Showing papers by "Neviaty P. Zamani published in 2019"

Practical Resilience Index for Coral Reef Assessment

Abstract: Assessing coral reef resilience is an increasingly important component of coral reef management. Existing coral reef resilience assessments are not practical, especially for developing countries. South-east Asian countries have been using line-intercept-transect (LIT) in coral reef monitoring for a long time. The present study proposes an index for assessing coral reef resilience based on data collected from the LIT method. The resilience index formula was modified from an existing resilience index for soil communities developed by Orwin and Wardle. We used an ideal resilient coral reef community as a reference point for the index. The ideal coral reef was defined from data collected from 1992 to 2009. Six variables were statistically selected for the resilience indicators: coral functional group (CFG), coral habitat quality (CHQ), sand-silt cover (SSC), coral cover (COC), coral small-size number (CSN), and algae-other-fauna (AOF) cover. Maximum values of five variables were determined as the best state, while the maximum value of CSN was determined from 1240 data-sets of Indonesian reefs. The resilience index performed well in relation to changes in COC, AOF, and SSC variables. Managers can use this tool to compare coral reef resilience levels among locations and times. This index would be applicable for global coral reef resilience assessment.

Distribution and abundance of the giant clams (Cardiidae: Bivalvia) on Kei Islands, Maluku, Indonesia

Abstract: . Triandiza T, Zamani NP, Madduppa H, Hernawan UE. 2019. Distribution and abundance of the giant clams (Cardiidae: Bivalvia) on Kei Islands, Maluku, Indonesia. Biodiversitas 20: 884-892. Giant clams, ecologically important bivalves in coral reefs, are under anthropogenic pressures in most parts of their range, necessitating the study of population status for conservation management. Here, we assessed species composition, distribution, size density, and habitat condition of giant clams in Kei Islands. A total of 9 reefs around the islands (Dar 1, Dar 2, Pulau Kur, Pulau Tanimbar Kei, Pulau Adranan, Pulau Dullah Laut, Difur, Labetawi, dan Ohoidertoom), were surveyed using quadrat-transect line in September-December 2017. We found five species of giant clams, i.e., Tridacna crocea, T. maxima, T. squamosa, T. noae, and Hippopus hippopus. Of these species, we report a new record for T. noae which was previously not known to be present in the region. The overall density was recorded at 0.0428 individual/m2. Juveniles clams were fewer than the adults clam, this may indicate that the survival rate of recruit is low. Most individuals were found living on dead coral algae substrate (75 %). Based on the findings, this study suggests that giant clam population in Kei Islands are imperiled, indicated by low population density and local extinction for species T. gigas and T. derasa. It is recommended to establish a protected area and restocking of giant clams by through implementing sasi laut (traditional law) with a minimum period of 5 years.

Larvae of the Coral Acropora tenuis (Dana 1846) settle under controlled light intensity

Abstract: Coral restoration using sexual reproduction could have many advantages over the currently more widely used asexual reproduction methods, in particular for maintaining genetic biodiversity. On-going research on controlled sexual reproduction of corals is seeking ways to achieve higher larval settlement and survival rates. Metamorphic settlement is a critical phase for the survival of coral larvae, due to morphological changes as well as threats of predation and competition. This study aimed to identify the effects of light intensity and substrate positioning on the metamorphosis of competent planula stage larvae. Five day old larvae of the Indo-Pacific coral Acropora tenuis (Dana 1846) were obtained from coral spawning under laboratory conditions. The light intensity experiments used 4 treatments: 170, 130, 90 and 45 μmol.m-2.s-1. Substrate positioning experiment treatments were vertical and horizontal orientations of the settlement plates. Coral larval settlement was not significantly correlated with light intensity, despite the higher settlement rates observed under light intensities between 130-170 μmol.m-2.s-1. The highest rate of settlement occurred on the ninth day post fertilisation and was significantly higher (α<0.05, df:2) than the rates on day seven and day eleven. The number of coral larvae settling on horizontal substrate was significantly higher compared to vertical plates, with a ratio of 11:1. This understanding of the factors affecting larval metamorphosis and settlement, in particular the importance of light intensity and substrate orientation, could be applied in the on-going efforts to mass produce juvenile corals for coral reef restoration.

Skreening Alga Hijau Halimeda opuntia (Linnaeus) sebagai Antioksidan dari Pesisir Aceh Barat

Abstract: H. opuntia is one of the green algae that distributes sufficiently dominant at the coastal of West Aceh. This research aims to screen the green algae H. opuntia that is potentia as an antioxidant agent. Extraction method in this research used mono maceration. The solvents that are used including ethanol (polar), ethyl acetate (semi-polar), and n-hexane (non-polar). With those three solvents it was obtained three crude extracts including ethanol crude extract, ethyl acetate crude extract, and n-hexane crude extract. Subsequently, the crude extracts were used to conduct the assay including phytochemical assay and the antioxidant activity with DPPH method. The results of phytochemical assay showed that ethanol crude extract of H. opuntia was detected to have active compounds including alkaloids, flavonoid, phenol, tannin, and steroids whereas ethyl acetate extract of H. opuntia was detected to contain phenol compound. Total phenol content of ethanolic extract of H. opuntia = 2460.25 mg GAE/g and ethyl acetate extract = 972.68 mg GAE/g. Antioxidant activity of ethanolic extract has IC50 value = 143.63 mg/L whereas ethyl acetate extract has IC50 value = 75.51 mg/L with Vitamin C as a positive control. This results show that extract of H. opuntia possesses a vital potency as an antioxidant agent that give value added in pharmacy industries.

MAXIMUM THERMAL TOLERANCE OF TROPICAL MARINE GASTROPODS, Haliotis squamata (Reeve 1846)

Abstract: Data mengenai toleransi suhu maksimum organisme laut dibutuhkan untuk mencegah kepunahan yang dikarenakan oleh pemanasan global. Tujuan dari penelitian kali ini adalah untuk mengetahui toleransi suhu maksimum dari Haliotis squamata. H. squamata ditempatkan di dalam wadah individual yang memiliki perlakuan suhu berbeda (27°C, 28,5°C, 30°C, 31,5°C, dan 33°C, n = 20). Suhu dinaikan 0,5°C setiap 12 jam. Mortalitas dihitung mulai dari setiap individu dipindahkan ke dalam wadah individual. Hasilnya memperlihatkan bahwa toleransi suhu maksimum H. squamata adalah 31,5°C dan 33°C sebagai suhu lethal yang merupakan level suhu dengan laju sintasan terendah (0,15). IPCC memprediksi kenaikan suhu permukaan laut hingga 4°C di abad mendatang, sedangkan rata-rata suhu permukaan laut di Indonesia saat ini adalah 26 – 31°C. Hal tersebut berarti bahwa di abad berikutnya rata-rata suhu permukaan laut Indonesia telah mencapai toleransi suhu maksimum dari H. squamata. Oleh karena itu, perlu dilakukan upaya konservasi dini dibutuhkan untuk melindungi keberlangsungan H. squamata.

The potency of Soft Coral Sarcophyton in Krakatau Seas as Cytotoxic Test

Abstract: Soft coral is one of the marine organisms that produce secondary metabolites materials and has potency as anticancer. There is much research to find bioactive compounds in the organism, but it still lacks data to find potency of bioactive in soft coral that lives under acidification pressure. The objectives of this study are to determine the characteristic of acidification in Krakatau seas and to assess the potency of cytotoxic activity from soft coral Sarcophyton . Sampling was conducted in three locations, Legon Tuo, Legon Cabe, and Umang-umang Island, to take the sample and measure water quality. Cytotoxic test using MTT method (3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolinon) to MCF-7 cancer cell line to measure growth inhibition percentage. Data were analyzed using ANOVA, post hoc analysis, and multivariate analysis. Water quality in Legon Tuo and Legon Cabe have significant different to Umang-umang Island. However, Legon Tuo and Legon Cabe are suitable as acidification site, while Umang-umang Island as the reference site. The characteristic of Krakatau seas, especially in Legon Tuo and Legon Cabe study site, was categorized in low acidification. In the cytotoxic activity, soft coral Sarcophyton from Legon Cabe (acidification site) is more potential than soft coral from Umang-umang Island (reference site).