A screening method for prioritizing non-target invertebrates for improved biosafety testing of transgenic crops
Environmental Biosafety Research
We have developed a screening method that can be used during the problem formulation phase of risk assessment to identify and prioritize non-target invertebrates for risk analysis with any transgenic plant. In previously published protocols for this task, five criteria predominated. These criteria have been combined by our method in a simple model which assesses: (1) the possible level of risk presented by the plant to each invertebrate species (through measurements of potential hazard and
... ial hazard and exposure, the two principal criteria); (2) the hypothetical environmental impact of this risk (determined by the currently known status of the species' population in the ecosystem and its potential resilience to environmental perturbations); (3) the estimated economic, social and cultural value of each species; and (4) the assessed ability to conduct tests with the species. The screening method uses information on each of these criteria entered into a specially designed database that was developed using Microsoft Access 2003. The database holds biological and ecological information for each non-target species, as well as information about the transgenic plant that is the subject of the risk assessment procedure. Each piece of information is then ranked on the basis of the value of the information to each criterion being measured. This ranking system is flexible, allowing the method to be easily adapted for use in any agro-ecosystem and with any plant modification. A model is then used to produce a Priority Ranking of Non-Target Invertebrates (PRONTI) score for each species, which in turn allows the species to be prioritized for risk assessment. As an example, the method was used to prioritize non-target invertebrates for risk assessment of a hypothetical introduction of Bacillus thuringiensis (Bt) Cry1Ac-expressing Pinus radiata trees into New Zealand. Keywords: screening method / non-target invertebrates / transgenic crops / ecological risk assessment * Corresponding author: email@example.com selected for consideration in the risk assessment of each type of transgenic plant. A widely accepted conceptual framework for ecological risk assessment begins with a problem formulation phase, in which particular environmental entities or attributes requiring protection from harm are defined (assessment endpoints), conceptual models describing their relationships are developed, risk hypotheses formulated, and an "analysis plan" for examining these hypotheses is made (Fig. 1) (USEPA, 1998) . The risk assessment then proceeds to the actual analysis and characterization of the risks posed by the stressor in question. Within this framework, the selection of assessment endpoints is a crucial early step, upon which the success of the entire risk assessment can depend (Raybould, 2007; USEPA, 1998). Criteria for selecting assessment endpoints include ecological relevance, susceptibility to known or potential stressors (sensitivity and exposure), and relevance to management goals (usually defined in policy) Article published by EDP Sciences and available at Schoener TW(1980) Length-weight regressions in tropical and temperate forest-understory insects. Ann. Entomol. Soc. Am. 73: 106-109 Schuler TH, Clark AJ, Clark SJ, Poppy GM, Stewart CN, Denholm I (2005) Laboratory studies of the effects of reduced prey choice caused by Bt plants on a predatory insect. Bull. Entomol. Res. 95: 243-247 Silby RM, Akçakaya HR, Topping CJ, O'Connor RJ (2005) Population-level assessment of risks of pesticides to birds and mammals in the UK. Ecotoxicol.