# Commission Decision (EU) 2017/848 of 17 May 2017 laying down criteria and methodological standards on good environmental status of marine waters and specifications and standardised methods for monitoring and assessment, and repealing Decision 2010/477/EU (Text with EEA relevance), Division: Specifications and standardised methods for monitoring and assessment

Extent: E+W+S+N.I.

1..For D11C1 monitoring:
(a)Spatial resolution: geographical locations whose shape and areas are to be determined at regional or subregional level, on the basis of, for instance, activities listed in Annex III to Directive 2008/56/EC.
(b)Impulsive sound described as monopole energy source level in units of dB re 1 μΡa2 s or zero to peak monopole source level in units of dB re 1μΡa m, both over the frequency band 10 Hz to 10 kHz. The Secretary of State, in consultation with the devolved policy authorities, may consider other specific sources with higher frequency bands if longer-range effects are considered relevant.
2..For D11C2 monitoring:
Annual average, or other suitable metric agreed at regional or subregional level, of the squared sound pressure in each of two ‘1/3-octave bands’, one centred at 63 Hz and the other at 125 Hz, expressed as a level in decibels in units of dB re 1 μΡa, at a suitable spatial resolution in relation to the pressure. This may be measured directly, or inferred from a model used to interpolate between, or extrapolated from, measurements. The Secretary of State, in consultation with the devolved policy authorities, may also decide at regional or subregional level to monitor for additional frequency bands.
Criteria relating to other forms of energy input (including thermal energy, electromagnetic fields and light) and criteria relating to the environmental impacts of noise are still subject to further development.
Units of measurement for the criteria:
D11C1: Number of days per quarter (or per month if appropriate) with impulsive sound sources; proportion (percentage) of unit areas or extent in square kilometres (km2) of assessment area with impulsive sound sources per year,
D11C2: Annual average (or other temporal metric) of continuous sound level per unit area; proportion (percentage) or extent in square kilometres (km2) of assessment area with sound levels exceeding threshold values.

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Source: https://www.legislation.gov.uk/eudn/2017/848/annex/part/I/division/9/division/2 (the official version)
Page: https://openlegislation.uk/eu-decision-2017-848/annex/part-I/division-9/division-2
Contains public sector information licensed under the Open Government Licence v3.0. Source: legislation.gov.uk, The National Archives.