Advanced

Reduced grazing rates in Daphnia pulex caused by contaminants: Implications for trophic cascades

Bengtsson, Göran LU ; Hansson, Lars-Anders LU and Montenegro, Katia LU (2004) In Environmental Toxicology and Chemistry 23(11). p.2641-2648
Abstract
Ecotoxicological endpoints based on behavioral traits (e.g., predator avoidance, feeding, and locomotion) may be more sensitive and give more insights into patterns of sublethal toxicity than survivorship tests. In this study, the density-dependent grazing rate of Daphnia pulex pre-exposed to p,p'-dichlorodiphenyldichloroethylene (DDE) (insecticide metabolite) and glyphosate (herbicide), via water or a vector, Scenedesmus spp., was assayed in laboratory experiments. The phytoplankton biomass was estimated from the chlorophyll content, and the pesticide uptake and turnover pattern in Daphnia and Scenedestnus were determined from parallel experiments with a radiolabeled source. Scenedestnus spp. relative net growth rate was inversely and... (More)
Ecotoxicological endpoints based on behavioral traits (e.g., predator avoidance, feeding, and locomotion) may be more sensitive and give more insights into patterns of sublethal toxicity than survivorship tests. In this study, the density-dependent grazing rate of Daphnia pulex pre-exposed to p,p'-dichlorodiphenyldichloroethylene (DDE) (insecticide metabolite) and glyphosate (herbicide), via water or a vector, Scenedesmus spp., was assayed in laboratory experiments. The phytoplankton biomass was estimated from the chlorophyll content, and the pesticide uptake and turnover pattern in Daphnia and Scenedestnus were determined from parallel experiments with a radiolabeled source. Scenedestnus spp. relative net growth rate was inversely and linearly related to the density of the grazer. Daphnia pulex exhibited significant reductions in grazing rate: 30% for those pre-exposed to p,p'DDE via water and 40% for D. pulex pre-exposed to glyphosate via Scenedesmus spp. Through the process of trophic cascading, this impaired grazing allowed Scenedesmus spp. to grow at higher rates, 70 and 60%, respectively. The reduced grazing efficiencies were associated with the treatments that gave the highest body burden of p,p'-DDE (70 mug/g dry wt) and the lowest of glyphosate (13 mg/g dry wt). The pattern of results suggests a toxic effect of p,p'-DDE on D. pulex and a growth enhancement of Scenedesmus spp. in response to nitrogen and phosphorus in glyphosate excreted by D. pulex. (Less)
Please use this url to cite or link to this publication:
author
organization
publishing date
type
Contribution to journal
publication status
published
subject
in
Environmental Toxicology and Chemistry
volume
23
issue
11
pages
2641 - 2648
publisher
SETAC and Alliance Communications Group
external identifiers
  • pmid:15559279
  • wos:000224517000016
  • scopus:5444265964
ISSN
0730-7268
DOI
10.1897/03-432
language
English
LU publication?
yes
id
363f57cf-8e8b-46d1-a5e3-5f1d6cbf2625 (old id 135800)
date added to LUP
2007-06-27 08:19:26
date last changed
2017-11-12 03:17:48
@article{363f57cf-8e8b-46d1-a5e3-5f1d6cbf2625,
  abstract     = {Ecotoxicological endpoints based on behavioral traits (e.g., predator avoidance, feeding, and locomotion) may be more sensitive and give more insights into patterns of sublethal toxicity than survivorship tests. In this study, the density-dependent grazing rate of Daphnia pulex pre-exposed to p,p'-dichlorodiphenyldichloroethylene (DDE) (insecticide metabolite) and glyphosate (herbicide), via water or a vector, Scenedesmus spp., was assayed in laboratory experiments. The phytoplankton biomass was estimated from the chlorophyll content, and the pesticide uptake and turnover pattern in Daphnia and Scenedestnus were determined from parallel experiments with a radiolabeled source. Scenedestnus spp. relative net growth rate was inversely and linearly related to the density of the grazer. Daphnia pulex exhibited significant reductions in grazing rate: 30% for those pre-exposed to p,p'DDE via water and 40% for D. pulex pre-exposed to glyphosate via Scenedesmus spp. Through the process of trophic cascading, this impaired grazing allowed Scenedesmus spp. to grow at higher rates, 70 and 60%, respectively. The reduced grazing efficiencies were associated with the treatments that gave the highest body burden of p,p'-DDE (70 mug/g dry wt) and the lowest of glyphosate (13 mg/g dry wt). The pattern of results suggests a toxic effect of p,p'-DDE on D. pulex and a growth enhancement of Scenedesmus spp. in response to nitrogen and phosphorus in glyphosate excreted by D. pulex.},
  author       = {Bengtsson, Göran and Hansson, Lars-Anders and Montenegro, Katia},
  issn         = {0730-7268},
  language     = {eng},
  number       = {11},
  pages        = {2641--2648},
  publisher    = {SETAC and Alliance Communications Group},
  series       = {Environmental Toxicology and Chemistry},
  title        = {Reduced grazing rates in Daphnia pulex caused by contaminants: Implications for trophic cascades},
  url          = {http://dx.doi.org/10.1897/03-432},
  volume       = {23},
  year         = {2004},
}