Since 29 May 2006, a mud volcano in Sidoarjo district of East Java, Indonesia, has been emitting hot mud at an average rate of more than 40,000 m3/day. The volcano is so called Lusi, which means “lu” for lumpur (mud) and “si” for Sidoarjo. From the geological standpoint, the mud is estimated to continue spewing for years. Mud volcanoes are geological phenomena due to overpressurized subsurface mud layers. Although it links to the gas exploration activities by Lapindo Brantas, the cause of the eruption has not yet been established. The nature of mud is still questioned since the reports show that the mud is not homogenous (UNEP/OCHA, 2006).
A more pressing concern after the eruption is how the mud should be discharged. Disposal scenario of dumping into the sea through Porong River is unpopular. It could lead to the water flow blockage and affect the coastal productivity. Some ecological engineers recommend the establishment of artificial mud island as the area of the waste material disposal. An artificial wetland system is proposed to receive and make use of deep earth eruptions and incorporate them into productive system (Awad, 2006, McLachan-Karr, 2006).
Mangroves are the natural habitats of the Porong River Area. They have evolved in filtering waste and stabilizing sediments that run from the Porong areas. Because of their unique characteristics, mangroves are already organized to receive the mud within the artificial wetland system. Mangroves are expected to deal with rapid and large changes in environmental inputs. In related to this assumption, a preliminary assessment has been done in 2006-2007 to prove whether mangrove could survive within this mud. This study aims to investigate the probability of dominant mangrove species in Porong, which is Avicennia, to survive in “Lusi”.
Result
Within 10 days, Avicennia sp has shown fine growth compare to Rhizophora sp. There are no significant difference between the growth of mangrove with the media of simply mud and mudwith fertilizer. Direct and indirect sunlight is also one of the treatments that applied in thesamples. The current result does not show the significant influence of their growth with thosedifferent solar radiations setting. However, further observation is needed to conclude the findings.
source : Marine Conservation Team – IMRO
