essentials (Hg, Pb, Cd, As, etc.) according to metal’s role in
biological functions of living organisms. Metals are highly
available in a marine environment with aromatic organic xenobiotic (PNUE 1999) and are among the most toxic contaminants (Azizi et al. 2018). Their low presence in the environment may cause adverse effects to living organisms (Viarengo
1985; Ramade 1998; Levinton 1995; Clark 1997; Drif 2012;
Rouane-Hacene 2013).
Heavy metals present in the marine environment accumulate in mussel tissues mainly through filtration. In general,
studies of environmental health in marine biotope use the
whole soft tissue to reveal contamination level of these pollutants (Baltas et al. 2016). Studies on metal repartition in organs
of mussels from natural sites are scarce, and provide utile
information on the exposure state of organs to heavy metal
pollutants. Therefore, the principal aim of this study is to
investigate the seasonal distribution of heavy metal concentrations in various tissues (gills, digestive gland, gonad, and rest
of soft tissues) of two different mussel species (Perna perna
and Mytilus galloprovincialis) from three sites of the Algerian
coast.
Mussels are valuable seafood; they constitute a precious
source of protein, vitamins, and essential minerals
(Stankovic et al. 2012). However, in case of contaminations,
potential health risks may occur when consuming contaminated mussels. Therefore, assessment of potential health risks for
Algerian and European population upon consumption of mussels from Algerian coast has been evaluated and the sampling
sites along the Algerian coastline have been classified based
on metal levels in mussel samples.
Materials and methods
The study area
The study area covers three sites of the Algerian central coast
(Fig. 1). The site of Figuier (36° 47′ 02.88″ N / 3° 31′ 01.84″
E) is located in the bay of Zemmouri, at 42 km from Algiers.
This site is considered relatively clean due to the weak industrial activity, but at the same time, it is exposed to domestic
discharges.
Sercouf site (36° 47′ 51.96″ N / 3° 18′ 35.12″ E) is located
also in the bay of Zemmouri, very close to the periphery of
Reghaia-Rouiba where two important industrial zones in
Algeria are existent. The industrial discharges produced are
heading to the sea by Reghaia river; therefore, mussels are
exposed to significant pollution.
The third site, Port of Algiers (36° 46′ 32.89″ N / 3° 03′
45.90″ E), occupies a particular geographical position either in
the Mediterranean basin or national scale. Covering an area of
about 126 ha, it is recognized as the first commercial port in
Algeria. High significant contaminants reach this site by
different ways (wadis, domestic and industrial discharges, rejections of boats, etc.) which have a tendency to persist for a
long time.
Sample collection, treatment, and analysis
Four seasonal samplings were carried out between June 2015
and May 2016 at three sites located in the Algerian central
coast (Table 1). A special care was given to avoid collecting
small individuals because bigger sized individuals (˃ 5 cm
length) provide more and sufficient amount of samples for
analyses. Samples were collected from rocky environment
using a scalpel to detach mussels from hard substrate of the
rocks. Thirty (30) collected individuals were put in plastic
bags and transported to the laboratory in a cooler.
Limestone, sediments, algae, and other organisms fixed to
the shell were removed. The leg and byssus of each individual
were also separated from the flesh to avoid all contamination
induced by their contact with the hard substrate. Bi-distilled
water was used to wash and clean the valves. The length and
width were accurately measured by digital caliper 0–200 mm
(resolution 0.01 mm).
The mussels were dissected and the gill, digestive gland,
gonad, and the rest of soft tissues were isolated and put in four
labeled pillboxes. The latter were weighed and frozen at a
temperature of − 20 °C. The samples were lyophilized,
weighed, and crushed to a fine powder and stocked in plastic
pots until analysis.
The treatment of samples for the trace metal determination
was performed following a standardized method for analysis
of AIEA (2004). After shaking sample pools for 2 min, a
quantity of 0.5 g was digested with 5 ml of HN0 3 (65%) in
labeled Teflon tube (50 ml) at 120 °C on a hot plate for 2 h
30 min. Blanks were prepared in a similar manner as samples,
using only HNO 3 . Heavy metal results are the mean of three
replicate measurements of each sample.
Quality of experimental work was checked by using the
certified reference material of mussel tissue (IAEA – MESLILC- TE /BIOTA 2017). The found values were consistent
with those certified of IAEA. The recovery for cadmium, lead,
nickel, and manganese varied between 90 and 107% and low
standard deviations were registered (Table 2).
The concentration of cadmium, lead, nickel, and manganese in all samples was measured by inductively coupled
plasma mass spectrometry (ICP-MS) (Agilent 7700x) in
Technologies and Development Division of SONATRACH.
Physiological index
Condition index
The condition index (CI), corresponds to the rapport between
the wet weight of whole soft tissue and the mussel total weight
Environ Sci Pollut Res
biological functions of living organisms. Metals are highly
available in a marine environment with aromatic organic xenobiotic (PNUE 1999) and are among the most toxic contaminants (Azizi et al. 2018). Their low presence in the environment may cause adverse effects to living organisms (Viarengo
1985; Ramade 1998; Levinton 1995; Clark 1997; Drif 2012;
Rouane-Hacene 2013).
Heavy metals present in the marine environment accumulate in mussel tissues mainly through filtration. In general,
studies of environmental health in marine biotope use the
whole soft tissue to reveal contamination level of these pollutants (Baltas et al. 2016). Studies on metal repartition in organs
of mussels from natural sites are scarce, and provide utile
information on the exposure state of organs to heavy metal
pollutants. Therefore, the principal aim of this study is to
investigate the seasonal distribution of heavy metal concentrations in various tissues (gills, digestive gland, gonad, and rest
of soft tissues) of two different mussel species (Perna perna
and Mytilus galloprovincialis) from three sites of the Algerian
coast.
Mussels are valuable seafood; they constitute a precious
source of protein, vitamins, and essential minerals
(Stankovic et al. 2012). However, in case of contaminations,
potential health risks may occur when consuming contaminated mussels. Therefore, assessment of potential health risks for
Algerian and European population upon consumption of mussels from Algerian coast has been evaluated and the sampling
sites along the Algerian coastline have been classified based
on metal levels in mussel samples.
Materials and methods
The study area
The study area covers three sites of the Algerian central coast
(Fig. 1). The site of Figuier (36° 47′ 02.88″ N / 3° 31′ 01.84″
E) is located in the bay of Zemmouri, at 42 km from Algiers.
This site is considered relatively clean due to the weak industrial activity, but at the same time, it is exposed to domestic
discharges.
Sercouf site (36° 47′ 51.96″ N / 3° 18′ 35.12″ E) is located
also in the bay of Zemmouri, very close to the periphery of
Reghaia-Rouiba where two important industrial zones in
Algeria are existent. The industrial discharges produced are
heading to the sea by Reghaia river; therefore, mussels are
exposed to significant pollution.
The third site, Port of Algiers (36° 46′ 32.89″ N / 3° 03′
45.90″ E), occupies a particular geographical position either in
the Mediterranean basin or national scale. Covering an area of
about 126 ha, it is recognized as the first commercial port in
Algeria. High significant contaminants reach this site by
different ways (wadis, domestic and industrial discharges, rejections of boats, etc.) which have a tendency to persist for a
long time.
Sample collection, treatment, and analysis
Four seasonal samplings were carried out between June 2015
and May 2016 at three sites located in the Algerian central
coast (Table 1). A special care was given to avoid collecting
small individuals because bigger sized individuals (˃ 5 cm
length) provide more and sufficient amount of samples for
analyses. Samples were collected from rocky environment
using a scalpel to detach mussels from hard substrate of the
rocks. Thirty (30) collected individuals were put in plastic
bags and transported to the laboratory in a cooler.
Limestone, sediments, algae, and other organisms fixed to
the shell were removed. The leg and byssus of each individual
were also separated from the flesh to avoid all contamination
induced by their contact with the hard substrate. Bi-distilled
water was used to wash and clean the valves. The length and
width were accurately measured by digital caliper 0–200 mm
(resolution 0.01 mm).
The mussels were dissected and the gill, digestive gland,
gonad, and the rest of soft tissues were isolated and put in four
labeled pillboxes. The latter were weighed and frozen at a
temperature of − 20 °C. The samples were lyophilized,
weighed, and crushed to a fine powder and stocked in plastic
pots until analysis.
The treatment of samples for the trace metal determination
was performed following a standardized method for analysis
of AIEA (2004). After shaking sample pools for 2 min, a
quantity of 0.5 g was digested with 5 ml of HN0 3 (65%) in
labeled Teflon tube (50 ml) at 120 °C on a hot plate for 2 h
30 min. Blanks were prepared in a similar manner as samples,
using only HNO 3 . Heavy metal results are the mean of three
replicate measurements of each sample.
Quality of experimental work was checked by using the
certified reference material of mussel tissue (IAEA – MESLILC- TE /BIOTA 2017). The found values were consistent
with those certified of IAEA. The recovery for cadmium, lead,
nickel, and manganese varied between 90 and 107% and low
standard deviations were registered (Table 2).
The concentration of cadmium, lead, nickel, and manganese in all samples was measured by inductively coupled
plasma mass spectrometry (ICP-MS) (Agilent 7700x) in
Technologies and Development Division of SONATRACH.
Physiological index
Condition index
The condition index (CI), corresponds to the rapport between
the wet weight of whole soft tissue and the mussel total weight
Environ Sci Pollut Res