52 research outputs found

    Increasing Carbon Dioxide Concentration and Temperature on Growth and Histopathology of Tropic Macroalgae Halimeda SP

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    The increasing CO2 concentration and temperature affected growth, chlorophyll content, calcium content, and histological tissue of tropical macroalgae Halimeda sp. The study was conducted to examine the interaction effect of the increased CO2 concentration and temperature on growth, chlorophyll-a content, calcium content, and histological tissue of tropical macroalgae Halimeda sp in a laboratory. Research was set with a completely randomized factorial design at 3 levels of factors (A) the CO2 concentration: 385 ppm (ambient), 750 ppm (medium), 1000 ppm (high), and 3 levels of factor (B) the temperature: 30oC, 32oC, 34oC. Microcolony of macroalgae Halimeda sp were selected and obtained from the Lae-lae island then growing in the aquarium 30 x 30 x 45 cm3. Biological parameters observed were growth rate (total, specific and relative), chlorophyll-a content, calcium content, and histopathology tissue. The results showed that the increased of CO2 concentration and temperature negatively affected on the growth of Halimeda sp, reduced of the growth rate, the chlorophyll-a content, calcium content and damaged to histopatology tissue of the Halimeda sp at trophical macroalgae

    Bakteri Assosiasi Di Karang Batu (Skleractinian) Yang Terinfeksi Penyakit Tumor (Growth Anomalies) Yang Berasal Dari Pulau Salemo Kabupaten Pangkep

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    Coral disease is one of the threats to the health of coral but is not yet widely known. This study was conducted todetermine the types of bacterial associations in hard corals infected with growth anomaly (GA). Coral samplesinfected with GA disease were taken by using SCUBA tool on Salemo Island, Mattiro Bombang Village, PangkepDistrict. Bacterial isolation was performed by removing mucus from corals infected by growth anomaly by 1ml and diluted to dilution 10-3 . Purification of bacteria is done by inoculating the solid medium of Marine Agar.Furthermore, Gram staining and biochemical tests were performed. Bacterial identification was performed basedon colony morphology and biochemical reaction test results. The results showed that GA disease can infectcoral Porites, Acropora digitate, Platygyra and pocillopora . Bacteria are found from the genus Flavobacterium,Acinetobacter and, Neiseria

    Pemetaan Spasio-temporal Ikan-ikan Herbivora di Kepulauan Spermonde, Sulawesi Selatan [Spatio-temporal Mapping Of Herbivorous Fishes At Spermonde Islands, South Sulawesi]

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    Ikan herbivora di terumbu karang menjadi salah satu indikator tingkat kesehatan ekosistem. Pada terumbu karang yang sehat biasanya ditandai dengan kelimpahan ikan herbivora yang tinggi. Penelitian ini bertujuan untuk memetakan distribusi spasial dan temporal ikan herbivora dalam kaitannya dengan kondisi kesehatan karang. Pendataan jumlah jenis dan kepadatan ikan herbivora dengan metode transek sabuk dan pencacahan dengan teknik visual sensus, sedangkan penilaian kesehatan karang dengan metode transek kuadran. Data sebaran diplot dengan teknik pemetaan sedangkan data kepadatan dikelompokkan berdasarkan pulau dan dianalisis perbedaannya dengan analisis ragam. Hubungan antara kepadatan ikan herbivora dengan kesehatan karang dilakukan dengan menggunakan regresi sederhana. Hasil penelitian menunjukkan rata-rata kepadatan ikan herbivora periode April-Agustus dengan kisaran 0,014-0,532 ekor.m-2. Hasil analisis ragam menunjukkan bahwa ada perbedaan kepadatan ikan herbivora antarpulau. Hubungan antara kepadatan ikan herbivora dengan kondisi kesehatan karang berkorelasi positif dan nyat

    High temporal resolution sampling reveals reef fish settlement is highly clustered

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    Coral reef fish larvae settle on reefs predominantly at night around the new-moon phase, after an early developmental period spent in the pelagic environment. Most sampling is conducted across whole nights, and any studies that have examined the frequency of arrival within nights have typically been limited to coarse sampling time scales of 1–5 h. Here, we present results for arrival numbers of fish caught between dusk and midnight from light traps sampled every 15 min at an Indonesian coral reef, providing the finest temporal resolution for this type of study to date. A spatial analysis by distance indices analysis, adapted to temporal data, revealed clustering of reef arrival times for many species, with an increase in catches immediately after dusk dropping off towards midnight. Importantly, the timing of clusters differed among species, indicating that different factors determine the timing of arrival among taxa. Our results support the hypothesis that larval behaviour influences the timing of arrival at a coral reef for different fish species

    Citizen science in data and resource-limited areas: A tool to detect long-term ecosystem changes

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    Coral reefs are threatened by numerous global and local stressors. In the face of predicted large-scale coral degradation over the coming decades, the importance of long-term monitoring of stress-induced ecosystem changes has been widely recognised. In areas where sustained funding is unavailable, citizen science monitoring has the potential to be a powerful alternative to conventional monitoring programmes. In this study we used data collected by volunteers in Southeast Sulawesi (Indonesia), to demonstrate the potential of marine citizen science programmes to provide scientifically sound information necessary for detecting ecosystem changes in areas where no alternative data are available. Data were collected annually between 2002 and 2012 and consisted of percent benthic biotic and abiotic cover and fish counts. Analyses revealed long-term coral reef ecosystem change. We observed a continuous decline of hard coral, which in turn had a significant effect on the associated fishes, at community, family and species levels. We provide evidence of the importance of marine citizen science programmes in detecting long-term ecosystem change as an effective way of delivering conservation data to local government and national agencies. This is particularly true for areas where funding for monitoring is unavailable, resulting in an absence of ecological data. For citizen science data to contribute to ecological monitoring and local decision-making, the data collection protocols need to adhere to sound scientific standards, and protocols for data evaluation need to be available to local stakeholders. Here, we describe the monitoring design, data treatment and statistical analyses to be used as potential guidelines in future marine citizen science projects

    Keberhasilan Rehabilitasi Terumbu Karang Akibat Peristiwa Bleaching Tahun 2016 dengan Teknik Transplantasi

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    The purpose of this study was to analyze the succesfullnes use of two coral reef transplantation methods in the rehabilitation ofcoral reefs damaged by the phenomenon of bleaching in 2016 at the waters of Liukangloe Island, Bulukumba, South Sulawesi.In this study two methods were implemented, i.e. methods frame-spider and methods of nails-natural substrates, with 5 unitsas replication, respectively. A total of three kinds of branching corals weretransplanted, namely Acropora robusta, Poritescylindrica, and Pocillopora verrucosa. On each unit transplantation models, attached 6 coral fragments with branch length of5-12 cm for each kind of corals. A total of 3 fragments for each species of corals were labeled and coded for the survival rateand absolute growth monitoring. All five unit of experiments on each model are placed on two areas separately and placedrandomly with depths ranging from 3-4 m in the northern part of island. Observations survival rate and absolute growth of coraltransplant were conducted for every 2 weeks for 28 days by counting the dead coral fragment or missing and measure the lengthof transplant coral branch with a measuring ruler. The effectiveness of the two methods was analyzed based on the survival andgrowth of the absolute value of coral transplant. Survival rate were analyzed descriptively and the average values of absolutegrowth were analyzed by t-student. The use of frame-spider methods and methods of nails-natural substrates as effective inrehabilitating the coral reefs from bleaching phenomenon based on the parameters of survival and growth of Acropora robusta,Porites cylindrica, and Pocillopora verrucos

    Spongivory in the Wakatobi Marine National Park, Southeast Sulawesi, Indonesia

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    Sponges are functionally important coral reef fauna and there is strong evidence from the Caribbean that predation has important impacts on sponge-Assemblage dynamics; whether the same is true for Indo-Pacific sponges remains unknown. As a first step toward understanding the potential effects of spongivores on sponge diversity and abundance, we identified sponge predators at nine sites in Wakatobi Marine National Park, Indonesia, and conducted a short-Term caging experiment to examine the effects of excluding predators on noncryptic reef sponges at this location. Nudibranchs were the most abundant invertebrate spongivores, although their low densities are likely to limit their influence on sponges. Fish were the most abundant vertebrate spongivores with 16 species from six families observed feeding on sponges. Based on their abundance and our feeding observations, the fish with the greatest potential to influence sponge assemblages in Wakatobi Marine National Park were Zanclus cornutus, Chaetodon kleinii, Pygoplites diacanthus, and Pomacanthus sexstriatus. We did not detect an effect of excluding spongivores on noncryptic reef sponge abundance in our caging experiment, which may be due to these species having evolved chemical defenses against predators. Important areas for further research include the chemical ecology of Indo-Pacific sponges and whether spongivory currently restricts some species to cryptic or nonreef habitats

    HydroMoth: Testing a prototype low‐cost acoustic recorder for aquatic environments

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    Passive acoustic monitoring (PAM) involves recording the sounds of animals and environments for research and conservation. PAM is used in a range of contexts across terrestrial, marine and freshwater environments. However, financial constraints limit applications within aquatic environments; these costs include the high cost of submersible acoustic recorders. We quantify this financial constraint using a systematic literature review of all ecoacoustic studies published in 2020, demonstrating that commercially available autonomous underwater recording units are, on average, five times more expensive than their terrestrial equivalents. This pattern is more extreme at the low end of the price range; the cheapest available aquatic autonomous units are over 40 times more expensive than their terrestrial counterparts. Following this, we test a prototype low-cost, low-specification aquatic recorder called the ‘HydroMoth’: this device is a modified version of a widely used terrestrial recorder (AudioMoth), altered to include a waterproof case and customisable gain settings suitable for a range of aquatic applications. We test the performance of the HydroMoth in both aquaria and field conditions, recording artificial and natural sounds, and comparing outputs with identical recordings taken with commercially available hydrophones. Although the signal-to-noise ratio and the recording quality of HydroMoths are lower than commercially available hydrophones, the recordings with HydroMoths still allow for the identification of different fish and marine mammal species, as well as the calculation of ecoacoustic indices for ecosystem monitoring. Finally, we outline the potential applications of low-cost, low-specification underwater sound recorders for bioacoustic studies, discuss their likely limitations, and present important considerations of which users should be aware. Several performance limitations and a lack of professional technical support mean that low-cost devices cannot meet the requirements of all PAM applications. Despite these limitations, however, HydroMoth facilitates underwater recording at a fraction of the price of existing hydrophones, creating exciting potential for diverse involvement in aquatic bioacoustics worldwide
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