Kondisi Terkini Presentase Tutupan Terumbu Pada Masa Pandemi Covid-19 di Gili Air, Taman Wisata Perairan Gili Matra, Nusa Tenggara Barat

Gili Matra Aquatic Tourism Park has two conservation targets, namely biological targets and social, cultural and economic targets. Coral reef ecosystems, apart from being a conservation target, are also an attraction for tourists to visit. This research was conducted to determine the condition of the coral reef ecosystem to be used as the basis for the management of conservation areas. The research was conducted by collecting coral reef data either through surveys or secondary data from the results of previous studies. Coral reef survey using the standard Line Intercept Transect method. The survey results show that the condition of coral reefs in the utilization zone is better than the core zone. Live coral cover in the utilization zone reached 71% so it was categorized as good, while in the core zone it only reached 8% so it was categorized as bad. Coral reefs in the core zone are unable to recover even though the number of tourists has decreased during the Covid-19 pandemic. Therefore, the location of the core zone on Gili Air needs to be evaluated further so that the effectiveness of Gili Matra TWP management can be improved. Key words: coral reefs; Gili Matra; Conservation

Current Ecological Status of Remote Coral Reefs of Clipperton Island, Tropical Eastern Pacific

Clipperton, an uninhabited and remote coral atoll from the Eastern Pacific, is an important steppingstone area that harbors a high marine biodiversity. Despite its biogeographic importance, little information on the ecological status of its coral reefs is available from the last decade. Herein, we characterized the benthic coral community and health status among four different shallow reef-zones (North to South) of Clipperton during the Tara Pacific expedition in 2018. The benthic composition and coverage percentage, as well as occurrence of a pink-spotted coral phenotype (trematodiasis infection) was assessed. Total live coral cover on Clipperton reefs was 66% (55-85%), differing between sites, with massive Porites and branching Pocillopora corals dominating the benthic community with an average 48% (32-66%), and 15% (3-21%), respectively. While Clipperton reefs exhibited significant live coral cover overall, the trematode infection was commonly observed, with a higher occurrence in massive corals (Porites 27%, and Pavona 31%). This observation is possibly related to the combined effects of previously heatwaves, and local inputs of guano-derived nutrients discharged during storms and hurricanes. These results demonstrates that even highly remote reefs supporting high coral cover can be subjected to local and global threats, including but not limited to parasite prevalence, likely in relation to natural disturbances such as thermal stress and tropical cyclones.

Benthic habitat mapping using Object-Based Image Analysis (OBIA) on Tidung Island, Kepulauan Seribu, DKI Jakarta

Tidung Island is one of the islands in Kepulauan Seribu, DKI Jakarta, Indonesia. This island has various benthic that live on the coastal areas, and benthic habitat has various functions both ecologically and economically. Nowadays, remote sensing technology is one way to detect benthic habitats in coastal areas. Mapping benthic habitat is essential for sustainable coastal resource management and to predict the distribution of benthic organisms. This study aims to map the benthic habitats using the object-based image analysis (OBIA) and calculate the accuracy of benthic habitat classification results in Tidung Island, Kepulauan Seribu, DKI Jakarta. The field data were collected on June 2021, and the image data used is satellite Sentinel-2 imagery acquired in June 2021. The result shows that the benthic habitat classification was produced in 4 classes: seagrass, rubble, sand, and live coral. The accuracy test result obtained an overall accuracy (OA) of 74.29% at the optimum value of the MRS segmentation scale 15;0,1;0.7 with the SVM algorithm. The results of benthic habitat classification show that the Seagrass class dominates the shallow water area at the research site with an area of 118.77 ha followed by Life Coral 104.809 ha, Sand 43.352 ha, and the smallest area is the Rubble class of 42.28 Ha.

Characterizing the spatial distribution of coral reefs in the South-Central Coast region of Viet Nam using Planetscope imagery

This study aims to understand the spatial distribution of coral reefs in the central region of Viet Nam. We classified live coral cover in Son Tra Peninsula (ST) and Cu Lao Cham Island (CLC) in the South-Central Coast Region of Viet Nam using the Maximum Likelihood Classifier on 3 m Planetscope imagery. Confusion matrices and the accuracy of the classifier were assessed using field data (1,543 and 1,560 photographs in ST and CLC, respectively). The results showed that the reef’s width ranged from 30 to 300 m across the study site, and we were able to detect live coral cover across a depth gradient of 2 to 6 m below the sea surface. The overall accuracies of the classifier (the Kappa coefficient) were 76.78% (0.76) and 78.08% (0.78) for ST and CLC, respectively. We found that 60.25% of coral reefs in ST were unhealthy and the live coral cover was less than 50%, while 25.75% and 11.46% of those in CLC were in good and excellent conditions, respectively. This study demonstrates the feasibility of utilizing Planetscope imagery to monitor shallow coral reefs of small islands at a high spatial resolution of 3 m. The results of this study provide valuable information for coral reef protection and conservation.

An assessment of small islands coral cover and coral-reef fish diversity at Oba Sub-district, Halmahera Island

Study on the percentage of coral cover four small islands of Oba Sub-district, Halmahera Island of North Maluku Utara Province was carried out in April 2021.The four small islands of Oba Sub-district studied are Woda Island, Raja Island, Tamin Island, and Guratu Island. The study applied systematic sampling method that included collecting coral reef data using UPT (Underwater Photo Transect) method and coral fish data collection using visual census method. Study results showed that live coral coverage of reefs on the four small islands of Oba Sub-district had the highest value of 5.415% and the lowest value of 4.29%. There was positive relationship between coral growth form diversity and fish diversity. High diversity of coral growth forms was significantly related to high diversity of target reef fish.

Wave exposure shapes reef community composition and recovery trajectories at a remote coral atoll

In a time of unprecedented ecological change, understanding natural biophysical relationships between reef resilience and physical drivers is of increasing importance. This study evaluates how wave forcing structures coral reef benthic community composition and recovery trajectories after the major 2015/2016 bleaching event in the remote Chagos Archipelago, Indian Ocean. Benthic cover and substrate rugosity were quantified from digital imagery at 23 fore reef sites around a small coral atoll (Salomon) in 2020 and compared to data from a similar survey in 2006 and opportunistic surveys in intermediate years. Cluster analysis and principal component analysis show strong separation of community composition between exposed (modelled wave exposure > 1000 J m−3) and sheltered sites (< 1000 J m−3) in 2020. This difference is driven by relatively high cover of Porites sp., other massive corals, encrusting corals, soft corals, rubble and dead table corals at sheltered sites versus high cover of pavement and sponges at exposed sites. Total coral cover and rugosity were also higher at sheltered sites. Adding data from previous years shows benthic community shifts from distinct exposure-driven assemblages and high live coral cover in 2006 towards bare pavement, dead Acropora tables and rubble after the 2015/2016 bleaching event. The subsequent recovery trajectories at sheltered and exposed sites are surprisingly parallel and lead communities towards their respective pre-bleaching communities. These results demonstrate that in the absence of human stressors, community patterns on fore reefs are strongly controlled by wave exposure, even during and after widespread coral loss from bleaching events.

Image Analysis to Quantify Coral Bleaching Using Greyscale Model v1

This protocol outlines a method of quantitatively measuring the degree of bleaching of a coral colony non-destructively in the field using image analysis. Previous studies have shown that mean intensity grey (MIG), also known as percent whiteness, is highly correlated with chlorophyll a and Symbiodiniaceae density (Chow et al. 2016, Amid et al. 2018), and therefore can be used to quantify the bleaching intensity of a coral colony. Color analysis can be done using digital photographs of live coral colonies either in situ (e.g., Maguire et al. 2003) or ex-situ in the lab (Amid et al. 2018; this protocol). Photographs must be taken prior to any preservation or processing of tissue, such as freezing, use of preservatives or fixatives, airbrushing etc., to ensure no alteration of the original coral color occurs. In this protocol, corals are photographed in front of a white reference standard and the resulting color images are subsequently converted to 8-bit greyscale and analyzed. There are two steps to this protocol: 1) Photographing live coral fragments 2) Image analysis of mean grey value This protocol was written by Dr. Rowan McLachlan and was reviewed by Dr. Andréa Grottoli. Acknowledgments I would like to thank Dr. Eugene Katrukha for kindly taking the time to teach me this method, and providing me feedback on how to produce higher quality images for analysis.

Tutupan Terumbu Karang pada Kedalaman Berbeda di Perairan Pantai Batu Sungu, Desa Les, Kabupaten Buleleng

Bali island has many magnificent underwater coral reef gardens that attract tourists. Besides Pemuteran and Menjangan island waters, Batu Sungu water has also potential to be a new tourist destination. Thus, to determine the potency and management plan in Batu Sungu waters, this research aimed to examine the overall coral cover, coral growth forms, other benthic forms, and each of their components in 5 and 10 m depths. The overall coral cover, coral growth forms, other benthic forms, and each of their components were counted by using the Line Intercept Transect (LIT) method. Before collecting data, study sites were observed by using the Manta Tow method. Data were collected in 2 depths (5 dan 10 m) with 5 sites each (replicates) that separates within 50 to 150 m. A 25 m LIT was spread parallel to the coastline above the reefs. Live coral colonies, other benthic forms below the transects were measured for the number, length, and growth forms. Water quality was measured in situ (temperature, current, and clarity) and ex situ (pH). Results showed that the category of coral coverage in Batu Sungu water is "good” in 5 m and "moderate” in 10 m whereas there was no significant difference among each component of the overall coral cover. The most dominant coral growth form among the 2 depths was Coral Massive whereas significantly abundant in 5 m. Moreover, the number of Coral Foliose was found significantly high in the same depth. Other coral growth forms were relatively similar in numbers in two depths. As likewise, the cover of other benthic forms and its component were not significantly different among two depths, except Dead Coral with Algae which significantly plentiful in 5 m. Sand was dominantly found in two depths with no significant difference. Furthermore, Coraline Alga was only observed in 5 m, however, there were no Macroalga and Alga Assemblages found at this depth. It is assumed that the similarity number of the overall coral cover, coral growth forms, other benthic forms, and each of their components is related to the alikeness of water quality among the two depths.

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,

Field measurements of a massive Porites coral at Goolboodi (Orpheus Island), Great Barrier Reef

An exceptionally large coral Porites sp. has been identified and measured at Goolboodi (Orpheus Island), Great Barrier Reef (GBR). This coral was measured in March 2021 during citizen science research of coral reefs in the Palm Islands group. We conducted a literature review and consulted scientists to compare the size, age and health of the Porites with others in the GBR and internationally. This is the largest diameter Porites coral measured by scientists and the sixth highest coral measured in the GBR. The health of the Porites was assessed as very good with over 70% live coral cover and minor percentages of sponge, live coral rock and macroalgae. An estimated age of 421–438 years was calculated based on linear growth models. Manbarra Traditional Owners were consulted and suggested that the Porites be named Muga dhambi (big coral) to communicate traditional knowledge, language and culture to indigenous, tourists, scientists and students.