleinii
, the family of Chaetodontidae. The number of reef fish which are classified according to the groups from each island can be seen in Figure 13,
14 and 15.
Figure 14. Abundance of major fish group according to Family in Siompu, Liwutongkidi and Kadatua Islands
Figure 15. Group of Indicator Fish abundance according to Family in Siompu, Liwutongkidi and Kadatua Islands
100 200
300 400
500 600
700 800
900
Ju m
la h
i n
d iv
id u
Family
Siom pu Kadat ua
Liw ut ongkidi
The presence of reef fish resources is closely associated with the presence of coral reef resources as it’s habitat. In the area of coral reefs, reef
fishes are dominant organism and conspicuous organisms. With the large numbers and spread among coral reefs, it can be clearly see that the reef fishes are support
existing relationship in coral reef ecosystem Nybakken 1992. In general, the interaction between reef fish with its habitat contain three
main forms. First, the direct relation between reef structures and shelter area. It will be obviously seen on a small fish. Second, the food chain interaction that
involves some reef fish and sessile biota, including algae. Moreover, this interaction is important to the existence of coral reef specifically for providing
basic substrates. Third, there is the interaction of role involving reef structure and feeding behaviour of planktivore and carnivore that associated with coral.
Target fish was found as many as 1.625 individuals. Some target fish that often found at the study site were comes from the family of Acanthuridae,
Caesionidae, Mulidae, Serranidae, Lutjanidae and Lethrinidae. The target fish is a species of consumption fish that become targeted of local fishermen catch, this
fish group dominates the other two groups. The existence of target fish in coral reef ecosystem are for feeding, spawning and nursering. Major fish is a group of
fishes that are not included into the two groups above. The number of major fish were found as many as 3.899 individuals from the family of Pomacentridae. The
existence of this fish group is as one of food chain in ecological system and food web in coral reef ecosystem.
Reef fish will do various activities based on their habits and functions, which eventually form a pattern of balance that supports the existence of coral
reef ecosystems. This type of fish generally searched for food and lived in coral reef ecosystem by eating plankton, algae, or smaller animals that found in both the
water column or in the surface of the reef. Reef fishes that are often found at all observation stations were from the family of Pomacentridae, Chaetodontidae,
Pomachantidae, Acanthuridae, Labridae, Caesionidae, Balistidae, Lutjanidae, Balistidae, Serranidae, Siganidae, and Anthiinae. Furthermore, Allen and Steene
1994 said reef fish that mostly found in coral reef ecosystem are from the family of Pomacentridae, Labridae, Chaetodontidae, Pomacanthidae, Apogonidae.
The existing interaction explains the magnitude of relation between biological diversity and uniformity of reef fish with observation stations.
Pomacentridae has the largest weighting on the strong interaction at all stations, which is influenced by food preferences and feeding habit. Stations with large
cover of Dead Coral Algae are related with Caesio and Chromis fish abundance caused by feeding habit and the need of shelter, whereas Caesio fish eats plankton
and small fish. While Chromis fish is herbivore act as grazer which is algae feeder, so the growth of algae that compete with corals living space can be
controlled. Pomacentridae fish is spread almost evenly on the entire station with the largest number in Kadatua Island waters. The distribution of this fish is
influenced by the need for shelter, whereas reef structure at this station suitable as a shelter for Pomacentridae fish.
From observations of reef fish communities around Siompu, Liwutongkidi, and Kadatua Islands, diversity index was ranged from 2.71 to 4.72
that categorized as moderate to high diversity. Evenness index of reef fish was between 0.69 to 0.92 that categorized as high uniformity, while the dominance
index for several fish species have a range between 0.04 to 0.29 which showed that there was no dominancy of a certain species Figure 16.
Figure 16. diversity index H, species evenness E and dominance index C of reef fish communities in Siompu S, Liwutongkidi L and Kadatua
K Islands
0.00 0.50
1.00 1.50
2.00 2.50
3.00 3.50
4.00 4.50
5.00
Keanekaragam an H Keseragam an E
Dom inasi C
From the chart above, it can be seen that at station 4 of Siompu Island had a high diversity of reef fish, causing high species evenness in line with the
growth and development of reefs with high coral cover 71.00. Further, Nybaken 1992 stated that one of the causes of reef fish high diversity is due to
the variations found in the reef habitat. Coral reefs are not consist of live coral cover only, but there’s also a sandy area, a variety of bays and openings, the algae
coverage, and also the area of shallow-water in different zones across the reef. A wide diversity of habitats is highly favored by many species of reef fish.
Based on the above results, there is a positive relationship between the number of reef fish diversity found and coral reef condition in these waters. Such
condition makes reef fish become more balanced and there is no dominance of reef fish species. Fish preferences on particular habitat caused a gap between the
landscape of coral reefs. This refers to the function of the coral reef itself, so the differences among pattern of reef fish habitat are depend on the existing and form
of coral reef. Interaction that happened explain the magnitude of close relation between reef fish diversity and species evenness among observing stations.
Pomacentridae had the largest number with a strong interaction at all research station, which is influenced by food and feeding habit.
In general, reef fish will adapt to its environment. Each species shows habitat suitability that considered by the availability of food, shelter and variation
of physical parameter. A large number of species that found on coral reefs is a direct reflection of opportunity magnitude given by habitat Allen 2000.