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Report Stefano Bonacci, Annalisa Iacocca, Soania Fossi, Lucia Lancini, Tancredi Caruso, Ilaria Corsi
and Silvano Focardi
Biomonitoring Aquatic Environmental Quality
in a Marine Protected Area: A Biomarker
Approach
The main aims of the present study, conducted in the
framework of the MONIQUA–Egadi Scientific Project,
were twofold: first, to make the first step in the develop-
ment and validation of an ecotoxicological approach for
the assessment of marine pollution in coastal environ-
ments on the basis of a set of biomarker responses in new
sentinel species; and second, to obtain preliminary
information on environmental quality in an Italian marine
protected area, the Egadi Islands (Sicily). Several cyto-
chrome P450–dependent mixed-function oxidase activi-
ties were measured in the following sentinel species:
rainbow wrasse Coris julis, gastropod limpet Patella
caerulea, and sea urchin Paracentrotus lividus. The
results suggest that specimens from the Favignana
Harbor may be exposed to P450 inducers, whereas most
of the other sites seem to share similar environmental
quality. The proposed approach has potential for assess-
ment of environmental quality in marine protected areas.
Introduction
Aquatic ecosystems are increasingly threatened by environmen-
tal pollution from industrial, agricultural, and urban sources.
Toxic compounds have deleterious effects on marine life and
human health, affect the diversity of marine resources, find their aquatic pollutants, such as PAHs, PCDDs, and PCBs (14, 16).
way into the aquatic environment irrespective of their origin,
and are often found far from the site of release (1). Polycyclic
aromatic compounds (PAHs), polychlorinated biphenyls
(PCBs), and polychlorinated dibenzo-para-dioxins (PCDDs)
have been recognized as being among the most hazardous toxic
chemicals released into marine environments (2, 3).
Recognition of the threat posed by human activities to
marine environments has led to increased conservation efforts.
Marine protected areas (MPAs) are a relatively new concept in
the repertoire of marine resource management (4). Many MPAs
have been established around the world, and their growing
popularity depends on the fact that they fulfill key functions in
modern conservation and may be used in synergy with
traditional forms of marine resource management (5, 6). They
basically consist of an area of sea in which legal restrictions
apply to certain human activities (7). Because protection
measures are related to specific management goals, the
effectiveness of the restrictions needs to be further elucidated
(8). In fact, MPAs shield populations within their confines but
do not guarantee any protection from major threats to marine
environmental quality, such as disease, infections, and chemical
pollution (9, 10). These threats to MPA effectiveness have been
highlighted by many studies that have shown that even marine
areas subject to various degrees of protection may be affected
by man-made contaminants such as persistent organic pollut-
ants (10, 11).
Regular monitoring programs and identification of suitable
bioindicator species in MPAs are therefore priority tasks.
308 Ó Royal Swedish Academy of Sciences 2007
http://www.ambio.kva.se
Ecotoxicological tools specific for assessing water quality and
pollution levels in MPAs must be developed, and resident key
species having potential as sentinel organisms for biomonitoring
programs must be identified. Such new tools should improve the
effectiveness of MPA management and make these areas more
useful for marine resource conservation.
Biological responses to stress and to pollutant exposure and
its effects, also known as biomarkers, are increasingly used as
indicators for pollution monitoring, enabling cause-and-effect
relationships to be established early (3, 12). Among biochemical
responses to toxic and persistent aquatic pollutants, particular
attention has been paid to metabolic and detoxifying enzymes
of the mixed function oxidase (MFO) system (EC 1.14.14.1)
(13).
The MFO system is known to play a major role in the
oxidative metabolism of a vast number of naturally occurring
and xenobiotic chemicals. Two peculiar features, specificity and
inducibility, enable it to be used as biomarker (14). The MFO
system includes a superfamily of structurally and functionally
correlated hemoproteins (15). Enzymes of the P450 1A
(CYP1A) subfamily are of special interest as biomarkers
because they may be strongly induced by many common
In fish species, the high sensitivity of two enzyme reactions
catalyzed by specific CYP1A-isoforms, EROD (7-ethoxyresor-
ufin-O-deethylase) and BaPMO (benzo[a]pyrene monooxygen-
ase), to exposure to toxic pollutants has been demonstrated in
various studies, and their induction is currently used in many
biomonitoring projects for the assessment of water quality and
chemical pollution (13).
The cytochrome P450 monooxygenase system is also present
in invertebrate species, although activity levels are usually lower
than in vertebrates (17). Many studies have assessed the
occurrence of these enzymes in aquatic species (18–22). As
regards the gastropod limpet Patella caerulea, the enzyme
activities catalyzed by components of the MFO system, EROD,
and NADPH–cytochrome c reductase (NADPH–cyt c red) were
reported by Yawetz et al. (23), but immunoblotting with
monoclonal antibody against scup cytochrome P450E failed to
reveal P4501A1 gene family hemoprotein. In a study carried out
by our research group, a marked increase of P450 enzymes such
as NADH ferricyanide reductase (NADH–ferry red) and
NAD(P)H cytochrome c reductase (NAD[P]H–cyt c red) and
total P450 content was observed in both 2,3,7,8-tetrachloro
dibenzo-para-dioxin (2,3,7,8-TCDD) (at 5 ppm nominal con-
centration) and benzo[a]pyrene (B[a]P) (at 0.1, 1, 5, and 10 ppm)
in vivo in exposed samples with respect to controls (Iacocca et
al., unpublished data).
There have been a few studies on the cytochrome P450
system in echinoderms, including asteroids, holothurians, and
echinoids: NADH–ferry red and NADH–cyt c red activities
have been detected in the microsomal fraction of the pyloric
caeca of two sea stars (Asterias rubens and Mathasterias
glacialis), in the hemoplexus of a holothurian (Holothuria
forskali), and in the gonads of a sea urchin (Echinus esculentus)
Ambio Vol. 36, No. 4, June 2007