Biodiversity of Associated Megabenthic Invertebrate of Corall Reef Ecosystem of Petong Island Batam Indonesia

Abstracts Global warming and climate changes were of the main environmental concern of marine scientist in the last three decade. As a biodiversity hotspot, marine coastal ecosystem faced an environmental threat because of increasing sea surface temperature (SST) and land base effluent, which in turn had an impact on the biodiversity of megabenthic faunal on coral reef community. The present paper studied the current condition of reef ecosystem as well as biodiversity of megabenthic community in Petong Island, a core zone of Batam Marine Management Area (BMMA), Riau Archipelago Province. Gradual changes of physical and chemical properties of seawater originated from coastal activities presumably has caused an effect on benthic faunal community structure. It revealed that benthic lifeform coral cover account for 30,53%, categorized into fairly good, whereas abiotic sand cover of 16,53%. The lifeform consists of Acropora (AC)1.73% and non-Acropora 28,80%. Death coral with algae (DCA) account for 40,40% and death corall (DC) 2,80%, Soft Corall (SC) 1,20%, fleshy seaweed (FS) 0,07%, other fauna (OT) 1,47%, and rubble (R) 7,00%. Apparently, only 4 of target species megabenthic fauna from eight, were eccounterred including; seaurchin (Diadema sp.), topshell (Drupella sp.), giant clam (Tridacna sp.), trochus (Trochus sp.), with density of each megabenthic fauna calculated 5929, 1857, 71 and 71 ind/ha, respectively. It appeared that sea urchin were the highest density and followed by topshell (Drupella sp). Sea urchin were noted as a bioindicator of reef ecosystem health. High density of sea urchin may indicate that reef in unhealthy state. The presence of Diadema Sitosum indicate that dead coral were present and it feed on algae growing in dead coral. High density of sea urchin may indicate that reef in unhealthy state

Feeding preference of herbivorous fish: Family Scaridae

Parrotfish is one of dominant species in Indo-Pacific areas which have 9 genera and 83 species. In ecological perspective, the feeding behaviours of these fish very important, due to control population of algae in coral reef ecosystem. They used their jaw to excavate and scrape alga which living on coral substrata, so sometime resulted on erosion in substrates and coral. The aim of this research to record the diet preference of Scariids fish in NCF Putri Menjangan conservation area, Bali on January to february 2020. Group of Scariids fish was recorded by underwater camera for one minute then the bites scared were calculated manually and photographed. The result of study showed that 10 species from two genera (Chlorurus and Scarus) was dominantly herbivorous fish in this area. The highest number of fish bites at station 1 was obtained from S. qouyi species with a total of 41.27 bpm, while stations 2 and 3 were obtained from S. rivulatus species with a number of 40.96 bpm and 41.59 bpm, respectively. The majority of parrotfish species found chose to forage on dead coral with algae substrates because the water conditions were not optimal for the growth of coral, so many corals died and their skeletons were overgrown by algae.

Status Terkini Tutupan Terumbu Karang di Perairan Dangkal Pulau Bedil, Desa Labuan Bajo, Kabupaten Sumbawa, NTB

Bedil Island is included in the Keramat, Bedil, and Temudong Small Island Park (TPK), which was approved by the Regent of Sumbawa. Administratively, this island is included in the Labuan Bajo Village area, Sumbawa, NTB. There is the existence of coral reef ecosystems in these waters that form a reef flat and reef slope profile, that stretches to the southwest and northeast. By its designation as a small island park, the coral reefs in Bedil Island are used as an underwater tourism object. This study aims to determine the current condition of coral reef cover in the waters around Bedil Island, especially in the eastern and southern parts of the island. Coral reefs in the north and west area are limited and there is the existence of seagrass beds. The line intercept transect method is carried out by spreading the roll meter as far as 50 meters on the east and south sides of the island with a depth of 2-3 meters. The coral lifeform that is tangent with the roll meter is then recorded and then analyzed for the average percent cover, clustering status, and coral mortality index. Coral reefs in the eastern and southern parts of Bedil Island are classified as very good/excellent because they have a percent cover value above 75%. In addition, the coral mortality index value is also relatively small which indicates that the corals are living well. Clearwater conditions and locations far from human settlements are thought to be factors that support coral survival. However, the presence of dead coral algae and rubble still indicates a threat of damage even though the value is small. Algae life on the surface of dead coral also indicates that the coral has been dead for a long time.

Ascidians Outbreak: A Threat For Coral Reefs in Panjang Island, Jepara

Eutrophication and sedimentation have become a major threat to coral reefs in nearby areas with anthropogenic activities. These threats are often accompanied by shifting ecosystems from coral-rich to fast-growing algae-dominated water, and high prevalence of coral disease. In Panjang Island, Jepara, we observed the outbreak of photosynthetic ascidians along with a high sedimentation at the eastern part of the island. The ascidians were seen overgrowing most substrates including corals, macroalgae, dead-coral-algae, and rubbles in April to May 2019. In July and August 2019, observation and data collection using quadrant transect were conducted to monitor the outbreak. The result showed that ascidians were still present in the area, despite becoming pale and smaller. This report shows that the outbreak of these photosynthetic ascidians was not persistent, however, the effect on coral reef health should not be overlooked.

KOMPARASI POLA SPASIAL KONDISI TERUMBU KARANG TAMAN NASIONAL KARIMUNJAWA

ABSTRACTComparative studies on the percentage of coral reef substrate cover have been carried out in 3 (three) management zones (protection zone, utilization and Non-MPA) Karimunjawa National Park (KNP). The Manta Tow broadscale coral reef assessment method was applied to the north side of Bengkoang Island and the south side of Cemara Besar Island (protection zone), southern side of Bengkoang Island and northern side of Cemara Besar Island (utilization zone) and Non-MPA (Seruni Island) to observe live coral cover, dead coral, coral rubble and soft coral. Substrate cover variations from 10-12 towing (track length 200m) from each side of the island have formed a spatial pattern of coral reef conditions. Furthermore, the condition of the coral reefs was confirmed using the UPT (Underwater Photo Transect) detailed assessment method with one station on each side of the island. The results showed that there were differences in the spatial pattern of coral reef conditions as indicated by significant differences in the percentage of live coral cover, dead coral, rubble and coral lifeform among management zones of the KNP. The condition of coral reefs of the MPA is better and has a higher diversity of coral species than Non-MPA of the Karimunjawa National Park. The spatial pattern of coral reef conditions can be used as an indicator of disturbances in the coral reef ecosystem and can be used for periodic analysis of coral reef monitoring data in conservation areas.Keywords: spatial pattern, coral reef condition, manta tow, underwater photo transect, Karimunjawa National Park.ABSTRAKStudi perbandingan persentase tutupan substrat terumbu karang telah di lakukan pada 3 (tiga) zona pengelolaan (zona perlindungan, pemanfaatan dan luar kawasan) Taman Nasional Karimunjawa. Metode penilaian terumbu karang skala luas Manta Tow diaplikasikan di sisi utara P. Bengkoang dan sisi selatan P. Cemara Besar (zona perlindungan), sisi selatan P. Bengkoang dan sisi utara P. Cemara Besar (zona pemanfaatan) dan luar kawasan (P. Seruni) untuk mengamati tutupan karang hidup, karang mati, pecahan karang dan karang lunak. Variasi persentase tutupan substrat dari 10-12 tarikan Manta Tow (panjang lintasan 200m) dari masing-masing sisi pulau telah membentuk pola spasial kondisi terumbu karang. Selanjutnya penilaian kondisi terumbu karang dikonfirmasi dengan menggunakan metode penilaian rinci UPT (Underwater Photo Transect) dengan satu stasiun setiap sisi pulau. Hasil menunjukkan terdapat perbedaan pola spasial kondisi terumbu karang yang ditunjukkan oleh perbedaan yang signifikan persentase tutupan karang hidup, karang mati, pecahan karang dan lifeform karang antar zona pengelolaan. Kondisi terumbu karang di dalam kawasan lebih baik dan memiliki keragaman jenis karang lebih tinggi daripada di luar kawasan Taman Nasional Karimunjawa. Pola spasial kondisi terumbu karang dapat dijadikan indikator terjadinya gangguan pada ekosistem terumbu karang di suatu kawasan dan dapat digunakan untuk analisis data pemantauan terumbu karang secara berkala di kawasan konservasi.Kata Kunci: pola pasial, kondisi terumbu karang, manta tow, underwater photo transect, Taman Nasional Karimunjawa,

Using the Goldilocks Principle to model coral ecosystem engineering

The occurrence and proliferation of reef-forming corals is of vast importance in terms of the biodiversity they support and the ecosystem services they provide. The complex three-dimensional structures engineered by corals are comprised of both live and dead coral, and the function, growth and stability of these systems will depend on the ratio of both. To model how the ratio of live : dead coral may change, the ‘Goldilocks Principle’ can be used, where organisms will only flourish if conditions are ‘just right’. With data from particle imaging velocimetry and numerical smooth particle hydrodynamic modelling with two simple rules, we demonstrate how this principle can be applied to a model reef system, and how corals are effectively optimizing their own local flow requirements through habitat engineering. Building on advances here, these approaches can be used in conjunction with numerical modelling to investigate the growth and mortality of biodiversity supporting framework in present-day and future coral reef structures.

CORAL REEFS ON INHABITED AND UNINHABITED SMALL ISLANDS, SPERMONDE ARCHIPELAGO, INDONESIA

The small islands in Indonesia is providing important ecosystem services. It is important to identify damages of a coral reef ecosystem and whether natural factors or anthropogenic factors are the main causes. Landsat images obtained with different sensors were analyzed for mapping coral reef on inhabited and uninhabited small islands, Spermonde archipelago, Indonesia. Overall accuracies of three habitats classification were 89.2% and 85.6%, respectively. They are live coral, dead coral and non-coral. Ground truth surveys were selected by using the unsupervised classification method The live coral in inhabited islands was slightly greater than in uninhabited. An increasing area of live coral was about 5.3 ha of the total area in 1990 per year while a decreasing of dead coral was 3.5 ha per year in inhabited islands. In uninhabited island, a decreasing speed of live coral habitat area was about 0.6 per year. During 29 years, a significant increase in the dead coral and decrease in live corals. It has been identified that the significant controlling factor for the disturbances in reef ecosystem is derived from natural and anthropogenic.

KONDISI EKOSISTEM TERUMBU KARANG DI PERAIRAN KRUENG RAYA, KABUPATEN ACEH BESAR

This study aims to analyze the condition of the coral reef ecosystem including the substrate, genus composition, and the level of coral mortality in the waters of the Malacca Strait, Masjid Raya District, Aceh Besar District. The research was conducted from October 2016 to October 2019 in the waters of the Malacca Strait, Masjid Raya District, Aceh Besar District. The research site is divided into three stations consisting of Lhok Mee Station, Ahmad Rhang Manyang and Benteng Inong Balee Station. Data were collected using the Point Intercept Transect method. The results showed that the condition of coral reefs at Lhok Mee Station was in the damaged category with coral cover ranging from 6.56% - 13.44%. Ahmad Rhang Manyang Station is included in the moderate to good category with coral cover ranging from 38.75% - 67.19%. Meanwhile, Benteng Inong Balee Station is included in the medium category with coral cover ranging from 45.94% - 56.88%. The monitoring results found that 30 coral genera with the highest composition of the coral genera came from the Porites genus, while other coral genera were unevenly distributed. The value of the mortality index for Lhok Mee Station shows a high increase in mortality of live coral to dead coral. Meanwhile, Ahmad Rhang Manyang and Benteng Inong Balee stations have low coral mortality index values.