The mangrove ecosystems on the coast of Sayung Sub-District provide huge benefits to the community. However, this region experienced a very severe coastal erosion during the last few decades. Also, information about mangrove ecosystem services is still very limited in this region. The purpose of this study, therefore, was to map the balance of mangrove ecosystem services on the coast of Sayung Sub-District, Demak District. Data were collected from three coastal villages, namely Bedono, Timbulsloko, and Surodadi, through in-depth interviews, questionnaires, and field observations. The data analysis was carried out using the Burkhard model approach, which involved an ecosystem service matrix, made up of a matrix of capacity, demand, and availability. The results showed that in all components of provisioning service, there was a surplus of availability. In regulating services, there were low surpluses in the components of carbon sequestration and water bioremediation services, while low deficits were found in the service components of reduce wave and current damage, and protecting from sea water intrusion. Then, in cultural services, the two components, shelter for rest area and recreation, experienced a surplus of availability. Mangrove rehabilitation needs to be continued to increase mangrove cover, given the availability of regulating services on components related to erosion prevention in the balace sheet tends to be deficit. Keywords: Burkhard Model, ecosystem services, mangrove ecosystem, Sayung coastal

Sayung coast is experienced very high coastal erosion and has a huge impact on the lives of the surrounding communities. One of the efforts in handling coastal erosion is the rehabilitation of the mangrove ecosystem.The purpose of this study was to prioritize mangrove ecosystem management strategies in rehabilitation areas. Data were collected from three coastal villages, namely, Bedono, Timbulsloko, and Surodadi, through in-depth interviews, questionnaires, and field observations. The data analysis was carried out using the Analytical Network Process (ANP) method. The result showed that the priority problems in the mangrove ecosystem management on the Sayung coast were: conversion of mangrove land, failure of mangroves to grow, lack of monitoring and supervision. Therefore, the priority solution for optimizing mangrove ecosystem management is rehabilitation and conservation, increasing community participation, and monitoring by involving the community.

Student textbooks were generally limited with examples and were also seldom found relevant to students’ daily lives which often caused biology learning not to run contextually. Meanwhile, there were many contexts around students that could be used as references or learning resources. One of the local potentials found on the east coast of South Sumatra was Musi estuary. There were many potentials such as the wealth of biotic components and their abiotic factors. Therefore, we needed teaching materials that could complete the use of textbooks in schools, this aimed to help students more easily understand concepts through relevant contexts. The development of teaching materials used the ADDIE approach; analysing, designing, developing, implementing and evaluating. Making alternative teaching materials for Musi estuary ecosystem had arrived at the development stage followed by evaluating each of the previous stages. This research was using the validation questionnaire of the National Education Standards Agency (BSNP) including aspects of the feasibility of content, the feasibility of language, the feasibility of presentation and the feasibility of graphics. The teaching material has validated by 3 experts and 3 high school Biology teachers. Based on the results of material validation by experts it was obtained an average score of 3.13 (77.38%), and high school biology teacher 3.33 (83.17%), which then concluded that the alternative teaching material of Musi estuary ecosystem was discovered eligible to be used as a supplementary of biology textbooks on grade X for ecosystem learning material.