title: Effects of chemical disturbances on intertidal benthic assemblages.
abstract: Contamination is a particular harmful type of chemical disturbance and predicting their effects on natural systems is very complex. Effects of disturbances vary in space and time and depend, among other things, on the type and age of organisms, the habitat being studied and the complex interactions occurring in the systems. Most impact analyses of contaminants are however still done with limited number of selected organisms under laboratory conditions. Manipulative experiments done in situ are important to measure ecologically relevant responses of contaminant effects on marine systems. Ecological approaches on contamination studies, accounting for interactions among species and the environment are essential to understand how such disturbances affect systems. We evaluated the effects of bleach and permethrin, two common and pervasive contaminants, on intertidal benthic assemblages in two different successional stages, mature and young. There were no impacts on the overall structure of assemblages, regardless of their age. The lack of effects on the structure of assemblages might be due to the intrinsic characteristic of the habitat studied, which provide few sinks for contaminants, as well as the inherent features of the organisms themselves. Bleach did cause, however, a decrease in the abundance of limpets, which can have further consequences to these systems. This study shows the importance of studies on chemical disturbances done under relevant natural scenarios and that efficient management policies of natural systems will only achieve successful responses with properly designed experiments under natural conditions.
authors.affiliation: Centre for Research on Ecological Impacts of Coastal Cities, Marine Ecology Laboratories A11, School of Biological Sciences, University of Sydney, NSW 2006, Australia. Electronic address: m.mayerpinto@unsw.edu.au.
authors.forename: Mariana
authors.initials: M
authors.lastname: Mayer-Pinto
authors.affiliation: Departamento de Ciências do Mar, Universidade Federal de São Paulo, Av. Almirante Saldanha da Gama 89, Ponta da Praia, Santos, CEP: 11030-400 SP, Brazil.
authors.forename: Barbara Lage
authors.initials: BL
authors.lastname: Ignacio
mesh_terms: D000818:Animals; D059001:Aquatic Organisms / Q000145:classification / Q000254:growth & development*; D044822:Biodiversity; D017753:Ecosystem; D004777:Environment; D004784:Environmental Monitoring; D007448:Invertebrates / Q000145:classification / Q000254:growth & development*; D014874:Water Pollutants, Chemical / Q000032:analysis / Q000633:toxicity*
chemical_list: D014874:Water Pollutants, Chemical
keywords: Bleach; Permethrin; Pesticide; Pollution; Rocky shores; Sodium hypochlorite