The marine area of the North-Western Mediterranean between Tuscany, Liguria, Corsica and PACA, has specific meteorological characteristics (eg. flood risk), oceanographic (eg. marine current of the north-Mediterranean) and environmental (Pelagos Sanctuary for the protection of cetaceans).
The improvement of sea monitoring and forecasting tools, on a transboundary level, involves a cooperation between partners in neighbouring regions. They are committed in designing, implementing and maintaining observation networks over time, and exchanging the knowledge acquired in their respective fields, involving transversally the interests of the territories bordering the area.
When we speak of non-natural pollution, and therefore of human (or man-made) origin, the pollution present in the marine environment is emitted mainly by industrial activities (including those related to the maritime sector), but not only by ports.
The inland industries can unfortunately discharge many pollutants into the rivers that end up in the sea. Port activities must be monitored because their proximity to the open marine environment means that the pollution they generate has a very rapid impact on the sea. Therefore, combining the economic development of ports and the protection of adjacent marine areas is a very important challenge.
In the transboundary marine area the most important ports are located near MPA.
In Tuscany, for example, the port of Leghorn is located a few miles from the MPA of Meloria and it is therefore important to estimate the environmental footprint of the port on the MPA, both at the current state, both in relation to future development and expansion projects.
The project studied the dynamics of the marine currents and the potential contaminants, between ports and AMP, identifying specificities for the various areas. It is precisely the prevailing dynamics of the sea currents that tend to transport along the coast, and not towards the MPA, the pollutants of port origin, the natural factor that preserves the MPA of Meloria.
The cooperation area is distinguished by the high concentration of ports – some of them include major enlargement works – located near protected marine areas.
In the framework of the IMPACT project, we want to combine the conservation of the marine reserves of Meloria, Cinque Terre, Port-Cros and Porquerolles and the Sea Park of Cap Corse and Agriates, with the development of port activities in the four areas of study of Leghorn, La Spezia, Toulon and Bastia.
Among the events that may represent a risk for the marine protected areas (MPA) there are not only spillages of pollutants due to maritime accidents, but also contaminations caused by actions for the maintenance or the enlargement of the port areas. This leads to the need of finding solutions and means to protect the MPA, allowing port activities.
The MPA are marine and coastal environments that are interesting for their natural, geomorphological, physical and biochemical characteristics. It is therefore clear that their establishment and protection are essential for all sectors and activities which are consequently protected: not only the conservation of valuable marine environments, but also their recovery in the event of overfishing, the management and safeguarding of the anthropological and historical values associated with them, the defence of the relevant productive activities such as fishing and tourism, as well as the promotion of education, training and scientific research activities.
For the purpose of establishing an MPA, a stretch of sea is identified, defined as a “marine area of finding” and, following the preliminary procedure, its delimitation, definition of the objectives and the protection discipline are achieved.
Sometimes some of the actors operating in these areas do not welcome the restrictions because they fear potential economic losses (as in the case of fishermen or tour operators). The correct sizing of an MPA is therefore essential not only for the most effective definition and protection of regulated areas, but also to reduce as much as possible social tensions, supporting each decision with scientific evidence that motivate the choices.
Marine currents can be compared to a river which moves large bodies of water, for long distances with a constant speed.
They can develop on the surface or in depth, and they can carry phytoplankton and zooplankton (including eggs and larvae of marine organisms) to different areas, but also pollutants in case of spills of any origin (e.g. maritime accidents, port activities, industrial activities).
The study of currents is therefore essential both to understand how they can affect the distribution of a number of organisms, both to make predictions and reduce damages, in the case of transport of pollutants.
Most marine species reproduce by emitting small eggs or larvae into the water (from a few tens of microns to a few millimeters), easily transportable by sea currents.
This dispersive phase can have two antagonistic effects on the maintenance of the population. On the one hand it decreases the local maintenance of the population due to retention rates (the percentage of individuals that remains in the original environment) sometimes too low to ensure the renewal of a population. On the other hand, it increases the regional diffusion of populations through the distribution of species on multiple sites, increasing the resilience (the ability of a system/species to adapt to changes) to local disturbances.
This diffusion occurs only if the larvae find a favourable place for their development.
The MPA are established with the aim of protecting the ecosystems and organisms living there. These organisms propagate thanks to the periodic release of larvae, transported by currents to the so-called recruitment areas, that is new substrates to be colonized. In some cases, they may fall close to the “mother” colonies, in others they may be transported far away from them.
The correct sizing of an AMP is important because, the inclusion of recruitment areas within it, when possible, becomes essential for the effectiveness of protection actions.
Connectivity is the ability of different systems to connect and communicate with each other, in order to exchange information. Marine connectivity is a crucial process that determines the persistence, resilience and productivity of marine ecosystems, including exploited marine species. In general, connectivity is a primary element of marine population dynamics, both on a local and a global scale. Connectivity studies commonly focus on habitats, fauna and flora and even mobile objects (e.g. plastic) at various spatial and temporal scales.
Understanding and quantifying connectivity between different habitats or spatially distant populations is essential to contribute to the sustainable management of ecosystems and to provide data, which are important in the decision-making process.
This knowledge is indispensable to be able to allocate the right conservation efforts to the areas that act as main nodes within a network of marine protected areas [definition by Michela Ballardini, Università di Bologna].
Habitat loss for a species occurs when a geographical area undergoes a change, for example a substrate rich in ravines becomes smooth, in the case of expansion of port areas. This habitat loss reduces the spatial distribution of a species’ populations, and this could even lead to the extinction of some of them.
The transport of eggs and larvae, by sea currents during the reproduction, helps maintain a network between marine populations: the renewal of the generations is tied to exchange rings between the populations, known as marine connectivity.
The disappearance of a habitat that is part of the connection network, can lead to the block of the connection and to the renewal of generations.
Ocean currents can be measured with a variety of instruments. Using mathematical models, that simulate currents, is the only way to know what the currents will be like in the future. In this case, ocean currents will be modeled by computational codes that solve equations derived from fluid mechanics, and they will be adapted to the oceanic domain of interest.
Several models are used for IMPACT: NEMO, ROMS, and MITgcm.
High Frequency radar (HF) are advanced remote sensing tools, that allow to acquire and make available information about the state of the sea, in particular about surface sea currents and wave motion, in a wide marine area.
They are located along the coast of cooperation regions, in strategic areas. They provide one “photograph” an hour of the speed of the surface current, over a significant portion of the transboundary marine area, with high resolution, equal to a value measured every 2 – 3 km.
As part of the IMPACT project, in synergy with other instruments such as floating buoys (drifters) and circulation models, HF radars help to improve knowledge of the dynamics of water masses and transport phenomena, and therefore to reduce uncertainty in the forecasts of the state of the sea. Improved forecasting allows more efficient management of marine environmental protection actions, such as measures to combat the spread of pollutants in the event of spills.
The term drifter comes from the verb ”to drift”. These are buoys designed to be transported by currents when released into the sea. They are also known as “Lagrangian buoys”, because they are integral in their motion with the watery element studied.
They can operate both on the surface and in depth. They consist of a submerged part, called “drogue”, while the part on the surface consists of a small antenna. The submerged part works as a floating anchor, more or less ballasted, depending on the depth at which you want to intercept the current. The emerged part transmits the position of the buoy through the satellite network and therefore allows to trace its trajectory over time.
From the trajectory we deduce very precise punctual information about the currents that dragged the buoy. The sending of the position takes place at intervals of time, which are defined according to the scale of the phenomena to be observed.
Numerical circulation models complete the information obtained from measuring instruments, such as HF radars and drifters, from the point of view of both spatial and temporal extension. First of all, they provide information along the water column, also below the sea surface, where the observational network, consisting of radar HF and drifter, cannot carry out measurements. The models can also provide a complementary contribution on the surface, in areas of interest not reached temporarily or permanently by the available observational network.
The sediment is sampled along a transept whose direction corresponds to that of the dominant current. The matrix is taken by a box corer, an instrument consisting of a ballasted metal box with a rectangular base, in which the recovery of the sediment is ensured by a basal closure. Organisms are collected by a scuba diver, at different distances from port areas.
Sediments are highly representative of the state of contamination of the marine environment. The study of this matrix, and of its chemical and physical characteristics, is considerably important in the field of monitoring activities, since it represents a kind of “historical memory”. It allows to draw indications not only on recent pollution events, but also on the previous ones.
In addition, it carries out an important action of vehicle and direct transport of some pollutants. It can act as a transitional and/or definitive tank, from which pollutants can be released and dispersed back into the environment.
First of all, chemical analysis measurements are carried out in different places of the study area, repeating these measurements over time to discover the temporal evolution of pollution rates.
The second part of the approach used by IMPACT is Lagrangian modeling. This modeling allows to simulate the transport of pollutants on a defined area, in any point of the space represented by the model, and with the possibility to evolve the diffusion of pollutants in the future. Field measurements are therefore used in numerical experiments as initial concentration conditions.
It is necessary to evaluate the potential flow of contaminants from areas with high anthropogenic pressure, such as industrial ports, to areas under protection, such as MPA (in this case Port of Leghorn and MPA of Meloria).
This evaluation is made on the most conservative matrix, such as sediments.
The level of environmental contamination also influences the microbial composition of sediments; for this reason, the definition of microbial patterns is a valid support in tracing the flows.
The main reason is to define a baseline that could represent a useful reference for the future strategies of port development, in particular in those industrial ports (e.g. Leghorn) facing zones of naturalistic importance, under protection (e.g. MPA of Meloria).
Currently, the levels of contamination and its effects on indicator organisms are the result of industrial activities and port traffic, together with the hydrodynamism of the area. Activities of port development (e.g. increase of the activities, construction of new artefacts) will have to take account that any modifications of the hydrodynamism of the study area could have direct consequences on the modification of the flows.
The data provided by this project can be a valuable support to decision-making processes.
This intertidal species, ubiquitous in the Mediterranean, is resistant to the xenobiotic substances. It lives both on the natural rocky coasts, and on the breakwaters and the artificial docks; it is commonly found also in the ports, and is easy to sample. The dispersion of pelagic larvae may be an indicator of flows between ports and MPA. Both the evaluation of the effects of environmental contamination (by measuring the main ecological parameters and bioaccumulation), both the analysis of biomarkers and levels of gene expression, allow to express an opinion on the state of health of the populations living in the different study areas.
The use of bivalve molluscs in the monitoring of chemical contamination of marine environments has been used for decades, both in the United States and in many European countries, in international programs of Mussel Watch.
A species can be used as a bioindicator only if it has certain characteristics. The essential ones are: the absence of mechanisms to regulate the tissue concentrations of contaminants (the organism concentrates these substances in its tissues proportionally to their environmental level), the sessility, the eating habits, the ease of collection, the wide geographic diffusion and the knowledge of the biological cycle.
The most innovative aspect of the IMPACT project is its transboundary approach, based on a modelling and monitoring plan. It capitalises and expands the existing network of transboundary infrastructure, which was built in the previous cooperation programme.
The IMPACT web-GIS platform will also provide new data useful for the management of MPA by the agencies and institutions in charge of the planning of maritime spaces.
The transboundary approach is central, both for the common problems in key and vulnerable areas, both to ensure the effectiveness of interventions, based on an infrastructure network and shared practices.
A GIS (Geographical Information System) consists of a series of software tools to acquire, store, extract, aggregate and display geo-referenced data, associated with precise geographical positions.
The GIS integrates the characteristics of the database (which allow to carry out researches, to store data, to draw up graphs), with those of an interactive map (that furnishes territorial data and geographic representations on multiple levels). These representations facilitate not only the planning of ordinary interventions, but also the identification of new actions that are necessary in the territory.
A WebGIS is a remote GIS accessible on the internet through a browser, it is the web extension of applications created and developed to manage numerical cartography. A webGIS is also distinguished from a GIS by its enhanced capabilities of communication and information shared, with other users.
The purpose of the webGIS of IMPACT, together with the guidelines for its use, is to provide a useful tool, based on objective information and scientific analysis, to support the optimal management of port areas and MPA in the study areas.
Thanks to the commitment of the partnership, a significant amount of data was collected and analyzed in the four study areas: information related to current distribution, collection of new data and historical data sets on the presence and distribution of contaminants in the water column and sediments, information on genetics, population structure and distribution of organisms of ecological importance and their dispersion or retention within the MPA concerned.
Webgis is a useful tool for the organization and consultation of all this information, used by political decision-makers in the transboundary marine area.
Corsica is the Mediterranean region of the area “Interreg-Maritime” less affected by chemical pollution, thanks to its small population and the absence of heavy industries.
However, the pollution of port areas, and the risks associated with maritime traffic in the Corsican Canal, are an important and growing risk that needs to be identified, in order to better manage it.
The only way to predict which areas will be more at risk is to know precisely the origin of the port pollution and the ways of diffusion at sea. These three components are the contribution of IFREMER to the IMPACT project.
The commercial ports of Corsica (Bastia, Ajaccio, Propriano and Porto Vecchio) are the most important ports in terms of maritime traffic, and they are therefore those at greater risk of pollution, both chronic and accidental.
In the IMPACT project area and in the Natural Park of Cap Corse, large marinas such as Saint-Florent are also possible sources of pollution, although they are less important than freight ports.
The dispersion studies, carried out with hydrodynamic assessments, show that the currents are directed mainly towards north, bringing pollution in the transboundary area of the island of Capraia in Italy, and towards the coast of the Natural Park.
These calculations were confirmed by releasing drifters (floating buoys) on the surface of the water. They also highlight the existence of a connection of sea currents between the east and west of Cap Corse, from Bastia to Saint-Florent, and vice versa, depending on the wind conditions. Long-term transport can also be extended to the Ligurian and Provençal coasts, along the underwater embankment.