Abstract:
In the aim to assess the level of metallic contamination along the Algerian coast in superficial sediments
and demersal fish and to measure the ecological risk associated with this contamination in these benthic
habitats, about fifty stations for surface sediment has been sampled covering the main fishing areas along
algerian coast. In parallel, samples of three species of fish (red mullet, hake and common pandora) were
collected from these stations. These samples were taken during the demersal resources evaluation survey
carried out on board the research vessel "GRINE BELKACEM" during the summer of 2015.
The analysis of trace metals in the sediment samples was carried out by ICP-MS. While, that in the fish
samples was carried out by SAA. Thus, the rate of organic matter and of fine fraction (<63μm) in the
sediment samples, That protein, lipid and carbohydrate were determined. The risk assessment of the
sediments of the main fishing areas was carried out by applying an ecotoxicological approach, based on the
calculation of multiple indices. This approach was supported by the calculation of trace metal
bioaccumulation factors.
The results of this study allowed us to assign for each fishing area an ecological status. In fact, the sediments
of the most fishing areas along Algerian coast have a low ecological risk for living species. Thus, the
Arsenic is the only metal that can have a potential ecological risk in 2/3 of the stations. The average
concentrations of Cr and Ni in most stations are above their values (ERL). The concentrations of Fe, Mn,
Co, Cu, V, Cd and Pb are all below their natural reference levels. However, Ni, Cr and As had maximum
contributions in the sum of the toxic units, but in the case of Cr and Ni, this is rather due to their low ERL
thresholds used for the calculation of the sum of toxic units. The results also show that the most polluted
stations are located in the central area of the Algerian coast.
The results of the present study showed that the three fish bioaccumulate the four metals (Zn, Cu, Ni and
Hg) in descending order of Zn ˃ Cu> Ni˃ Hg. Thus, fish from the western part of the Algerian coast
(Ghazaouet, Beni Saf and Mostaganem) bioaccumulate high concentrations compared to fish in the central
part. The results also reveal a greater bioaccumulation in the liver and gonads compared to muscle for the
three fish. However, significant differences in trace metal concentrations by sex and size were revealed.
In addition, at the sampling time, no health risk related to contamination by the four metals (Zn, Cu, Ni and
Hg), can be caused by the consumption of these three fish caught along the Algerian side.
Key words: trace metal elements, sediments, ecological risk assessment, bioaccumulation, Algerian coast.
In the aim to assess the level of metallic contamination along the Algerian coast in superficial sediments
and demersal fish and to measure the ecological risk associated with this contamination in these benthic
habitats, about fifty stations for surface sediment has been sampled covering the main fishing areas along
algerian coast. In parallel, samples of three species of fish (red mullet, hake and common pandora) were
collected from these stations. These samples were taken during the demersal resources evaluation survey
carried out on board the research vessel "GRINE BELKACEM" during the summer of 2015.
The analysis of trace metals in the sediment samples was carried out by ICP-MS. While, that in the fish
samples was carried out by SAA. Thus, the rate of organic matter and of fine fraction (<63μm) in the
sediment samples, That protein, lipid and carbohydrate were determined. The risk assessment of the
sediments of the main fishing areas was carried out by applying an ecotoxicological approach, based on the
calculation of multiple indices. This approach was supported by the calculation of trace metal
bioaccumulation factors.
The results of this study allowed us to assign for each fishing area an ecological status. In fact, the sediments
of the most fishing areas along Algerian coast have a low ecological risk for living species. Thus, the
Arsenic is the only metal that can have a potential ecological risk in 2/3 of the stations. The average
concentrations of Cr and Ni in most stations are above their values (ERL). The concentrations of Fe, Mn,
Co, Cu, V, Cd and Pb are all below their natural reference levels. However, Ni, Cr and As had maximum
contributions in the sum of the toxic units, but in the case of Cr and Ni, this is rather due to their low ERL
thresholds used for the calculation of the sum of toxic units. The results also show that the most polluted
stations are located in the central area of the Algerian coast.
The results of the present study showed that the three fish bioaccumulate the four metals (Zn, Cu, Ni and
Hg) in descending order of Zn ˃ Cu> Ni˃ Hg. Thus, fish from the western part of the Algerian coast
(Ghazaouet, Beni Saf and Mostaganem) bioaccumulate high concentrations compared to fish in the central
part. The results also reveal a greater bioaccumulation in the liver and gonads compared to muscle for the
three fish. However, significant differences in trace metal concentrations by sex and size were revealed.
In addition, at the sampling time, no health risk related to contamination by the four metals (Zn, Cu, Ni and
Hg), can be caused by the consumption of these three fish caught along the Algerian side.
Key words: trace metal elements, sediments, ecological risk assessment, bioaccumulation, Algerian coast.