Studi Tentang Nilai Produktivitas Primer di Pangururan Perairan Danau Toba

Abstract

The research about “ The Study of Primary Productivity in Lake Toba, Pangururan” was done in February 2009. The aim of this research was to investigate the value of primary productivity in lake toba, Pangururan and it’s relation with the value of physic-chemistry factors of water (abiotic) and the abundance of phytoplankton (biotic). The sampling station was determinated by Purposive Randome Sampling Method. Samples were collected from 4 sampling stations and devided into 3 deepness, they are 0 metres (surface), 4 metres, and 8 metres by 2 restarting treatments in each depth. The determination of 3 depths were based on the penetration of light. The value of primary productivity was measured by the Winkler method with light and dark bottles. While the concentration of chlorofill a was measured by using spectrophotometer. The result showed that the value of primary productivity ranged from 75,072 to 300,288 mgC/m3 /day with the highest value obtained at station I and the lowest value at station IV. According to statistical test obtained that there is no significance diffrence of primary productivity value between stations and between deepness. While the correlation analysis showed the correlation between primary productivity and physic-chemistry factors ranged from very low to medium value. Correlation analysis also showed the primary productivity correlated in low value with chlorofill a, and correlated in medium value with the abundance of phytoplankton.