DOCSLIB.ORG

Aquatic Toxicology Isananalysiswhich Aquatic Toxicology Toxicity Issues

Total Page：16

File Type：pdf, Size：1020Kb

Download full-text PDF Read full-text
Aquatic Toxicology Isananalysiswhich Aquatic Toxicology Toxicity Issues Aquatic Toxicology Aquatic Toxicology is an analysis which Why Choose Eurofins studies the adverse effects of chemicals Environment Testing US? on aquatic organisms. These organisms • Consulting: With more than 25 years are subjected to varying concentrations of experience, our knowledgeable and of an aqueous solution to determine if credible scientists can be called upon to lethal or sub-lethal effects are observed. help determine and solve toxicity issues. Bioassay tests can also be applied to soil • Credentials: As a NELAC-accredited and sediment materials with plant and laboratory, we have the ability to terrestrial invertebrate species. perform tests in any state participating in the NELAP program. In addition, During the 1970’s Whole Effluent Toxicity we maintain certifications or approvals (WET) tests were developed by the in states that do not participate in the United States Environmental Protection NELAP program. Agency (USEPA) as a means to enforce • Permit Review and Regulatory the Clean Water Act’s prohibition of the Compliance: We are able to provide discharge of toxic pollutants in toxic assistance in order to effectively amounts. Each EPA Region and the interpret state and federal waste states within those regions adapted the discharge compliance requirements. EPA protocols to meet those objectives. • In-house Cultures: The majority Today every state and territory of the US of the organisms we test with are cultured within our facility. This ensures is required to have a program of aquatic a continuous and reliable supply of toxicology testing in place. healthy organisms for testing. As one of the premier aquatic toxicology • Fast and Accurate Results: All of our laboratories in the Mid-Atlantic, our data goes through peer and internal QA/ 9555 0516 QC checks prior to being submitted to experts have been providing bioassay the client. Reports are custom designed services to wastewater clients in support to meet client’s requirements for internal of the Clean Water Act (CWA) since 1987. and regulatory reporting. We also We have a long history of helping clients employ the latest statistical software meet their compliance requirements and to calculate endpoints precisely. Even solving problems for those who have with these layers of review and custom toxicity issues. designed reports, our TAT is typically less than one week. Our Capabilities • Field sampling We offer a broad range of aquatic • Completely customized testing toxicology testing including the design of All testing is conducted in our state- client-specific test protocols required to of-the-art facility designed specifically satisfy CWA specifications and other non- for aquatic toxicology testing. All of our wastewater needs. aquatic toxicology tests are performed Our testing capabilities include: in accordance with USEPA methods. • Acute and Chronic Whole Effluent If required, customized protocols are Toxicity testing with freshwater and employed for non-wastewater sources marine species to comply with other regulatory agency requirements. • Sediment/Soil Assays • Toxicity Identification Evaluations Our culture laboratory consists of systems (TIEs) designed for the purpose of breeding healthy organisms with genetic traceability. • Chlorophyll a analysis Monthly Standard Reference Toxicant • Water Effect Ratios (WERs) (SRT) tests are performed on all organisms • Pure compound testing. cultured in house. Concurrent SRT tests are • Stream surveys (biological/chemical) performed on organisms brought in from for impact and eutrophication outside culture laboratories. All SRT data is studies graphed and evaluated for consistency. Methods for Routine Bioassay Testing Species Method Pimephales promelas (Fathead Minnow) EPA 1000.0; 2000.0 Ceriodaphnia dubia (Water Flea) EPA 1002.0; 2002.0 Selenastrum capricornutum (Microalga) EPA 1003 Cyprinodon variegatus (Sheepshead Minnow) EPA 1004; 2004.0 Menidia beryllina (Inland Silverside) EPA 1006; 2006.0 Mysidopsis bahia (Mysid Shrimp) EPA 1007; 2007.0 Cyprinella leedsi (Bannerfin Shiner) EPA 2000.0 Daphnia pulex (Water Flea) EPA 2021.0 Hyalella azteca EPA 100.1 / 100.4 Chironomus dilutus (formerly tentans) EPA 100.2 / 100.5 Lumbriculus variegatus EPA 100.3 Other specialized testing on demand Eurofins Environment Testing US - Centers of Excellence Eurofins Air Toxics Eurofins Calscience Eurofins Eaton Eurofins Frontier Eurofins Lancaster Eurofins QC Eurofins Spectrum Folsom, CA Garden Grove, CA Analytical Global Sciences Laboratories Southampton, PA Analytical 800-985-5955 714-895-5494 Monrovia, CA Bothell, WA Environmental 215-355-3900 Agawam, MA 626-386-1100 425-686-1996 Lancaster, PA Horsham, PA 413-789-9018 South Bend, IN 717-656-2300 215-355-3900 North Kingston, RI 574-233-4777 401-732-3400 www.EurofinsUS.com/Env.
Load more

Recommended publications
  • Aquatic Toxicology MEES 743 3 Credits SPRING 2019 (Also Listed As TOX 625)
    Aquatic Toxicology MEES 743 3 credits SPRING 2019 (also listed as TOX 625) Course Objectives / Overview This course will provide students with a broad perspective on the subject INSTRUCTOR DETAILS: of aquatic toxicology. It is a comprehensive course in which a definitive description of basic concepts and principles, laboratory testing and field Faculty Details: situations, as well as examples of typical data and their interpretation and Dr. Carys Mitchelmore use by industry and water resource managers, will be discussed. The fate [email protected] and toxicological action of environmental pollutants will be examined in 410-326-7283 aquatic ecosystems, whole organisms and at the cellular, biochemical and molecular levels. Current and emerging issues will be used as case studies CLASS MEETING DETAILS: throughout the course to illustrate specific ecosystems (e.g. Chesapeake Bay), pollution events (e.g. Deepwater Horizon Oil Spill), particular Date: Monday/Wednesday organisms (e.g. coral reefs) or a specific class of contaminants. Classes Time: 12-1.30pm will consist of lectures by the instructor together with some guest Originating Site: UMCES, CBL speakers in addition to group discussions. IVN bridge number: (800414) Phone call in number: (***) Expected Learning Outcomes Room phone number: CBL, Ed Houde Teaching suite Following completion of this course students will; (1) Have experience applying basic concepts in environmental COURSE TYPE: science, including environmental chemistry, biology and Check all that apply physiology, ecosystem health, management and regulatory issues, ☐ as they relate to pollution of aquatic ecosystems. Foundation (2) Be able to identify a current topic of concern and summarize ☐ Professional Development current data/papers in an oral presentation including directing an ☐ Issue Study Group open discussion with the rest of the class.
    [Show full text]
  • AN INTRODUCTION to AQUATIC TOXICOLOGY This Page Intentionally Left Blank €ƒÂ€ an INTRODUCTION to AQUATIC TOXICOLOGY
    AN INTRODUCTION TO AQUATIC TOXICOLOGY This page intentionally left blank AN INTRODUCTION TO AQUATIC TOXICOLOGY MIKKO NIKINMAA Professor of Zoology, Department of Biology, Laboratory of Animal Physiology, University of Turku, Turku, Finland AMSTERDAM • BOSTON • HEIDELBERG • LONDON NEW YORK • OXFORD • PARIS • SAN DIEGO SAN FRANCISCO • SINGAPORE • SYDNEY • TOKYO Academic press is an imprint of Elsevier Academic Press is an imprint of Elsevier The Boulevard, Langford Lane, Kidlington, Oxford, OX5 1GB, UK 225 Wyman Street, Waltham, MA 02451, USA Copyright © 2014 Elsevier Inc. All rights reserved. No part of this publication may be reproduced or transmitted in any form or by any means, electronic or mechanical, including photocopying, recording, or any information storage and retrieval system, without permission in writing from the publisher. Details on how to seek permission, further information about the Publisher’s permissions policies and our arrangement with organizations such as the Copyright Clearance Center and the Copyright Licensing Agency, can be found at our website: www.elsevier.com/permissions This book and the individual contributions contained in it are protected under copyright by the Publisher (other than as may be noted herein). Notices Knowledge and best practice in this field are constantly changing. As new research and experience broaden our understanding, changes in research methods, professional practices, or medical treatment may become necessary. Practitioners and researchers must always rely on their own experience and knowledge in evaluating and using any information, methods, compounds, or experiments described herein. In using such information or methods they should be mindful of their own safety and the safety of others, including parties for whom they have a professional responsibility.
    [Show full text]
  • Harmful Algal Blooms (Habs) and Public Health: Progress and Current Challenges
    Harmful Algal Blooms (HABs) and Public Health: Progress and Current Challenges Edited by Lesley V. D’Anglada, Elizabeth D. Hilborn and Lorraine C. Backer Printed Edition of the Special Issue Published in Toxins www.mdpi.com/journal/toxins Lesley V. D’Anglada, Elizabeth D. Hilborn and Lorraine C. Backer (Eds.) Harmful Algal Blooms (HABs) and Public Health: Progress and Current Challenges This book is a reprint of the Special Issue that appeared in the online, open access journal, Toxins (ISSN 2072-6651) from 2014–2015 (available at: http://www.mdpi.com/journal/toxins/special_issues/HABs?sort=asc). Guest Editors Lesley V. D’Anglada U.S. Environmental Protection Agency USA Elizabeth D. Hilborn United States Environmental Protection Agency USA Lorraine C. Backer National Center for Environmental Health USA Editorial Office MDPI AG Klybeckstrasse 64 Basel, Switzerland Publisher Shu-Kun Lin Managing Editor Chao Xiao 1. Edition 2016 MDPI • Basel • Beijing • Wuhan • Barcelona ISBN 978-3-03842-155-9 (Hbk) ISBN 978-3-03842-156-6 (PDF) © 2016 by the authors; licensee MDPI, Basel, Switzerland. All articles in this volume are Open Access distributed under the Creative Commons Attribution license (CC BY), which allows users to download, copy and build upon published articles even for commercial purposes, as long as the author and publisher are properly credited, which ensures maximum dissemination and a wider impact of our publications. However, the dissemination and distribution of physical copies of this book as a whole is restricted to MDPI, Basel, Switzerland. III Table of Contents List of Contributors ............................................................................................................ VII About the Guest Editors......................................................................................................... X Preface Reprinted from: Toxins 2015, 7, 4437-4441 http://www.mdpi.com/2072-6651/7/11/4437 ....................................................................
    [Show full text]
  • Comparative Study of Potential Transfer of Natural and Anthropogenic Cadmium to Plankton Communities in the North-West African Upwelling
    1 Science Of The Total Environment A chimer February 2015, Volume 505 Pages 870-888 r http://archimer.ifremer.fr http://dx.doi.org/10.1016/j.scitotenv.2014.10.045 http://archimer.ifremer.fr/doc/00252/36310/ © 2014 Elsevier B.V. All rights reserved. Comparative study of potential transfer of natural and anthropogenic cadmium to plankton communities in the North-West African upwelling Auger Pierre-Amael 1 * , Machu Eric 1, 4, Gorgues Thomas 1, 4, Grima Nicolas 3, 4, Waeles Mathieu 2, 4 1 UBO, IRD, IFREMER, LPO,UMR 6523,CNRS, F-29280 Plouzane, France. 2 UBO, IRD, Lab Environm Mario LEMAR, UMR 6539,CNRS, F-29280 Plouzane, France. 3 CNRS, France 4 Ifremer, France * Corresponding author : Pierre Amael Auger, tel.: + 33 298498662 ; email address : [email protected] Abstract : A Lagrangian approach based on a physical-biogeochemical modeling was used to compare the potential transfer of cadmium (Cd) from natural and anthropogenic sources to plankton communities (Cd-uptake) in the NorthWest African upwelling. In this region, coastal upwelling was estimated to be the main natural source of Cd while the most significant anthropogenic source for marine ecosystem is provided by phosphate industry. In our model experiment, Cd-uptake (natural or anthropogenic) in the North-West African upwelling is the result of an interplay between the Cd dispersion (by advection processes) and the simulated biological productivity. In the Moroccan waters, advection processes limit the residence time of water masses resulting in a low natural Cd-uptake by plankton communities while anthropogenic Cd-uptake is high. As expected, the situation is reversed in the Senegalo-Mauritanian upwelling where natural Cd-uptake is higher than anthropogenic Cd-uptake.
    [Show full text]
  • Hypoxia Tolerance Variance Between Swimming and Resting Striped Bass Morone Saxatilis
    Journal of Fish Biology (2015) doi:10.1111/jfb.12735, available online at wileyonlinelibrary.com BRIEF COMMUNICATION Hypoxia tolerance variance between swimming and resting striped bass Morone saxatilis J. A. Nelson* and G. K. Lipkey Towson University, Department of Biological Sciences, 8000 York Road, Towson, MD 21252, U.S.A. (Received 29 June 2014, Accepted 28 May 2015) Individual striped bass Morone saxatilis were each exposed in random order to aquatic hypoxia (10% air saturation) either while swimming at 50% of their estimated critical swimming speed (Ucrit) or while at rest until they lost equilibrium. Individuals were always less tolerant of hypoxia when swimming (P < 0⋅01); the average fish was over five times more tolerant to the same hypoxia exposure whennot swimming. There was no relationship between an individual’s rank order of hypoxia tolerance (HT) under the two flow regimes, suggesting that different factors determine an individual’s HT when atrest than when swimming. © 2015 The Fisheries Society of the British Isles Key words: environmental oxygen concentration; flow; individual; loss of equilibrium. Environmental oxygen concentration [O2] is generally considered a limiting resource for fish (Fry, 1971). As2 [O ] decreases, the difference between maximum metabolic rate (MMR) and resting routine metabolic rate (RMR) or metabolic scope decreases (Claireaux et al., 2000) limiting an animal’s capacity to engage in metabolically expen- sive activities such as swimming and digestion. If an animal exceeds its metabolic scope, energy demand must be met anaerobically. Anaerobic metabolism captures only c. 8% of the energy from food that can be extracted aerobically (Gnaiger, 1993) and is generally not sustainable.
    [Show full text]
  • Control and Management of Harmful Algal Blooms
    This is a repository copy of Control and management of harmful algal blooms. White Rose Research Online URL for this paper: http://eprints.whiterose.ac.uk/123767/ Version: Published Version Book Section: Barrington, DJ orcid.org/0000-0002-1486-9247, Xi, X, Coggins, LX et al. (1 more author) (2015) Control and management of harmful algal blooms. In: Botana, LM, Louzao, MC and Vilariño, N, (eds.) Climate Change and Marine and Freshwater Toxins. De Gruyter , Berlin, Germany , pp. 313-358. ISBN 978-3-11-033303-9 https://doi.org/10.1515/9783110333596-012 © 2015 Walter de Gruyter GmbH, Berlin/Boston. Reproduced in accordance with the publisher's self-archiving policy. Reuse Unless indicated otherwise, fulltext items are protected by copyright with all rights reserved. The copyright exception in section 29 of the Copyright, Designs and Patents Act 1988 allows the making of a single copy solely for the purpose of non-commercial research or private study within the limits of fair dealing. The publisher or other rights-holder may allow further reproduction and re-use of this version - refer to the White Rose Research Online record for this item. Where records identify the publisher as the copyright holder, users can verify any specific terms of use on the publisher’s website. Takedown If you consider content in White Rose Research Online to be in breach of UK law, please notify us by emailing [email protected] including the URL of the record and the reason for the withdrawal request. [email protected] https://eprints.whiterose.ac.uk/ Dani J.
    [Show full text]
  • Annex 9 Guidance on Hazards to the Aquatic Environment
    Copyright@United Nations, 2017. All rights reserved A8.5 eerences 1. Patty, (Ed.) 1994). ndustrial Hygiene an oxicology. th Ed. xxx-xx w York: iley- Interscience. 2. Smyth, F., Carpenter, .P., Weil, . and ozzan U. (1954). ange finding xicity data. Arch. nd. Hyg. ccup. ed. 3. Fasey, drick, k d undquis (1987). cute, -day, n -week apour nhalation studies n balen Hazexy Systemol. Fundamental and pplied Toicology. 4. Wyeth, egor, r d ad 1989). valuation of developmen xicity f Globalen Hazexy ystemo n Fischer 344 and w Zealand h abbits. Fundamental and pplied Toicology. 5. Etc. ANNE GUIDAN AZARDS AQUATIC IRONMENT - - Copyright@United Nations, 2017. All rights reserved Annex 9 GUIDANCE ON HAZARDS TO THE AQUATIC ENVIRONMENT Contents Page A9.1 Introduction ..................................................................................................................................... 449 A9.2 The harmonized classification scheme .................................................................................................... 452 A9.2.1 Scope ..................................................................................................................................... 452 A9.2.2 Classification categories and criteria ........................................................................................ 452 A9.2.3 Rationale ................................................................................................................................... 452 A9.2.4 Application ..............................................................................................................................
    [Show full text]
  • Life Histories, Salinity Zones, and Sublethal Contributions Of
    Estuaries and Coasts (2012) 35:603–621 DOI 10.1007/s12237-011-9459-6 Life Histories, Salinity Zones, and Sublethal Contributions of Contaminants to Pelagic Fish Declines Illustrated with a Case Study of San Francisco Estuary, California, USA Marjorie L. Brooks & Erica Fleishman & Larry R. Brown & Peggy W. Lehman & Inge Werner & Nathaniel Scholz & Carys Mitchelmore & James R. Lovvorn & Michael L. Johnson & Daniel Schlenk & Suzanne van Drunick & James I. Drever & David M. Stoms & Alex E. Parker & Richard Dugdale Received: 13 January 2011 /Revised: 15 June 2011 /Accepted: 25 October 2011 /Published online: 23 November 2011 # Coastal and Estuarine Research Federation 2011 Abstract Human effects on estuaries are often associated chronically violate legal water quality standards; however, with major decreases in abundance of aquatic species. direct effects of contaminants on fish species are rarely However, remediation priorities are difficult to identify observed. Lack of direct lethality in the field has prevented when declines result from multiple stressors with interact- consensus that contaminants may be one of the major ing sublethal effects. The San Francisco Estuary offers a drivers of coincident but unexplained declines of fishes useful case study of the potential role of contaminants in with differing life histories and habitats (anadromous, declines of organisms because the waters of its delta brackish, and freshwater). Our review of available evidence M. L. Brooks (*) : J. R. Lovvorn N. Scholz Department of Zoology, Southern Illinois University, NOAA Fisheries, Northwest Fisheries Science Center, 1125 E. Lincoln Dr., MC 6501, Environmental Conservation Division, Carbondale, IL 62901, USA 2725 Montlake Blvd. E., e-mail: [email protected] Seattle, WA 98112, USA : C.
    [Show full text]
  • Water Pollution: One of the Main Limnology Challenges in the Anthropocene Poluição Hídrica: Um Dos Principais Desafios Da Limnologia No Antropoceno
    Thematic Section: Mini-Reviews in Applied Limnology Acta Limnologica Brasiliensia, 2019, vol. 31, e203 https://doi.org/10.1590/S2179-975X5118 ISSN 2179-975X on-line version Water pollution: one of the main Limnology challenges in the Anthropocene Poluição hídrica: um dos principais desafios da Limnologia no Antropoceno Gabrielle Rabelo Quadra1* , José Reinaldo Paranaíba Vilela Alves Teixeira1 , Nathan Barros1 , Fábio Roland1 and André Megali Amado1,2 1 Programa de Pós-graduação em Ecologia, Laboratório de Ecologia Aquática, Departamento de Biologia, Universidade Federal de Juiz de Fora, Rua José Lourenço Kelmer, Campus Universitário, Bairro São Pedro, CEP 36036-900, Juiz de Fora, MG, Brasil 2 Departamento de Oceanografia e Limnologia, Centro de Biociências, Universidade Federal do Rio Grande do Norte, Via Costeira, Praia de Mãe Luiza, CEP 59014-002, Natal, RN, Brasil *e-mail: [email protected] Cite as: Quadra, G.R. et al. Water pollution: one of the main Limnology challenges in the Anthropocene. Acta Limnologica Brasiliensia, 2019, vol. 31, e203. Abstract: Humankind is defining a new geological time. The Anthropocene epoch is marked by changes in the geological processes, hydrological regimes, biosphere structure, among other processes, due to human expansion over the landscape worldwide. Biogeochemical cycle’s acceleration, the high load of pollutants in water resources, rampant deforestation, increase in the greenhouse gas emissions to the atmosphere, eutrophication and biodiversity losses are some indications that reflect human’s pressure over several ecosystems, especially aquatic ones. Therefore, here we reviewed some aspects from a huge anthropogenic influence on ecosystems: water pollution. For decades, humankind has increasingly placed demands on aquatic environments without any concern.
    [Show full text]
  • Impact of Pesticide Application on Zooplankton Communities With
    Aquatic Toxicology 72 (2005) 373–382 Impact of pesticide application on zooplankton communities with different densities of invertebrate predators: An experimental analysis using small-scale mesocosms K.H. Chang ∗, M. Sakamoto, T. Hanazato Research and Education Center for Inlandwater Environment, Shinshu University, Kogandori 5-2-4, Suwa 392-0027, Japan Received 27 July 2004; received in revised form 28 January 2005; accepted 1 February 2005 Abstract We assessed the responses of zooplankton communities with different population densities of an invertebrate predator, Meso- cyclops pehpeiensis, to insecticide (carbaryl, 0.5 mg L−1) in small-scale mesocosm tanks (20 L). Cladocerans were eliminated by carbaryl application at both high and low predator densities. The density of rotifers increased after the elimination of the cladocerans by carbaryl application at low-predator density but not at high-predator density. Carbaryl application increased the relative importance of predatory interactions in the zooplankton community. The results suggest that predator abundance can affect the response of a zooplankton community to carbaryl application through predation on surviving zooplankton. © 2005 Elsevier B.V. All rights reserved. Keywords: Pesticide; Zooplankton; Mesocosm; Food web; Predation 1. Introduction groups most sensitive to toxic chemicals (Hanazato, 2001). Thus, they have been frequently used in eco- Zooplankton are important organisms in freshwater toxicological tests (OECD, 1981; Japanese Society of ecosystem since they occupy a central position in the Environmental Toxicology, 2003). Among many toxic food chain. They transfer energy from primary pro- chemicals, pesticides affect zooplankton at individ- ducers to higher trophic organisms such as fish, and ual, population, and community levels (Goodrich and their community structure, biomass, and production Leach, 1990; Dodson et al., 1995; Hanazato, 1998a, influence the whole food web structure of freshwa- 2001).
    [Show full text]
  • Effect of Hypoxia, Normoxia and Hyperoxia Conditions on Gill Histopathology in Two Weight Groups of Beluga (Huso Huso)
    Effect of hypoxia, normoxia and hyperoxia conditions on gill histopathology in two weight groups of beluga (Huso huso) Item Type article Authors Bagherzadeh Lakani, F.; M. Sattari, M.; Sharifpour, I.; Kazemi, R. Download date 28/09/2021 03:32:13 Link to Item http://hdl.handle.net/1834/36543 Caspian J. Env. Sci. 2013, Vol. 11 No.1 pp. 77~84 ©Copyright by University of Guilan, Printed in I.R. Iran CJES [Research] Caspian Journal of Environmental Sciences Effect of hypoxia, normoxia and hyperoxia conditions on gill histopathology in two weight groups of beluga (Huso huso) F. Bagherzadeh Lakani1 *, M. Sattari 1, I. Sharifpour 2, R. Kazemi 3 1-Dept. of Fisheries Sciences, Faculty of Natural Resources, University of Guilan, P.O.Box: 1144, Someh Sara, Iran. 2-Iranian Fisheries Research Organization, P.O.Box: 14155-6116 Tehran, Iran. 3-International Sturgeon Research Institute, P.O.Box: 41435-3464 Rasht, Iran. * Corresponding author’s E-mail: [email protected] (Received: Jun. 24. 2012, Accepted: Oct. 19. 2012) ABSTRACT The influence of dissolved oxygen concentration on gill histopathology of great sturgeon (Huso huso) was evaluated in two weight classes (initial weight 280.9±49.2 g and 1217.9±138.1 g respectively). Oxygen treatments included hypoxia (2-3 mg/l), normoxia (5-6 mg/l) and hyperoxia (9-10 mg/l). The fish were acclimated to experimental tanks for one week then randomly distributed into 9 tanks in each of the initial weight classes (3 and 6 fish per tank in higher and lower initial weight classes respectively) for 8 weeks.
    [Show full text]
  • A Tale of Two Pesticides: How Common Insecticides Affect Aquatic Communities
    Freshwater Biology (2011) 56, 2391–2404 doi:10.1111/j.1365-2427.2011.02667.x APPLIED ISSUES A tale of two pesticides: how common insecticides affect aquatic communities MAYA L. GRONER AND RICK A. RELYEA Department of Biological Sciences, University of Pittsburgh, Pittsburgh, PA, U.S.A. SUMMARY 1. Recent ecotoxicology studies show that pesticide exposure can alter community composition, structure and function. Generally, community responses to pesticides are driven by trait- and density-mediated indirect effects resulting from sublethal and lethal effects of pesticide exposure on vulnerable taxa. These effects depend upon the concentration of the pesticide and the frequency of exposure. 2. While more research is needed to understand community-level responses to pesticide exposure, testing the effects of multitudes of registered chemicals on ecologically relevant communities isoverwhelming. Recent reviews suggest that contaminants with similar modes of action should produce comparable community-level responses because they have similar direct effects and, as a result, similar indirect effects; this hypothesis remains largely untested. 3. We subjected pond communities [containing zooplankton, phytoplankton, periphyton and leopard frog tadpoles (Rana pipiens)] to several applications (single applications of medium or high concentrations or weekly applications of a lower concentration) of two acetylcholine esterase inhibiting insecticides, malathion and carbaryl that have comparable toxicity for aquatic organisms. 4. We found that both insecticides cause comparable trophic cascades that affect zooplankton and phytoplankton abundances; however, their effects on amphibians diverged, especially when exposed to higher concentrations of insecticides. Malathion caused a trophic cascade beginning with a decline in cladocerans followed by increases in phytoplankton. At a medium concentration, this cascade also caused a subsequent decrease in periphyton.
    [Show full text]