Potential effects of triclosan on spatial displacement and local population decline of the fish Poecilia reticulata using a non-forced system

Author(s)

Silva, Daniel C. V. R. ; Araujo, Cristiano V. M. ; Lopez-Doval, Julio C. ; Neto, Morun B. ; Silva, Flavio T. ; Paiva, Teresa C. B. ; Pompeo, Marcelo L. M.

• Document type: Journal article
• Source: Chemosphere; v. 184, p. 329-336, OCT 2017.
• Web of Science Citations: 13

Abstract

Triclosan (TCS) is an emerging contaminant of concern in environmental studies due to its potential adverse effects on fish behavior. Since avoidance has been shown to be a relevant behavioral endpoint, our aims were: (i) to determine if TCS is able to trigger an avoidance response in Poecilia reticulata; (ii) to predict the population immediate decline (PID) caused by TCS exposure, by integrating lethality and avoidance responses; and (iii) to verify the overestimation of risk when mortality is assessed under forced exposure. Fish were exposed to TCS in a forced exposure system, to assess mortality, and to a TCS gradient in a non-forced exposure (NFE) system. Two NFE scenarios were simulated: (\#1) a spatially permanent gradient, including low and high concentrations; and (\#2) a scenario with high concentrations, simulating a local discharge. The fish avoided TCS concentrations as low as 0.2 mu g L-1 (avoidance of 22%). The AC50 obtained from scenario \#1 (8.04 mu g L-1) was about 15 times more sensitive than that from scenario \#2 (118.4 mu g L-1). In general, up to the highest concentration tested (2000 mu g L-1), the PID was determined by the avoidance. Mortality from the forced exposure was overestimated (48 h-LC50 of 1650 mg L-1), relative to the NFE. The reduced mortality in a non-forced environment does not imply a lower effect, because part of the population is expected to disappear by moving towards favorable environments. TCS is a potential environmental disturber, since at environmentally relevant concentrations (< 2 mu g L-1) it could cause a decline in the fish population. (C) 2017 Elsevier Ltd. All rights reserved. (AU)

• FAPESP's process: 14/22581-8 - The European Union's Water Framework Directive: applications to Brazilian reservoirs reality
• Grantee: Marcelo Luiz Martins Pompêo
• Support Opportunities: Regular Research Grants