Strategic Management of Principals In Improving Quality Junior High Schools

Abstract

The present study reports the first comprehensive study on the freshwater macroinvertebrates and its habitat preferences
in Bilah River, the largest riverin the Northern Sumatra. The riverside is characterized by the presence of anthropogenic
and industrial activities which may alter the macroinvertebrate assemblage and biodiversity. Five months of investigation
on 10 sampling stations from December 2016 to October 2017 was conducted based on the river flow in Bilah River.
Principal component analysis indicated a decrease in trophic status from upstream to downstream of the river. A total of
27 taxa were recorded, with the most abundant group were members of Odonata, Gastropoda, and Decapoda. The
highest density of macroinvertebrate was observed from station 1 (160 ind m-2), while the lowest density was observed
from station 9 (38.64 ind m-2
). Based on species distribution and similarity, two groups of habitats may be distinctively
recognized based on the Bray-curtis similarity coefficient. Group 1 consisted of station 1, 2, 3 and 4 while group 2
consisted of station 5, 6, 7, 8, 9, and 10. Based on the diversity indices as ecological parameters, the habitat condition in
Bilah River is categorized from low to moderately polluted. Spatial patterns in both environmental conditions affecting
the macroinvertebrate assemblage was observed using canonical correspondence analysis (CCA) revealed the
preferences from each macroinvertebrate species towards environmental conditions.