Identification and Diversity of Organisms in the Lake Toba Area

Retnita Ernayani Lubis ,Ibrohim Ibrohim

doi:10.15294/jpii.v8i3.19043

Abstract

This research is an explorative research/Land-Based Survey. The purpose of this research is to identify an organism in the Lake Toba water to see organism diversity in the area of Lake Toba, and some factors which influence the kind and diversity of organism in Lake Toba. This research was conducted by using methods of a trap in May 2016 until April 2017 in three regencies of Lake Toba Area, including Samosir, Simalungun, and Porsea Regency. The result of the research showed that the organisms found in the waters of Lake Toba were Plakton, Macrozoobentos, and Nekton. The index of macrozoobenthos diversity in three regencies are categorized into low. The highest value of diversity was in Samosir Regency (1,6) then followed by Tobasa (1,5), and Simalungun (0,43). The value of plankton diversity index in three regencies are; Samosir (2,47), Tobasa (1,41), and Simalungun Regency(1,63). The index of fish diversity in three regencies was categorized into low; Samosir (1,97), Tobasa (1,16), and Simalungun Regency (1,61). In those three districts, there were 25 species of plankton, 12 species of macrozoobenthos and 8 species of fish. The change of the environmental condition influenced the diversity of animal. The research suggests that the need for conservation as the management planning to cope with the environmental condition to maintain the quality of Lake Toba environment.

Highlights

Lake Toba is one of the largest lakes in Indonesia with the type of volcano-tectonic lake
Based on the above explanation, the purpose of this study is to identify the organisms in Lake Toba water, to see the diversity of organisms in the Lake Toba Area, and the factors that influence the diversity of organisms in the Lake Toba Area
Macrozoobentos found in Samosir Regency were found 9 genera, Tobasa 17 genera, and Simalungun 3 genera

Summary

Introduction

Lake Toba is one of the largest lakes in Indonesia with the type of volcano-tectonic lake. The explosion of Toba volcano (tumor Batak) formed Lake Toba. It located in the coordinates of 2010’N-300’N and 98020” E-99050”E or in the Bukit Barisan mountains of North Sumatra Province. The Lake Toba area consisted of seven districts, namely North Tapanuli Regency, Humbang Hasundutan, Toba Samosir, Samosir, Simalungun, Karo, and Dairi (Siregar, 2008). Lukman et al,( 2012) stated that the water of Lake Toba comes from rainwater and rivers flowing into the lake. The pattern of water flow is dominated by inlets from small rivers which is 289 rivers and only 71 permanent rivers, and others are seasonal. The outline of the Lake Toba water flow originates only from the Asahan River, which empties into the East Coast of Sumatra (figure 1a)

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