Marine Research in Indonesia (MRI - E-Journal)
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SHARKS AND RAYS IN INDONESIA
No full textIndonesia is considered to have a high diversity of sharks and rays due in part to its position in the equatorial line, between two continents and two oceans. According to recent studies and various publications, the number of chondrichthyan species known to date is 207 species of 44 families, comprised of 109 species of sharks, 96 species of batoids, and two species of ghost sharks (chimaera). The Dasyatidae (stingrays) is the most speciose family of chondrichthyans occurring in Indonesia, followed by the Carcharhinidae (whaler sharks). Most species of elasmobranchs commonly occur on the continental or insular shelves and rays are more commonly found than sharks. This type of habitat can be found mostly in the western part of Indonesia (the Java Sea, Karimata Strait, South China Sea, Malacca Strait, and Macassar Strait). Due to the separation by the Wallace Line, there are some differences in species diversity between western and eastern region. The shark and ray fauna of the eastern region is more similar to the Australian fauna, while the fauna in the western region is more similar to the Asian fauna. There are also some endemic species known to occur in Indonesian waters. The endemicity of some species can be restricted in a certain area or in a regional area such as the Indo-West Pacific
BIODEGRADATION OF POLYCYCLIC AROMATIC HYDROCARBON (PAH), PHENANTHRENE BY MARINE BACTERIUM THALASSOSPIRA SP. C.260
No full textPhenanthrene is a polycyclic aromatic hydrocarbon (PAH) compound that is known to be reported toxic to marine flora and fauna. Remediation of this environmental pollutant using chemical and physical methods causes environmental issues. Bioremediation using marine has been applied to degrade such various PAH compounds. Screening of marine microorganism in degrading this recalcitrant is very importance for bioremediation application in Indonesian waters. The purpose of this study was to screen and isolate bacterial with potential application in biodegradation of phenanthrene and other harmful PAH in marine environments. Several potential bacteria strains were isolated from oil contaminated sea water in Cilacap area. Sequence analysis using 16S rRNA gene marine bacterium strain C.260 showed 96% sequence homology to sequence of Thalassospira sp. In biodegradation of phenanthrene, within 28 days experiments, this bacterium degraded 50% and 99.75% of phenanthrene in medium with and without enrichment with NPK fertilizer respectively. Using sublimation method, this bacterium also degradeds phenothiazine, fluoranthene, and dibenzothiophene
INVESTIGATION OF THE COASTALLY TRAPPED WAVES IN THE SOUTH OF INDONESIAN ARCHIPELAGO
No full textAnalysis of sea level data derived from Jason-1 altimetry satellite reveals the basic characteristics of a coastally trapped wave along the waveguide in the south of Indonesian archipelago. The most robust signatures of the trapped wave are recorded recurrently in the months of May-June. Hovmoller and coherence analysis synonymously agree that the wave propagates at a speed of 2.8-2.9 m/s towards the eastern end of the waveguide. The trapped wave is dependent upon the stratification regime, and a Wentzel-Kramers-Brillouin (WKB) analysis on the stratification profile inferred from several CTD casts indicates that the trapped wave may be classified as a first mode baroclinic wave
SEASONAL VARIATIONS OF NUTRIENT BUDGETS IN JAKARTA BAY, INDONESIA
No full textThis study aims to quantify the fluxes of carbon, nitrogen, phosphorus, and silicate in Jakarta Bay and use these flux data to gain an initial understanding of the biogeochemical processes occurring in the system. We investigated water, suspended matter and sediments fluxes from estuarine, coastal water and outside of the bay. Water samples were analyzed for dissolved nutrients, chlorophyll-phytoplankton abundance, and their composition. Suspended matter and sediment were analyzed for carbon and nitrogen. Nutrient concentrations were high in the rivers or estuaries and then decreased rapidly seaward. Calculation budget results showed that Jakarta Bay is a sink for DIP, DIN and DSi during dry season and rainy season. In the dry season, the system is in the slightly fixation condition ([nfix-denit] = 0.03 mmol N m-2 d-1). In contrast, denitrification exceed nitrogen fixation ([nfix-denit] = -9.74 mmol N m-2 d-1) in the rainy season. Moreover, the bay produced net carbon about 2.6-32 mmol C m-2 d-1
LITTER PRODUCTION OF THE MANGROVE FORESTS IN TIRIS, INDRAMAYU, WEST JAVA, INDONESIA
No full textThe Tiris mangrove forest, Rhizophora apiculata-R. mucronata community, grows in the area with highly human induced stress and typically by silty clay substrate. The litterfall studies in Tiris, Indramayu (Lat. 6º 10'-7º 49' S and long. 107º25'-108º25' E), using litterfall trap and plot techniques indicate that the mangrove forest is very productive. Litter productivity, as measured by litter trapping of a R. apiculata dominant mangrove forest at Tiris is 1,290.95 dry g/m2 /year, and estimated as 12.90 dry t/ha/year and leaf shared is 40.70%. This is a high value when compared with the mangrove forests in the Indo-West Pacific and/or Malesian regions, and even with R. mucronata plantation in Tritih, Segara Anakan, Cilacap (Lat. 7º 41'-7º 45' S and Long. 108º 46'-109º E). Correlations between litter components with rainfall, number of rain-day, wind run, mean maximum temperature, mean minimum temperature, and mean monthly temperature, and relative humidity are calculated for understanding their role in litter production. These correlations are discussed and it is suggested that seasonality of mangrove need to be considered in terms of whole tree physiology rather than isolated environmental factors. Also, the high production of litter means an important contribution to support food-webs of many marine organisms. The results suggest that, in terms of litter, the mangrove forests in Tiris may be one of the most productive forest types in Java
EIGHTEEN SEA CUCUMBER SPECIES FISHED IN KARIMUNJAWA ISLANDS, JAVA SEA
No full textIndonesia has been supplying the highest diversity of dried sea cucumbers (trepang) to world markets for decades even though species validation on the trepang from any producing areas throughout the country is still needed. Karimunjawa (Islands off north coast of Java) is one of trepang habitats. Several visits from May to November 2009 had been made to collect trepang from the fishers and collectors in that area. Eighteen aspidochirote species were identified, more varied than those reported in 1988 and 1992 although 7 species have no longer been found. Three species among those: Actinopyga banwarthi, Bohadschia subrubra, and Holothuria fuscocinerea have never been reported in Indonesia before, neither on the list of commercial sea cucumbers in Asia nor world trade provided by Choo (2008) and Toral-Grande (2007). These species composition shifts may indicate a threat to species diversity, starting with excessive removal of natural stock. Up to now, 28 species of trepang have been recognized from Karimunjawa waters
PERFORMANCE OF GILLNET-MESH SIZE SELECTIVITY FOR THREE FLYINGFISH SPECIES IN AMBON WATERS, MOLUCCAS PROVINCE
No full textThe gillnets' performance for capturing flying fish was obtained from the selectivity parameters of each mesh size. Gillnet selectivity parameters for flying fish were estimated using multi-panel drift gillnets with four different mesh sizes in southern Ambon Island. The black-spot flying fish Cheilopogon suttoni reached peak selectivity at 20.34 cm for mesh size of 1.25", 24.37 cm (1.5") and 28.47 cm (1.75"). Peak selectivity occurred at 22.16 cm for the 1,25" mesh size in the yellow-spot flying fish Cheilopogon abei, with the maximum size selectivity at 31.61cm for the 1.75" mesh. The optimum size for the black-plain flying fish Hirundichthys oxycephalus was 18.67 cm for the 1.25" mesh size, and 22.37 cm for 1.50" mesh size. Selectivity was highest at 26.12 cm for the 1.75" mesh size. Gillnet used in this study was constructed specifically for targeting flying fish suggesting that information on mesh selectivity examined here should has direct applicability to local flying fish fishery
OVERVIEW OF THE SUCCESSFUL CORAL REEF MANAGEMENT IN INDONESIA
No full textIndonesia is the largest archipelagic country in the world, composed of 18,110 islands with a coastline of 108,900 km long, extending some 5000 km long and 2000 km wide located between Asia and Australia. Coral reefs have important meaning and value for the coastal communities in term of economic, social, and cultural conditions. About 1.5 million people are traditional fishermen who live in subsistence level and depend on their lives fully on coral reefs' resources. The Indonesian coral reef contributed 14% of the world, distributed unevenly from Sabang to Merauke with the highest concentration around Sulawesi and Maluku. The species richness and the biodiversity of the Indonesian corals amounted to 590 species belonging to 82 genera or about 80% of the currently existing coral species in the world. Monitoring program has been done from 1993 to 2010 and it shows the trend of improvement in the term of live coral cover. The condition of coral reefs in Indonesia taken from 84 locations and 1048 sites were 50.54% in excellent condition, 26.72% in good condition, 37.21% in fair condition, and 30.82% in bad condition. Improving trends in live coral cover across all project sites shows that the live coral covers has increased in all monitored sites across all project districts with average yearly live coral coverage increase is about 2-5%. The National Policy, Strategy, and Action Plan was established, with its main objective of managing the coral reef ecosystems based on the balance between conservation and utilization, and it was reflected in the Law No. 27 of 2007 concerning coastal management and small islands. The most remarkable result of the program is community awareness, namely the decrease of fishing activities shows that the destructive fishing activities in all project district are now non-existent of at a minimal level. A special text books on marine lives for elementary, secondary, and high school is the most widely adopted by local education service as a book of local content. Whereas institutional strengthening program constitutes the most difficult, energy and time consuming activities. It is due to the rivaly between the local institution and the lac of officials' and the communities' knowledge on the conservation based management principle
TRANSPLANTING ENHALUS ACOROIDES (L.F) ROYLE WITH DIFFERENT LENGTH RHIZOME ON THE MUDDY SUBSTRATE AND HIGH WATER DYNAMIC AT BANTEN BAY, INDONESIA
No full textThis study is a part of transplanting Enhalus acoroides carried out from November 2006 to February 2007 as a compensation of 1.6 ha loss of seagrass beds at Bojonegara, which was facilitated by NGO Rekonvasi Bhumi and funded by oil drilling company, PT Apexindo. The transplanting site was located at Terate, Banten Bay which has muddy substrate with high water dynamic. Healthy transplant seedlings were collected from monospecific vegetation with muddy substrate of donor site at Kepuh. The seedlings of Enhalus have different length of rhizome, 5 and 10 cm, with leaf length of 60 cm and removed roots. Transplanting of Enhalus acoroides was conducted using single shoot seedlings with 9 seedlings per unit in 1 meter square with 5 replicates. Light coefficient (1.17-5.06) and percentage of silt and clay (86.45 ± 2.18 %) at transplant site Terate were both higher than the donor site Kepuh with light coefficient values of 1.21-2.46 and percentage of silt and clay 64.00 ± 5.57 %, respectively. Seedling growth survival of Enhalus acoroides in February 2007 with rhizome length of 10 cm was higher (51.11 ± 25.58%) than seedlings with rhizome length of 5 cm (17.78 ± 18.59%). Leaf length and wide Enhalus acoroides transplants decreased during the study. Water dynamic (waves) influenced light coefficient and turbidity at the transplant site. Field observations showed that mortality of Enhalus acoroides transplants was caused by mud smoothering the leaves and barnacle growing on them. They made the leaves lost their buoyancy, laid on the surface, rotten and finally died. Wave is one of the important physical factor affecting the transplanting seagrass on the muddy substrate
ONGROWING TECHNIQUES FOR JUVENILE DONKEY EAR ABALONE (HALIOTIS ASINIA) AT PEMENANG WATERS, NORTH LOMBOK, INDONESIA
No full textAbalone is one of the most prized sea delicacies in the world. In Indonesia, although donkey ear abalone (Haliotis asinina) forms a valuable fishery, little is known about its culture techniques. A study has been conducted to find out the most suitable technique for ongrowing donkey ear abalone, for to the local farmer in Indonesia. Juveniles used in study were collected from the southern Lombok coastal waters. They were reared in different type of structure (CNC = circular net cage and TNC = tyre net cage) and set at different depths. Juveniles were fed ad-libitum by macroalgae, Gracilaria spp. Results of the study showed that juveniles of donkey ear abalone have a better growth when cultured offshore in a TNC than in CNC. To gain a better growth, juveniles abalone need to be reared in cages which provided more shelter and less light. Donkey ear abalone was considered a hardy species, survival rate was not influenced by the type of structure (CNC or TNC) and setting position (depths)