Blue World Institute of Marine Research and Conservation, Kaštel 24, 51551 Veli Lošinj, Croatia.
J Acoust Soc Am. 2013 Mar;133(3):1368-76. doi: 10.1121/1.4789003.
This study aims to provide an objective mapping of the underwater noise and its sources over an Adriatic coastal marine habitat by applying the self-organizing maps (SOM) method. Systematic sampling of sea ambient noise (SAN) was carried out at ten predefined acoustic stations between 2007 and 2009. Analyses of noise levels were performed for 1/3 octave band standard centered frequencies in terms of instantaneous sound pressure levels averaged over 300 s to calculate the equivalent continuous sound pressure levels. Data on vessels' presence, type, and distance from the monitoring stations were also collected at each acoustic station during the acoustic sampling. Altogether 69 noise surveys were introduced to the SOM predefined 2 × 2 array. The overall results of the analysis distinguished two dominant underwater soundscapes, associating them mainly to the seasonal changes in the nautical tourism and fishing activities within the study area and to the wind and wave action. The analysis identified recreational vessels as the dominant anthropogenic source of underwater noise, particularly during the tourist season. The method demonstrated to be an efficient tool in predicting the SAN levels based on the vessel distribution, indicating also the possibility of its wider implication for marine conservation.
本研究旨在通过自组织映射（SOM）方法，对亚得里亚海沿海生境中的水下噪声及其来源进行客观映射。在 2007 年至 2009 年间，在十个预先设定的声学站进行了海洋环境噪声（SAN）的系统采样。针对 1/3 倍频程标准中心频率，以每 300 秒平均的瞬时声压级进行噪声水平分析，以计算等效连续声压级。在声学采样期间，还在每个声学站收集了船只存在、类型和与监测站的距离的数据。总共将 69 次噪声调查引入到 SOM 预先设定的 2×2 阵列中。分析的总体结果区分了两个主要的水下声景观，主要与研究区域内航海旅游和渔业活动的季节性变化以及风和波浪作用有关。分析确定休闲船只为水下噪声的主要人为来源，特别是在旅游季节。该方法证明是一种根据船只分布预测 SAN 水平的有效工具，也表明其在海洋保护方面的更广泛应用的可能性。
