BIODIVERSITAS ISSN: 1412-033X Volume 20, Number 4, April 2019 E-ISSN: 2085-4722 Pages: 978-986 DOI: 10.13057/biodiv/d200407 Economic valuation of Lansa Mangrove Forest, North Sulawesi, Indonesia CALVYN F.A. SONDAK  , ERLY Y. KALIGIS, ROBERT A. BARA Department of Marine Science, Faculty of Fisheries and Marine Science, Universitas Sam Ratulangi. Kampus Unsrat Bahu, Manado 95115, North Sulawesi, Indonesia. Tel.: +62-431-868027,  email: calvyn_sondak@unsrat.ac.id Manuscript received: 13 November 2018. Revision accepted: 12 March 2019. Abstract. Sondak CFA, Kaligis EY, Bara RA. 2019. Economic valuation of Lansa Mangrove Forest, North Sulawesi, Indonesia. Biodiversitas 20: 978-986. Mangrove forest gives many benefits and services to human and environment. Even though it contributes many benefits and services, coastal ecosystems threatened as one of the most critical ecosystems in the world. The study aims to estimate the economic value of ecosystem services provided by Lansa mangrove forest, Wori Sub-district, North Minahasa District, North Sulawesi Province, Indonesia. Here, we describe the use value (direct and indirect value) and non-use value (option and existence value), and emphasize the components of ecosystem services fish resources, firewood, coastal protection, biodiversity, carbon (C) removal and mangrove sustainability because these directly influence human welfare. Their market price calculated fish and C removal value. Coastal barrier and firewood were approached using the replacement cost method. Biodiversity value was calculated using Indonesia mangrove forest biodiversity value. Contingent Valuation method was used to find out people willing to pay for the sustainability of mangrove forest. Lansa mangrove forest total economic value (TEV) was IDR 4,431,197,603 or equal to US$ 305,600 (US$ 1,959 ha -1 ). The success of this mangrove valuation has potentially large implications for future policy-making of its’ ecosystem service values. Keywords: Ecosystem service, mangrove forest, valuation INTRODUCTION Mangrove forest is one of the coastal ecosystems that can be found mostly in tropical regions. Indonesia has the largest mangrove forest area in the world. Data of Indonesian mangroves area was varied. Giesen (1993) reported that the Indonesia mangrove forest area was about 2.5 million ha, while 4.5 million ha claimed by Spalding et al. (1997). Meanwhile, recent data shows, mangrove forest area from 2016-2016 were 4.4 million ha, 3.7 million ha, and 3.9 million ha respectively (BPS 2017; MMAF 2017). In Indonesia, mangrove forest appeared in all 34 provinces. The largest area was found in Papua Province about 1.1 million ha, while Yogyakarta Province was the smallest about 40.10 ha (BPS 2017). Mangrove forest gives many benefits and services to human and environment, such as coastal protection, food resources, species biodiversity and conservation (Vo et al. 2012). Even though, it contributes many benefits and services, coastal ecosystems threatened as one of the most critical ecosystems in the world. This condition due to the fact that approximately 340,000-980,000 ha mangrove forests destroyed annually (Murray et al. 2011), while Indonesia mangrove forest lost approximately 5.6% (204,698 ha) annually (BPS 2017). Globally, mangrove, seagrass, and salt marsh area lost to about 67%, 35% and 29% respectively (Pendleton et al. 2012). If this phenomenon continue, mangrove can lose the services that it provides for human and adjacent ecosystems. Ecosystem services (ES) sustain, strengthen, and enrich various aspects of human life (Kumar and Muradian 2009). Natural ecosystems such as those associated with forest, freshwater, marine, or coastal environments interact with cultivated ecosystems (Wattage 2011). The term ‘ecosystem services’ is sometimes used interchangeably with ‘environmental services’ or ‘ecological services’ (FAO 2002). It has been defined as the array of processes and functions that benefit and support human welfare (Daily 1997; de Groot et al. 2002; MA 2005). These services have been classified as provisioning, regulating, supporting, cultural etc., which would otherwise remain hidden or unappreciated, can be revealed through estimates of value (Wilson et al. 2005). Only a few of these ecosystem services have been marketed, and integration has not been completed between the functions of ecological production and economic valuation within many key estuaries and coastal ecosystem services (Barbier et al. 2011). Economic value is one way to define and measure worth based on a person’s wants or preferences (King and Mazzota 2000). It is often considered the maximum amount an individual is willing to forego in other services and goods to obtain some services, products, or state of the world (Lipton et al. 1995). Economic valuation can also be described as an effort to allocate a quantitative value to the products and services provided by natural ecosystems (Costanza and Folke 1997; Daily et al. 1997). Recognizing the services and economic value of ecosystems is essential because of the great importance that humans place on their well-being, resource sustainability, and fairness in