Study of Trochus Niloticus Growth Population as Determination Base of Number and Harvest Time Distance in Rhun Island Waters

Abstract

The increasing occurrence of Trochusniloticus asking every year has caused explotation being more and more intensive. It caused the more decreasing of production including extinction. This study aims: 1) to determine population growth and potential of T.niloticus in the explotation area (zone edge reef) and 2) to determine the use level and distance of harvest time for continuity of population. Monitoring of groth population was done monthly for 16 months. The area wide of observation was 2400 m 2 or17.14% of the area wide of study with 2 m width, 400 m length and 6 units transect line. Citing was done by divers using snorkel and scuba with transect line.Every observation was put 6 units transect line using parallel line with coastal line. The monitoring on maximum population density was carried out by using quadran with the size of 5m x 5m to determine the use level for the continuity population. The result showed that the maximum density of T.niloticus population in the exploitation zone during 16 month was 0.08 ind m-2 whilst, the population density average was 0.0254 ind m-2 with the potential of 356 ind (14000 m 2) or 254 ind ha-1. The use level namely 243 ind (68.25%) of potency and around 113 ind (31%) was prepared as plasma nutfa. In addition, The distance of harvest time to recoverT.niloticus resource is 15 months.