Introduction

System for the monitoring of a marine coastal environment and the use of the same to monitor a stretch of coastline and counter the illegal fishing of Lithophaga lithophaga, a bivalve marine mollusk (protected by the current legislation), through an integrated system of hydrophones housed in anchored buoys on the seabed and terrestrial geophones positioned on the coast, both connected via wi-fi to a land-based monitoring and control station. The environmental monitoring system uses passive technologies to counter the illegal fishing of the mollusc Lithofaga lithofaga (Sea Date) which, by chiselling, produces a substantial instability of the submerged part of the cliffs. In addition, the system can protect sea areas off-limits to navigation by ensuring 24-hour surveillance of the coastal environment.

Technical features

The monitoring system includes:

• A marine part, structured in one or more floating geo-buoys equipped with a hydrophone, and with special electronics and multi-parameter sensors;
• A terrestrial part structured on one or more terrestrial devices and sensors, including geophones to be installed on the mainland;
• A control station that communicates with both the marine and terrestrial parts of the system via a Wi-Fi network. The different sensors and the control station communicate with each other through specific communication modules.

The passive acoustic sensors pick up the signal produced by the hammering and chiselling action to or from the marine engine of the boat that crosses the reserve area, triggering an alarm that is sent to the control station possibly managed by the competent authorities. The sensors installed also acquire a series of geo-environmental data (temperature, conductivity, density, etc.) useful for assessing the physical state of sea water. Finally, the acoustic signals received by the hydrophones are collected in a database for the study of underwater noises.

Possible Applications

• Coastal protection from illegal fishing of the Lithophaga lithophaga;
• Surveillance of marine protected areas from the illegal access of  motor boats;
• Geo-environmental monitoring of physical parameters of coastal seawaters and measurement of underwater noises.

Advantages

• Use of web technologies for alarm management and data sharing;
• Remote monitoring with passive, non-polluting technologies;
• Low production cost thanks to the use of Open Source components;
• Validity of the system for issues related to environmental protection and knowledge dissemination.