| Popis: |
This study documents the largest cumulative loss of mangroves due to oil-related activities, including 4415 ha due directly to oil spillage (operational and illegal activities) and 105 ha due to pipeline corridors. Additionally, 217 illegal refinery sites are found which destroyed 116 ha of high ground habitat adjacent to mangroves. Source information utilized includes satellite imagery (1999–2016), aerial videography and photographs (2000, 2010, 2015), and field surveys (1983, 2013, 2015). Mangrove losses began in 2008/2009 due to four spills (three caused by corrosion, one from illegal activity) that caused ~2000 ha of damage. Two of these spills are part of a legal settlement with the resident Bodo community involving a mangrove loss of ~1000 ha. Illegal tapping of the major north-to-south oil-transport pipelines along with a concurrently large increase in illegal refineries became evident in the eastern part of the study area in 2010 and 2011, causing an additional ~1000 ha loss. In 2010, illegal activities also increased in the north causing >300 ha of mangrove loss. After 2013, mangrove losses are small as military operations substantially decreased but did not stop illegal activities. Field studies in 2015, designed to provide guidance to cleanup operations and mangrove restoration, found large areas with very high concentrations of surface and subsurface oil that will inhibit mangrove recovery. Indications are that natural recovery will take much longer than 30 years and, in some areas, may never occur without intervention due to substrate changes that now inhibit seed settlement and growth. |
