Benthic diatoms are good indicators in analyzing the condition of an environment. Benthic diatoms of Naviculoid and Nitzschioid types are important diatoms that indicate eutrophication in water. Unfortunately, until now, there are very few references about the existence of diatoms in Indonesian freshwater.
The purpose of this study was to determine the diatomic flora found in the Ijen sulfur mountain watershed, Banyuwangi Regency, East Java, Indonesia. This research was conducted in four rivers from the Ijen sulfur mountains, Bendo River (Station 1) and Kampung Anyar River (Station 2) as upstream, Banyuwangi River (Station 3), and Kalilo River (Station 4) as downstream.
Three diatom samples from each river were taken and stored using Lugol 1%. Samples were washed three times using 30% H 2 O 2 to remove organic material, then washed again using distilled water. Furthermore, centrifugation was carried out for 30 minutes at speeds of 1500-2000 rpm to separate the natant from the supernatant. Diatom slide preparation referred to the method used by Charles et al. (2002). Diatom identification and taxonomic classification were carried out referring to Round et al (1990), Krammer and Lange-Bertalot (1991).
A total of 11 taxa were found in the class Naviculaceae (Naviculoid) and Bacillariaceae (Nitzschioid). There were 7 taxa from Navicula sp. found in Bendo River (Station 1) and Kampung Anyar River (Station 2) consisting of Navicula escambia, Navicula symmetrica, Navicula subminuscula, Navicula saprophil, Navicula cryptotenella, Navicula cryptocephala and Navicula caterva . Species from the Naviculaum group are generally found in all freshwater, marine and epipelic waters, though, the presentation of this species distribution is not very broad.
In general, the Navicula found in this study was gold in color, the cells were long like a ship, the basic shape of penales, pennate-type ornaments, had central nodules and polar nodules and the tip of the cell was tapered. Diatoms are generally found in waters that contain little detergent, normal pH, and low oxygen.
Furthermore, as many as 4 taxa from the Nitzschioid family were found in the Banyuwangi River (Station 3) and the Kalilo River (Station 4) such as Nitzschia amphibia, Nitzschia palea, Nitzschia frustulum, and Nitzschia perminuta. In general, Nitzschia species are not only scattered in muddy areas, but the distribution of these organisms is also found to the substrate with diatoms and attached to rocks.
The waters at station 3 and station 4 are waters that are rich in organic material, this may be because in these waters there are tempe and tofu industries and household activities. Nitzschia amphibia is a glass-covered algae which likes muddy water habitat and is an indicator of water that contains a lot of phosphorus.
Author: Suciyono, S.St.Pi., M.P
Link related to this article:
Suciyono, A.A. Sabil, E. D. Masithah, D.D. Nindarwi, M.H. Azhar and M.F.Ulkhaq. 2019. Diatom Naviculoid and Nitzschioid Composition in the Sulfur Mountains Watershed East Java, Indonesia. Indian Veterinary Journal. 96 (09) : 31 – 36