Provide decision support tools and remedial solutions
The objective of this research axis will be to complete the diagnosis carried out by objectives 1 and 2 aimed at better understanding and predicting the interactions between contaminants and marine ecosystems. This line of research will have two main purposes.
Provide decision support tools based on research results
Propose solutions to remedy the pollution
The results of this line of research will mainly be intended for decision-makers and managers in charge of coastal zone management in Tunisia.
Decision-making tools
The integrated management of coastal zones (ICZM) imposed itself in the face of the observation of the inability of traditional systems (regulations, spatial planning, etc.) to consider, by a cross-sectional analysis, the issues of coastal territories. The implementation of ICZM under the impetus of networks of actors makes it possible to develop new modes of “governance” of the coast. Governance refers to a set of institutions, networks, guidelines, regulations, standards, political and social customs, public and private actors that contribute to the stability of a society and a political regime. , its orientation, the ability to lead, to provide services and to ensure its legitimacy (Unesco, 2001).
In this context, the role of research is essential and must make it possible, in connection with the stakeholders of ICZM, to propose results and information that can be used by the different parties to set up a rational and sustainable management policy, without forgetting the local constraints (economic activity versus environmental protection). Through its research activities, the LMI COSYS-Med will be able to provide a number of decision support tools in different forms :
- Cartography (distribution of pollutants and planktonic diversity, hydrodynamics, residence time of water masses, particle transport)
- Food web functioning indicators (stability, resilience, efficiency) from modeling
- Identification of bioindicators, biological species sensitive or resistant to contamination pressure
- Contaminant load indicator
These indicators will be proposed to the users’ committee (see governance) in an ICZM approach. This user committee will also make it possible to jointly define other useful indicators for ICZM according to the geographical context of the latter.
Remedial solutions
During phase 1, the LMI COSYS-Med set up research projects aimed at reducing the toxicity of contaminants by using biotechnology. Two main bioremediation schemes are proposed, biostimulation and bioaugmentation :
- Bio stimulation, defined as the addition of various forms of nutrients and electron acceptors such as phosphorus, nitrogen, oxygen or carbon to increase the population or activity of naturally available microorganisms in the system under consideration.
- Bio-augmenting by adding microorganisms that have been selected for their ability to biotransform or biodegrade contaminants. The added microorganisms can be native or exogenous species.
The various bioremediation techniques will be studied using experiments in microcosms which will aim to reproduce the conditions of optimal oxygenation according to the pollutant considered, degradation/sequestration possibly taking place under aerobic and / or anaerobic conditions. At the same time, control microcosms will be set up to study the natural degradation of the pollutant. A more particular interest will be given to sulphate reducing and magneto-tactical bacteria, the latter due to their metabolic capacities (production of sulphide and magnetism) can facilitate the trapping of metals which can be in high concentration in the phospho gypsum.
Once the optimal conditions have been defined, the installation of aerobic or anaerobic bioreactors on a pilot scale can be proposed to the CBS with the support of INRAP for the analytical part.
Bioremediation techniques will also be tested with bio sourced polymers manufactured at INRAP, materials which have significant adsorption capacities, thus making it possible to reduce the concentration of pollutants in a sedimentary or aquatic matrix.