Algerian Coast Research Articles

Antifungal activity of methanolic extracts of four Algerian marine algae species

Since ancient times antimicrobial properties of seaweeds have been recognized. In this study, antifungal activity of four species of marine algae of Bejaia coast (Algeria) was explored. This activity was evaluated by agar diffusion method. The minimum inhibitory concentrations were also determined for all the strains. All the extracts used in this study exhibited antifungal activity. The highest inhibiting effect was noted for Rhodomela confervoides (red algae) and Padina pavonica (brown algae), respectively against Candida albicans (diameter of inhibition zone: 24 mm) and Mucor ramaniannus (diameter of inhibition zone: 26 mm) for the first one and Candida albicans (diameter of inhibition zone: 26 mm) for the second one. Aspergillus niger showed resistance against majority of methanolic extracts. The evaluation of minimum inhibitory concentrations showed that extracts of Padina pavonica, Rhodomela confervoides and Ulva lactuca were very efficient against Mucor ramaniannus and Candida albicans. These results suggest that seaweeds collected from Algerian coast present a significant capacity which makes them interesting for screening for natural products.

Descriptions of digeneans from Sardina pilchardus (Walbaum) (Clupeidae) off the Algerian coast of the western Mediterranean, with a complete list of its helminth parasites

Five species of digeneans parasitic in the pilchard Sardina pilchardus (Walbaum), a little studied host, from off the Algerian coast of the western Mediterranean are redescribed. These are Parahemiurus merus (Linton, 1910) Manter, 1940, Aphanurus stossichii (Monticelli, 1891) Looss, 1907, Aphanurus virgula Looss, 1907, Lecithaster confusus Odhner, 1905 and Pronoprymna ventricosa (Rudolphi, 1819) Poche, 1926. One of these, A. virgula, is a new record for this host. One other digenean, Hemiurus luehei Odhner, 1905, was also recorded from this host. A complete checklist of the helminth parasites of S. pilchardus throughout its distributional range, comprising 104 host-parasite records of 39 taxa, is presented.

Economic Study of Nuclear Seawater Desalination for Mostaganem Site

Algeria has experienced over the past four decades, several periods of drought which led to the use of seawater desalination through a vast program initiated in 2003. The program is implemented to achieve 13 seawater desalination units, to produce 2.3 million m3/day in 2011, to meet needs for potable water, as well as those of small and medium industries in the coastal regions and neighboring regions. This capacity will reach 2.5 million m3/day in 2015, taking into account the tourism development in these regions. Because the program set up is based solely on fossil energy and that desalination technology is a major consumer of energy, to ensure sustainability of water resources and save the energy source (natural gas), it became necessary to initiate prospective studies to replace, for this purpose, fossil energy by other energy sources such as: renewable energy and nuclear energy. Currently, nuclear power is presented as a more attractive solution through the development and technological expertise recorded in the field of nuclear desalination integrated systems. Several demonstration units have been realized which have gained an undeniable know how. The experience accumulated in this area is estimated to 247 reactor-years. For this purpose, a study of nuclear desalination unit is performed for a potential site located in the Western Algerian coast, which is characterized by a very low rainfall rate of 400mm/year. This study is taken in the national context. Indeed, the energy sources outputs that are candidates in this study are based on the Indicative Program of Electricity Generation developed in Algeria. The outputs related to nuclear energy are in respect with the threshold fixed to 10% of the maximum power installed. The definition of nuclear desalination unit capacity is fixed to meet the water demand of the population of this region covering a period of 25 years beyond 2025.The cogeneration option is taken into account in this study. In this study, we present the economic evaluation results of coupling several nuclear reactors with two desalination processes MED and RO, using DEEP3.1 software. These results are compared with those obtained with fossil energy sources based on Natural Gas.

Argulus vittatus (Rafinesque-Smaltz, 1814) (Crustacea: Branchiura) parasitic on Algerian fishes

Eighteen female specimens of Argulus vittatus (Rafinesque-Smaltz, 1814) were recently collected from the Algerian coast. As until now this species was poorly described, this contribution redescribes this species with more precise drawings on the general morphology and appendages, using this fresh material. For the first time, two new hosts are identified. Host specificity and some ecological data are also reported.

The Effects of Season and Site of Catch on Morphometric Characteristics, Mineral Content, and Fatty Acids of Sardines (Sardina pilchardus) Caught on the Algerian Coast

The variation of morphometrics, mineral content, and fatty acid composition of sardines was determined in relation to season and site of catch in the Mediterranean Sea. Sardines were caught in two regions of the Algerian coast: Mostaganem and Béni-Saf. In both sites, the contents of phosphorus (223 and 211 mg 100 g−1) and sodium (95 and 10 mg 100 g−1) were higher in June than in February. Total lipid content was related to the season, being low in winter (2.9%) and high in summer (11.3%). The fatty acid composition shows a high content of polyunsaturated fatty acids (PUFA) dominated by n-3 fatty acids eicosapentaenoic acid (EPA C20:5 n-3; 10%) and docosahexaenoic acid (DHA C22:6n-3; 25%). However, the content of n-6 fatty acids was relatively low both in winter (3.4%) and summer (4.7%). The saturated fatty acid (SFA) content was appreciable in sardines, which range from 34% to 37% according to season. This is in agreement with the literature related to the Mediterranean sardine.

The El Asnam 1980 October 10 inland earthquake: a new hypothesis of tsunami generation

SUMMARY The Western Mediterranean Sea is not considered as a high seismic region. Only several earthquakes with magnitude above five occur each year and only a handful have consequences on human beings and infrastructure. The El Asnam (Algeria) earthquake of 1980 October 10 with an estimated magnitude Ms= 7.3 is one of the most destructive earthquakes recorded in northern Africa and more largely in the Western Mediterranean Basin. Although it is located inland, it is known to have been followed by a small tsunami recorded on several tide gauges along the southeastern Spanish Coast. In 1954, a similar earthquake having occurred at the same location induced a turbidity current associated to a submarine landslide, which is widely known to have cut submarine phone cables far from the coast. This event was followed by a small tsunami attributed to the landslide. Thus the origin of the tsunami of 1980 was promptly attributed to the same kind of submarine slide. As no evidence of such mass movement was highlighted, and because the tsunami wave periods does not match with a landslide origin in both cases (1954 and 1980), this study considers two rupture scenarios, that the coseismic deformation itself (of about 10 cm off the Algerian coast near Tenes) is sufficient to produce a low amplitude (several centimetres) tsunami able to reach the Spanish southeastern coast from Alicante to Algeciras (Gibraltar strait to the west). After a discussion concerning the proposed rupture scenarios and their respective parameters, numerical tsunami modelling is performed on a set of bathymetric grids. Then the results of wave propagation and amplification (maximum wave height maps) are discussed, with a special attention to Alicante (Spain) Harbour where the location of two historical tide gauges allows the comparison between synthetic mareograms and historical records showing sufficient signal amplitude. This study is part of the active tsunami hazard assessment in Mediterranean Sea especially concerning its occidental part, that is, the Algerian, Spanish and French coasts.

Temporal changes in the diet of deep-water Penaeoidean shrimp (<i>Parapenaeus longirostris</i> and <i>Aristeus antennatus</i>) off Algeria (southwestern Mediterranean)

With the aim of analyzing the trophic dynamics of deep-sea shrimp over the central Algerian slope, stomach contents of 219 individuals of Parapenaeus longirostris and 263 Aristeus antennatus were collected at night at depths between 200 and 400 m on a seasonal scale in 2007. Fullness ( f ), which is a measure of feeding intensity, showed significant seasonal changes in Aristeus antennatus , and the highest f was found in pre-reproductive periods (3.3% in January; 3.0% in April) before the beginning of gonad maturation (April-September in the area). This trend was coupled with the period of high surface productivity off the central Algerian coast (November-April). In that pre-reproductive period A. antennatus consumed more crustaceans (e.g. large decapods such as Processa sp.) with a high energetic value. These kinds of seasonal oscillations in f were not found in P. longirostris , probably because it was distributed shallower than A. antennatus and does not have a single marked peak in its reproductive cycle. The dietary composition of P. longirostris and A. antennatus was clearly segregated in the MDS analysis, which suggests there is good resource partitioning between the two species. Foraminiferans, bivalves and polychaetes were the most frequent prey in the diet of both P. longirostris and A. antennatus . Small micro and mesoplankton prey (radiolarians, tintinnids, copepods and pteropods) were more important in the diet of P. longirostris , while A. antennatus fed more on benthos. Planktonic prey found in the diet of the two shrimp were more frequent in January-February and April-May, e.g. in periods of higher water homogeneity coupled with periods of higher surface production. The large contribution of zooplankton to the diet of the deep-water shrimp over Algerian slopes is probably due to the importance of eddies in the area, which may enhance water column production locally. The high surface temperature (lowest T in January of 15.2°C) may accelerate the degradation of the organic matter that reaches Algerian slope bottoms, thus reducing the biomass of macrobenthos. We hypothesized that this low availability of benthic food resources may favour night time migratory movements by benthopelagic shrimp off the Algerian coast in search of more productive, shallow bottoms.

Ecological Quality Status of the soft-bottom communities on the algerian coast: General patterns and diagnosis

Between 1995 and 2001, the soft-bottom communities along the 1180km of the Algerian coast were sampled in nine gulfs and 12 harbours, providing a total of 655 samples. Eight macrozoobenthos-based biotic indices (S, N, H′, BQI, AMBI, BENTIX, BO2A and ITI) were selected to describe the general patterns of the coastal water quality status and to establish a quality diagnosis for the different zones subjected to anthropogenic pressure (e.g., harbour construction, industrial and urban pollution). Reference values were determined for each of the eight indices selected by analyzing the indices’ parameter distribution. The Ecological Quality Ratio (EQR) was estimated for each index, resulting in an EQR Mean Score and an EQR Bad Score. From these EQR, we defined an EQS for each sample. The agreement between these EQS was analysed using the Kappa method in order to propose a survey strategy for the Algerian coastal waters that would take into account the soft-bottom biological compartment. The results clearly indicate that high and good quality assessments are prevalent in the gulfs, while quality assessments in harbours vary greatly from bad to good. The effect of pollution observed in the harbours can be classified in two main groups, according to when they were constructed and their relative degree of openness to the sea, which permits better water circulation and probably dilutes the pollution.

Caligus uranoscopi Vaissière, 1955 (Copepoda, Caligidae), a rare parasitic copepod from Algeria

AbstractCaligus uranoscopi Vaissière, 1955 (Copepoda, Caligidae) is redescribed based on specimens collected from the gill arches of red mullet, Mullus barbatus barbatus L., 1758, caught off the Algerian coast. Caligus uranoscopi is reported for the first time from the east coast of Algeria and M. barbatus barbatus is a newly recorded host for this parasite. The parasite is uncommon and may be restricted to Algerian coasts. Some remarks are given on the species of Caligidae known from Algeria.

First record of the invasive alga Caulerpa racemosa (Caulerpales, Chlorophyta) in the Gulf of Arzew (western Algeria)

The first invasive record of the green alga Caulerpa racemosa (Forsskal) J. Agardh in the Mediterranean Sea was in 1990 in Tripoli (Libya) (J. Agardh) and since that period, this Chlorophyta has been rapidly spreading to all Mediterranean countries. However, very few assessment studies have been carried out along the Algerian coast. In this paper, we present, for the first time new observation data concerning an indicated proliferation of this invasive species in Salamandre and Stidia (Gulf of Arzew, western Algeria); both these sites are very important for sea fishing activities and traffic.

Mesozooplankton abundance and biomass related to hydrological structure along the Algerian coasts (S.W. Mediterranean Sea)

Mesozooplankton abundance and biomass related to hydrological structure along the Algerian coasts (S.W. Mediterranean Sea)

Acanthobothrium minusn. sp. (Tetraphyllidea : Onchobotriidae) parasite deRaja asterias(Elasmobranchii : Rajidae) en Méditerranée

Among tetraphyllidean cestodes, parasitic in the spiral valve of Raja asterias Delaroche, colected from Algerian coasts, we obtained an onchobothriid of the genus Acanthobothrium, differing from all species of Acanthobothrium previously reported from Rajidae from Mediterranea and european Atlantic coast. This Cestode is characterized by its very small size (1-2 mm), its number of segments of the strobila (4-8), the morphology and size of hooks, the limited number (17-25) of testes and ovarian morphology. Together, these features places this Acanthobothrium in group "2" as defined by Ghoshroy & Caira (2001). We describe this onchobothriid as Acanthobothrium minus n. sp.

Spatial, temporal and ontogenetic variation in diet of anchovy ( Engraulis encrasicolus) on the Algerian coast (SW Mediterranean)

The diet of anchovy Engraulis encrasicolus was studied in three regions (Béjaia, Bénisaf and Ghazaouet) along the Algerian coast. Ontogenetic, spatial and seasonal variations in anchovy diet were investigated using multivariate analyses and analysed in relation with sea surface temperature and chlorophyll- a. 46 prey taxa of varying size between 0.57 mm ( Euterpina acutifrons) and 6.8 mm (fish larvae) were recorded. Whatever the season, the region or the fish size, anchovy is exclusively zooplanktivorous and copepods were the most present prey, constituting 87% by number of the prey taken and found in 98% of the anchovy stomachs examined. However, their occurrence and number varied according to the different areas, seasons and fish size. During its first year of life, anchovy feeds almost exclusively on copepods (mainly small and medium size prey). As anchovy grows, copepods are gradually substituted by large crustaceans such as decapods and amphipods. Hierarchical cluster analysis, analysis of similarities (ANOSIM) and similarities percentage (SIMPER) indicated a distinct diet of anchovy of the bay of Bejaia from those of the bays of Bénisaf and Ghazaouet probably due to differences in hydrologic conditions. Diet differences also occurred between seasons. Summer and spring have distinct prey assemblages each and showed low diet similarities with the two other seasons. More prey species were found in the diet during winter (36) and autumn (30) and the vacuity index was lower in winter. Temporal variability in satellite-derived chlorophyll- a matched the seasonal variability in the diversity of the anchovy prey and feeding intensity as reflected by the vacuity index, suggesting further investigation of the potential use of satellite-derived chlorophyll- a data as a proxy for anchovy feeding intensity.

Stratigraphy, sedimentology and structure of the Numidian Flysch thrust belt in northern Tunisia

The Oligo-Miocene Numidian Flysch of northern Tunisia has long been divided into three distinct lithostratigraphic units considered as vertically superimposed: the lower unit or the “Zouza member”, the middle unit or the “Kroumirie member” and the upper unit or the “Babouch member”. According to this reconstruction the two first members are mostly Oligocene in age and only the third member was assigned as early Miocene in age. In this study, we present new biostratigraphic data, based on planktonic foraminiferal analysis, demonstrating that both the Zouza and the Kroumirie members are Oligocene–early Miocene in age and are, therefore, coeval. Four distinct facies associations have been identified within the Numidian Flysch including: (a) massive sandstones; (b) conglomerate; (c) an interbedded mudstone–sandstone association; and (d) a mudstone facies association. Slide-slump units and injectionite sands occur within the more mud-rich associations. The likely depositional setting is a muddy slope–apron system, cut locally by sand-rich channels, which fed channel-terminal lobe deposits. Paleocurrent data support strongly a flow from N and NW. Modal analysis, demonstrates that the Numidian sandstones are quartz-arenite type (QFL, 97.25:1.25:1.5) derived from middle to high grade-metamorphic and granitic rocks. Zircon geochronology, yielding ages of 514 ± 19 Ma from Tunisia and 550 ± 28 Ma from Sicily, would support the basement terrain that crops out along the Algerian coast and forms part of Calabro–Peloritani–Kabylian zone, as the most likely parental source of the Numidian Flysch for both Sicily and Tunisia. Zircon data from the Fortuna Formation yields ages of 1698 ± 67 Ma, which is more compatible with an African craton source ( Fildes et al., 2009). Structural consideration of the basal contact of the Numidian Flysch with the underlying Tellian rocks, as well as newly interpreted seismic data; confirm the allochthounous position of the Numidian complex and its displacement southward. Facies comparison with the equivalent Oligo-Miocene Bejaoua siliciclastic deposits outcropping towards the south shows that the Numidian complex is an “out-of-sequence thrust unit” and that the two Oligo-Miocene sedimentary systems are quite distinct and were sourced from wholly different source regions.

New records of marine amphipod fauna (Crustacea: Peracarida) on the Algerian coast

Recent sampling surveys (1995–2001) of the shallow (3–136 m) soft-bottom communities along the Algerian coast in nine bays and gulfs and twelve harbours have allowed 206 species of marine amphipod to be recorded. Among the species recorded, 45 species appear to be new in terms of the inventory of the marine amphipod fauna of Algeria (Bakalem & Dauvin, 2005). This note reports on the number of specimens sampled for each of these 45 species and provides data on sediment type and depth at which they were sampled. Sixteen of these species are considered to be endemic to the Mediterranean Sea, twenty-six are north-eastern Atlantic species, and the last three have a wide geographical distribution in the Indo-Pacific and the Atlantic Oceans. The sampling also permitted the confirmation of the presence of five other Atlantic amphipod species not already reported in the inventory of the Mediterranean amphipod fauna (Bellan-Santini et al., 1998). The total number of marine amphipod fauna in Algeria is now 298.

First observations of the Indo-Pacific bluespotted cornetfish Fistularia commersonii (Fistulariidae) from Algerian coasts

Some adult specimens of the bluespotted cornetfish, Fistularia commersonii (Osteichthyes: Fistulariidae), are recorded for the first time along the Algerian coasts, in Skikda Bay (eastern Algeria) and offshore Bou Ismail Bay (central Algeria). More than 100 fish measuring from 73 to 88 cm were captured by fishermen. A sample of three specimens is described here. This species is the first lessepsian immigrant fish in Algeria, indicating its fast spreading ability and its success in the Mediterranean environments.

Large boulder accumulation on the Algerian coast evidence tsunami events in the western Mediterranean

Evidence of catastrophic mega-block deposition is presented for the Algerian coast from Tipaza to Dellys. The region is prone to large earthquakes, several of which are inferred to be tsunamigenic in origin, as attests the 2003 Zemmouri earthquake (Mw 6.8). It is argued here that several former tsunamis have resulted in the detachment of large boulders from the nearshore zone and their deposition inland. The estimated size, weight (volumetric mass) and distance from the shoreline of more than 100 boulders has enabled estimates to be made of the nature of the hydrodynamic waves responsible for their transport. The boulders weigh up to 200 tons and are scattered along ∼ 150 km of rocky headlands and pocket beaches, in isolated or grouped elements, from the subtidal to supratidal zones. Boulders covered by biogenic incrustations show morphological features which suggest detached, reversed and reworked pieces. Statistical and hydrodynamic analyses indicate that large boulder transport requires either ∼ 30-m-high waves or 5 to 10-m-high waves for catastrophic storm or tsunami events, respectively. Bio-indicators allow us to date two inferred tsunamis as having struck the Algerian coastline between AD 400–600 and ∼ AD 1700.

The 1856 Tsunami of Djidjelli (Eastern Algeria): Seismotectonics, Modelling and Hazard Implications for the Algerian Coast

On August 21st and 22nd 1856, two strong earthquakes occurred off the seaport of Djidjelli, a small city of 1000 inhabitants, located 300 km east of Algiers (capital of Algeria). In relation to these two earthquakes, an important tsunami (at least one) affected the western Mediterranean region and the eastern Algerian coastline between Algiers and La Calle (Algero-Tunisian border). Based on historical information as well as on data recently collected during the Maradja 2 survey conducted in 2005 over the Algerian margin, we show that the tsunami could have been generated by the simultaneous rupture of a set of three en echelon faults evidenced off Djidjelli. From synthetic models, we point out that the area affected along the Algerian coast extended from Bejaia to Annaba. The maximum height of waves reached 1.5 m near the harbor of Djidjelli.

Benthic indices and ecological quality of shallow Algeria fine sand community

Abstract This study applies six macrozoobenthos-based biotic indices in the shallow coastal waters along the Algerian coast (southern Mediterranean Sea) to establish a reference situation for future use. These shallow fine sand communities were sampled in seven bays along the Algerian coast during the 1980s and the beginning of the 1990s. For the first time, some of the benthic indices used nowadays in Europe for the implementation of the WFD and/or in North America for the Clean Water Act were used to analyze the data collected twenty years ago in order to assess the biological quality status of the Algerian shallow fine sand communities and to provide ecological classifications for the fine sand community along the Algerian coast. The faunal composition showed that the fine sand communities belonged to a Well-Calibrated Fine Sand (WCFS) biocenosis characterized by high species richness and high H ′ Shannon-Weaver diversity, with moderate abundance levels only. In the bays of Fetzara, Jijel, Bejaia, Bou Ismail and Arzew (though not in bays of Algiers and Oran), H ′ is >4.5, which implies highly diversified communities. The results of the six benthic indices ( H ′, AMBI, M-AMBI, BENTIX, BOPA and ITI) suggest that good and high quality status assessments are prevalent in all seven bays for the benthic shallow sand communities along the Algerian coast. Nevertheless, the effect of pollution was observed at a small number of sites in the Arzew, Oran and Algiers bays. For example, in Algiers Bay, an east-west quality gradient revealed the effect of organic matter input.

Radionuclide tracing of water masses and processes in the water column and sediment in the Algerian Basin

Caesium-137 and 239,240PU were analysed in the water column along the Algerian coast. The 137Cs activity concentration in surface water increased from the west to the east from 1.6 to 3.3 mBq L −1, documenting a presence of Modified Atlantic Water (MAW) in the region. Higher concentrations observed in deep waters may be due to an intrusion of Levantine Intermediate Water (LIW), which has been carrying higher levels of 137Cs from Chernobyl accident. The 239,240Pu sub-surface concentration peaked at about 250 m water depth as a result of biogeochemical processes in the water column. The observed 239,240Pu/ 137Cs activity ratio at the surface (0.003) was significantly lower than that in global fallout (0.04). This decrease exceeds that expected from radioactive decay of 137Cs, and confirms that Pu due to its adsorption on sinking particles is more effectively removed from surface layers than is 137Cs. An increase of the 239,240Pu/ 137Cs activity ratio with depth suggests that 239,240Pu, similarly as 137Cs, should be also transported by advection to maintain the observed ratios in deep waters. An intrusion of LIW may enhance therefore both the 137Cs and 239,240Pu concentrations in deep waters. The average 238Pu/ 239+240Pu activity ratio in seawater was 0.03 ± 0.02, confirming a global fallout origin of Pu in the Algerian Basin. Caesium-137 and 239,240Pu inventories in the water column were estimated to be from 2.7 ± 0.5 kBq m −2 to 3.8 ± 0.7 kBq m −2, and from 13.8 ± 2.6 Bq m −2 to 41 ± 7 Bq m −2, respectively. The 137Cs massic activities in surface sediment were almost constant, the average activity was 9.0 ± 0.8 Bq kg −1. Sedimentation rates obtained using the 210Pb method were from 0.1 to 0.7 cm y −1, and resulting penetration depths of 137Cs in the sediment cores were from 15 to over 40 cm. The 137Cs peaks found in the sediment cores were associated with the Chernobyl accident (1986) and global fallout (1964). The 137Cs inventories in the sediment were increasing from the west (180 Bq m −2) to the east (350 Bq m −2).