Climate changes have a tremendous impact on coastal and littoral areas, strongly affected by seaquakes and floods. Moreover, global warming causes a drastic change on the biodiversity of rivers, seas, lakes, including in biodiversity hotspots and protected areas, such as the Venice Lagoon in Italy. A similar impact is caused by pollutants: this called for a largescale long-term action that aims to monitor aquatic environmental parameters in order to predict, manage and mitigate these effects. Yet, coastal systems are highly heterogeneous in space and variable over short (daily), medium and long (seasonal, interannual) timescales, making reliable but affordable monitoring a challenging task. This paper proposes to automate this process with the use of a low-power sustainable integrated underwater and above water Internet of Things sensor network, able to collect water measurements in a cloud database and make them available to researchers to monitor the status of a certain area and develop their predictions models. Simulation results highlight how Low-Power Wide-Area Networks can support the data collection from a dense sensor deployment.