Rachid Amara

Université du Littoral Côte d'Opale (ULCO) | ULCO · Laboratoire d'océanologie et géosciences

This study aims to characterize and compare the feeding ecology of the European eels ( Anguilla anguilla L.) during the continental phase (i.e. yellow and silver) along a salinity gradient (i.e. lower, middle and upper) in six northern France estuaries (i.e. brackish water). The diet and stable isotopic (i.e. δ ¹⁵ N and δ ¹³ C values) compositions...

In order to assess the health risks associated with the consumption of Sardina pilchardus (Walbaum, 1792) and to study the spatiotemporal dynamics of three potentially toxic metals, lead (Pb), cadmium (Cd) and mercury (Hg) concentrations were measured in the muscle and the liver of 872 specimens of sardine sampled between October 2017 and September...

This study investigates several methods to identify microplastics (MPs) of small size ranges (<10 µm) in the copepod Eurytemora affinis collected in the Seine estuary (France) and identified using epifluorescence microscopy and Raman microspectroscopy. In order to calibrate the methodology, copepods obtained from cultures were used. Firstly, we lab...

The main objective of this study was to improve our knowledge on the responses of fish populations to multistress (diffuse pollution and warming waters) in estuaries. Adult flounders were caught in two estuaries in the Eastern English Channel: the heavily polluted Seine estuary vs the moderately contaminated Canche estuary. Fish samplings were cond...

Microplastics (MPs) (plastic particles < 5 mm in size) have become the most ubiquitous type of anthropogenic litter contaminating aquatic environments worldwide, and are capable of harming aquatic organisms and entering the food web. Microplastic research has rapidly evolved over several decades, with many studies sampling microplastic in surface w...

The aim of this paper is to examine fishermen's Local Ecological Knowledge (LEK) relating to Marine Protected Area (MPA) planning and the overlap with fisheries management in the future “Taza” MPA (Algeria, SW Mediterranean). The case study focuses on both commercial and recreational coastal fisheries from the fishing harbour of Ziama (NE Algeria)....

The Algerian coast receives significant inputs of metallic pollutants. To assess the accumulation of potentially toxic elements (Pb, Cd, Hg) by benthic fish and the consequent health risks for consumers, red mullet specimens (Mullus barbatus barbatus, Linnaeus, 1758) were sampled (n=424) in 3 sites along the Algerian coast (Algiers, Bejaia and Dell...

Despite emerging and increasing concerns related to marine micro and macroplastics, no systematic surveys have been undertaken yet in the Lebanese marine area. To understand the spatio-temporal variation of plastic litter (macro and microplastics) in the Lebanese marine environment and to determine the sources of pollution, this study investigated...

The otolith, found in both inner ears of bony fish, has mainly been used to estimate fish age. Another application that has been developing significantly in recent years, however, is the use of otolith shape as a tool for stock identification. Often, studies have directly used the shape asymmetry between the right and left otoliths. We tested the m...

Nowadays, recreational fisheries (REC) have a great impact on marine ecosystems and create conflicts with other human coastal activities such as commercial small-scale fisheries (SSF). In the proposed “Taza” marine protected area (MPA) (Algeria, SW Mediterranean), recreational boat fishing is poorly regulated and its catches remain unmonitored. In...

Estuaries are highly important nursery habitats for a range of fish species because they provide refuge and food, especially for juveniles. However, the importance of specific salinity zones and adjacent shallow marine habitats (subtidal and surf zones) for fish feeding is not well understood, particularly in small macrotidal estuaries. Using the e...

Microplastics (MPs), plastics with particles smaller than 5 mm, have been found almost in every corner of the world, especially in the ocean. Due to the small size, MPs can be ingested by animals and enter the marine trophic chain. MPs can affect animal health by physically causing damage to the digestive tract, leaking plastic chemical components,...

The objective of this study was to develop an integrative approach in ecotoxicology (from biomarkers to population genetics) to assess the ecological status of fish populations. Flounders (Platichthys flesus) collected after the spawning season in the heavily polluted Seine estuary were compared with the moderately polluted Bay of Douarnenez. The m...

In this study, levels of 20 trace elements (Al, Ti, V, Cr, Mn, Fe, Co, Ni, Cu, Zn, As, Se, Ag, Cd, Sn, Sb, Ba, Hg, Pb and U) and the respective biota–sediment accumulation factors (BSAF) were assessed for three marine species from the Eastern Mediterranean (Lebanese coast) belonging to different trophic levels in the food chain (algae, bivalves and...

A total of 1229 specimens representing 11 commercial fish species caught off the coast of Algeria were examined for parasitic nematodes (larvae) from November 2015 to April 2017. Four nematode species belonging to Anisakis (1 species) and Hysterothylacium (3 species) genera were identified. The presence of A. simplex parasitism in Trachurus trachur...

A simple, rapid and robust method for routine speciation analysis of methylmercury (MeHg) by reversed phase high-performance liquid chromatography coupled to inductively coupled plasma-mass spectrometry (RP HPLC-ICP-MS) following closed microwave-assisted extraction was optimised and validated using the accuracy profile approach. An effective separ...

Eutrophication as a consequence of anthropogenic nutrient enrichment is one of the major threats to biodiversity in nearshore and coastal marine waters, and consequently, for ecosystem functioning. This study explores changes in the biological organization of copepod assemblages along a Chl a gradient through an upscaling analysis of regional datas...

Levels of 20 trace elements (Al, Ti, V, Cr, Mn, Fe, Co, Ni, Cu, Zn, As, Se, Ag, Cd, Sn, Sb, Ba, Hg, Pb, and U) were assessed in livers and muscles of two demersal fish species (Siganus rivulatus and Lithognathus mormyrus) and one pelagic species (Etrumeus teres) from the Lebanese coast located in the Eastern Mediterranean. The samples were collecte...

Estuaries serve as nursery grounds for many marine fish species. However, increasing human activities within estuaries and surrounding areas lead to significant habitat quality degradation for the juveniles. In recent years, plastic pollution has become a global environmental issue as plastic debris are found in all aquatic environments with potent...

The effectiveness of mussel caging for active microplastics (MPs) biomonitoring was investigated for the first time by comparing abundance and characteristics (shape, size, color and type of polymers) of MPs ingested by caged depurated blue mussels with those ingested by native mussels collected at the same sites and with those found in their surro...

Otolith shape is an efficient tool for fish stock discrimination. Therefore, it is crucial to identify the environmental parameters that could influence otolith morphogenesis and growth. Current global ocean warming negatively affects the production of polyunsaturated fatty acids (EPA and DHA) by phytoplankton and thus their availability in marine...

Nematodes parasites infect the peritoneal cavity and also the ovaries of fishes. Nematodes infect Pagellus erythrinus at a high rate (prevalence = 73.19%; mean intensity = 7.23 parasites per infected fish). Philometra filiformis infects particularly the ovarian parenchyma (prevalence = 5.72% and mean intensity = 1.29 parasites per infected host). O...

This study investigated the role of a municipal wastewater treatment plant (WWTP) effluent and an abandoned coastal landfill as pathways for microplastics (MPs) input into the marine environment. MPs were first analyzed in raw sewage influent, sludge and effluent samples, and their fate was studied along a distance gradient from the WWTP in three m...

Estuaries are important areas highly vulnerable to anthropogenic pollutions. Therefore, the assessment of estuarine water quality is a major ecological issue. In this study, we sampled juveniles of the European flounder in the "pristine" Canche estuary, and caged them in Canche and in two polluted sites of the Seine estuary, Rouen and Fosse Nord. A...

This study reports the contamination assessment of Pb, Cd, Hg and As in three fish species, one shrimp and one bivalve sampled from the Eastern Mediterranean (Lebanese coast). The samples were collected from three sites characterized by different types and levels of pollution. Pb, Cd, Hg and As levels were measured by inductively coupled plasma mas...

The diversity and structure of fish populations in southern Mediterranean lagoons are poorly documented. Spatial and temporal variation in uses of shallow habitats for fish fauna in Bizerte Lagoon in Tunisia was investigated in relation to environmental parameters. Fish sampling was carried out over four seasons at four stations with a 3 mm mesh be...

The establishment of marine protected areas (MPAs) in Algeria faces several obstacles, particularly lack of legislation and poor management of local resources. The attempt to establish an MPA at Taza (Gulf of Béjaia, SW Mediterranean) is part of a broader project to set up a network of MPAs in the Mediterranean basin. The MPA of Taza was first prop...

This study asses the reproductive strategy of the common sardine, Sardina pilchardus along the Algerian coast. Between January and December 2010, sampling was conducted at various inshore fishing landing sites in the Gulf of Bejaia. A total of 2919 individuals were collected, including 1317 males, 1053 females and 549 immature fish ranging in total...

Otolith shape analysis is an efficient fish stock identification tool. However, most applications used left and right otoliths or only one of them arbitrarily chosen without testing for biases resulting from potential directional bilateral asymmetry (DA) in otolith shape, i.e., a unimodal population-level deviation form bilateral symmetry between r...

Artisanal Small-Scale Fisheries (SSFs) are a primordial and very diverse activity in the Mediterranean, also within Marine Protected Areas (MPAs). This diversity is explained in terms of target species, gears, and fishing strategies. The main objective of this work was to investigate the spatio-temporal dynamics of artisanal SSFs of the future MPA...

Estuaries serve as nursery grounds for many marine fish species. However, increasing human activities within estuaries and surrounding areas lead to significant habitat quality degradation for the juveniles. In recent years, plastic pollution has become a global environmental issue as plastic debris are found in all aquatic environments with potent...

World Seas: An Environmental Evaluation, Second Edition, Volume One: Europe, The Americas and West Africa provides a comprehensive review of the environmental condition of the seas of Europe, the Americas and West Africa. Each chapter is written by experts in the field who provide historical overviews in environmental terms, current environmental s...

Plastics are found to be major debris composing the marine litter, microplastics (MP, <5 mm) being found in all marine compartments. Microplastics number tends to increase with decreasing size leading to a potential misidentification when only visual identification is performed. These last years, pyrolysis coupled with gas chromatography/mass spect...

European anchovy, Engraulis encrasicolus, is a small pelagic coastal marine fish largely spread from the North Sea to central Africa, including the entire Mediterranean and the Black and Azov Seas. The aim of this study is to identify the potential different populations of European anchovies and their relationship between the Northeast Atlantic, th...

Six-hundred and forty-five specimens of Boops boops (L.) were sampled in the Gulf of Bejaia (Eastern coast of Algeria) and examined for their parasite fauna from February 2013 to March 2014. Among the 15 identified parasites species, Tetrochetus coryphaenae (Yamaguti, 1934) and Pseudaxine trachuri (Parona & Parugia, 1890) were collected for the fir...

Otolith shape analysis was examined to determine its utility for stock identification of the bogue Boops boops (L.) along the Algerian coast. The outlines of 179 otoliths collected in three locations (Oran, Bejaia and Annaba) between 2013 and 2016 were digitised and analysed for shape variation by elliptical Fourier analysis. Potential confounding...

Between January 2011 and January 2013, parasitofauna of 1643 specimens, obtained both from wild sources (n=1545) and aquaculture (n=98) were studied. From 14 fish species, 17 parasitic species were isolated, of which three species represent a new geographical record. Despite their low infestation rate, some isolated parasite species induce serious...

The presence of Cd, Pb, Hg, PAHs and PCBs was investigated in the edible flesh of six marine species of the Senegalese coastal waters. Samples were collected from five sites in 2013. Variations in pollutant concentrations were recorded both among species and among sites. The mussels (Perna perna) contained the highest concentrations of Cd (0.394 ±...

Anthropogenic climate change is already affecting marine ecosystems and the responses of living-resources to warming waters are various, ranging from the modifications in the abundance of key species to phenologic and biogeographic shifts. Here, we used a recently developed Ecological Niche Model (ENM) to evaluate the potential effects of global cl...

Background. Southern Mediterranean lagoons are poorly studied. The Mellah Lagoon is the only coastal lagoon in Algeria. Characterized by low anthropogenic pressure it has a crucial environmental and socioeconomic role because of its fishing activities and conservation status. The spatial and temporal variations of fish assemblage structure in relat...

rate, some isolated parasite species induce serious necrosis, alterations and atrophies to the muscle, Pyroderma cylindricum (P=9.37%; I=1); Lerneolophus sultanus (P=9.09%; I=1), and Ceratothoa oestroides Naeobranchia sygniformis (P=27.27%; I=1). Among the most abundant isolated parasites was the nematode, Anguillicola crassus European eel, Anguill...

The aim of this study was to provide some new data on the infection rate of Anguilla anguilla in Soummam River (Northeast coast of Algeria) by nematode Anguillicola crassus. Between January 2012 and December 2013, 87 specimens of A. anguilla had been caught in the downstream portion of the Soummam River. They were examined for their Nematoda parasi...

From 1998 to 2011, the effects of environmental conditions on the spatial and temporal trends of sardine and sardinella catch rates in the Mauritanian waters were investigated using generalized additive models. Two models were used: a global model and an oceanographic model. The global models explained more of the variability in catch rates (60.4%...

This study examines the geographic variability in otolith shape of round sardinella Sardinella aurita as a tool for stock discrimination. Fish were analysed from six sampling locations from Senegal to the Mediterranean coast of Morocco. A combination of otolith shape indices and elliptic Fourier descriptors was investigated by multivariate statisti...

This paper presents the results of seasonal (wet and dry seasons) and spatial (five sites) variation of mercury concentration in seven marine organisms representative for shallow Senegalese coastal waters and including species of commercial importance. Total mercury levels were recorded in the green algae (Ulva lactuca); the brown mussel (Perna per...

This study evaluated diet variation of European anchovy Engraulis encrasicolus in productive and oligotrophic areas. The diet of the European anchovy was studied at 13 different sites along its geographic distribution range. In all sites, the diet was mainly based on copepods that represented 33 to 98% of the prey identified and were found in over...

The Nador lagoon, located in the northeastern part of the Moroccan Mediterranean coast, was sampled with a beach seine at six stations during different seasons, from 2012 to 2014. The African halfbeak, Hyporhamphus picarti was collected, among the fish species and some aspect of its biology and ecology (colonization of the lagoon, spawning period a...

Over the past decade, the distribution of harbour porpoises Phocoena phocoena has undergone a southward shift in the North Sea, which has led to an increase in the number of stranded porpoises in its southern part. Since the changes in distribution and relative abundance of porpoises may be linked to the changes in prey availability, the aim of the...

The first objective of this study consists of an exhaustive description of growth, reproduction and age of 2 species of pelagic fish: the sardinella Sardinella aurita (N = 649) and the sardine Sardina pilchardus (N = 648). Samples were collected monthly from November, 2012 to October, 2013 along the Algerian eastern coasts. Concerning S. aurita, 7%...

Habitat quality of an intertidal nursery ground in the eastern Channel for 0-group plaice Pleuronectes platessa was investigated by following settlement, condition and growth during seven years (2005 to 2007 and 2010 to 2013) between March to June. Plaice settlement period extended from mid-March to late May and both date of pic of settlement and p...