Benthic Macroinvertebrate Assemblage in Bulod River, Lanao del Norte, Philippines

Macroinvertebrates are biomonitor species in determining the water quality in freshwater bodies. Benthic macroinvertebrates were assessed in upstream, midstream and downstream of Bulod River, Tubod, Lanao del Norte, Philippines during the month of October-November 2013. The dip net method was used to collect the macroinvertebrates in each station.  Identification of species was done using taxonomic keys. A total of 1198 individuals belonging to 24 families of aquatic insects, mollusks, flatworms and aquatic earthworms were identified. Aquatic insects (Class Hexapoda) mostly dominated the area which accounted 91% of the total abundance. Rarefaction analysis showed highest taxa richness in station 3. Family biotic index (FBI) indicates very good water quality in Station 1 (upstream) and Station 3 (downstream) which is evident by the presence of pollution-sensitive fauna, such as Ephemeroptera, Trichoptera and Plecoptera. The fairly poor water quality in Station 2 (midstream) indicates massive pollution due to various drastic disturbances due to agricultural and other anthropogenic activities.

 

Keywords: aquatic insects, dip net method, freshwater, pollution, species diversity.