Segara Anakan Research Articles

Heavy Metals Bioaccumulation Pattern of Bivalve Geloina spp., and Crustaceans Penaeus marguensis and Scylla serrata from the Southern Central Java Ocean Margin, and Its Consumer's Safety

Aquatic organisms exposed to low lovel natural heavy metals pollutant tend to accumulate in their tissue by means of metabolic and biosorption processes. However, the influence of external environment to heavy metal bioavailability and internal organism characteristics to bioaccumulation processes remain uncertain. In this work, the influence of Cu, Zn, Cd and Hg bioavailability, feeding strategies and heavy metals homeostasis regulations or detoxification mechanisms to bioaccumulation pattern in aquatic bioindicators were studied. Only Hg in Segara Anakan water samples was determined, while Cu, Zn and Cd were not detected. Sediment samples of Segara Anakan indicated higher heavy metals level than those of Serang river mouth, but only Hg concentration in sediment samples of Segara Anakan which is significantly higher than those of Serang river mouth, while Cd was not detected. The trend of heavy metals bioconcentration ratio of filter feeder Geloina spp and planktonic grazer Penaeus marguensis follows the desorption coefficient, i.e. Zn>Hg>Cu, but the bioconcentration trend in Scilla serrata, which is macrobenthos predator, is Hg>Zn>Cu. The exposed Cu was not accumulated by Geloina spp., but accumulated at highest concentration in the exoskeleton of Penaeus marguensis and cartilage of Scilla serrata. Highest accumulation concentration of Zn and Hg were determined in meat, and lower concentrations were determined at other tissues. The extent of heavy metals bioaccumulation in Geloina spp. and Scilla serrata reflect the pollution of the surrounding environment, but the extent of heavy metal bioaccumulation in Penaeus marguensis were influenced more by its physiological status. Since the environmental exposure of Hg in Segara Anakan estuary was relatively high, pregnant women from this region should consider the potential hazard of Hg to their fetus when consuming aquatic organism of higher trophic level such as estuarine crabs.

SUKSESI SEKUNDER PADA LAHAN TAMBAK TERLANTAR DI KAWASAN HUTAN MANGROVE SEGARA ANAKAN CILACAP JAWA TENGAH

The study of secondary succession was carried out on Segara Anakan mangrove forest, since the secondary succession has been the significant problem in the mangrove forest Segara Anakan as the impact of illegal cutting and the neglected fishpond activities. Side-by-side comparisons method and quadrat sampling method were employed in this study. There were 3 areas of abandoned fishpond with different levels of succession. The sample stands were determinated subyectievely and the quadrat sample were put at random. Ordination method was used to see the correlation between vegetation pattern using environment parameters observed. The result of this study indicated that the important value on the stratum of mangrove herb was succession process. The ordination pattern of mangrove was not related to environment factors. In general, some spesies: Avicennia alba, Acanthus ilicifolius, Paspalum sp., Fimbristylis alboviridis, Bulbostylis puberula had the important role in the process of secondary succession.

Biomass and productivity of a Rhizophora mucronata Lamarck plantation in Tritih, Central Java, Indonesia

Perum Perhutani (The State Forestry Corporation) is establishing large-scale mangrove plantations for reforestation and/or afforestation, and the production of wood for fuel as well as other purposes in Java. The mangrove species used currently in Segara Anakan Cilacap is Rhizophora mucronata Lamarck. The above-ground biomass, litter production and litter accumulation in a 7-year-old stand in Tritih were studied. The mean diameter at breast height (DBH) or 30 cm above the highest prop root was 5.91 cm. The mean annual increment in DBH of individual trees was 0.89 cm. The total above-ground biomass of the stand was 93.726 t ha −1 of dry weight, consisting of 60.442 t of stem, 13.906 t of branch, 14.708 t of prop root and 4.670 t of leaf material. Litter production ranged from 7.058 to 10.395 t ha −1 year −1 of dry weight with leaf litter making up 73.29–84.30% of the total. Leaf litter accumulation amounted to 16.922–20.511 t ha −1 year −1 of dry weight and the turnover constant ( k) of leaf litter was estimated at 0.2943–0.4082. The high productivity is discussed in relation to lower turnover ( k) of litter.

Managing coastal resources in Cilacap, Indonesia, and Lingayen Gulf, Philippines—an ASEAN initiative

Cilacap and its dynamic Segara (lagoon) Anakan on the southern coast of Java, Indonesia, and the Lingayen Gulf area in northwest Philippines are typical of many areas experiencing intense multiple resource use conflicts, overexploitation of coastal resources and environmental degradation. Coastal settlements are generally densely populated with widespread poverty, especially among fishing communities. The Segara Anakan is a nursery ground that supports both a lagoon and offshore shrimp fishery. Mangroves are extensive and are traditionally exploited by the coastal communities. Key management issues are the decreasing size of the lagoon due to heavy sediment input from upland activities, water quality problems, particularly pesticides runoff from upland agriculture and poor economic conditions of the coastal inhabitants. Lingayen Gulf is a major fishing ground in the Philippines and an important aquaculture site for milkfish and oysters. In addition, coral reefs and seagrass beds are extensive and sandy beaches along the eastern side are popular tourist attractions. Significant management issues include destruction of coral reefs due to blast fishing, cyanide poisoning and trawling activities as well as rural poverty. Also, coastal water quality is undermined by indiscriminate dumping of untreated domestic wastes, pesticides and mine tailings from upland mining operations. Efforts to develop integrated coastal area management plans for the two sites are currently being undertaken to resolve the aforementioned issues and provide some strategies for the sustainable development of the coastal resources as well as alternative livelihood for the coastal inhabitants. The mechanisms of plan development for both sites, including legal and institutional support, are discussed in the context of regional and local organizations/communities participation.

Abstrak Konggres dan Seminar Nasional Penggalang Taksonomi Tumbuhan Indonesia (PTTI) Universitas Sebelas Maret Surakarta, 19-20 Desember 2003

Sonneratia spp. was genetically unique genera. They had some members in Java, especially Sonneratia alba and S. caseolaris. This species have ability to cross reproduction, and produce fertile hybrid, although the fertility is lower than the parent, so they hard to differ morphologically. This research had been done in 6 sites (populations) of the southern and northern coast of Java, i.e. Bogowonto estuary, Kulonprogo (1 pop.), Segara Anakan, Cilacap (2 pops), coast of Pasar Bangi, Rembang (1pop), Juwana estuary, Pati (1 pop), and Canal Wulan estuary, Demak (1 pop). The research indicated that S. alba was more dominant, but there were some confused inmorphological character, that may be caused by hybridization. Isozymic analyses on peroxidase and esterase marker to 60 individuals (10 per population) had been no differing in isozymic band significantly. They have similarity index value more than 60%. It indicated, that they tend to same species than separate it.Keywords: isozyme, diversity, Sonneratia, northern andsouthern coast of Java.

R E V I E W: Citanduy river diversion, advantages and disadvantages plan to conserve mangrove ecosystem in Segara Anakan

Mangrove ecosystem at Segara Anakan lagoon, Cilacap having specific characteristics so that in developing this areashould consider the conservation aspect. This area is the widest conserved-mangrove ecosystem at Java, and the placefor breeding of many species of fish, crustacean and others. Thousand families of fisheries were supported both direct andindirectly from this ecosystem. However, along with the development activities in the watershed of Citanduy,Cimeneng/Cikonde and other rivers connected to the area has brought about the increase of sediment, and threaten theexistence of the lagoon and surrounding mangrove ecosystem. Diversion of Citanduy river, dredging sediment, and reboisation of the watershed river was a preference of conserving the ecosystem, however, the diversion could be forming a new ecosystem, that actually threat the fisheries and tourism activities at Pangandaran, Ciamis.© 2003 Jurusan Biologi FMIPA UNS SurakartaKey words: mangrove, Citanduy river, Segara Anakan lagoon, sedimentation, diversion