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Publication
Ecotoxicological effects of Barcelona harbor sediments in Capitella teleta
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Abstract(s)
A major decline of the world’s biological diversity has been associated to human activities. Life in our planet depends on the oceans and the threat to marine life comes in various forms, noting the uncontrolled waste discharges and the different sources of pollution. Harbor environments are permanently associated to high contamination and bottom sediments are considered as the final repository. Filter-feeding and burrowing organisms, such as polychaete communities, are amongst the most exposed organisms.
Regarding the previous statement, efforts are needed to predict contamination and prevent organisms from irreversible effects (e.g. death or impaired organismal function), which sometimes are only visible at a stage in time when it is too late to take preventive or abatement measures. Chemical analysis provide us with information about the contamination level in the environment, however they may not be enough. Ecotoxicological endpoints are needed to improve this lack of information. Evaluation of individual-level effects, such as growth and feeding, are crucial but an assessment at the sub-cellular level is also quite interesting since biochemical data give a more detailed and earlier evidence of pollution. Such biochemical responses include enzymatic efficiency and are nowadays often used. Polychaetes, such as Capitella teleta, are filter-feeding and burrowing organisms. Their high suitability and ecological relevance, together with their easy culture and maintenance in the laboratory, has led them becoming increasingly used in ecotoxicological studies.
This study aimed to assess the potential effects of Barcelona harbor sediments on the polychaete worm Capitella teleta. Sediments were collected from three different locations of the Barcelona (Spain) harbor with a positive gradient of pollution from the mouth of the harbor towards the innermost zone. Body weight (growth) and egestion rate (feeding), as well as antioxidant enzymes (catalase and superoxide dismutase) and neurotransmission related enzyme (acetylcholinesterase) were evaluated. Since no data about the main cholinesterase (ChE) present in C. teleta was available, a previous ChE characterization assay was performed.
The results showed the existence of only one ChE form, the acetylcholinesterase. The sensitivity of ChE to the model anticholinergic inhibitor chlorpyrifos-oxon was moderate (IC50 was 60.72 nM). Sediments from all sites decreased significantly the growth, egestion rates and the studied enzyme activities of C. teleta. This study highlights the relevance of ChE characterization before its use as a biomarker in ecotoxicology, and reinforces the use of C. teleta as biomonitor for early-warnings of pollution effects on marine soft-bottom macrobentonic communities.
Description
Dissertação para obtenção do Grau de Mestre em Biotecnologia dos Recursos Marinhos apresentada à ESTM - Escola Superior de Turismo e Tecnologia do Mar do Instituto Politécnico de Leiria.
Keywords
Growth Feeding Biomarkers Acetylcholinesterase Superoxide dismutase Catalase Polychaetes