INTERNATIONAL JOURNAL OF AGRICULTURAL TECHNOLOGY

Volume 14, No. 07, Month DECEMBER, Year 2018, Pages 1181 - 1192

Inhibition of acetylcholinesterase activities in whitegoby, glossogobius giuris from the east bay of laguna lake, philippines

Fajardo, L. J. and Ocampo, P. P.

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Laguna Lake, the largest freshwater lake in the Philippines, has been threatened by fertilizers and pesticides runoff from agricultural land use in the eastern bay. Glossogobius giuris, whitegoby, is one of the native and commercially important fishes in the lake and is reported to be of declining population. Inhibition of acetylcholinesterase (AChE) activity is widely known as biomarker of exposure to organophosphates and carbamates pesticides. The study determined AChE activities in brain and muscle using rapid colorimetric method in wild fish populations obtained from two predominantly agricultural sites (Bay and Santa Cruz) in Laguna and a reference population, reared in concrete tanks. Measured brain AChE activity across populations was significantly (P<0.05) higher than muscle. This resulted to a significantly (P<0.05) higher inhibition rate in muscle than brain in wild populations. However, inhibition rates were not significantly (P>0.05) different between agricultural sites. Depressed AChE activity levels may indicate fish exposure and toxicity to anticholinesterase pesticides in the eastern bay of the lake. This could be supported by carbamates and organophosphates usage in rice and vegetable production along the lakeshore as revealed through key informant interviews and focus group discussions. Findings may assist in the monitoring of the lake’s ecological status and on management actions pertaining to agricultural inputs and other wastes that possibly contribute to the deteriorating water quality and declining fish production in the lake. Further studies with increased sample size from other bays and tributaries of the lake, and the analyses of water and sediment samples for detection of pesticides and other neurotoxic compounds (e.g. heavy metals) affecting AChE activity levels are recommended for an overall assessment on the status of this fishery resource.

Keywords

biomarker, carbamate, fish muscle, organophosphate

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