Pesticide Application and Detection in Variable Agricultural Intensity Watersheds and Their River Systems in the Maritime Region of Canada

Abstract

Applications of pesticides in areas of agricultural production have been an environmental concern for the past several decades. Varying-sized watersheds draining regions of intense agriculture in the Maritime Provinces of Canada were monitored between 2003 and 2007 to determine the major in-use pesticides and to gain an understanding of the risks posed to aquatic ecosystems. A questionnaire collected from farmers in one watershed intensively cropped with potato indicated that 43 pesticides were applied with 18 of them being detected in that watershed. Our results across the Maritime region suggested that detection frequencies ranged from 0.0 to 22 % during the study period. Chlorothalonil, linuron, metalaxyl, and metribuzin were detected in 17-22 % of samples collected during rainfall events every year. Other pesticides, such as azinphos-methyl, atrazine, cypermethrin, permethrin, fonofos, and β-endosulfan were detected in ≤17 % of the samples during some years of the study. Concentrations of several pesticides were found to exceed their Canadian Council of Ministers of the Environment (CCME) aquatic life water-quality guidelines in pulses after rain events. The highest proportion of detections exceeding a CCME guideline was for chlorothalonil at 12.9 %, β-endosulfan at 6.0 %, and linuron at 3.4 %. Despite indications that remedial measures offer protection to aquatic environments, spatial and temporal gaps in the data prevented a full evaluation. A dedicated long-term multiple-watershed monitoring program for this region of Canada is therefore recommended.

Relationships between past and present pesticide applications and pollution at a watershed outlet: The case of a horticultural catchment in Martinique, French West Indies

“…Studies were performed at the catchment scale in temperate conditions to better understand the effects of hydrology, pesticide application rates, land uses, and molecular characteristics on the water contamination by pesticides (Blanchard and Lerch, 2000;Guo et al, 2004;Leu et al, 2004;Lewis et al, 2016). Studies focused on water pollution resulting either from pesticides used in agriculture (Palma et al, 2004;Wightwick et al, 2012;Xing et al, 2012) or in urban area (Blanchoud et al, 2004). In the tropical context, several research has been conducted on water contamination by pesticides (Lewis et al, 2016), but few were conducted in tropical context at the catchment scale (Houdart et al, 2009).…”

Impact of an Acute Sublethal Exposure of Endosulfan on Early Juvenile Lobster (Homarus americanus)

“…It is found in soils and in the atmosphere, making drift issues a major environmental problem (Weber et al, 2010;White et al, 2006). Endosulfan was detected in freshwater streams in about 6% of the samples in 1-4 years over a 5-year period (2003-2007) in intensive potato production regions of PEI (Xing et al, 2012). Maximum endosulfan concentration in freshwater streams for PEI was about 10 µg•L -1 with a highest annual mean of 0.64 µg•L -1 which exceed endosulfan concentrations recommended by the Canadian Water Quality Guidelines for the protection of aquatic life (CCME, 2010), which is 0.09 µg•L -1 for a short-term exposure in marine water or 0.06 µg•L -1 for freshwater.…”

Enzymatic, Immunological, Biochemical, and Antioxidative Responses of the Rainbow Trout to Dietary p-Coumaric Acid upon Exposure to Ronstar Herbicide

“…The aforementioned process induces changes in the chemical composition of the water, subsequently influencing the organisms inhabiting the area [5]. Previous studies have indicated that herbicides can have adverse effects on fish, such as reduced reproduction, alterations in behavior, loss of biodiversity, and genetic, neurological, and hemato-immunological disorders [6][7][8][9].…”