Coastal Ecology and Ecotoxicology Unit

science of, Tunisia

Coastal Ecology and Ecotoxicology Unit

science of, Tunisia
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Mahmoud N.,Coastal Ecology and Ecotoxicology Unit | Dellali M.,Coastal Ecology and Ecotoxicology Unit | Bour M.E.,National Institute of Marine science and Technologies of Salammbo | Aissa P.,Coastal Ecology and Ecotoxicology Unit | Mahmoudi E.,Coastal Ecology and Ecotoxicology Unit
Ecological Indicators | Year: 2010

Five biomarkers, catalase (CAT) activity, glutathione-S-transferase (GST) activity, the neural transmitter enzyme acetylcholinesterase (AChE), reduced glutathione (GSH) and malondialdehyde (MDA) levels were measured in specimens of Fulvia fragilis collected from Bizerta lagoon (Tunisia). Results demonstrated that F. fragilis showed differential biomarker response according to the importance of the anthropogenic pressure and the nature of pollutants that affect the lagoon. A clear organotropism was also observed with a higher biomarker response in digestive gland than in gills of this bivalve. These results indicate that F. fragilis constitutes a useful tool as sentinel organism for biomonitoring of aquatic pollution. © 2009 Elsevier Ltd. All rights reserved.


Boufahja F.,Coastal Ecology and Ecotoxicology Unit | Ismaily S.,Coastal Ecology and Ecotoxicology Unit | Beyrem H.,Coastal Ecology and Ecotoxicology Unit
Cahiers de Biologie Marine | Year: 2014

An experiment was conducted to make out if an antimitotic agent, the Colchicine, may have negative effects on a nematode community from the "Rimel" beach (Bizerte bay, NE Tunisia). Three sedimentary doses of Colchicine (in Dry Weight) (1.5428 ppm, 15.428 ppm and 154.28 ppm) were tested during 30 days of exposure. Univariate analyses showed a clear decrease in terms of quantity and quality of nematodes present in Colchicine treatments compared to the control. Multivariate analyses revealed a discernible reorganization of the community evidently due to the different species sensitivities against Colchicine. The nematode species Ptycholaimellus ponticus, Theristus modicus and Kraspedonema reflectans were identified as Colchicine-sensitive, due to population reduction after treatment. The Colchicine seems acting on these species by direct epidermic contact, by internalization through cuticular pores or by ingestion of contaminated sediment particles. Our results appeared rejecting the eutely for cells of the cuticular epidermis and those of the digestive tube of Ptycholaimellus ponticus, Theristus modicus and Kraspedonema reflectans.


Boufahja F.,Coastal Ecology and Ecotoxicology Unit | Hedfi A.,Coastal Ecology and Ecotoxicology Unit | Amorri J.,Coastal Ecology and Ecotoxicology Unit | Aissa P.,Coastal Ecology and Ecotoxicology Unit | And 2 more authors.
Biological Trace Element Research | Year: 2011

Microcosms were used to assess the impact of chromium on free-living marine nematodes. Nematodes were exposed to three chromium concentrations (500 ppm (dm, dry mass), 800 ppm (dm) and 1,300 ppm (dm)), and effects were examined after 4 weeks. Results showed significant differences between univariate measures of control nematodes and those from medium- and high-chromium microcosms. Most, decreased significantly with increasing level of chromium contamination. The medium-chromium treatment seems to be the minimal concentration that could has a negative effect on nematodes. Results from multivariate analyses demonstrated that responses of nematode species to chromium treatments were varied: Leptonemella aphanothecae was eliminated at all doses tested and seemed to be intolerant species to chromium; Daptonema normandicum and Sabatieria longisetosa which significantly increased at 500 ppm chromium (dm) appeared to be "opportunistic" species at this dose whereas the two Bathylaimus species (Bathylaimus capacosus and Bathylaimus tenuicaudatus) which increased at all the doses tested seemed to be "chromium resistant". As we think such "opportunistic" and "resistant" species could be used as sensitive indicators of unsafe marine food. The use of microcosms has allowed the effects of the chromium on nematodes to be assessed individually, which was not possible in the field. © 2010 Springer Science+Business Media, LLC.


PubMed | Coastal Ecology and Ecotoxicology Unit
Type: Journal Article | Journal: Biological trace element research | Year: 2011

Microcosms were used to assess the impact of chromium on free-living marine nematodes. Nematodes were exposed to three chromium concentrations (500 ppm (dm, dry mass), 800 ppm (dm) and 1,300 ppm (dm)), and effects were examined after 4 weeks. Results showed significant differences between univariate measures of control nematodes and those from medium- and high-chromium microcosms. Most, decreased significantly with increasing level of chromium contamination. The medium-chromium treatment seems to be the minimal concentration that could has a negative effect on nematodes. Results from multivariate analyses demonstrated that responses of nematode species to chromium treatments were varied: Leptonemella aphanothecae was eliminated at all doses tested and seemed to be intolerant species to chromium; Daptonema normandicum and Sabatieria longisetosa which significantly increased at 500 ppm chromium (dm) appeared to be opportunistic species at this dose whereas the two Bathylaimus species (Bathylaimus capacosus and Bathylaimus tenuicaudatus) which increased at all the doses tested seemed to be chromium resistant. As we think such opportunistic and resistant species could be used as sensitive indicators of unsafe marine food. The use of microcosms has allowed the effects of the chromium on nematodes to be assessed individually, which was not possible in the field.

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