Dynamic model of the Sustainable Management of Mangrove Ecosystems in Wulan Estuary Demak

Abstract

Mangrove serves as spawning grounds and nursery grounds for various species of fish, shellfish and other species. Mangrove litter such as leaves, twigs and other biomass fall to become food sources for organisme in the water and nutrients that determine the productivity of marine fisheries. However, the benefits and functions of mangrove are not fully understood because they are not seen directly and within a short time. Difficulty in assessing the benefits of mangrove causes local governments and communities do not consider it in management. So that the mangrove ecosystem is converted to multiple uses such as aquaculture. The purposes of this study were to calculate the value of the potential benefits of the litter of mangrove fisheries donations, determine the level of utilization of mangrove ecosystems, and create a dynamic model of mangrove management for sustainable fisheries. This study was conducted in February-April 2013 in the mangrove area, Wulan estuary, Demak, Central Java. Primary data were characteristics of mangrove, physical and chemical parameters of the environment, the primary productivity of mangrove ecosystems, socio-economic data of fishermen and farmers associated with the utilization of mangrove ecosystems. Secondary data were number of fishermen, number of farmer, pond and mangrove area. The methods of analysis were analysis of the relationship of mangrove characteristics and enviromental parameters, analysis of important value index and diversity indices, analysis of primary productivity, and analysis of mangrove area changes, and analysis of the use value with the consumer surplus approach. Data were collected through sampling and direct measurement in the field, followed by measurements in the laboratory. Then the processed data was used in making management model. The results showed an average production of mangrove litter 4,52 g/m²/year or 16.508,95 kg per hectare per year. Litter was expected to contribute to the fishery potential of 1.405,25 kg per hectare per year. The economic value of mangrove ecosystem for fisheries was Rp538.345.015,00 per hectare per year. Economic value for the use of ponds was Rp20.417.269,00 per hectare per year. Of the model developed shows that the addition of mangrove least 5 ha / year to maintain sustainable use of fisheries at Wulan Estuary Demak. So that the protection of the mangrove ecosystem is expected to maintain sustainable use of fisheries for the surrounding community.