RICERCA ITALIANA     

BIOMONITORING OF COASTAL MARINE ENVIRONMENTS: DEVELOPMENT AND APPLICATIONS OF NEW INTEGRATED CYTOCHEMICAL AND MOLECULAR METHODOLOGIES

Università degli Studi di Messina

Abstract

The aim of the national project is the study of selected marine costal areas, in which there is the presence of a heavy impact due to industrial activities. These areas are located in two Italian regions (Liguria and Sicily). The control sites will also be selected in the same regione with ecological and superimposable characteristics.
The methodological approach focuses on the use of organisms as bioindicators and on the use of biomarkers as signal of exposure, effect and damage.
In the selected environments the effects of contaminants, and especially heavy metals, will be evaluated with particular reference to the elements in traces on marine organisms (bioindicator).
Caged bivalve molluscs and two fish species belonging to different trophic levels will be used as bioindicators.
Statistical analysis of data and the comparison of results on the investigated species in the control areas will provide important information about the toxicological status of the target areas. The integration of data obtained by this Unit with data from other Research Units will allow formulating an evaluation of environmental hazard (and eventually risk).
This project will try to investigate the impact of industrial activities on the benthic community of a coastal ecosystem, comparing it with a control area.
Benthic organisms will be used as bioindicators together with a series of parameters, as “sensitive indicators” of the presence and effects of >>>

Principal Investigator

Salvatore Fasulo Università degli Studi di MESSINA

Research Objectives

This project will try to investigate the impact of industrial activities on the benthic community of a coastal ecosystem, comparing it with a control area. Benthic organisms will be used as bioindicators together with a series of parameters, as “sensitive indicators” of the presence and effects of metals and other environmental contaminants. Benthic organisms from coastal marine environments, and invertebrates such as bivalves will be considered in neighbouring natural environments, characterised by contaminants of different type and origin, predominantly heavy metals and organic compounds. Specimens of the same species from a control area and/or other will be used for comparison.
The main advantages of using bivalve molluscs in biomonitoring programmes are the knowledge of their biological cycle and feeding habits, as well as the ease in collecting them and their wide geographic distribution.
Although the Ministry of the Environment created the data bank Sistema Difesa del Mare (Si.Di.Mar.) within the framework of the Programme of Monitoring for Control of the Marine Environment, the amount of data on heavy metals and organochlorine compounds in coastal marine environments is still extremely limited, due to the low density of sampling sites and due to the fact that effects of these contaminants are not evaluated. Scorpaenidae and Blenniidae are benthic fish that have rarely been used in biomonitoring programmes. Both families have many representatives in the >>>

First Results

The project wants to deepen the ecophysiological aspects of species exposed several types of impact, industrial/urban drainages, harbour areas, anthropic activities, and to estimate, for biological way, the level of pollution of areas marine. It defines the cytotoxic effects of the pollution on the branchial epithelium of all the sentinel organisms taken in examination and in particular on the cellular specialize types like the paraneuronal elements.
The biomolecolar data, on the organs considered of individuals subordinates to natural and/or induced stress, could evidence a various expression of the geniuses of the metallothioneins, NOS, aquaporine and heat shock proteins, regarding the control exemplary. The damage of DNA, in terms of chromosomic mutations and of breach of the filament of DNA (single or double), will show the genotoxic damage attributable to the present polluting agents.
These results will show a model related to the processes of exposure-effect of the heavy metals in the species considered. Such model, in the successive phase in nature, will concur a better interpretation of results obtained. Such studies will concur to evidence the levels of bioaccumulation of the metals in the organisms sampling supplying a measure of their bioavailability environmental. On this last aspect, they depend processes of interference to the level of the enzymatic activities. The synthesis of these information will supply the final data on the state of >>>

Timescale

24 months

National and international background

Many persistent substances, i.e. substances that do not break down in the environment or are not metabolised, may accumulate in the body under certain conditions if assumed with food, through the gills or through the skin. Bioaccumulation occurs when an organism takes up substances and concentrates them in the tissues and there is a direct relation between concentrations in tissues and exposure level and period. Levels of bioaccumulation are normally used to evaluate environmental contamination by heavy metals.
Bioaccumulation of elements such as cadmium, lead and arsenic generally does not seem to be related to trophic level but rather to trophic niche (e.g. filtering organisms, detritivores, sediment dwellers). Mercury is the only metal that biomagnifies in the food chain, because its organic form, methylmercury, is relatively stable and has affinity with biological structures.
Although mercury tends to be methylated by bacteria in anoxic sediment, the methylmercury molecule is very sensitive to photodegradation. Production of methylmercury and its entrapment in the living biomass is therefore very efficient in the dark depths (Bacci 1989).
There have been reports of cases in which bioaccumulation of mercury in bioindicator organisms was correlated with depth of capture (Leonzio et al. 1981). Heavy metal concentrations may be measured in whole (small) organisms or in selected tissues or organs which are particular sites of bioaccumulation (digestive >>>