« Previous AbstractOzone pollution disrupts plant-pollinator systems    Next Abstract"Plant-natural enemy association in the tritrophic system,Cotesia rubecula-Pieris rapae-brassiceae (cruciferae): I. Sources of infochemicals" »

Environ Toxicol Chem

Title:		Promoting effects on reproduction increase population vulnerability of Daphnia magna
Author(s):		Agatz A; Hammers-Wirtz M; Gabsi F; Ratte HT; Brown CD; Preuss TG;
Address:		"University of York, Heslington, York, United Kingdom. annika.agatz@fera.gsi.gov.uk"
Journal Title:		Environ Toxicol Chem
Year:		2012
Volume:		20120512
Issue:		7
Page Number:		1604 - 1610
DOI:		10.1002/etc.1862
ISSN/ISBN:		1552-8618 (Electronic) 0730-7268 (Linking)
Abstract:		"Environmental risk assessment of chemicals is based on single species tests at the individual level with single compounds. However, the protection goal is the sustainability of a population, which faces several natural stressors and mixtures of chemicals in the environment. Therefore, experiments were undertaken to quantify the combined effects of chemicals with different modes of action on Daphnia magna populations. Populations continuously exposed to dispersogen A and at abundance equilibrium were treated with a 2-d pulse of p353-nonylphenol. In previous studies, dispersogen A was shown to act as a natural info-chemical, promoting the reproduction of daphnids (higher offspring quantity) coupled with reduced offspring fitness, whereas nonylphenol in pulsed-exposure caused size-selective mortality. Dispersogen A caused accelerated population growth to maximum abundance, shifted the population structure towards smaller individuals, and increased the population sensitivity to nonylphenol. The authors showed that a positive effect observed at the individual level can be transposed to a negative effect when monitored at the population level. So far, positive effects are not addressed in environmental risk assessment, and even in higher-tier testing, population structure is not quantified. Both factors indicate a potential mismatch between protection aim and risk assessment practice"
Keywords:		"Animals Daphnia/*drug effects/growth & development Naphthalenesulfonates/*toxicity Phenols/*toxicity Population Growth Reproduction/drug effects Water Pollutants, Chemical/*toxicity;"
Notes:		"MedlineAgatz, Annika Hammers-Wirtz, Monika Gabsi, Faten Ratte, Hans Toni Brown, Colin D Preuss, Thomas G eng Research Support, Non-U.S. Gov't 2012/05/03 Environ Toxicol Chem. 2012 Jul; 31(7):1604-10. doi: 10.1002/etc.1862. Epub 2012 May 12"