MARVIE D. AGURO, XENIA ENRIKA F. LAGTAPON, MARY CAMILLE E. REYES (FEBRUARY 2007)
Philippine Science High School Western Visayas Campus – Department of Science and Technology (DOST-PSHS WVC), Brgy. Bito-on, Jaro, Iloilo City 5000, Philippines
ABSTRACT
Benthic diatoms are microscopic algae which are powerful water quality bioindicators – life forms whose function, population or status can be used to assess water condition. Several countries use diatoms as indicators of river health.
This study dealt with the water quality assessment and taxonomic classification of benthic diatoms in Badbaran River in Dumarao, Capiz. Relative abundance and diversity index of the diatoms were also determined. Water quality parameters included salinity, conductivity, temperature, turbidity, dissolved oxygen (DO) content, pH, and total dissolved solid (TDS) concentration.
In-situ water quality tests were conducted in a 40-meter stretch of the river divided into four 10-meter sites. Diatom sample collection from five randomly selected rocks in each site followed. Laboratory water quality parameters were measured and taxonomic classification of diatoms followed.
Mean salinity for all four sites is 0.1 ppt. The range of the following measured parameters are: conductivity, 117.008 μs to 120.933 μs, temperature, 31.417 °C to 32.058 °C; dissolved oxygen content, 7.1425 mg/L to 7.7058 mg/L.; pH, 7.49 to 7.78; TDS, 0.167 g/L to 0.056 g/L.
Forty-one species under thirty genera were found in the samples. Genus Nitzschia and Gomphonema had the most number of species, 5 and 4 respectively. Nitzschia communis had the highest relative abundance of 15.74%. Species diversity determined using Shannon-Wiener index was 2.78 nats.
Badbaran River, having a high diversity index, supports a diverse community of diatoms, and is ecologically stable. The river is unlikely to change rapidly and is not greatly affected by pollution or human activities.