Differential Affinities of a Pocillopora damicornis Galectin to Five Genera of Symbiodiniaceae at Different Temperatures

The symbiosis of coral-Symbiodiniaceae is the quintessential basis of the coral reef ecosystem, and its breakdown results in coral bleaching, one of the most severe ecological catastrophes in the ocean. Critical to the establishment of the symbiosis is the host’s specific recognition of the symbionts through the binding of the coral host’s pattern recognition receptors (PRRs) to the symbiont cell surface’s glycoconjugates. However, the molecular basis for this recognition process is poorly understood. The present study investigated the binding affinities of the coral galectin PdGLT-1 to different symbiodiniacean species under different temperatures. At 25°C, the PdGLT-1 recombinant protein (rPdGLT-1) exhibited different binding affinities to different symbiodiniacean species from five genera, with a significantly higher binding affinity (p < 0.05) to Fugacium kawagutii (2.6-fold) and Cladocopium goreaui (1.9-fold) than Symbiodinium microadriaticum. The binding topology of rPdGLT-1 differed among the five symbiodiniacean species; for S. microadriaticum, Breviolum minutum, and Durusdinium trenchii, the binding was on some specific sites on the cell surface, whereas for C. goreaui and F. kawagutii, the binding signals were detected over the whole cell surface. Interestingly, PdGLT-1 binding induced agglutination of F. kawagutii cells but not of C. goreaui, explaining why C. goreaui was the most dominant symbiodiniacean symbionts in corals. Moreover, the affinity of rPdGLT-1 to Symbiodiniaceae was affected by temperature, and the highest binding affinities were observed at 30, 20, 30, 35, and 30°C for S. microadriaticum, B. minutum, C. goreaui, D. trenchii, and F. kawagutii, respectively. The optimal binding temperatures were consistent with the current understanding that D. trenchii was the most thermal resistant among these species. These results suggest that the binding affinity of the PRR PdGLT-1 may determine the specificity of host-symbiont pairing and explain why Cladocopium is the dominant symbionts of coral P. damicornis at normal temperature, and corals with Durusdinium symbionts may survive better at high temperature.

Reef fish community on Sabira Island, Kepulauan Seribu Regency, DKI Jakarta

Sabira Island is an island close to Jakarta Province but still has good water conditions and a coral reef ecosystem with a high level of diversity. The condition of the coral reef ecosystem affects the community structure of the reef fish there. This study aims to determine the community structure of the reef fish on Sabira Island. The research was conducted in August 2019 on Sabira Island, Kepulauan Seribu Regency, DKI Jakarta Province. Observations of reef fish were carried out using the Underwater Visual Census method at four observation stations. There were 47 species of reef fish found on Sabira Island from 12 families. The total reef fish found were 1315 individuals, consisting of 79 indicator fish, 417 individual target fish, and 819 major fish. The highest diversity index value on Sabira Island was found at the South Station, with a diversity index value of 2.39. Based on the community structure index at the four observation stations, the reef fish community’s condition on Sabira Island is still good ranging from unstable to stable condition with moderate diversity and low dominance index values.

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.

VALUASI EKONOMI EKOSISTEM TERUMBU KARANG PULAU WARBAL DI KAWASAN KONSERVASI KEI KECIL KABUPATEN MALUKU TENGGARA

Economic valuation plays an important role as a comprehensive instrument to assess prices (price tags) on the existence of goods and services of an ecosystem. This research aims to analyze utilization conditions including utilization value, non-utilization value and total economic value of coral reef resources and formulate a strategy for managing the reef ecosystem of Warbal Island and surrounding waters. The research on the economic valuation of warbal island coral reef ecosystem and surrounding waters was conducted in July-November 2019. Primary data collection was done through field observations and interviews, while secondary data was obtained through references from the Village Government, Southeast Maluku Fisheries Service, WWF Indonesia and scientific publications. Data was analyzed using methods of analysis of total economic value from use valueand non-use value. Based on the results of the study obtained the total economic value of the utilization and non-utilization of coral reef resources in Warbal Island and surrounding waters reached IDR. 7.275.603.819/year. The value of utilization of coral reef resources of Warbal Island and surrounding waters amounted to IDR. 7.257.318.819/year, while the non-utilization value of coral reef resources amounted to IDR. 18.250.000/year. At least, there are 11 strategies and 22 management directives recommended for the management of Warbal Island coral reef resources and surrounding waters. ABSTRAK Valuasi ekonomi berperan penting sebagai instrument yang komperhensif untuk memberi penilaian harga (price tag) terhadap keberadaan barang dan jasa suatu ekosistem. Penelitian ini bertujuan untuk menganalisisnilai pemanfaatan, nilai non pemanfaatan dan nilai ekonomi total sumberdaya terumbu karang serta merumuskan strategi pengelolaan ekosistem terumbu kawasan Pulau Warbal dan perairan sekitarnya. Penelitian tentang valuasi ekonomi ekosistem terumbu karang Pulau Warbal dan perairan sekitarnya dilakukan pada Juli-Nopember 2019. Pengumpulan data primer dilakukan melalui pengamatan lapangan dan wawancara, sedangkan data sekunder diperoleh melalui referensi dari Pemerintah Desa, Dinas Perikanan Maluku Tenggara, WWF Indonesia dan publikasi ilmiah. Data dianalisis menggunakan metode analisis nilai ekonomi total dari use value dan non use value. Berdasarkan hasil penelitian diperoleh nilai ekonomi total dari pemanfaatan dan non pemanfaatan sumberdaya terumbu karang kawasan Pulau Warbal dan perairan sekitarnya mencapai Rp. 7.275.603.819/tahun. Nilai pemanfaatan sumberdaya terumbu karang Pulau Warbal dan perairan di sekitarnya sebesar Rp. 7.257.318.819/tahun, sedangkan nilai non pemanfaatan sumberdaya terumbu karang sebesar Rp. 18.250.000/tahun. Terdapat 11 strategi dan 22 arahan pengelolaan yang direkomendasikan untuk pengelolaan sumberdaya terumbu karang Pulau Warbal dan perairan di sekitarnya. Kata kunci: valuasi ekonomi, ekonomi total, nilai pemanfaatan, terumbu karang, Maluku Tenggara

Analysis of hard coral condition on coral reef ecosystem in Ternate Island

Hard coral is a type of coral building structure in coral reef ecosystems. Hard coral is a coral reef entity that plays an important function in a coral reef ecosystem, especially related to physical and ecological functions in shallow marine waters environment. This study aimed to study percentages of coral cover, species life form, diversity index, dominance index, and distribution clusters of hard corals based on environmental parameters around Ternate Island. Hard coral cover sampling was carried out systematically using the underwater photo transect (UPT) method. The number of sampling stations were 30 location points with 750 photos. The method used for analyzing ecological conditions of hard corals was coral point count with excel extensions (CPCe). Environmental parameters measured included salinity, temperature, pH, brightness level, and dissolved oxygen. The distribution of hard coral clusters was analyzed statistically using the classify-hierarchical cluster. Study results showed that coral cover percentages ranged from 19% to 93% with an average cover of 67%, species diversity range was 7 to 40 species with an average of 19 species, diversity index (H ') with a value of 1.14 to 6.02 with an average of 2.07, dominance index (D) with a value of 0.13 to 0.53 with an average of 0.23. The results of the analysis of the distribution of hard corals consisted of four clusters. The study also found that distribution of hard coral clusters in Ternate Island was related to substrate topography.

The Bouraké semi-enclosed lagoon (New Caledonia) – a natural laboratory to study the lifelong adaptation of a coral reef ecosystem to extreme environmental conditions

According to current experimental evidence, coral reefs could disappear within the century if CO2 emissions remain unabated. However, recent discoveries of diverse and high cover reefs that already live under extreme conditions suggest that some corals might thrive well under hot, high-pCO2, and deoxygenated seawater. Volcanic CO2 vents, semi-enclosed lagoons, and mangrove estuaries are unique study sites where one or more ecologically relevant parameters for life in the oceans are close to or even worse than currently projected for the year 2100. Although they do not perfectly mimic future conditions, these natural laboratories offer unique opportunities to explore the mechanisms that reef species could use to keep pace with climate change. To achieve this, it is essential to characterize their environment as a whole and accurately consider all possible environmental factors that may differ from what is expected in the future, possibly altering the ecosystem response. This study focuses on the semi-enclosed lagoon of Bouraké (New Caledonia, southwest Pacific Ocean) where a healthy reef ecosystem thrives in warm, acidified, and deoxygenated water. We used a multi-scale approach to characterize the main physical-chemical parameters and mapped the benthic community composition (i.e., corals, sponges, and macroalgae). The data revealed that most physical and chemical parameters are regulated by the tide, strongly fluctuate three to four times a day, and are entirely predictable. The seawater pH and dissolved oxygen decrease during falling tide and reach extreme low values at low tide (7.2 pHT and 1.9 mg O2 L−1 at Bouraké vs. 7.9 pHT and 5.5 mg O2 L−1 at reference reefs). Dissolved oxygen, temperature, and pH fluctuate according to the tide by up to 4.91 mg O2 L−1, 6.50 ∘C, and 0.69 pHT units on a single day. Furthermore, the concentration of most of the chemical parameters was 1 to 5 times higher at the Bouraké lagoon, particularly for organic and inorganic carbon and nitrogen but also for some nutrients, notably silicates. Surprisingly, despite extreme environmental conditions and altered seawater chemical composition measured at Bouraké, our results reveal a diverse and high cover community of macroalgae, sponges, and corals accounting for 28, 11, and 66 species, respectively. Both environmental variability and nutrient imbalance might contribute to their survival under such extreme environmental conditions. We describe the natural dynamics of the Bouraké ecosystem and its relevance as a natural laboratory to investigate the benthic organism's adaptive responses to multiple extreme environmental conditions.