Tidal Variation of Water Quality from Mouth of River to Offshore Area in Buloh River, Selangor Cockle Culture Ground, Malaysia

Abstract

Though blood cockle is an important and cheap protein source for the Malaysian population, the production in Selangor decreased drastically from 2010 to 2013. However, production was basically constant in Perak and Penang, which are north of Selangor, during the same period. This suggests something happened specifically in the Selangor cockle culture ground. The present study investigated the influence of tidal variation over a 25-hour period on water quality from mouth of river to offshore area in Buloh River, Selangor cockle culture ground, Malaysia. Water below pH 5.7–6.5 is generally thought to be harmful to aquatic animals. The water in the tidal flat had acidic pH when ammonium was high, whereas pH was alkaline when ammonium was low; therefore, toxicity due to ammonia might be low in that area. However, pH was 4.3–5.3 at ebb tides in cockle culture ground, which suggests that pH rather than ammonia may influence cockle growth and survival rate. Accordingly, the upper stream region of this river should be surveyed to determine the origin of ammonia and pH in this water.

Keywords: blood cockle, ammonium, pH, Buloh River, Selangor, Malaysia