THE CURRENT STATE OF ARTIFICIAL REEFS IN LEBAH COASTAL WATERS , KARANGASEM , BALI : AN EVALUATION ON THE COASTAL RESOURCE REHABILITATION PROJECT lsa

The study was conducted in May 2001 wlth aims to identifl and examine changes the biotic condition of coastal resources. The study used dual approaches of old and new data collections followed by statistical test of Wilcoxon Rank Sum Test.

of the basis of approval of the development permit, they must be checked.
During a chronological period of the artificial reef successions, there is an opportunity to study the ecosystem development in relation to the rehabilitation effort.This is not only timely but also important, as it can clearly indicate whether or not the ameliorating process will continue.This study is to response the absence of project monitoring and evaluation activities.lt focuses on an evaluation of the marine biota growth after ten years of implementing of the project.This study explored the following questions: what were the impacts of the process on the biotic conditions of the coastal waters?What were the appropriate indicators for this change?
The specific objectives of this study are to identify the biotic condition of coastal resources using selected indicators, including coral cover percentages, fish indicator species and fish reef diversity in vicinity of the artificial reefs and natural reefs.

Study Site
The coastal waters of Tukadse and Jemeluk that were the project affected areas (Figure 1), are placed 20 in Lebah Hamlet of Purwakerti Village under an administrative authority area of the Abang District of Karangangem County, eastern Bali.

Data Collection
Data collection was carried out in May 2001.A dual method approach was employed in the data collection such as on field measurement and secondary data uses.The latest was employed to comoile the initial data related to similar indicators.
The line intercepts transect method using a 50 m transect lengrth was conducted to determine natural coral reef condition, particularly the hard coral cover.
The method was used to assess the benthic community of reefs using lifeform categories, which provide a morphological description of the reef community.The categories were recorded on data sheets by divers who swam along lines, which were placed roughly parallel to the reef crest or fringing reefs at certain deoths of each selected site based on the initial study in 1991 or 1994.The method estimates the cover of an object or group of o$ects within a specified area by calculating the fraction of length of the line that is intercepted by the object (English et a|.,1994).
Likewise, individual colonies of benthic community growing on the artificial reefs were measured to determine percent cover and diversity by using a quadrate sampling method.
The data of reef fish was obtained by using the visual census on the line transect in conjunction with recording benthic lifeform on the reef.The fish population was divided into three groups showing their status as well as indicator species, major species, and target species (English et al., 1994).The indicator species are mostly of the family Chaetodontidae.The major species are either ornamental or non ornamental fishes that are usually found in coral reefs both as a resident and as a crosser.The target species are fishes that are caught for consumption and/or sale by fishers.

Data Analysis
The computed values of the reef fish and benthic community on the artificial reefs derived from the Shannon-Weaver Diversity Index calculation.Coral conditions were analyzed and categorized based on the criteria of coral sound referring to percentage of transects with coral cover of excellent >75o/oi good <75o/o->50o/o; fair <50->25%; and poor <25o/o (Chou, 1998).The LIFEFORM.EXE software recommended by the ASEAN-Australia Countries was used in the analysis of data.The software analyzed the fraction of length of the benthic or group of reef objects that were measured by the line intercept transect.Purwakerti Village map showing the study site and project location relative health and diversity of coral reefs.Base on lrian Jaya Reef Diversity Index (lRDl=Cr/41x100) established by Nash (1989) to compare the reef diversity condition to species indicator attenoance roughly, the species number of Chaetodont (Cx)

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presented at each study site can be an indication of local reef diversity condition.According to Nash (1989), a high position (75+) on a regionat trian uaya Reef Diversity Index scale suggests regions of exceptional overall species diversity and those rmpoftant for reef conservation and production of commercially desirable fish species.A low (30_) regional lrian Jaya Reef Diversity Index numDer suggests poor diversity, reflecting low hard coral diversity and its associated fauna or a depleted fauna as a result of harvesting or environmental damage.
Tentatively, individual reefs with an index of 45 or more could be considered very diverse, while an index oI 25 or less suggests poor biodiversitv.

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Sali lsland r_ lsa Nagib Edrus and Suprado The significantly changes of selected indicator as mentioned above between before and after the project implementation (1991 and 2001) were examined by using Wilcoxon Rank Sum Test for independent sampre.

Coral Cover Percentages
The pioneer organisms in the artificial reefs were many algae, sponges, bryozoans, tunicates' amphipods, sand shrimps, small crabs,..cnidarians,ascidians coralline algae and barnacles with a percent cover averag e of 21.52o/o, mean divers^ity index (H) of O.gOtO.22 and mean density per m' of 0'90t0'10 (Table 1).These lifeforms dominated the artificial ieefs in 1991.In 1994, there was a shift in the dominance of lifeforms, from the pioneer organisms to hard corals (acropore and non acropore) and other organisms with a percent cover average of 19.25.Possibly, the 1994 value was lower because of the absence of macro algae and the decrease in the population of sessile organisms.However, there was an increase in benthic community diversity (1.3610.14).lt is interesting to note that the absence of macro algae in 1994 was noticed not only in the artificial reefs, but also in the natural reefs.Some local fishers also noted the absence of macro algae in natural reefs.The absence of macro algae was possibly due to the effect of flooding and the consumption by schools of fish, as mentioned by the local fishers, or due to the displacement by other sessile organisms like coralline algae.The displacement of the macro algae by other sessile organisms can be considered as a part of the succession of species in the community.
According to a result of a study (Pusat penelitian dan Pengembangan Perikanan, 1993) in the early years of the artificial reef be observed, the major sessile organisms were dominated by macro algae (Potycarpa aurata and Virgulaia sp.) and barnacles (Batanus sp.) and then followed by Padina sp., Upuas, Eucema sp.A few hard corals started to grow with diameters of 0.5 to 8 cm and 1.4 to 6 cm length' These kinds included Favia sp., Porites sp., Goniopora sp., Monostrea sp., Acropora sp., Pocillopora sp., Sen'afopora sp., Tubastrea sp., and Diptoastrea sp.All of these organisms attracted other marine organisms to come in, such as crustaceans (ornamental shrimps and sand crabs), mollusks (Throchus, Cones, and Cyprae sp.), and echinoderms (Deadema sp. and Echinus escu/afus).This shows that the areas, originally cleaned out, became productive.
In 2001, an additional 9 new lifeforms were noted among the artificial reefs (Figue 2).In this year, more lifeforms were observed among the artificial reefs than 22 on the natural reefs (Table 1).The data show that the percent cover of the benthic community among the artificial reefs significantly increased from 21.52o/o in 1991 to 88.33% in 2001.The total coral cover in the artificial reefs and natural reefs are comparable to that of 2001 (Table 1).This implies that the diversity of organisms among the artificial reefs could approximate the diversity among natural reefs within a decade.
The benthic community diversity in the artificial reefs increased from 0.92 in 1991 to 1.36 in 1994 and to 1.95 in 2001.A Wilcoxon rank sum test (Table 2) that was used to analyze the benthic diversity indexes among the artificial reefs showed that there was a low significant difference (at level-9t q=O !5) for the diiersity between 1991 and 1994 and between 1994 and 2d01 as well.The low significant ditference indicated that changing in the diversity for the short time period (4 or 7 years) in the artificial reefs was not showh enough, because, as mentioned by Fucik et a/' (1984), recovery of coral reefs tends to be a long term process.According to Fucik ef al. (1984) and Rinkevich & Loya (1577), small scale localized destruction generally requires less than 10 years for recovery.Heavy destruction requires 10 to 20 years for full recovery.In line with this, the same test for this study showed a highly significant change in diversity indexes between 1991 and 2001 at level cr=0.025.lt means that rehabilitation efforts have generated positive impacts on marine organisms, as reflected in the high diversity and density of benthic community among the artificial reefs.
The increased lifeform diversity among the artificial reefs in 2001 brought about an increase in the density of the colony of benthic communities among the artificial reefs.The density increased from 0.75 in 1994 to 7.86 in 2001.Some additional colonies of acropores (ACT, ACE), non acropores (CE, CF' CMR' anci CME), turf algae, and soft coral that were observed among the artificial reefs in 2001 contributed to the increased density among the artificial reefs in 2001 (Table 1).Other contributions also were given by the growing of branching corals, macro algae' coralline algae, sponge, and other sessile organisms.
Although the artificial reefs had improved, the adjacent natural coral reefs were threatened due to anthropogenic activities and natural phenomena.The coral cover in Jemeluk Bay has been dwindling Table   The damage areas at Jemeluk Coastal water identified as a result of diver steps.
Usually, the phenomena of turf algae covered coral (standing but dead) is a result of anthropogenic activities such as sedimentation, cyanide fishing, blast fishing, dragging boat anchors, and natural factors such as starfish predation, storm waves, hurricanes, and El Nifro (Chou, 1998).There was also observed bleaching in the bay.The 1997 to 1998 El Niffo (elevated sea surface temperature) was believed to have been responsible for bleaching large areas of corals across the Indonesia seas, including Tulamban, Amed, Nusa Penida, and Nusa Lambongan, Bali (Brown & Suharsono, 1990;Chou, 1998;Jamani ef a/.,2000).
Reef Fish Diversity and Density Table 5 presents reef fish diversity indexes and density (number per m') in both artificial and natural reefs.Details in family, genus and species are presented in Table 6 and Appendix.The diversity index was used to evaluate the changes in fish population in the viclnity of the artificial reefs and to compare the diversity of fish population between the artificial reefs and natural reefs.
According to Kakimoto (1979), a trend of fish diversity in the vicinity of artificial reefs usually follows growth of attached organisms on the artificial reef.He observed that after 20 years, appearance of the artificial reefs changed due to high intensity of the groMhs of the attached organisms together with associated organisms that make the food chain or web in the artificial reefs.
The results of Wilcoxon rank sum test at level of cr=0.025 and 0.050 (Table 7) shows that fish diversity between 1991 and 1994 and between 1991 and 2001   in vicinity of the artificial reef was highly significant ditferent.The significant differences between the fish diversity in the artificial reefs between 1991 and 1994 as well as 1991 and 2001 could be due to the succession process in artificial reefs as mentioned by Kakimoto (1979).As succession proceed in the aftificial reefs, more benthic lifeforms that settle on the substrates attract more fish to come.Some of the lifeforms serve as food for the fish.The diversity of lifeforms in the artificial reefs increased from 0.90 in 1991 to 1.95 in 2001 (Table 1).This increase may lead to the increase in fish diversity.
The same test shows that there was no a significant difference of reef fish diversity between the artificial reefs and natural reefs in 2001.The relationship of fish diversity between the artificial reefs and natural reefs may be related to the observation that both have comoarable diversities.These comparative diversities mav have similar attracts.Between 1991 and 2001, the density of reef fish in the artificial reefs has considerably increased, from 0.87 in 1991 to 17.07 in 2001 (Table 5).Trend in reef fish density could be due to the on going succession process, as mentioned above.The increase in benthic community diversity led to the increase in fish density in the same years among the artificial reefs.Meanwhile, fish density was higher among artificial reefs than in natural reefs in 2001.Fish, particularly in schools, usually moved freely from one area to another, so that this result could also indicate that fish have a strong atfinity to artificial reefs that may lead to influx of fish from nearby natural reefs.Studies on behavior of fish in vicinity of artificial reefs placed around natural reefs showed that fish have an affinity for artificial reefs (Kakimoto, 1984).Possibly, the artificial reefs have additional sources of food and shelter.

Fish Indicator Species
The growing uses of the species indicator corresponding to coral soundness determination showed that it was a simple method in coral reef monitoring.lt is not only for experts, but also for non specialists.For example, the presence of Chaetodonts in coral reef water may reflect the relative health and diversity of hard coral (Nash, 1989).Chaetodonts are major noticeable polyp feeders among reef's ichthyofauna (Mackay, 1994).This species are easy to identify and to census individually because they have definite territories and they are often found in pairs.In addition, they are often employed as better measures for health of coral reefs (Rees, 1977).In general, low lrian Jaya Reef Diversity Index (below 35%) of Chaetodonts may indicate poor Table 7 diversity of hard cover (Nash, 1989).The idea to use Chaetodonts as indicator in determining the soundness of reefs was derived from a study conducted by Reese (1977).Reese (1977)  " Ho= Probability distribution of samples corresponding to the old measurement of fish diversity index (A) and new measurement of fish diversity index (B) are identical (There is no a significant change on the fish diversity during the definite years) H" = The probability distribution for B lies above (to the right of) to the A (There is a significant change on the fish diversity during the definite years) The succession process in terms of hard coral grovth on artificial reefs may be indicated by the abundance of chaetodont species.Table 8 shows the lRDl values in different years.Although the lRDl rates observed in different years were still very low as compared to the regional lrian Jaya Reef Diversity lndex scale, that is, 35%, there is an increasing trend in lrian Jaya Reef Diversity Index rates among all sites, particularly between 1991 and 2001 (Table 8).This suggests that their gradual increases are of great importance in evaluating a transient condition of hard coral growth.The increasing trend in lRDl rates from 1991 to 2001 follows the increasing trend in the diversity of hard coral cover among the artificial reefs.
Table 8 The lrian Jaya Reef Diversity Index of butterfly fish (Chaetodontidae) used to determine the Sites Sites rRDr (%) 4.9 7.3 2.4 2.4 7.3 4.9 4.9 29.3 22 14.6 14.6 9.8 34.2 Sources: Wasilun ef a/. (1991)Edrus ef a/. (1996) Primary data The relationshio between coral cover percentages and chaetodont diversity showed a high significant correlation at several studies (Edrus & Syam 1998;Hutomo et a/., 1985).These studies showed that the rising lrian Jaya Reef Diversity Index rates in all sites were related to the existing growth of hard coral, indicating a transient succession by artificial reef organisms to arrive at a 28 climax condition.Under this condition, the hard coral together with other reef fauna organisms would attain optimum groMh corresponding to the area of substrates available on the artificial reefs.Likewise, the Chaetodonts would settle in favorable areas and expect that their abundance and species number would grow in the future.In this study, there is still space for on going coral groMh.

CONCLUSION
The specific impacts of the rehabilitation effort on biotic oarameters of coastal resources that can be concluded address to the following major points: 1. Positive environmental changes in vicinity the artificial reefs enable to be a basic premise of success of the project in bringing about tangible impacts on the local coastal resources.
2. The major areas of biotic-parameter changes in vicinity of the artificial reefs include increases in coral percent cover, reef fish diversity and density, and chaetodontid abundance indexes.
3.    .$t$=Hir*$,s ,r, s 9.,fr.$g Figure 1.Purwakerti Village map showing the study site and project location Rank Sum Test for independent sample ci thi! artificial reefs benthic lifeform diversity index variables in different time Probability distribtttion of samples corresponding to the old measurement of benthic lifeform diversity index (A) and new measurement of benthic lifeform diversity index (B) are identical (There is no a significant change on the lifeform diversity during the definite years).H"= The probability distribution for B lies above (to the right of) to the A (There is a significant change on the lifeform diversity during the definite vears).

Table 3
Compariscn cf percent ccver of natural hard corals and their health conditions by different sites and years at Lebah coastal waters, Balr

Table 4
Percent covers of the coral reefs by different sites and years in Lebah Coastalwaters, Bali, noted that two kinds of polyp feeders(Chaetodon trifascillis and The statistical tests to above respective e $ E sFg$ FFgFFFF