The Relationship between Sedimentation and Ecosystem of Coral Reef in the Lampung Bay, Province of Lampung

Abstract

Sedimentation is one of the limiting factor for coral distribution through both the suspended and deposited sediment causing the reduce of light penetration and smothering the polip of coral reefs that can lead to coral death. The purpose of this study was to analyze the relationship of sedimentation with conditions of coral reef ecosystem through observing of the sedimentation rate and analyze community of coral reef. The transects were deployed at the three line series perpendicular wuth an interval of 50 m between the line. Each transect was pleaced at every 10 m along the line. Date within the transect were observed using the underwater camera. The images were analyzed by using CPCe software (Coral Point Count with Excel extensions). Sedimentation rate was measured by a sediment trap using PVC pipe with a diameter of 5 cm and 11.5 cm in height and partition (baffles) cover at the top. Sediment traps were mounted on a 12 mm diameter steel poles at a height of 20 cm from the bottom. Sediment traps were deployed for 20 days, then the recovered sediment was dried in an oven at 60 0C for 24 hours. Sedimentation rate varied between the stations with a range of values from 3.09 to 44.29 mg/cm2/day. The lowest rate of sedimentation was found in Station 7, while the highest was found at Station 1. Sedimentation rates are generally grouped into light untill moderate condition, whereas in some Stations (1, 3, and 6) showed heavy sedimentation rates. The high rate of sedimentation at Station 3 was probably due to close to the mouth of the river. Coral cover ranged from 8.75 to 60.85%, generally showing moderate categories. Severe damages were found in Station 1, 3, and 6 with a dominant form of massive coral, while good categories were found at Station 9 which located in a relatively remote area of influence of the river and dominated by foliose and brancing form. There was a strong indication of relationship sedimentation and coral reefs cover this research area.