Aplikasi Teknologi Bioengineering Jebakan Sedimen di Sub DAS Citanduy Hulu

Citanduy watershed has been classified as a critical watershed in West Java. Sedimentation load at Citanduy watershed reach 5 milion cubic meters/years. It is indicated that lagoon area “Segara Anakan” was decreased about 823 hectars. Land use changes for cultivation area at Citanduy upland causes acceleration land degradation. Various efforts of the civil engineering and vegetative approach have been applied to control erosion and sedimentation. Alternative technology for controlling soil erosion and sedimentation is the application of sediment trap bioengineering. It is application on micro catchment area, environment-friendly, and easily adapted for the farmers community. The main for material of bioengineering sediment trap is made of Bamboo. Results of design that is applied in the critical area at Bukit Bitung up land (Citaduy upland) Kecamatan Tambaksari, Ciamis Region, measuring the width between 100 cm to 150 cm, whereas the height are between 80 cm to 100 cm. The application of this technology is effective sediment traps for micro catcment area of <5 hectars. Therefore for a broad cachment area more sediment traps are required. In a period of not more than 1.5 month, the sediment trap has been able to capture sediments up to 1 m3 per unit. The performance of sediment traps bioengineering also shown that bamboo as main components has grown up to not more than 30 days. The trapped sediments were restored back to the land for agricultural purposes after being add by agricultural waste. Sediments that have been processed at the same time also functions as soil amelioration or soil improvement

Trans-equatorial migration and mixing in the wintering areas of a pelagic seabird

Despite increasing interest in long-distance migration, the wintering areas, migration corridors, and population mix in winter quarters of most pelagic marine predators are unknown. Here, we present the first study tracking migration movements of shearwaters through the non-breeding period. We used geolocators (global location sensing [GLS] units based on ambient light levels) to track 22 Cory's shearwaters (Calonectris diomedea) breeding in three different areas. Most birds wintered in one or more of three relatively small areas, all clearly associated with major coastal upwelling systems of the tropical and south Atlantic. Trans-equatorial movements were dominated by prevailing trade winds and westerlies, while calm, oligotrophic areas were avoided. Breeding populations clearly differed in their preference amongst the three major wintering areas, but showed substantial mixing. This illustrates the exceptional value of GLS, not only for determining and describing the influence of oceanographic features on migration patterns, but also for assessing population mix in winter quarters. This knowledge is essential to understanding the impacts of population-level threats, such as longlining, offshore windfarms, and oil spills on multiple breeding sites, and will be critical in devising conservation policies that guarantee the sustainable exploitation of the oceans