**2. Hydrometeorological impact of river mouth on coastal water quality**

Most human activities are related to water and take place in coastal areas or along riverbanks. The correct management of these areas is therefore primarily referred to as the basin-scale [18] where the territorial planning activities need to consider the aggregate effects of hydrographic changes caused by human activities at sea and on land [18, 30–32].

The Marine Strategy Framework Directive [6] highlights the importance of the assessment of the hydrographical conditions through seawater physical-chemical parameters, that is, temperature, salinity, depth, currents, waves, turbulence, turbidity (from a load of suspended particulate matter), upwelling, wave exposure, mixing characteristics, residence times, the spatial and temporal distribution of nutrients, oxygen, and acidification [30, 33–35]. All these variables are essential for understanding the dynamics of marine ecosystems that can be altered by anthropic presence.

Hydrographical conditions are site-specific and depend on landscape features, morphology, and lithology and are often conditioned by large-scale forcings, such as tide, general ocean circulation and climate. Small-scale features, such as land use and human-induced pressures, are also relevant to the river dynamics, especially in coastal areas.

The offshore waters of the Mediterranean Sea are extremely oligotrophic, and the coastal areas have been historically known to be influenced by natural and anthropogenic inputs of nutrients, mainly concentrated in the Adriatic basin [36].

Monitoring of contamination in different mollusc species is a well-known methodology, applied to assess the level of sea-water contamination, which exploits the bivalve capability to accumulate and retain contaminants. Moreover, mollusc edible species contamination is constantly monitored to ensure the introduction of safe products in the food market.

The European Regulation No 627/2019 [37] assesses the official control programmes for bivalve molluscs and provides the classification of mollusc production areas based on microbiological monitoring for the bacterium *E. coli* in the mollusc flesh and intervalvular liquid, used as a faecal indicator organism (FIO). Since rivers are routes for the transfer of organic matter including faecal bacteria from inland to the sea, the contamination is strongly affected by the inland drainage network, which collects also the most important abiotic factors affecting bacterial contamination of molluscs [38].

Even if the influence of FIO on the quality of coastal waters is studied since the XVIII century, few studies exist that attempt to evaluate the relationship between fluvial transport and shellfish hygiene in the sea [39, 40].

The land-sea-river system is extremely complex; therefore, it is not straightforward to establish a relationship between runoff, precipitation, and contamination levels. Connections are site-specific and dependent on the

#### *Coastal Water Quality: Hydrometeorological Impact of River Overflow and High-resolution… DOI: http://dx.doi.org/10.5772/intechopen.104524*

physiographical characteristics of each catchment and, in addition to the existing, local human pressures. Nevertheless, contamination decay is also connected to local environmental parameters which affect the bacterial dilution and the self-purification process of the bivalves.

The analysis of mollusc contamination has a socio-economic value; therefore, it is doubly important to evaluate in terms of both monitoring contamination levels and attempting to forecast possible pollution events. Nevertheless, different competencies may be required to achieve this purpose; on one hand, prediction of environmental processes requires deep knowledge of earth system modelling and data interpretation. On the other hand, environmental implications on food security monitoring are requested to adequately assess the design of useful tools or instruments able to really ameliorate the bivalves' productions. A wide number of capabilities should be connected to work together to find ICT solutions: biologists, physicists, engineers, and economists, for example. A virtuous example of this collaboration was the CapRadNet project (http://cetemps.aquila.infn.it/capradnet/), which originated a fruitful collaboration between different institutional levels and different actors usually involved in diverse activities. The outcome of the presented work is born from the project collaboration. The main aim of the present research was to investigate the relationships between two main environmental variables (flow discharge and precipitation) and the contamination level of molluscs harvested areas in a target site. The feasibility study resulted from the capitalisation of other two previous projects, funded by the IPA-Adriatic CBC Programme. The proposed analysis has taken advantage of *E. coli* concentration data analysed in the framework of the CAPS2 project (www.caps2.eu) and the hydrological modelling system developed in the same area to predict possible flood events due to severe meteorological events, as an outcome of the AdriaRadNet project (http://cetemps. aquila.infn.it/adriaradnet/).

The good practices defined in the CapRadNet project are being tested in a new project financed at the regional level, which intends to create the Early Warning System as a final product to improve the economic and production efficiency of the plants through the environmental information made available to aquaculture producers, which will be described below.
