Keanekaragaman Moluska pada Tambak Silvofishery di Desa Tanjung Rejo Kecamatan Percut Sei Tuan

Abstract

Silvofishery activity is an effort to protect mangrove ecosystems that are able to restore their function as a buffer for land and sea ecosystems, one of which is macrozoobenthos. Molluscs and mangrove density data were collected in situ at two locations with 2 times of data collection, namely before and after the rehabilitation of silvofishery ponds in the mangrove area of Tanjung Rejo Village, Percut Sei Tuan District. Mollusc sampling was carried out on sub-plots measuring 1 x 1 m² in the mangrove vegetation transect, mangrove density measurements were carried out by counting the number of stands directly on all types of mangroves in each pond. at the observation site found 15 types of mollusks consisting of classes Gastropods and Bivalves. The abundance of mollusks in July in pond I was 20 ind/m2 and pond II was 9 ind/m2. In October after pond II rehabilitation, abundance was inversely proportional to July In October, the highest abundance was found in pond I at 10.3 ind/m2 and in pond II at 8.88 ind/m2. Value of H’ after rehabilitation, pond I and II which showed a decrease in the index value from 2.82 and 2.98 to 2.52 and 2.68. The types of mangroves found in the two ponds were Avicennia marina, Bruguiera gymnorihiza, Excoeceria agallaocha, and Rhizopora stylosa. The mangrove density in pond I was 887 ind/ha and pond II was 686 ind/ha. The substrate in this study showed that the substrate for both ponds had the same type, namely clay. Nitrate concentration values on the substrate in both ponds ranged from 0.27-0.29%, phosphate 0.07 - 0.09%, C-organic ranged from 3.00 - 5.72%