Abstract

Genetically modified (GM) plants, expressing traits such as insect resistance or herbicide tolerance, are widely adopted in agriculture. GM maize, soybean, cotton and calona have the largest acreage worldwide. Environmental risk assessment of GM crops is a science based process to assess the likelihood of adverse effects on the environment. Numerous studies have assessed the nontarget effects on terrestrial species, while the potential effects on aquatic organisms do not draw much attention. In this review, we provide an overview on environmental risk assessments of GM crops on aquatic ecosystem published in past 5 years, including our recent works on Bt rice risk assessment on paddy zooplanktons. The assessment processes mainly focus on the ways of GM crop materials entering into aquatic ecosystem and the effects on aquatic organisms. Some of the assessments indicate that aquatic organisms such as caddisflies (trichopteran) and a water flea (Daphnia magna) were adversely impacted by byproduct of GM maize expressing Bacillus thuringiensis (Bt) endotoxin. We suggest that special emphasis should be placed on aquatic ecosystem in risk assessment of GM crops in the future.

Keywords: Aquatic ecosystem; GM crop; Soil microorganisms; Biodiversity