Ecotoxicological impact of agricultural contaminants on selected aquatic organisms

Issue Date

10-2008

Abstract

The Pagsanjan-Lumban watershed is the main source of fresh water to Laguna Lake but is surrounded by farms with intensive agricultural activities. Off-site diffusion of pesticides and nutrients from fertilizer applications can have an effect on aquatic life and quality of water resources. Toxicological tests of pesticides (cypermethrin, lambda cyhalothrin, deltamethin and malathion), currently used in agricultural farms (rice, vegetable and coconut) within the watershed, were done in the laboratory on Tilapia fingerlings and duckweed Lemna sp., an important fish food. Deltamethrin, Lambda cyhalothrin and cypermethrin affected Lemna growth at concentrations ≥ 10 ppm. Malathion also affected the growth of Lemna at ≥ 25 mg/L in water. Composite samples of water collected weekly from Majayjay, Laguna had negative impact on the growth parameters of duckweed and the growth and survival of Tilapia fingerlings compared to water collected from Pagsanjan, Cavinti and Lukban. Calculated doubling time of Lemna fronds for Lukban, Pagsanjan, Majayjay and reconstituted fresh water was 9.4, 9.6, 40.4 and 12.5 days, respectively. No recovery of the chlorotic Lemna was observed after exposure of the treated Lemna for 7 days in clean water.

Source or Periodical Title

Philippine Entomologist

ISSN

0048-3753

Volume

22

Issue

2

Page

206-207

Document Type

Article

Frequency

semi-annually

Language

English

En – AGROVOC descriptors

LEMNA; AQUATIC ORGANISMS; CYPERMETHRIN; FRESHWATER; FRESHWATER ECOLOGY; PESTICIDES; AQUATIC ECOLOGY; PHILIPPINES

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