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Common/Harbour seal (Phoca vitulina) estimated at-sea usage (mean) - Seal usage maps 2017

Marine Scotland Information NMPi icon

These maps are an update of the previous seal usage maps described in Jones et al. (2015). There are three key updates: (1) The telemetry data have been updated and now include data from 1991 - 2016 (inclusive) resulting in a marked increase (grey seals: 23%; harbour seals: 39%) in sample size for the UK; (2) The count data now include effort data and have been updated resulting in estimates of usage scaled to the estimated population size in 2015; (3) Haulout sites have been clustered together resulting in an increase in the proportion of sites for which there are associated telemetry data and thus increased accuracy of estimated distribution. The estimates reflect the expected mean number of seals in each 5 x 5 km cell at any given time. The estimates do not distinguish between the type of usage (e.g. foraging or travelling behaviour) and similar usage values could be a result of many individuals using a given area a small amount, or a small number of individuals that area intensively. Temporal variation in usage (seasonally or annually) is not represented. The confidence intervals reflect confidence in the estimate of mean usage in each cell, rather than showing the variability in usage. Thus, the confidence intervals are per cell and so do not represent uncertainty in distribution across the maps. Telemetry data were aggregated in order to provide the most complete spatio-temporal coverage around the UK, thus any differences in distribution by sex or age are not reflected. These maps only reflect estimates of usage resulting from seals that haul out in the UK and the Republic of Ireland; usage emanating from continental Europe is not considered.

ECOMMAS Proportion Dolphin Detection-Positive Days (2013-2016 time aware content)

Marine Scotland Information NMPi icon

ECOMMAS is a long-term, on-going study into how underwater noise generated by offshore industry impacts the distribution of dolphins and porpoises in the Scottish North Sea. 
Acoustic recorders (C-PODs and SM2Ms) are deployed at 30 sites across 10 locations along the east coast.  They record underwater noise and count echolocation clicks to measure dolphin and porpoise presence and absence.  They are deployed in the spring and are recovered after ~ 4 months.  In 2015 and 2016, a second deployment was issued in July/August.

Data is presented as detection-positive days (DPD) and detection-positive hours (DPH) for both species.

DPD = The detection of echolocation clicks per day
(1 = Detection-positive, 0 = Detection-negative)

DPH = The number of hours echolocation clicks are detected per day

Nall = Total number of clicks detected per day

Ndays = Total number of days recorded

PorpDPH_median = Median porpoise detection-positive hours for each site

DolDPH_median = Median dolphin detection-positive hours for each site

Proportion_PorpDPD = Proportion of porpoise detection-positive days (out of total days recorded, Ndays)

Proportion_DolDPD = Proportion of dolphin detection-positive days (out of total days recorded, Ndays)

Data has been prepared as ArcGIS maps showing median DPH and proportion of DPD for both species across all 30 sites.  It has also been converted to be viewed on the NMPi, and for direct download as a spread sheet (.csv)

ECOMMAS Median Porpoise Detection Positive Hours (2013-2016 time aware content)

Marine Scotland Information NMPi icon

ECOMMAS is a long-term, on-going study into how underwater noise generated by offshore industry impacts the distribution of dolphins and porpoises in the Scottish North Sea. 
Acoustic recorders (C-PODs and SM2Ms) are deployed at 30 sites across 10 locations along the east coast.  They record underwater noise and count echolocation clicks to measure dolphin and porpoise presence and absence.  They are deployed in the spring and are recovered after ~ 4 months.  In 2015 and 2016, a second deployment was issued in July/August.

 

Data is presented as detection-positive days (DPD) and detection-positive hours (DPH) for both species.

DPD = The detection of echolocation clicks per day
(1 = Detection-positive, 0 = Detection-negative)

DPH = The number of hours echolocation clicks are detected per day

Nall = Total number of clicks detected per day

Ndays = Total number of days recorded

PorpDPH_median = Median porpoise detection-positive hours for each site

DolDPH_median = Median dolphin detection-positive hours for each site

Proportion_PorpDPD = Proportion of porpoise detection-positive days (out of total days recorded, Ndays)

Proportion_DolDPD = Proportion of dolphin detection-positive days (out of total days recorded, Ndays)

Data has been prepared as ArcGIS maps showing median DPH and proportion of DPD for both species across all 30 sites.  It has also been converted to be viewed on the NMPi, and for direct download as a spread sheet (.csv)

ECOMMAS Proportion Porpoise Detection-Positive Days (2013-2016 time aware content)

Marine Scotland Information NMPi icon

ECOMMAS is a long-term, on-going study into how underwater noise generated by offshore industry impacts the distribution of dolphins and porpoises in the Scottish North Sea. 
Acoustic recorders (C-PODs and SM2Ms) are deployed at 30 sites across 10 locations along the east coast.  They record underwater noise and count echolocation clicks to measure dolphin and porpoise presence and absence.  They are deployed in the spring and are recovered after ~ 4 months.  In 2015 and 2016, a second deployment was issued in July/August.

Data is presented as detection-positive days (DPD) and detection-positive hours (DPH) for both species.

DPD = The detection of echolocation clicks per day
(1 = Detection-positive, 0 = Detection-negative)

DPH = The number of hours echolocation clicks are detected per day

Nall = Total number of clicks detected per day

Ndays = Total number of days recorded

PorpDPH_median = Median porpoise detection-positive hours for each site

DolDPH_median = Median dolphin detection-positive hours for each site

Proportion_PorpDPD = Proportion of porpoise detection-positive days (out of total days recorded, Ndays)

Proportion_DolDPD = Proportion of dolphin detection-positive days (out of total days recorded, Ndays)

Data has been prepared as ArcGIS maps showing median DPH and proportion of DPD for both species across all 30 sites.  It has also been converted to be viewed on the NMPi, and for direct download as a spread sheet (.csv)

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