Confounding Factors in Biomonitoring Using Fish

Abstract

Pollution of water ecosystems is considered one of the most serious problems in the current days. In order to predict the effects of pollutants present in the water before overt disease and/or death in aquatic biota, bioindicators, as fish, and biomarkers have been widely used in biomonitoring studies. Notwithstanding, biomarkers responses might be modulated by non-pollutant factors and not only by environmental contaminants. As these premises are not always observed, this review attempts to explore confounding factors related to the modulation of the biomarker responses applied in biomonitoring studies. Among others, gender, temperature and feeding habitat are some factors which affect biomarker responses. However, the use of this tool is still important to assess the health of aquatic ecosystems. Thus, it is strongly recommended to use different biomarkers and, whenever possible, to analyze water and sediment physicochemical parameters.

Comparative study of microbial, proximate and heavy metal compositions of some gastropods, bivalve and crustacean seafood

“…S. aureus is a normal human flora and can easily contaminate processed food product, control of its presence in raw foods will help minimize the presence in finished products. Contamination by these microorganisms of water bodies from where the seafood were harvested could be from human activities such as bathing, disposal of faecal matters, sewage discharge by municipal authorities, runoff, unhygienic handling and improper packaging/transportation and storage by the fishermen and seafood vendors (39,40,41). Fish and other free-swimming marine animals do not usually carry those organisms generally considered to be typical of the mammalian microflora, including Escherichia coli, the 'faecal coliforms', and enterococci.…”

The EU Interreg Project “GEREMIA” on waste management for the improvement of port waters: results on monitoring the health status of fish as bioindicator

“…Such complex scenario needs accurately developed monitoring plans aiming to precisely assess the degree of environmental impacts: these should not only refer to the presence of contaminants in water column and sediments but also address accumulation and possible effects of such contaminants in wild organisms; in fact, the investigation of the health status of organisms is a useful parameter for assessing the level of contamination, reflecting the quality of the environment where they live and feed (Gupta and Singh 2011 ). Thus, integrative approaches that include biological monitoring and multidisciplinary investigations are nowadays considered an important tool for detecting critical environmental conditions (Dalzochio and Gehlen 2016 ) and are strongly encouraged by European Directives such as the Marine Strategy Framework Directive (European Commission 2008a ) and the Water Framework Directive (European Commission 2000 ). Biological monitoring is performed through target organisms, defined as bioindicators, which are tolerant to the presence of contaminants, but at the same time sensitive enough to show sub-lethal changes in their physiological state (Zhou et al 2008 ), which are detectable through biological investigations (biomarkers), e.g., histological and enzymatic techniques (Valavanidis and Vlachogianni 2010 ).…”

Descripción Analítica De Los Ácidos Para La Digestión Química en Muestras Biológicas Expuestas a Metales

“…Una de las preocupaciones sobre los metales pesados (MP) es su rápida acumulación en los tejidos biológicos (Dalzochio & Gehlen, 2016;Alegre et al, 2018). Ante la biodisponibilidad de los MP (Moreno et al, 2018) y su ecotoxicidad (Huang et al, 2018;Zhang et al, 2019;Li et al, 2020) existe la tendencia en los estudios ambientales que éstos puedan basarse en las fracciones extraíbles y reducibles por ser las secuenciales de relevancia potencialmente tóxicas (Tessier et al, 1979;Huang et al, 2007;Zhai et al, 2014;Jin et al, 2016;Zeng et al, 2018).…”