Mangrove Restoration in the Vicinity of Oil and Gas Facilities: Lessons Learned from a Large Scale Project

Abstract

Mangroves are critical ecosystems given their key role in conserving biodiversity, protecting coastlines from erosion and supporting coastal resources. They may be impacted by oil and gas activities, either directly or indirectly. Restoring them is therefore of prime importance. In the Mahakam Delta (East Kalimantan, Indonesia), oil and gas exploration and production have been conducted for more than 40 years. This industry has operated in a quasi-pristine area barely affected by human activities until the mid 80's. Toward the late 1980's and until 2000, the delta was subject to massive and rapid development of shrimp farming and by 2001, 85% of the delta mangroves were destroyed and most of it replaced by ponds used for aquaculture. By the end of 1990's, shrimp farm productivity in the delta decreased due to a lack of nutrients in ponds and the occurrence of shrimp diseases. Numerous ponds were abandoned in the delta. This economic situation generated social instabilities that could threaten the oil and gas industry in the region. Therefore, in order to better protect mangroves and optimize restoration of damaged areas, Total E&P Indonesie embarked on a mangrove restoration initiative of the Mahakam Delta aimed at understanding and contributing to the restoration processes through both natural recolonization and planting techniques. The general methodology implemented has been to i) describe the land cover using satellite imagery, interpreting aerial photos, conducting field work, and establishing GIS maps, ii) inventory the fauna and flora (including mangroves, birds, mammals, reptiles), iii) monitoring the naturally re-colonized areas, replanted areas and original forest in selected areas. Results show that natural recolonization of a mangrove area can be very quick under certain conditions (subject to availability of seeds and easy access of seeds to the area to be recolonized). But in areas where seeds cannot easily move, or where seed supply is scarce, replanting remains the best option. Social aspects have also to be taken into account given that replanting can promote the local commitment to sustainable environmental conservation.

Monitoring mangrove forests after aquaculture abandonment using time series of very high spatial resolution satellite images: A case study from the Perancak estuary, Bali, Indonesia

“…In Indonesia, in the period between 1980 and 2003, characterized by weak governance of the aquaculture sector (Ilman et al 2016), thousands of hectares of coastal zone were transformed into a mosaic of aquaculture ponds, of which about 250,000 ha have remained disused ever since (Gusmawati et al this issue). The scale of the conversion is particularly visible in large areas like the Mahakam delta covering about 75,000 km² in East Kalimantan, Borneo Island (Dutrieux et al 2014). Anyone using Google Earth, with its high-resolution satellite images, can see and understand the scale of the impact of aquaculture on such coastal areas.…”

Tingkat Rujukan Emisi Hutan Mangrove Delta Mahakam

“…Selisih nilai dimungkinkan oleh aktivitas pembukaan lahan tambak yang tidak hanya di hutan mangrove tetapi juga lahan non hutan mangrove atau di area tanah timbul. Sebagai wilayah delta, tingkat sedimentasi di Delta Mahakam cenderung tinggi sehingga penambahan daratan dapat terus terjadi dan menimbulkan perluasan lahan mangrove secara alami (Dutrieux et al, 2014). Hal ini dapat terlihat dengan bertambahnya luas wilayah studi selama periode pengamatan (Tabel 1).…”

“…Pada tahun 2004 (Fase 3), mangrove kembali beregenerasi (recovery) baik secara alami maupun penanaman (plantation), ditandai dengan kenaikan luasan hutan mangrove sekitar 10.000 hektar, meliputi di area ex-tambak, jalur pipa dan tanah timbul, antara tahun 2001-2011 (Dutrieux et al, 2014). Hal ini disebabkan oleh banyaknya tambak yang ditinggalkan (non produktif) karena produksi yang menurun (Bosma, Sidik, van Zwieten, Aditya, & Visser, 2012).…”

Population Density and Habitat Characteristics of Nipa Fruticans in Degraded Mangrove Ecosystem (Case Study in Mahakam Delta, East Kalimantan)

“…Many studies have reported that mangrove forest plays various ecological functions, such as biodiversity conservation and as coastline protection from erosion (Dutrieux et al, 2014). In addition, mangrove ecosystem is also essential for providing resources for the livelihoods of local communities.…”

“…Mahakam Delta has become a notable mangrove ecosystem in East Kalimantan due to its ecological, social and economic importance. Mangrove forests in Mahakam Delta function as feeding source as well as spawning and nursery grounds for aquatic organisms, which become a primary source of local communities' livelihoods (Dutrieux et al, 2014;Sidik, 2010). Zain et al (2014) also noted that mangrove forest in Mahakam Delta has high economic value for communities, from both direct use and indirect use values.…”