INTEGRATING BIOCHEMICAL MARKERS AND TARGET POLLUTANT CONCENTRATIONS
IN EUROPEAN EELANGUILLA ANGUILLA FOR ECOSYSTEM HEALTH ASSESSMENT
OF A COASTAL LAGOON
Corsi I., Mariottini M., Badesso A., Bianchini A., Bonacci S., Borghesi N., Iacocca A., Lancini L., Focardi S. *
Dipartimento di Scienze Ambientali “G. Sarfatti”, Università di Siena, Siena, Italy
Abstract
Many lagoons are impacted by human activities, which lead to progressive ecosystem degradation. In order to assess the ecological risk
of the Orbetello lagoon (Tuscany, Italy), several biomarkers as EROD, B(a)PMO, reductases NADH cytochrome c, NADH ferrycianide,
AChE and levels of polychlorinated biphenyl (PCB) were measured in European eel (Anguilla anguillaL.) collected in seven sites of the
lagoon. Results suggested that the lagoon is mainly impacted by agricultural run-off and nutrient-rich effluents rather than by industrial
activities.
Keywords: biomarkers, lagoon, European eel, pollution
Rapp. Comm. int. Mer Médit., 37,2004
336
Introduction
Lagoon ecosystems, like most brackish environments, are biotopes
of great ecological value which could be at risk without appropriate
management and risk assessment (1). In order to assess the ecological
risk in a brackish environment, specimens of European eel (Anguilla
anguillaL.) were collected from a moderately polluted brackish
environment, the Orbetello Lagoon (Southern Tuscany, Italy) known
for its complex seasonal physico-chemical ?uctuations (1). The aim of
this work was to investigate the site-specific variability of several
biomarkers in eel and its sensitivity as bioindicator. Liver 7-
ethoxyresorufin-O-deethylase (EROD), benzo(a)pyrene monooxy-
genase (B(a)PMO), NADH cytochrome c (NADH cyt c red) and
NADH ferrycianide (NADH ferry red) reductases and muscle
Acetylcholinesterase (AChE) were investigated and integrated with
levels of polychlorinated biphenyl (PCBs) in muscle tissue to provide
an idea of the overall fish and ecosystem resistance/susceptibility to
chemical disturbance in the lagoon.
Materials and methods
Sampling was conducted in June 2002 in the Orbetello Lagoon, a
2600-hectare area on the southern coast of Tuscany (Lat. 42°30’N;
Long. 11°10’E), bordered by two sandbars. Seventy eels were
collected from seven sites (Fig. 1) and their liver microsomal fraction
as previously described (4) was used to determine EROD, B(a)PMO
and NADH cyt c and NADH ferryred activities based on (5), (6) and
(7) respectively. AChE activity was measured in crude muscle
preparations according to (8). Total protein was measured based on
(9). PCBs were extracted from pooled muscle tissues according to
(10) and expressed as Aroclor 1260, calculated on wet weight basis
(w.w.). Log-transformed data were analysed using analysis of
variance (ANOVA). Post-hoc Tukey compromise tests were used to
determine statistical differences in means among sites.
Fig. 1.
Biochemical
markers in
European eels
from seven sites:
enzyme activities
are shown as
percentage of
variation with
respect to the
lowest activity
recorded among
seven sites.
Results and discussion
All the enzymes analysed in eels from the seven sites varied
significantly (Fig. 1). EROD, NADH ferry red and NADH cyt c red
were significantly higher at site 5 (p<0.05) in the middle of the
western basin compared to values in other sites while B(a)PMO
activities were highest at site 6 in the middle of eastern basin. The
most congruent and lowest enzyme activities were found in organisms
from site 1 located in the Nassa canal. AChE activities also differed
among sites, although no significant differences were observed except
for sites 1, 3 and 5 (located near Nassa canal, Albegna river mouth and
the middle of western basin, respectively). Considering the average
AChE activities recorded in eels from all sampling sites, the
differences were below 50%, suggesting that there is no neurotoxic
risk for this species. The highest PCB levels (Table 1) were found in
eels collected from site 5 while the lowest ones were recorded in
specimens from site 2, near the fertilizer plant. On the basis of the
results obtained, European eel seems to be a suitable bioindicator of
environmental quality for the Orbetello lagoon.
Table 1. PCB levels
expressed as ng g
-1
wet
weight in liver of
European eels collected
from seven sites of
Orbetello lagoon
(n = number of samples;
l.w. lipid weight in liver
tissue).
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