Completing the picture: collecting data on small vessels for underwater noise impact assessment in Canada

Due to an expected increase in vessel traffic in the Salish Sea, Canada, it is of paramount importance to assess current underwater noise levels from vessel activities and their disturbance on acoustically sensitive cetaceans,... [ view full abstract ]

Due to an expected increase in vessel traffic in the Salish Sea, Canada, it is of paramount importance to assess current underwater noise levels from vessel activities and their disturbance on acoustically sensitive cetaceans, particularly to the endangered killer whale population. In order to carry out these assessments, many studies rely on marine traffic data collected using Automatic Identification System (AIS) onboard vessels. However, AIS only captures a fraction of the actual vessels present because it omits many of the smaller vessels, which are not legally required to carry AIS. Without this information, our assessments of vessel-associated disturbances based on AIS are inherently flawed, and underestimated.

The NEMES (Noise Exposure to the Marine Environment from Ships) project is particularly interested in this unknown component of marine traffic as non-AIS vessels are likely contributing a considerable amount to the overall noise budget of the Salish Sea. With the assistance of various technologies and data analysis (e.g. aerial surveys, satellite imagery analysis, and shore-based cameras, we have been able to collect vessel traffic information for both AIS and non-AIS vessels. Preliminary results indicate that non-AIS vessels can account for up to 60% of the overall vessel traffic in surveyed areas. The majority of these vessels are recreational vessels, particularly during the summer months.

Through this work, we are now able to build a more complete picture of the distribution and type of vessels using the Salish Sea, and contribute to have a better understanding of their potential impacts to the marine ecosystem.