10.7 Environmental considerations

Many salient problems that could cause inconveniencies and lead to conflicts are summarized as follows for each lagoon:

• The Ichkeul lake is facing three main problems that constitute a conflict of interest for the use of water (between the users for that water for irrigation and to supply the surrounding and far away populations with drinking water), an antagonist position from the surrounding populations toward the concessioner company (that is exclusively using the lake to catch eels and other fish by the three main types of fishing gear: bordigue, nets and capetchades) and the decrease of fish juveniles recruitment, especially juveniles of eels, a problem which is mostly due to the settlements which have been installed with the aim of safely managing water within the lake (for example the “escalier a poisons”
for eels).
• The Bizerte lagoon is facing a problem of environmental quality, especially as far as the sewage from the surrounding towns and the nearby industrial factory is concerned. Some zones within the lagoon are suffering from eutrophication with its numerous negative effects on the environment. Another problem should be raised, coming from the absence of a management plan, something that should avoid or at least decrease the conflicts between farmers and fishers.

• The Tunis lagoon is suffering from its position being close to the overpopulated capital and suburban areas, history and the recent restoration works which improved the water flow but, at the same time, caused a drastic drop in fishing productivity and biodiversity. The other weakness consists in the disorder that is prevailing at the level of the stakeholders (fishery, tourism and culture) on the one part and the absence of a serious “cahier de charges” for the proper exploitation of the lagoons on the other part.
• In the case of the Ghar El Melh lagoon, the main handicap is related to the communication with the sea, which is frequently obstructed. In order to meet the fishers claims to allow their boats to enter into the nearby fishing port (on the north side of lagoon) frequent works are being done to open the obstructed communication and to refresh the water into the lagoon. A management plan should be prepared starting from a solution that must be found out to secure an acceptable seawater entry.
• The El Bibane lagoon is the largest and the most productive one. The current exploitation system is not good, especially since the lagoon was licensed to private companies that did not respect their commitments toward its responsible exploitation. The current exploitation system is essentially based on the “bordigue”, which assures the largest part of the fish capture. However, this device is very heavy to handle in terms of cost and manpower.
The development perspectives and interventions from the public administration are as follows:
• The public administration in charge of fisheries and aquaculture produced many valuable rules for the rational exploitation of fisheries resources and the protection of wild life (minimum fish size, protection of sensitive areas, safeguard of birds’ communities, etc.), including sensitive habitats and ecosystems. The issue that is now a matter of urgency is the application of the specific provisions of such rules and legislations. A plan for the conservation of eels was prepared to meet the requirements of the EU.
• As far as the lake Ichkeul is concerned, a large and exhaustive study is being carried out, including the use of the lake for fisheries and aquaculture (Gestion Integree des resources en eau du basin versant de l'Ichkeul: GIRE eco-Ichkeul, May 2009–December 2011). Meanwhile, the private company to which a 30 years concession was granted continues to exploit the lake without limitations, causing severe problems to the surrounding populations and NGOs.
• The Ghar el Melh lagoon is suffering of problems coming essentially form the limitation of the sea-lagoon water exchanges. A solution was found to timely limit sand accumulation on the shoreline, particularly to meet the fishers’ requirement for their access to the fishing harbour, situated nearby; but the current bad state of the lagoon with regard to its communication with the sea is a real problem that prevents the proper exploitation of the lagoon.
• In the El Bibane lagoon, many studies were or are in the process to be performed; but what is urgently required is a study oriented to improve the exploitation of the lagoon for fisheries and possibly for aquaculture. Such a study should start by making an exhaustive anaylis of the status quo, including the damages that were caused by the irrational exploitation in the last 10 years (a shrimp-oriented fisheries, use of unacceptable gear, exploitation of flora like species, etc.) and overfishing of certain species with a fishing effort that leads to catches being over the maximum sustainable yield.
• In spite of their efforts (although limited for the moment) to contribute to some investigations, the relevant research institutes should prepare and implement fisheries and aquaculture oriented projects; something that has been proposed through the National Commission for the evaluation of research (an official body working under the authority of the Ministry of High School and Research).

10.8 References

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ANPE. 1990. Etude preliminaire de l’ecologie du lac de Bizerte. Tunis, Agence nationale de protection de l’environnement. 100 pp.
DGPA. 1995–2009. Annuaire des statistiques de peche.
Bejaoui, B., Ben Charrada, R., Moussa, M., Ben Hamadou, R., Harzallah, A. & Chapelle, A. 2005. Caracterisation hivernale de la lagune de Bizerte. Bulletin de l’Institut national des sciences et technologies de la mer, Salammbo, 32: 79–91 .
Ben Charada, R. 1992. Le lac de Tunis apres les amenagements: parametres physicochimiques de l’eau et relations la croissance des macro algues. Marine life, 1: 29–44. Ben Maiz, N. 1992. Analyse de la qualite des eaux et evolution des peuplements vegetaux du lac nord de Tunis. Rapports internes. Societe de Promotion du lac nord de Tunis. pp. 1– 28 + annexes pp. 29–94
Bellakhal-Fartouna, M. 2004. Contribution a l'etude de la structure du peuplement phytoplanctonique de la lagune de Bizerte. Universite de Carthage, Tunis. 128 pp. (Memoire de diplome de mastere Production et eco systemes aquatiques, INAT)
Belkhir M., Hadj Ali Salem, S. 1981. Contribution a l’etude des mecanismes d’eutrophisation dans le lac de Tunis: parametres physicochimiques et biologiques. Bulletin de l’Institut national des sciences et technologies de la mer, Salammbo, 11(81): 41–69.
Ben Rejeb-Jenhani, A., Kartas, F., Lemoalle, J. & Amblard, C. 1991. Phytoplancton du lac Ichkeul (Tunisie): Composition, structure et activite photosynthetique. Internationale Revue der Gesamten Hydrobiologie, 76 (2): 244–256.
Chauvet, C. 1986. Dynamique du peuplement ichtyologique de la lagune de Tunis. Universite de Perpignan. 503 pp. (These de doctorat d’Etat)
Guelorget, O., Frisoni, G.F. & Pertuisot, J.P. 1982. Contribution a l'etude biologique de la Bhiret el Bibane, bassin paralique du sud tunisien. Mem.Soc. Fr., 144: 173–186. BRL Ingenierie Idea Consult. 2008. Preparation d’un plan de gestion de la lagune des Bibans, diagnostics et mesures d’urgence. Groupe STUDI, Tunis, Tunisia. 162 pp.
MEA. 1995. Etude de la diversite biologique en Tunisie. Ministere de l’Environnement et de l’Amenagement du Territoire ANPE, IUCN, PNUE. 233 pp.
Medhioub, K. 1979. La Bhirat el Bibane. Etude geochimique et sedimentologique d'une lagune du sud-est tunisien. Paris, 13, Travaux laboratoire de geologie de l’Ecole normale superieure. 150pp
Romdhane, M.S. 1985. Lagune de Ghar el Melh: milieu, peuplement et exploitation. These de doctorat de specialite en biologie marine et oceanologie. 245 pp.
Romdhane, M.S. 2002. Etat des reserves de la Biosphere de la Tunisie, la reserve de la Biosphere de l’Ichkeul. Commission Nationale du MAB Tunisie.
Skandrani, Y., Bellakhal-Fartouna, M., Bellakhal, M., Hnana, F. & Missaoui, H. 2007. Rapport de mission de prospection physico-chimique et halieutique dans la lagune des Bibans.
Trabelsi-Annabi, N. 2001. Contribution a l’etude de l’environnement du lac nord de Tunis : repartition et structure des peuplements planctoniques. Faculte de sciences, Sfax. 162 pp. (Memoire de DEA)