**Ivan Felis Enguix 1,\*, Marta Sánchez Egea 1, Antonio Guerrero González <sup>2</sup> and David Arenas Serrano <sup>1</sup>**


Received: 11 August 2019; Accepted: 26 October 2019; Published: 28 October 2019

**Abstract:** Recording underwater impulsive noise data is an important aspect of mitigating its environmental impact and improving maritime environmental management systems. This paper describes the method used and results of the spatial monitoring of both the baseline noise level and the impulsive noise sources in the Port of Cartagena. An autonomous vessel was equipped with a smart digital hydrophone with a working frequency range between 10 and 200 kHz and a received voltage response (RVR) of, approximately, −170 dB re 1V/μPa. A GIS map was drawn up with the spatiotemporal distribution of the basal sound pressure levels by coupling the acoustic data with the vessel's GPS positions to identify the sources of the impulsive noise of interest and their temporal characteristics. The loading of cargo containers was identified as the main source of impulse noise. This study is the first of a series designed to obtain accurate information on underwater noise pollution and its potential impact on biodiversity in the Port of Cartagena.

**Keywords:** underwater noise monitoring; impulsive underwater noise; continuous underwater noise; marine contamination; hydrophone; marine strategy framework directive; ASV
