Publications internationales

2021
Ouniss, Makhlouf, Laskri, Hadjer, Ziouch, Omar-Ramzi, Justic, Dubravko.. (2021), Riverine and wet atmospheric nutrient inputs to the Southwestern Mediterranean region of North Africa. . Marine Chemistry 228 (2021) 103915.https://doi.org/10.1016/j.marchem.2020.103915. : Elsevier, https://doi.org/10.1016/j.marchem.2020.103915

Résumé: This study describes the first simultaneous long-term effort to examine the nutrient inputs to the southern Mediterranean Sea from rivers and wet atmospheric deposition. Extensive daily rainwater sampling (280 samples) from the Annaba region (SW Mediterranean Sea, Algeria) and from river discharges (144 samples) at two river outlets feeding the Annaba Bay, the Seybouse River (SR) and the Mafragh River (MR),were collected and analyzed for dissolved nutrients from 2012 until 2017. During the 6-year study period, the Annaba region experienced contrasted hydrological conditions varying from heavy rainfall events during winter that have triggered large river flooding in 2012 and 2015 to the severe drought of 2016, which have profoundly affected both the atmospheric and riverine freshwater and nutrient inputs. The annual freshwater volume delivered to Annaba Bay averaged approximately 1.7 km3, of which 51% was from MR, 33% from SR, and 16% from precipitation. Precipitation over the Annaba region was associated with unusually high levels of DIP and DSi, resulting in deposition rates (0.54 mmol Si m-2 yr-1 1and 6.22 mmol P m-2 yr-1, respectively) that are several times higher compared to the average values reported for the Mediterranean region. In contrast, both the DIN and DON deposition rates were relatively low (16.2 and 4.7 mmol N m-2 yr-1, respectively) compared to the values reported for the Mediterranean region. Interestingly, the levels of nitrogen compounds in rainwater were similar to those in the MR waters. For all nutrient species analyzed in this study, SR waters always contained higher nutrient levels compared to those in MR and rainwater. The majority of nutrient loading entering Annaba Bay was delivered through the riverine inputs, averaging 2744, 962 and 92 t yr-1 for DSi, DIN and DIP, respectively. The wet atmospheric deposition contributed only 2.5% of DSi, 10% of DIN and 7% of DIP total annual flux. The riverine stoichiometric N:P and Si:N ratios were imbalanced in most cases, averaging 28 and 0.84, respectively. The N:P and Si:N ratios in rainwater were more balanced, particularly during the dry season when Saharan airflow dominated the region and supplied more DIP and DSi.

2020
Ziouch, O.R., Laskri, H., Chenakera, H., Ledjedel, NE., Daifallaha, T., Ounissi, M.. (2020), Transport of nutrients from the Seybouse River to Annaba Bay (Algeria, SWMediterranean). Marine Pollution Bulletin 156 (2020) 111231.https://doi.org/10.1016/j.marpolbul.2020.111231. Marine Pollution Bulletin : Elsevier, https://doi.org/10.1016/j.marpolbul.2020.111231

Résumé: Freshwater and dissolved nutrient inputs that entered the lower Seybouse River estuary were assessed in 2012 through a fortnightly surface water sampling both at a lower river station and at the estuary outlet. The Seybouse estuary delivered annually 950 × 106 m3 of freshwater yielding 83 kg N km−2 yr−1 of N-NH4 and 12 kg P km−2 yr−1 of P-PO4. More than 2/3 of the annual inputs of freshwater, Si(OH)4 and NO3 entered the sea during the flooding event of late February 2012. Si-Si(OH)4 and N-NO3 yields in the Seybouse estuary represented<1/ 3 those of the Mediterranean rivers. Annaba Bay is subjected to highly polluted waters from the Seybouse estuary, with significant NH4 (72 ± 37 μmol L-1) and PO4 (7 ± 4 μmol L-1) amounts. However it is characterized by low Si(OH)4 (104 ± 43 μmol L-1) amounts. Alteration of Si:N:P ratios at this bay suggest potential risk of eutrophication, except during and weeks after flood episodes.

2018
Ounissi, Makhlouf, Amira, Aicha.Beya, Dulac, François. (2018), Riverine and wet atmospheric inputs of materials to a North Africa coastal site (Annaba Bay, Algeria). . Progress in Oceanography : Elsevier, https://doi.org/10.1016/j.pocean.2018.04.001

Résumé: This study simultaneously assesses for the first time the relative contributions of riverine and wet atmospheric inputs of materials into the Algerian Annaba Bay on the Mediterranean coast of North Africa. Surface water sampling and water discharge estimates were performed weekly in 2014 at the outlets of the Mafragh River (MR) and Seybouse River (SR). Riverine samples were analyzed for dissolved nutrients and particulate matter (suspended particulate matter: SPM; particulate organic carbon: POC; biogenic silica: BSi; chlorophyll a: Chl a; particulate organic nitrogen: PON and particulate organic phosphorus (POP). Rainwater samples were jointly collected at a close weather station on a daily basis and analyzed for dissolved nutrients. The rainwater from the Annaba region was characterized by high concentrations of phosphate (PO4) and silicic acid (Si(OH)4) that are several times the average Mediterranean values, and by strong deposition fluxes. Conversely, the levels of dissolved inorganic nitrogen (DIN) and dissolved organic nitrogen (DON) and associated fluxes were remarkably low. The dissolved nutrient fluxes for the two catchments were low following the lowering of the river flows, but those of particulate matter (POC, Chl a, BSi) displayed significant amounts, especially for the MR catchment. BSi and POP represented approximately a third of the total silicon and total phosphorus fluxes, respectively. The levels of dissolved N and P in the MR water were comparable to those in rainwater. MR appeared to be a nearly pristine ecosystem with low nutrient levels and almost balanced N:P and Si:N ratios. SR water had low Si(OH)4 levels but was highly charged with NH4 and PO4 and showed unbalanced N:P and Si:N ratios in almost all samples. These conditions have resulted in large phytoplankton biomasses, which may lead to eutrophication. More importantly, the rainwater was identified as a relevant source of fertilizers for marine waters and agricultural land in the Annaba area and can partially balance the loss of Si(OH)4 from rivers to the bay due to dam retention.

2016
Ouniss, Makhlouf, Laskri, Hadjer, Khelifi-Touhami, Meriem. (2016), Net-zooplankton abundance and biomass from Annaba Bay (SW Mediterranean Sea) under estuarine influences. Mediterranean Marine Science : Hellenic Centre for Marine Research, Greece, http://www.medit-mar-sc.net DOI: http://dx.doi.org/10.12681/mms.1474

Résumé: Zooplankton samples were collected in Annaba Bay (Algeria) from January 2009-March 2011 at three coastal sites differently affected by estuarine plumes and external currents. Aim of this survey was to analyze zooplankton composition, abundance and biomass and compare the results with previous studies to reveal possible populations and environmental changes. The mean zooplankton abundance varied between 1,200-6,000 ind. m-3 and biomass 6.70-25.70 mg DW m-3, according to the site. Copepods constituted the main fraction of zooplankton community, and Oithona similis and Paracalanus indicus successively dominated during autumn-winter and spring-summer. The dinoflagellate Noctiluca scintillans was one of the major zooplankton components, and developed high numbers during February-April, becoming common in neritic and coastal regions. The singularity of the zooplankton from Annaba Bay is the prevalence of P. indicus throughout the entire bay and the decrease in Acartia (Acartiura) discaudata and Acartia (Acartiura) clausi (with respect to previous years), possibly replaced by A. negligens. Additionally, Oithona nana abundance markedly decreased with the large development of O. similis. Annaba Bay also differs from other similar Mediterranean coastal areas by the large development of Centropages ponticus populations during the warm period. Among the identified copepod species, the alien species Pseudodiaptomus australiensis and P. arabicus are reported for the first time in the Mediterranean Sea. The occurrence of copepodid V stages of P. australiensis suggests that this species survives and reproduces in Annaba Bay, but so far without developing an abundant population.

2014
Ounissi, Makhlouf., Ziouch, Omar Ramzi, Aounallah, Ouafia. (2014), Variability of the dissolved nutrient (N, P, Si) concentrations in the Bay of Annaba in relation to the inputs of the Seybouse and Mafragh estuaries.. Marine pollution Bulletin : Elsevier, http://dx.doi.org/10.1016/j.marpolbul.2013.12.030.

Résumé: Dissolved inorganic nitrogen (DIN), phosphate (PO4) and silicic acid (Si(OH)4) loads from the Seybouse and the Mafragh estuaries into the Bay of Annaba, Algeria, were assessed at three stations of the Bay over three years. The Seybouse inputs had high levels of DIN and PO4, in contrast to the Mafragh estuary’s near-pristine inputs; Si(OH)4 levels were low in both estuaries. The DIN:PO4 molar ratios were over 30 in most samples and the Si(OH)4:DIN ratio was less than 0.5 in the Seybouse waters, but nearly balanced in the Mafragh. The specific fluxes of Si–Si(OH)4 (400–540 kg Si km2 yr1) were comparable in the two catchments, but those of DIN were several-fold higher in the Seybouse (373 kg N km2 yr1). The inner Bay affected by the Seybouse inputs had high levels of all nutrients, while the Mafragh plume and the outer marine station were less enriched

2013
Ounissi, Makhlouf, Bouchareb, Noureddine. (2013), Nutrient distribution and fluxes from three Mediterranean coastal catchments (NE Algeria) under large damming.http://dx.doi.org/10.1016/j.crte.2013.02.002. CR Geoscience : Académie des Sciences / Elsevier Masson , http://dx.doi.org/10.1016/j.crte.2013.02.002

Résumé: Nutrient distribution and fluxes into and from dams and into coastal waters from three rivers (NE Algeria) were assessed during a one-year period in three stations for each river: at the entrance and the exit of dam and at the outlet. The main characteristics of the rivers were the high levels of NH4 and PO4, even in dam entrances, contrarily to SiO4 levels that are still low upstream the dams. From the inorganic nutrient incoming fluxes, the dams trapped annually 42 to 93%, depending on the nutrient, but released in great levels dissolved organic forms at their exits. At catchment scale, dissolved nitrogen loadings reach 338 kg/km2/yr, in which the organic fraction forms up to 34%; while those of dissolved phosphorus reach 172 kg/km2/yr, with a great organic fraction. The Si:N ratios decreased while N:P ratios increased at river outlets, indicating large inputs of N over P in the lower catchments.

2007
Meriem KHELIFI-TOUHAMI, Rachid SEMROUD, El Hadi HAMDI, Makhlouf OUNISSI, Ahcène HARIDI, Mohamed NÉJIB DALY and Patricia AISSA. (2007), The planktonic copepod communities from the southern Mediterranean Sea (Algeria, Tunisia) with a re-description of Paracalanus indicus Wolfenden 1905 (Copepoda: Calanoida). Cahiers de Biologie Marine : Station biologique de Roscoff, France,

Résumé: The composition, diversity and ecological affinities of pelagic copepods from the eastern Algerian coast and the contiguous Tunisian littoral (Bizerte shelf) were studied. The synthesis of the results showed peculiarities of the communities inhabiting these shelf waters. One hundred forty three copepod species were identified from which Copilia lata Giesbrecht 1891 is recorded for the first time in the Mediterranean Sea. The copepods of the continental shelf of eastern Algeria seemed to be abundant and highly diversified. Ecological affinities revealed the influence of local and regional oceanographic conditions. Paracalanus indicus Wolfenden 1905 was recorded for the first time in the Algerian and Tunisian coastal waters. Because of the close morphological characteristics of P. indicus and P. quasimodo Bowman 1971 inhabiting the Atlantic Ocean, a compared study to distinguish between both species was undertaken. Despite its abundance in the Algero-Tunisian coast, representing 46% of total copepods, P. indicus was not found in the Mediterranean oriental basin or the north occidental part of the Mediterranean Sea. Although with careful morphological study, it is very difficult to distinguish between the two species.

2006
Khélifi-Touhami, Meriem, Ounissi, Makhlouf, Saker, Imadeddine, Haridi, Ahcene, Djorfi Saadane, Abdenour, Cherif. (2006), The hydrology of the Mafrag estuary (Algeria): Transport of inorganic nitrogen and phosphorus to the adjacent coas. Journal of Food, Agriculture & Environment Vol.4 (2) : 3 4 0 - 3 4 6 . : WFL Publisher- Science and Technology, www.world-food.net

Résumé: The Mafrag hydrographic complex represents a rare Mediterranean estuary located in a northeastern wetland of Algeria. The main hydrological characteristics of this estuary have been analyzed from five cruises at a fixed estuarine station. In each cruise, physicochemical parameters (temperature, salinity, tide regime, flood water inputs and nutrient salts) have been measured hourly from 7 to 18 h. At the end of autumn and in winter the estuary is mostly renewed by high river flow. In spring and summer, tidal semi-diurnal regime reappears and allows an increase of salinity. When estuarine water level and wind stress decrease in autumn, a new offshore bar appears and may close the estuary’s mouth. All hydrological parameters show large fluctuations between tidal phases and seasons. The hydrologic cycle functioning of the Mafrag was found as an original state, comprising three phases (river, estuarine and lagoonal), with about four months interval for each one. Surface salinity varies from 2 in river phase to 33 for the rest of the studied period. Values of deep water salinity ranges between 33 and 35 in estuarine and lagoonal phases, during which the estuary is very stratified. Tidal regime was found semidiurnal. In ebb tide, the water flood advected into the adjacent coast with up to 36-60 m3.s-1. In winter, spring and autumn, nutrient salts were abundant compared to summer values. Ammonium and phosphate depleted in surface water at summer but were discharged in high amounts in autumn and the rest of the year: up to 2,200 kg.d-1 inorganic nitrogen and 400 kg.d-1 P-PO4. The absolute continental flux in terms of inorganic nitrogen and phosphate has been computed and compared to that of marine coastal intrusion

Livres

2015
Draredja, Brahim and Ounissi, Makhlouf. (2015), Structure et fonctionnement d’un milieu lagunaire méditerranéen: Lagune Mellah (El-Kala, Algérie Nord-Est) : Éditions universitaires européennes,

Résumé: La lagune Mellah est l'unique lagune en Algérie, c'est une partie intégrante du Parc National d’El-Kala (Algérie Nord-Est). Elle est exploitée de façon traditionnelle pour la pêche et la conchyliculture. Le besoin économique et le contexte écologique de la lagune en tant que partie intégrante de la zone humide, ont valorisé cette étendue restreinte (875 ha), peu profonde (<6 m) mais fortement productive. La lagune Mellah communique avec la mer par un long (900 m) et étroit (5 à 10 m) chenal, sujet au colmatage progressif réduisant les échanges avec la côte adjacente. L’objectif de cette étude est de décrire la structure et comprendre le fonctionnement de la lagune à travers l’analyse du plancton, du benthos et de leurs environnements physico-chimiques respectifs.

Chapitres de livres

2023
Khelifi-Touhami, Meriem., and Ounissi, Makhlouf. (2023), Paracalanus Boeck, 1864. ICES Identification Leaflets for Plankton No. 199. 22 pp. https://doi.org/10.17895/ices.pub.21724394. SERIES ICES Identification Leaflets for Plankton : SERIES EDITOR/S Antonina dos Santos; Lidia Yebra, https://doi.org/10.17895/ices.pub.4941

Résumé: Species of the genus Paracalanus Boeck, 1864 have been reported as abundant and often dominant in coastal to oceanic waters from temperate and tropical regions. They inhabit mainly the epipelagic zone (0–200m) and as small filter feeders (Benedetti et al., 2018) they represent an important link in marine food webs. Total length of the species ranges from 0.5 to 1.5 mm. In the ICES region, seven of the twelve Paracalanus accepted species are recorded: P. aculeatus, P. denudatus, P. indicus, P. nanus, P. parvus, P. pygmaeus and P. quasimodo. A taxonomic key of the Paracalanidae family is presented, allowing Paracalanus genus distinction. ICES Identification Leaflet for Plankton No. 35 (Farran, revised by Vervoort, 1951) provided information on and description of three Paracalanus species. This new leaflet is an update and revision of the original, based on the following: a) recent molecular studies (Cornils and Held, 2014; Hidaka et al., 2016; Kasapidis et al., 2018); b) books by Bradford-Grieve (1994), Bradford-Grieve et al. (1999), Vives and Shmeleva (2007), and Soh et al. (2013); and c) information provided by the website on marine planktonic copepods by Razouls et al.(2005–2022). The leaflet presents the geographical distribution and a key to differentiate the twelve Paracalanus species. Possible confusions during identification are also discussed.

2018
Ounissi, Makhlouf, Amira, Aicha.Beya, Haridi, Ahcene. (2018), Long Term Survey of Dissolved Nutrient (N, P, Si) Fluxes from Seybouse and Mafragh Estuaries into Annaba Bay (NE Algeria). A. Kallel et al. (eds.), Recent Advances in Environmental Science from the Euro-Mediterranean and Surrounding Regions, Advances in Science, Technology & Innovation, https://doi.org/10.1007/978-3-319-70548-4_484 : Springer International Publishing,

Résumé: Seybouse and Mafragh rivers’ outlets together delivered large amount of TDN and PO4, but mainly due to Seybouse River inputs. At Seybouse River outlet NH4 levels and fluxes have remarkably dropped from 2011, and dissolved organic nitrogen (DON) contributed to 25–50% the TDN. During years with flash flood events, the Mafragh inputs become the major source of all nutrient loads, but very low loads of SiO4 occurred by dry years. During the studied decade the near-pristine features of the Mafragh waters are still unchanged with balanced Redfield ratios (Si:N and N:P), in contrast to Seybouse waters input which were largely unbalanced.