Marine Research in Indonesia (MRI - E-Journal)
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ESTIMATION OF SEASONAL VERTICALLY INTEGRATED PRIMARY PRODUCTIVITY IN AMBON BAY USING THE DEPTH-RESOLVED, TIME-INTEGRATED PRODUCTION MODEL
No full textSeasonal vertically integrated primary productivity (IPP) in eight stations of Inner Ambon Bay (IAB) and ninestations of Outer Ambon Bay (OAB) was estimated using the depth-resolved, time-integrated production model andvertical-a distribution model which was mainly dependent on chlorophyll-a profile. The profile was modeled as Gaussfunction in which its parameters were determined by minimizing the difference between the model and the averageof in situ chlorophyll-a concentration from 2008 to 2012. The data was collected by UPT BKBL-LIPI Ambonduring monitoring program in Ambon Bay. Based on this model, the results showed that the primary productivityduring the southeast monsoon was to some degree higher than that of other seasons. The main factors causing the higherIPP in this season were upwelling phenomenon and high rainfall intensity. From the results, it could be concludedthat run-off gave more impacts in IAB than in OAB while upwelling in Banda Sea affected the IPP more in OABthan that in IAB. Then, the existence of the sill located between IAB and OAB inhibited the mixing of IAB andOAB waters so that the levels of IPP and chlorophyll-a concentration in IAB were higher than that of in the OAB
PHYTOPLANKTON SPECIES COMPOSITION IN SEAWATER AND TISSUE OF GREEN MUSSELS (PERNA VIRIDIS), AT KALI BARU-CILINCING, NORTH JAKARTA
No full textSpecies composition and abundances of phytoplankton in the shellfish farming area in Jakarta Bay, Kali Baru-Cilincing, were examined in order to identify harmful algae species. Phytoplankton contained in the shellfish was also observed to detect the presence of toxic species, as well as the phycotoxin contained in visceral of green mussel (Perna viridis) collected from the farming area using brine shrimp lethality test (BSLT). We detected the presence of Alexandrium spp. (PSP causing species), Dinophysis caudata, D. miles and D. rotundata (DSP causing species), and Pseudo-nitzschia spp. (ASP causing species). The last mentioned species was also detected in thestomach content of green mussel. The toxicity of green mussels tested was recorded LC 50 ≤ 1,000 ppm and indicatedthe presence of an active compound in the green mussel viscera. Meanwhile, preliminary PSP test of shellfish did not showed any toxin
COMMUNITY STRUCTURE OF CHAETODONTIDAE IN THE WEST OF BANDA SEA
No full textDistribution and composition of Indonesian Chaetodontid species may vary among different locations. However, illegal fishing practices such as bombing and poisoning on reef ecosystems have significant contribution to environmental degradation and can change the community structure of fish especially that of Chatodontids that act as indicator species in in the given areas. Therefore, it is important to do periodic surveys to know the current condition and their changing. A study on community structure of Chaetodontidae has been conducted from July toAugust 2011 on coral reef ecosystems of the Banda Sea and its adjacent waters including Banggai, Kendari, and Lamalera Islands. Scuba equipment was used and underwater visual census method was applied for collecting the data at 21 stations. A total of 1399 individual Chaetodontid fishes was observed, belonging to thirty species and seven genera, i.e. Chaetodon (20 species), Heniochus (4 species), Forcipiger (2 species), Chelmon (1 species), Coradion (1 species), Hemitaurichthys (1 species), and Parachaetodon (1 species). Chaetodon kleinii was the most dominant species in the Banggai (74,38%) and Lamalera (71,71%). Kendari was characterized by the presence of C. octofasciatus that contributed 55,20%. There were two dominant groups of Chaetodontidae based on the feeding guild. Facultative coral feeder was the most abundance in Banggai and Lamalera, while the most commonChaetodontidae in Kendari belonged to obligate coral feeder. Chaetodontid diversity in Banggai was the lowest compared to that of in other studied areas. Anthropogenic pressure may become a major factor causing the low diversity and studied species richness in the coral reef ecosystem of Banggai waters
SUITABILITY ANALYSIS OF MULTISPECTRAL SATELLITE SENSORS FOR MAPPING CORAL REEFS IN INDONESIA CASE STUDY: WAKATOBI MARINE NATIONAL PARK
No full textProviding accurate information on suitable multispectral satellite sensors for mapping coral reefs in Indonesia is a challenge for coastal remote-sensing experts. As coral reefs vary in spatial extent, shape, length, perimeter and/or distance to shore, the mapping of coral reefs will need different satellite sensors depending on the objectives and the kind of information required. This work compares the suitability of two kinds of multispectral satellite sensors for mapping coral reefs in Indonesia, high and moderate spatial resolution. This was done through a case study of Wakatobi Marine National Park since that represents many types of coral reef in Indonesia (fringing, barrier, atoll, and patch). Indonesian coral reef shapefile data 2010 was downloaded from UNEP (United Nations Environment Programme) website, and Landsat 7 ETM + images, path/row 112/064 was used to determine the terrestrial area of Wakatobi Islands. Both high and moderate spatial resolution sensors are suitable for mapping the benthic communities and geomorphic zones on coral reefs. The former are more accurate but they are also much less cost-effective, especially over large areas
VARIABILITY OF SEA SURFACE CHLOROPHYLL-A, TEMPERATURE AND FISH CATCH WITHIN INDONESIAN REGION REVEALED BY SATELLITE DATA
No full textThe investigation of sea surface chlorophyll-a (SSC) and sea surface temperature (SST) in relation to fish catch variability within the Indonesian region were conducted by using satellite data of NOAA-AVHRR, SeaWiFs and Aqua MODIS. The investigation focused in the region of the coastal area of Java, Lampung Bay and South Kalimantan as representation of the environment diversities of the Indonesian seas. The result shows that seasonal variation in fish productivity has a strong correlation with SSC variability. High fish productivity corresponded well with high concentration of SSC, and the productivity tended to decrease when the SSC concentration was declined. High SSC variability in the coastal area of Java and Lampung Bay was governed by the upwelling that induced high nutrient load into the sea surface during the southeast monsoon, while in the northern coastal area of Java and South Kalimantan, it was governed by high precipitation ocurring during the northwest monsoon that enhanced the nutrient load through the rivers and coastal discharge
BEHAVIOR OF ANOXIC WATER IN THE BANGPAKONG ESTUARY
No full textWe carried out hydrographic observations in the Bangpakong estuary during transient period from rainy season to dry season in 2011 and 2012. The main objective of the hydrographic observations was to elucidate the behavior of anoxic water mass in the Bangpakong estuary, which was the possible cause of mass mortality of cultured shellfishes in the study area. We had succeeded the CTD and mooring observations in both years, and we had obtained time–series data of DO, salinity, and current velocity for approximately 2 months, which were the first long-term continuous records in terms of water quality in the Bangpakong estuary. From mooring data, it was revealed that DO and salinity at the bottom layer in aquaculture area oscillated with large amplitude, and the period of the oscillation corresponded to tidal variation. Amplitude of the oscillation was large in September and became small in October, and anoxic condition lasted for several days in October in 2011 and 2012. Current direction at station M1 in 2011 was opposite to that of in 2012 throughout the mooring period southward in 2011 and northward in 2012. Wind conditions in Chonburi in both years were almost the same, but river discharge in 2011 was much higer than that of in 2012. Therefore, it was possible that the difference of current direction at station M1 occurred due to change of buoyancy flux, and persistent period of anoxic condition was different between 2 observed years associated with circulation change. It was suggested that mass mortality of cultured shellfishes in Bangpakong estuary was caused by anoxic water because timing of mass mortality corresponded to that of anoxic water appearance qualitatively. It was also suggested that the anoxic water mass in aquaculture area was transported from off shore area by residual currents
THE ABUNDANCE OF POTENTIALLY TOXIC EPIPHYTIC DINOFLAGELLATES AND NUTRIENTS FROM BALI AND GILI TRAWANGAN, INDONESIA
No full textThere are strong indicators that the degradation of coral reefs may increase the intensity and frequency of ciguatera fish poisoning (CFP) outbreaks when denuded reef surfaces are colonised by macro algae that are the preferred hosts of toxic dinoflagellates that can cause the disease. Ciguatera field studies have concentrated on the dinoflagellate genus Gambierdiscus, well known to be the producer of ciguatoxin precursors. Moreover the potential of toxins from other dinoflagellate genera such as Prorocentrum and Ostreopsis is less often considered. Whilstit is known that toxic compounds produced by Ostreopsis species include ostreotoxins (OTX) and ostreocins, the potential harmful impacts of Ostreopsis, Prorocentrum and Gambierdiscus species on coral reef organisms (and ecological impacts) are largely unknown. In addition, CFP has historically largely occurred on the oceanic islands of the world’s tropical seas, but has only recently been reported in the major archipelagoes of Indonesia and thePhilippines. In view of their degraded coral reef ecosystems and the potential link between reef health and CFP, this study examined three sites in Bali and Gili Trawangan over one year, to assess the prevalence and distribution of CFP related dinoflagellate species. Beside finding Gambierdiscus, Ostreopsis and Prorocentrum at most sites, water column nitrogen nutrient levels were also found on the average to be 3−4 times higher than that recommended for a healthy coral reef (0.013mg/L). However the maximum abundance of Prorocentrum, Ostreopsis and Gambierdiscus found were low (103, 2,860 and 28 cells per gram of wet weight of host macroalgae, respectively). A factor thatmay play a part in the potential for toxicity at these sites is the abundance of sea grass (and associated micro flora and fauna) which are often present within and adjacent to coral reef ecosystems across the Indonesian archipelago
ECHINODERM FAUNA OF THE LEMBEH STRAIT, NORTH SULAWESI: INVENTORY AND DISTIBUTION REVIEW
No full textIndonesia is particularly rich in Echinoderms and North Sulawesi lies at the geographic centre of this biodiverse marine realm. While further studies on Sulawesi Echinodermata are required in order to obtain full understanding ofcurrent biodiversity status, preliminary SCUBA and intertidal surveys in early 2012 in the vicinity of the Lembeh Island, a region little explored previously, recorded a total of 76 species of 4 classes (Asteroidea, Ophiuroidea, Echinoidea and Holothuroidea) from shallow waters (0-40 m) at 36 sites (sea grass, coral rubble and reef). The class Crinoidea is not reported here. A review of Echinoderm literature for North Sulawesi noted that there are 114 species belonging to 5 classes of Echinodermata
PRELIMINARY STUDY OF SPECIES COMPOSITION AND DISTRIBUTION OF ECONOMICALLY VALUABLE PRAWNS IN THE NORTHEASTERN COASTAL WATERS OF VIETNAM
No full textThe northeastern coastal waters of Vietnam contains diverse and abundant prawns with economic importance. In recent years, overexploitation and marine environmental pollution have led to the decrease of prawns. The purpose of this study is to identify the current diversity and distribution of prawns in this region. Prawns were sampled by a trawl net at four sites in 2011. A total of 21 species of three families of the superfamily Penaeoidea was distributed in this area. The family Penaeidae is the most diverse with 19 species, while each of family Sicyoniidae and Solenoceridae has only one species
FISH SPECIES COMPOSITION IN SEAGRASS BEDS OF TANJUNG MERAH (NORTH SULAWESI), INDONESIA
No full textSeagrass beds are found along the shore of Tanjung Merah (North Sulawesi, Indonesia). This ecosystem covers approximately 20 hectars, and are well known to support local fisheries. Thalassiahemprichii was the dominant seagrass species at the study site. This study in the given area was aimed to monitor any changes in fish assemblage structure, and examine the function of seagrass beds for marine fish. Fishes were sampled using the small beam trawl in March 2003, April 2004 and September 2005. A total of 137 species belonging to 34 families were identified. Twenty four species were found abundantly in terms of individual numbers, however Apogon margaritophorus and A. hartzfeldii were the most dominant. These two species were permanent resident, indicated by a catch of large number in different stages of life cycle. We also noticed that many adults of A. margaritophorus kept fertilized eggs in their mouths. This evidence also confirmed that seagrass beds function as both spawning and nursery ground for marine fishes. During three years’ monitoring, there was a slightly seasonal variety in fish assemblage structures