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Le Bulletin de l'Institut National des Sciences et Technologie de la Mer (INSTM) est publié depuis 1924 et indexé dans 'Aquatic Sciences and Fisheries Abstracts' (ASFA - FAO). Il fait suite au "Bulletin de l’Institut National Scientifique et Technique d'Océanographie et de Pêche" (INSTOP) et au "Bulletin de La Station Océanographique de Salammbô" (SOS).
Recent Submissions
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Age and growth of Carcinus aestuarii Nardo,1847 (Portunidae) and Maja squinado Herbst, 1788 (Majidae) in the Gulf of Gabes, Southeastern Tunisia, Central Mediterranean.INSTM Bulletin: Marine and Freshwater SciencesThe Mediterranean green crab, Carcinus aestuarii Nardo, 1847 (Crustacea, Brachyura, Portunidae), and the spider crab Maja squinado (Herbst) are common inhabitant of the shallow waters in the Gulf of Gabes (southern Tunisia, central Mediterranean). The Von Bertalanffy growth parameters CW∞/CL∞, k and t0 were estimated on the basis of Length-frequency modal progression analysis method. The values of CW∞ (mm), K (year-1) and t0 (year) would be, respectively, 95.61, 0.84 and -0.104 for males; 73.92, 1.11 and -0.149 for females in Carcinus aestuarii and, CL∞ (mm), K (year-1) and t0 (year) would be, respectively, 172.46, 0.68 and -0.147 for males; 147.05, 0.6 and -0.175 for females in Maja squinado. These results were obtained, as the first attempt to study age and growth of these two crustaceans which will be of a great use for their eventual stock assessment studies.
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Human health risk assessment of heavy metal(oid)s in four fish species harvested from the Bizerte lagoon (Tunisia).INSTM Bulletin: Marine and Freshwater SciencesThis study investigated the levels of cadmium (Cd), lead (Pb), arsenic (As), iron (Fe), copper (Cu), and zinc (Zn) exposure in the child and adult populations in Tunisia. The heavy metal(loid) (HM) content in muscle and the organ mixture of four commercial species of fish widely available and consumed were determined (Sparus aurata, Dicentrarchus labrax, Liza aurata, Sarpa salpa). The fish samples were prepared using a wet digestion method, and the HM analysis was carried out using an inductively coupled plasma mass spectrometry (ICP-MS). The results indicated that all fish organs had high amounts of Pb and As and high levels of Cd and Zn in some organs. Based on the exploratory data analysis, fish species can be differentiated according to their diet. The estimated daily intake values for the children's population have exceeded the permissible levels for Cd and As, whereas they were only exceeded for As for the adult population. Only Fe's Target Hazard Quotient exceeded the permissible limit. The evaluation of the carcinogenic risk associated with the consumption of the four fish species from the Bizerte lagoon indicated a potential carcinogenic effect related to lead (Pb) exposure. In this lagoon, HM contamination of fish is requiring both a short-term and long-term approach to ensure the safety of marine products.
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Frequency histograms, condition parameters and size-depending metal accumulation in two species belonging to Phorcus genus.INSTM Bulletin: Marine and Freshwater SciencesThis work is a biological and ecotoxicological investigation in two Trochidae species Phorcus turbinatus and Phorcus articulatus taken from four stations, monthly for biological study and seasonally for size-depending metal monitoring. Our results related to biological characterization suggested mostly polymodal frequency histograms associated with a continual renewal of juveniles indicating a laying period spread over several months. The condition index revealed similar values slightly decreasing during hot seasons probably due to the coincidence of the spawning period with the spring and the summer. As for the condition factor, it also presented close values with a slight increase during the periods of March-April, June-July and even September-November probably resulting from algal proliferation and trophic availability during those months. The estimation of metal pollution indicators proposed an increasing classification of contamination related to the amounts of waste ejections at each locality coming from industrial activity, large fishing ports and mooring areas. Size-depending metal analyses revealed that despite the strong contamination, a moderate concentration decrease was associated with size growth. This life strategy would allow these species to counteract unfavorable conditions and ensure their persistence and thus justify their frequent use as bio-indicators of the state of health in coastal ecosystems.
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Effect of the green macroalgae Chaetomorpha linum liquid extract on the germination, growth and pigments concentration of the chickpea Cicer arietinum L., 1753.INSTM Bulletin: Marine and Freshwater SciencesFertilizer production and application are growing excessively with increased agricultural expenses and environmental damage. As alternatives, organic fertilizers issued from natural resources such as seaweed liquid extracts (SLE) are considered as potential plant biostimulant agents. In this study, the impact of the green algae Chaetomorpha linum SLE on seed germination, yield and pigmenting characteristics of the chickpea Cicer arietinum was investigated in laboratory settings and in pots. Several SLE concentrations varying from 1%, 3%, 5%, 8% to 10% were prepared using distilled water. The application of SLE significantly affected all assessed parameters over the control (0%). Use of SLE at the lowest concentration (1%) showed maximum seed germination, root and shoot length and contents of total chlorophyll, chl (a), and chl (b). Accordingly, the results suggest that C. linum SLE could be used as an alternative organic fertilizer because it is environmentally friendly and profitable. This extract, rich in plants growth components, could find its future use in various sectors.
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Resistance profiling, evolution of biofilm formation and genetic diversity of Vibrio alginolyticus isolated from aquaculture systemsINSTM Bulletin: Marine and Freshwater SciencesThis study analyzes 26 presumptive Vibrio alginolyticus strains extracted from two fish farms (Khenis and Hergla, East Tunisia) that raised sea bream (Sparus aurata) and sea bass (Dicentrarchus labrax). In addition, from a shellfish farm located in Menzel Jmil, North Tunisia that raises mussels (Mytilus edulis) and oysters (Crassostrea gigas). We have evaluated (i) the discriminatory power of PCR-RFLP for identification of closely related strains, (ii) the antibiotic resistance of the V. alginolyticus strains and (iii) their ability to form a biofilm in aquaculture farm. Results showed that there is great heterogeneity in the diversity observed via the PCR-RFLP method related to the number of 20 genotypes generated by the two enzymes SduI and FaqI tested. The heterogeneity was observed in both fish (aquaculture farm) and bivalve (shellfish farm) origins, as well as in the same sample. For antibiotic resistance, all isolates present a high resistance to ampicillin, erythromycin, cefotaxime, kanamycin and doxycycline. The resistance is displayed by 15 distinct profiles. The Multiple Antibiotic resistance (MAR) index was ranged from 0.55 to 0.80 for the isolates from the aquaculture farm of Hergla followed by the index aquaculture farm of Khenis (0.55 to 0.75). While for the shellfish farm of Menzel Jmil the index ranges from 0.50 to 0.65. This finding indicated high-risk sources of antibiotic contamination in the three locations. Isolates from aquaculture systems with strong biofilm formation have been found to be resistant to antibiotics, which may allow them to survive longer in these environments. Present findings could be relevant in aquaculture systems and underscore the importance of the linkage between adhesion, antibiotic susceptibility, and genetic diversity of these pathogenic bacteria to avoid fish and shellfish diseases. The results will provide helpful guidance on how to use antibiotics to control Vibrio alginolyticus diseases in aquaculture to be healthy.
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Acute and subacute toxicity of naphthalene in a filter-feeding species Styela plicata (Chordata, Ascidiacea).INSTM Bulletin: Marine and Freshwater SciencesThe aim of the current study was the assessment of a Polycyclic aromatic hydrocarbon (PAHs) toxicity on an ascidian species, Styela plicata. Acute and subacute toxicity of naphthalene (NAP) has been determined using five increasing concentrations (0.5, 1, 1.5, 2.5 and 5 mg/l) during 96h of exposure. The half lethal concentration (LC50, 96h) value of naphthalene for S. plicata was 2.41 mg/l. Furthermore, the filtration activity decreased in the five tested concentrations of NAP; a significant decrease by 69% and 91.8% was observed after 1h in the groups exposed to C1 and C5, respectively. A similar pattern was noted after 2h of filtration; the decrease was estimated to 39% in C1 and 72.5% in C5. The results from this bioassay confirmed the toxicity of NAP on S. plicata; we also provided information about the use of S. plicata as a potential bioindicator species for the assessment of PAHs toxicity.
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A rare stranding event of the short beaked common dolphin (Delphinus delphis) in the eastern Tunisian coastlineINSTM Bulletin: Marine and Freshwater SciencesA short beaked common dolphin was found stranded on March 3rd 2021, on Hammamet beach (Central-eastern Tunisia). This is a rare stranding event since it represents the third documented stranded individual reported on Tunisian coastline for half a century. Necropsy of the freshly dead female dolphin was conducted to know the presumable cause of death. The pregnant dolphin was bearing a mid-term female fetus with fully developed organs. Detailed biometric data were taken for both individuals. Samples were collected and preserved in the tissue bank of the national stranding network. The freshly dead fetus is preserved at the oceanographic museum for scientific collection. The rare stranding of this species observed here would be attributed to the small population frequenting Tunisian waters. This note improves knowledge on this poorly studied species in the south-central Mediterranean area.
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First Record of the tropical seagrass Halophila stipulacea (Forsskål) Ascherson, 1867 in the Punic Port of Carthage-Salammbô (Northern Tunisia).Bulletin de l'Institut National des Sciences et Technologies de la Mer de SalammbôThe bioinvasion has increased in recent years with climate change, and some invasive species have caused significant damage to the marine ecosystem, including a great loss of biodiversity. The studied seagrass is a marine tropical phanerogam introduced in the Mediterranean at the end of the 19th century and in southern Tunisia in 2003. In this study we record this species for the first time in northern Tunisia, precisely in the Punic Port of Carthage-Salammbo. Surveys were carried out on foot around the Punic Port, and measurements/photos were taken on site, and others in the laboratory on taken samples. Most of these measures do not differ from those carried out elsewhere in the Mediterranean. For the moment, the plant does not occupy a large part of the port buttom, but it may invade all the area in the future.
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Eroding coastal sandy barriers under changing aeolian flux in the Gulf of Tunis (Tunisia).INSTM Bulletin: Marine and Freshwater SciencesSandy barriers are coastal features formed and reworked by terrestrial and marine-induced processes along decadal to millenary scale periods. In the semi-arid areas along the extended North African coast, these coastal landscapes are undergoing accelerated morphodynamical changes induced by intensifying anthropogenic and climate drivers in the last century. To quantify the latter, we assess the changes in sediment dynamics of the Ghar El Melh sandy barrier extended over the northern part of the Gulf of Tunis in Tunisia using sedimentological analysis and quantification of the aeolian flux. A total of 37 subsurface samples and 30 surface aeolian trapped ones were collected at the coastal dunes of Ghar El Melh. Our sedimentological analysis reveals a distribution of 97% of sandy sediments and 3% of silty facies. The modal statistical analysis suggests that there are three distinguishable sediment types with 87% of samples formed by fine sands with modal value of 0.16 mm. The mixture of these indicates mixed terrigenous and marine sources redistributed by the hydrodynamic processes. The measurement of the aeolian flow suggests a maximum value of 0.0022 kg.m.-1min-1 which occurs in dust storms. This study reveals the low detrital sand supplies to the lagoon-sea barrier of Ghar El Melh, results in its gradual submersion, further exposing the coastal lagoon and engendering severe ecological degradations.
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Striped red mullet (Mullus surmuletus, Linnaeus, 1758) from Rafraf-Sidi Ali Mekki region (Bizerte, Tunisia): length-weight relationship and histological assessment of gonad maturation.INSTM Bulletin: Marine and Freshwater SciencesThe aim of this study is to investigate thegonadal changes of striped red mullet (MullussurmuletusLinnaeus, 1758) in Rafraf –Sidi Ali Mekki region in Tunisia. A total of 243specimens were collected monthlybetween March 2014 and February 2015.Fulton’s condition factor (K) and the length-weight parameters were estimated. There was correlation between the fish total length and weight (R2:0.75). The K values ranged between 0.93 and 3.38. The values of b parameter ranged from 3.18. gonadosomaticand hepatosomatic indicesshow maximum values during April. Different stages in females and inmales were observed according to gonadal development.
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Preliminary inventory of metazoan parasites of the Lessepsian bluespotted cornetfish Fistularia commersonii in the Gulf of Gabès, TunisiaINSTM Bulletin: Marine and Freshwater SciencesBiological invasions are widely acknowledged as a serious threat to biodiversity, but the role of parasites in marine ecosystem processes is still poorly understood. The so-called Lessepsian migration, or invasions through the Suez Canal from the Red Sea to the Mediterranean Sea, also fits this description. Here, we studied the parasitofauna of Fistularia commersonii collected from the Gulf of Gabès of Tunisia. 43 individuals of F. commersonii were sampled from the Gulf of Gabès. Parasite richness, prevalence and intensity were investigated, Additionally, we reviewed the literature to identify native and invasive parasite species recorded. Our results suggest the co-introduction of nine parasite species that are assumed to be originate from the Red Sea. In addition, we found that the invasive fish has acquired nineteen parasite species that are native from the Mediterranean Sea. The Lessepsian migrant may potentially change the dynamics of native and invasive parasite-host interactions through parasite co-introduction and parasite acquisition, according to these results. The higher F. commersonii infection rates in the area that has been invaded are also consistent with the predictions made by the "Enemy Release Hypothesis." These results show the importance of using community studies, such as the one described here, to understand the role of parasites in Lessepsian migration.
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First record of Alopias superciliosus Lowe,1841 (Elasmobranchii: Alopiidae) in Tunisian waterINSTM Bulletin: Marine and Freshwater SciencesOn July 2021, one specimens of Alopias superciliosus Lowe,1841 was captured as bycatch in Kelibia (Tunisia) at the following coordinate 36°30’740” N; 11°48’451” E, by a trawler at 400 m depth. It was a mature male of 350 cm total length and 159 kg in eviscerated weight. This represents the first record of the bigeye thresher shark in the area.
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Seasonal variation of the ectoparasite infestation levels of Trachurus picturatusin Bizerte (Tunisia).INSTM Bulletin: Marine and Freshwater SciencesThe blue jack mackerel, Trachuruspicturatus, is a commercially important resource in the Mediterranean Sea and the North-East Atlantic. The main aim of this work was to assess the infection levels and diversity of the ectoparasites of the blue jack mackerel.Over a one-year period, between March 2017 and February 2018, 126 specimens of T. picturatuswere collected seasonally from the Bizerte coast (Tunisia). The ectoparasite fauna of the examined host was composed ofthe two monogenean species, Pseudaxinetrachuriand Gastrocotyletrachuriand a copepod species,Peniculusfistula fistula. This is the first record of thiscopepod parasite inTunisia. The analysis revealed that the infection levels fluctuated throughout the year. Both monogeneans (P. trachuriand G. trachuri) had high prevalences during the warm season (P%=87.1, P%= 32.3, respectively). Additionally, P. trachurishowed some seasonal variations in mean abundance and mean intensity between summer and the other seasons. Furthermore, there was a highly significant variation in the mean abundance of G. trachuribetween the summer and autumn-winter seasons. The resultsof the current study may be explained by the seasonal variations in environmental conditions, the life cycles of the hosts and parasites, the feeding and migratory patterns of the hosts, the chemicals released by the hosts, and the interspecific competition between the two monogenean species.
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L'ostréiculture en Tunisie: résultats acquis dans le lac de Porto-farina.Le commerce des coquillages en Tunisie est chaque jour plus important si certaines espèces les clovisses arapèdes, murex, coteaux, pholades, haricots et dattes de mer, et pour une certaines part, les moules sont pechèes dans le pays.
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Comparative study on the composition and functional properties of chitin/chitosan extracted by new combined bioprocess.INSTM Bulletin: Marine and Freshwater SciencesBio-extraction of chitin is a greener and eco-friendly process than the conventional chemical method. Taking shrimp waste of Pandalus borealis recovered from plant as a model, two methods were applied for chitin extraction; a chemical and a yeast-based processes (Ch-C and Ch-B respectively). The recovered chitins and chitosan were tested for their biochemical and functional properties. Compared to commercial chitin, both lots, have similar chitin recovery (~26%) and physiochemical properties with ash<1%, protein <10%, with degrees of acetylation (DA) varying 70-80%. However, chitosan obtained from Ch-B lot showed significantly lower molecular weight (MW) and DA (MW: 6.34 KDa, DA: 23.4%) than that found in Ch-C chitosan (MW: 11.36 KDa, DA: 33.4%). The new method proved to be efficient for the production of chitosan of good quality which allowed the elaboration of the membrane.
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Effects of chitosan-microparticles-coating on the quality of vacuum-packed sea bass (Dicentrarchus labrax) fillets during refrigerated storage.INSTM Bulletin: Marine and Freshwater SciencesIn this work, a combination of vaccum pachaging and bio-coating by chitosan were used to coat sea bass (Dicentrarchus labrax) fillets in order to delay growth of total mesophilic aerobic bacteria, psychrophilic bacteria during refrigerated storage (22 days). The preservative effect of refrigerated and vacuum-packed seabass (Dicentrarchus labrax) fillets treated at two different percentage doses (0.2% and 0.5% w/w) of co-products of shellfish was evaluated on the basis of microbiological, proximate composition, pH, total volatile basic nitrogen (TVB-N), trimethylamine (TMA), thiobarbyturic acid (TBArs), and fatty acids (FA). Two ways ANOVA and multiple comparisons were applied, factors being storage time and treatment. During refrigerated storage, the treatment with chitosan from separate co-products exhibited more antimicrobial activity and the lowest value of the TVB-N, TMA and TBArs compared to control lots. The bio-coating by 0.5% dose of chitosan preserved quality and the prolonged shelf-life for 10 days longer. Overall, this treatment may open new promising opportunities for the biopreservation of fish products by enhancing the period of storage of refrigerated and vacuum-packed seabass fillets.
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Overview of Bottlenose dolphin depredation in Teboulba region (East of Tunisia).INSTM Bulletin: Marine and Freshwater SciencesThis work was carried out in response to the numerous fishermen claims following to the interaction between dolphins and fishing gears along the coast of Teboulba. The aims of this work were: to establish an inventory of dolphins present in the study area and interacting with fisheries, to define the most affected fisheries by the depredation and to attempt to assess it economic consequences. For this purpose, field surveys as well as weekly monitoring of a sample of the fleet and sea trips were carried out in order to respond to the previously mentioned objectives. The findings of this study led to the conclusion that there are two dolphin’s species: the Bottlenose dolphin and the Striped dolphin. These two species have a different demographic and ecological distribution. They also interact in two different ways with the fishing boats and their nets. According to the surveys, the most depredated fisheries is the small scall fisheries. Set gillnet and trammel nets were the types of the fishing gear most vulnerable to dolphin depredation. The depredation rate and economical loss due to depredation vary slightly between gillnets and trammel nets. The depredation induces many holes with different size requiring mending operations that can be onerous. Likewise for landing, the resulting bites on the catch leave it unsaleable. It is necessary to continue this study in order to identify the factors that can cause the depredation and propose mitigation measures to avoid any ecological and economic blunder.
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Age et croissance de l'allache ou sardinelle ronde (Sardinella aurita Valenciennes, 1847) dans le Cap Bon (Tunisie).Bulletin de l'Institut National des Sciences et Technologies de la Mer de SalammbôA new esseous part, the opercula bone, is used to estimate age of 2009 round sardine (Sardinella aurita Valenciennes, 1847) captured in the Cap Bon area. The period of sampling with a monthly rhythm, is spread out June 1994 at December 1995 and from June to September 1996. Th relation between the length of fish (LF) and the ray of opercula (RT) is LF= 22,25 RT 0,994 . The validation of age estimate method is carried out directly by the monthly follow-up of overage marginal lengthening and the percentage of individuals with marginal hyaline zone. This study showed that the round sardine has a double cycle of growth of the age-length shows that the females dominate in the majority of age groups the parameter of growth in length according to the model of Von Bertalanffy are estimated by direct enumeration of the hyaline zone and retrocalcul. The curves of growth obtained by employ retrocalculed data describe better the growth of the round sardine in Cap Bon area.
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First record of the Siphonophore physalia physalis (Linnaeus, 1758) in the gulf of Tunis (Tunisia)Bulletin de l'Institut National des Sciences et Technologies de la Mer de SalammbôThe Portuguese man-of-war Physalia physalis (Linnaeus, 1758), is a pleustonic cnidarian commonly found in the tropical and subtropical areas of the world’s oceans. To date, and to our knowledge no signalization of P. physalis has been reported in Tunisia. In this note, we report for the first time, the presence of P. physalis in Tunisian coast on April 2, 2021. One colony was stranded at Carthage Amilcar beach. Three others were collected alive by fishermen in the open sea in front of Rades and Hammam Lif coasts. The specimens showed an unsymmetrical pneumatophore with a wrinkled longitudinal ridge consisting of a transparent purple-blue membrane, between 15 and 25 cm in length. The tentacles were approximately 50 to 130 cm in length. The presence of P. physalis in the Tunis gulf has coincided with the stranding of the jellyfish Velella velella (Linnaeus, 1758). Given the potential danger of this species for humans, it is essential to integrate it into the monitoring and observation network of the coastline.
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About new records of the mole crab (Albunea carabus l. 1758, decapoda, anomura, hippoidea) in Tunisian waters (central Mediterranean sea)Bulletin de l'Institut National des Sciences et Technologies de la Mer de SalammbôFour observations of the mole crab albunea carabus were registered from 2019 to 2021: one specimen was filmed digging the sand in 5 october 2019 by a scientific citizen in the sandy beach of ghar el melh (northern tunisia); a second specimen was observed in november 2019 on rimel beach (bizerta); the third one was caught by gillnet at 3 m depth in ras kapoudia (east of tunisia) in 1 october 2020 and the fourth one was captured by a fishing rod in 18 april 2021 in menzel horr (east of tunisia). the third specimen (from ras kapoudia) was a female measuring 42.1 mm total length (tl), 19.4 mm carapace length (cl), 21.6 mm carapace width (cw) and 22.7 mm abdominal somites and telson length (stl). no measurements were made for the other specimens. these occurrences confirm well the presence of the species in tunisia, since two carapaces and one cheliped of a. carabus were observed in october 1972 in the bay of tunis.
