Assessment and monitoring of ocean noise in Irish waters

Abstract

This desk study was aimed to help Ireland meet the requirements of the Marine Strategy Framework Directive (MSFD) (2008/56/EC) under Descriptor 11: The introduction of energy, including underwater noise, is at levels that does not adversely affect the marine environment. The main aim of the MSFD is that European seas achieve Good Environmental Status (GES) by 2020. By 2014, it is expected that all Member States will have established and implemented longterm monitoring programmes. Under Descriptor 11, two indicators have been developed with specific criteria in order to measure whether GES has been achieved. These indicators are 11.1.1, low and midfrequency impulsive noise, and 11.2.1, low frequency continuous noise. To assist in the assessment of the indicators and facilitate the implementation of a longterm monitoring programme, the following project objectives were identified: • Catalogue and describe acoustic data sets collected within the Irish Exclusive Economic Zone (EEZ) within the 10 Hz to 10 kHz band. • Report on the existence of data sets that have been collected within the Irish EEZ at higher frequency bands. • Create a register of licensed activities, within the Irish EEZ that contribute to ocean noise, focussing on seismic surveying. • Assess and quantify seismic survey metadata from various sources to establish the proportion of days within a calendar year or defined period over a specified area in which target sounds are recorded (‘bang days’) and measured as sound exposure level or as peak sound pressure level at 1 m, within the 10 Hz to 10 kHz frequency band. • Describe an approximate disturbance area for baleen whales. • Collaborate with the UK in the creation of a joint register of licensed activities for Irish and UK waters, focussing on seismic surveying contributing to regional reporting. • Create a series of noise maps of seismic survey pressure in Irish waters across the years 2000–2011 based on equipment characteristics. • Spatially map vessel density across the Irish EEZ using Vessel Monitoring System (VMS) data and Automatic Identification System (AIS) data. • Deploy acoustic monitoring equipment and assess noise levels and evaluate the use of this technique as a means for Ireland meeting requirements under the MSFD. • Present a conceptual framework for a network of ambient noise monitoring sites within the Irish EEZ. • Explore monitoring strategies and assess potential technical solutions for a cost-effective noise monitoring programme in Irish waters.