Seasonal and spatial contamination of trace elements in sediments and fish tissues (Mugil Chephalus) from Annaba gulf (North East of Algeria).

This research is devoted to assessing the pollution within a Mediterranean Sea area in the East coast of Algeria, which is known for its port and industrial activities. This study aims to assess the health status of the Gulf of Annaba located in the extreme North-East of Algeria by examining the contamination level by trace elements (Cu, Zn, Pb, Cd, Hg) in the sediments and muscles of Mugil cephalus fish. The obtained results manifest significant variations in metal levels in the sediments throughout the stations and the sampling seasons. The contamination by (Zn, Cu, Pb, Cd) of Joannonville and Sidi Salem stations is observed during both seasons whereas at the Chapuis station occurs only during the summer. The contamination indices are higher than 3, hence classifying the sediments of these three stations as "sediments at risk". Joannonville station manifests high levels of Hg only during the summer. For the muscles of M. cephalus, the contamination levels are found to be dependent on the species and the studied station. The fish inhabiting Joannonville and Sidi Salem show higher levels of (Zn, Pb, Cd) compared to the FAO/WHO standards, whereas the Pb level at Chapuis exceeds the standard during summer. Accordingly, the consumption of fish from Joannonville, Sidi Salem and Chapuis stations presents a serious threat regarding the toxicological risks based on the observed levels of contamination.

Occurrence and characterization of surface sediment microplastics and litter from North African coasts of Mediterranean Sea: Preliminary research and first evidence.

The aim of this research work is to investigate the abundance of macroplastics and microplastics from North African coasts of Mediterranean Sea in the Gulf of Annaba (Algeria). The study areas are well known for the high population and high industrial activities that can contribute to the plastic pollution. In this case, microplastics were sampled from the surface sediments at four different stations representing different local activities. The microplastics were extracted by the density separation method from collected samples. Each particle was identified using Fourier transform infrared spectroscopy (ATR-FTIR). Furthermore, beach litters were obtained according to the adopted methodology - guidance on monitoring of marine litter in European seas. The obtained mean concentrations are 182.66 ± 27.32 and 649.33 ± 184.02 kg-1 sediment (DW), respectively. A detailed spatial and quantitative analysis revealed that their distribution was a function of proximity to populated areas and associated with wastewater effluents, industrial installations, degree of shore exposure and complex tidal flow patterns. Five types of microplastics were identified; the most common were fibers (70%), fragments (21%), pellets (5%), films (2%) and foams (2%). Attenuated total reflectance Fourier transform infrared spectroscopy (ATR-FTIR) analysis showed that the main polymers detected in the studied microplastics were polyethylene (48%), polypropylene (16%), polyethylene terephthalate (14%), polystyrene (9%), butyl branham (7%), ethylene propylene (3%) and cellulose tri acetate (3%). The obtained results provided a holistic view of the abundance, distribution, and characteristics of microplastics in the Gulf of Annaba. This study confirmed the presence of microplastics in the Gulf of Annaba, albeit further studies remain necessary for better understanding of sources and fate.

Modelling environment contamination with heavy metals in flathead grey mullet Mugil cephalus and upper sediments from north African coasts of the Mediterranean Sea.

Heavy metals are a serious hazard for aquatic ecosystems and human health. They negatively affect aquatic life functioning through accumulation resulting physiological/growth disturbances in aquatic lifeforms. This survey focused on the assessment of heavy metal pollution in the Gulf of Annaba (northeastern Algeria), the largest and most diversified industrial hub in Africa, using a multi-compartment approach (water-sediment-biota). The study aims to characterize the spatiotemporal variation of trace metal (TM) contamination and its effects on the growth of the Flathead grey mullet (Mugil cephalus). It reviewed TM concentrations in upper sediments and organs of M. cephalus from various hydrosystems worldwide. Five sites distributed along the Gulf were sampled to determine water physicochemical parameters as well as the contamination of surficial sediments and muscles of M. cephalus by zinc, copper, lead, cadmium and mercury. The spatiotemporal variations of the measured parameters were tested and discussed following the synergetic effects of water, sediment and muscle variables on fish biometrics. The sediments at the Port, Joinoville and Sidi-Salem sites were classified as heavily polluted by lead, copper, zinc and cadmium, whereas only at the Port by mercury. Muscular lead concentrations exceeded international standard values in Joinoville and Port, and zinc in Port. The increase of water dissolved oxygen induced a significant decrease in sediment TM. The increase of sediment TM caused a significant increase in muscle TM levels. The S-shaped logistic models indicated that muscle contaminations reached a saturation plateaus following the current sediment pollution. TM concentrations in fish muscles negatively affected fish weight, but only copper and cadmium significantly influenced fish length. The consumption of fish from the Port, Joinoville and Sidi-Salem can be dangerous because concentrations of lead, zinc and cadmium exceeded the international standards. This study validates the effectiveness of biomonitoring using M. cephalus as bioindicator in polluted coasts.

Modeling seasonal and spatial contamination of surface waters and upper sediments with trace metal elements across industrialized urban areas of the Seybouse watershed in North Africa.

Industrialization and urbanization are the main sources of pollutions worldwide and particularly in developing countries. This study aims the determination of anthropogenic inputs with trace metals in aquatic ecosystems at the Plain of Annaba (NE Algeria), which is known as one of the largest industrial areas in Africa. Samples of surface waters and upper sediments were conducted in six stations: four in Meboudja wadi and two in Seybouse wadi. Contents of iron, copper, chromium, nickel, zinc, and manganese were measured by atomic absorption spectrophotometry, whereas Cd and Pb were determined using electrothermal atomic absorption spectrometry. Measurements of Hg were carried out using atomic fluorescence. Spatiotemporal variations of metal concentrations were tested using generalized linear models (GLM), whereas the influence of water pollution on sediment contamination was tested with generalized additive models (GAMs). Metal contents measured in surface water and sediments varied differently from upstream to downstream of the study wadis and between seasons. The results showed that the surface water was polluted with high levels of iron, nickel, chromium, lead, and cadmium. Values of the contamination index revealed that the surface sediments were contaminated by iron, chromium, lead, and cadmium. The GAMs indicated that water-phase metal concentrations had no significant effects on trace metal concentrations in the sediment. This suggests that seasonal metal concentrations in water phase, which are measured during the study period (2012) and are time-dependent, contribute increasingly and gradually over time-not immediately-to the accumulation of metals into the sediments. Therefore, the long-term accumulation of metals in the sediments resulted from the continuous discharges of metals in the water phase. The anthropogenic impacts are marked by high contaminations of Meboudja wadi particularly in downstream areas of the steel factory and the nearby industrial areas. The direct industrial discharges into the water and atmosphere (iron, lead, cadmium) as well as urban disposals and agricultural activities are at the origin of these contaminations.

Factors contributing to heavy metal accumulation in sediments and in the intertidal mussel Perna perna in the Gulf of Annaba (Algeria).

This paper presents the results of a seasonal survey of heavy metals accumulated in sediments and in the soft parts of the body of the mussel Perna perna at four stations in the Gulf of Annaba (Algeria). Pooled soft tissues from 10 mussels representing the entire range of sizes were digested in nitric acid. Statistical analysis reveals a significant seasonal effect on all the measured metals, the highest values being recorded in winter. With the exception of Cr, the levels for all metals were significantly higher in the east, at the outlet of the Seybouse River, than at all other monitoring stations. The study also shows that north-western waters are subject to a significantly lower degree of heavy metal pollution than elsewhere in the gulf. Levels were nevertheless within the limits of public health standards. The results confirm the usefulness of P. perna as a bioindicator for heavy metal pollution.