Data from: Harbour porpoise responses to pile-driving diminish over time

Estimating impacts of offshore windfarm construction on marine mammals requires data on displacement in relation to different noise levels and sources. Using echolocation detectors and noise recorders, we investigated harbour porpoise behavioural responses to piling noise during the 10-month foundation installation of a North Sea windfarm. Current UK guidance assumes total displacement within 26 km of pile driving. In contrast, we recorded a 50 % probability of response within 7.4 km (95 % CI = 5.7 – 9.4) at the first location piled, decreasing to 1.3 km (95 % CI = 0.2 – 2.8) by the final location; representing 28 % (95 % CI = 21 – 35) and 18 % (95 % CI = 13 – 23) displacement of individuals within 26 km. Distance proved as good a predictor of responses as audiogram weighted received levels, presenting a more practicable variable for environmental assessments. Critically, acoustic deterrent device (ADD) use and vessel activity increased response levels. Policy and management to minimise impacts of renewables on cetaceans have concentrated on pile-driving noise. Our results highlight the need to consider trade-offs between efforts to reduce far-field behavioural disturbance and near-field injury through ADD use.

Readme.txt file for data packages associated with paper on “Harbour porpoise responses to pile-driving diminish over time”

Description of data packages

Graham_BOWL_cMMMP_Data_Packages_Readme_2019-05-01.txt



R code to prepare porpoise responses & construction activity data

R code to prepare the data file for analyses of porpoise responses to pile-driving, acoustic deterrent device (ADD) use and vessel activity. Filename = "Graham_BOWL_cMMMP_R_code_to_prepare_porpoise_response_data_2019-01-18.R"

Graham_BOWL_cMMMP_R_code_to_prepare_porpoise_response_data_2019-05-01.R



Zip folder with 100 data files on porpoise occurrence

Zip folder with 100 CPOD data files on porpoise occurrence for analyses of responses of porpoises to construction activity. Filename = "Graham_BOWL_cMMMP_CPOD_porpoise_ClickCounts_data_2019-01-18.zip” Each file has the data from a single CPOD deployment, cropped to remove data up to 23:59 on the day of deployment and from 00:00 on the day of retrieval. Each file has five columns = File, ChunkEnd, Nfiltered, Nall, MinsOn File is the filename of the original CPOD data file. ChunkEnd is the time in minutes. Nfiltered is the number of high and moderate quality porpoise clicks for each minute. Nall is the total number of unfiltered clicks for each minute. MinsOn indicates whether the CPOD was recording during that minute (1) or not (0).

Graham_BOWL_cMMMP_CPOD_porpoise_ClickCounts_data_2019-01-18.zip



Data on piling activity by turbine/OTM location

Data on the piling activity summarised by turbine/OTM location (see Table S1). Filename = “Graham_BOWL_cMMMP_Piling_summary_by_turbine_data_2019-01-18.csv” Twelve columns = turbine, start_time, end_time, piling_duration, piling_duration_hours, total_blow_count, max_energy, interval_days, daystocomplete, piling_order, lat, long. Turbine is the code for the turbine/OTM location. Start_time is the time when piling of the first pile started. End_time is the time when piling of the fourth pile ended. Piling_duration is the duration of active piling in minutes. Piling_duration_hours is the duration of active piling in hours. Total_blow_count is the total number of hammer blows. Max_energy is the maximum hammer energy (kJ). Interval_days is the time difference (in days) between the end of piling at the previous location and the start of piling at the current location. Daystocomplete is the number of days from the start to the end of piling. Piling_order is the order in which locations were piled, equivalent to the cumulative number of locations piled at the end of piling at that location. Lat is the latitude in decimal degrees. Long is the longitude in decimal degrees.

Graham_BOWL_cMMMP_Piling_summary_by_turbine_data_2019-01-18.csv



Data on piling activity by turbine/OTM location & day

Data on the piling activity summarised by turbine/OTM location and day. Filename = “Graham_BOWL_cMMMP_Piling_summary_by_day_data_2019-01-18.csv” Twenty-two columns = julian, start_time, end_time, total_duration, total_duration_hours, total_blow_count, max_energy, no_turbines_piled, turbine1, start_time1, end_time1, duration1, duration_hours1, blow_count1, max_energy1, turbine2, start_time2, end_time2, duration2, duration_hours2, blow_count2, max_energy2.

Graham_BOWL_cMMMP_Piling_summary_by_day_data_2019-01-18.csv



Data on CPOD deployments

Data on the CPOD deployments. Filename = “Graham_BOWL_cMMMP_POD_deployment_data_2019-01-18.csv” Eight columns = Dep_no, POD_number, Deployment_date, Location_ID, Latitude, Longitude, Retrieval_date, Data_end_date. Dep_no is the unique number assigned to each CPOD deployment. POD_number is the unique individual number for the CPOD used in that deployment. Deployment_date is the date when that CPOD was deployed at sea. Location_ID is the numeric identifier for the location at which that CPOD was deployed. Latitude is the latitude in decimal degrees for that deployment. Longitude is the longitude in decimal degrees for that deployment Retrieval_date is the date when that CPOD was retrieved at sea. Data_end_date is the date when the data on the CPOD’s SD card ended.

Graham_BOWL_cMMMP_POD_deployment_data_2019-01-18.csv



Data on AIS detections within 1km of CPODs

Data on the Automatic Identification System (AIS) vessel detections within 1km of each CPOD. Raw AIS data for 2017 for the Moray Firth were supplied to BOWL by Astra Paging Ltd., Sliven, Bulgaria. This AIS data consisted of the location (latitude and longitude) of each AIS vessel at 5 minutes intervals. These data were processed in R to select only those AIS vessel locations within 1 km of each CPOD when the CPOD was operational (i.e. deployed and recording data). Filename = “Graham_BOWL_cMMMP_5min_boat_withineach_1kmCPODbuffer _data_2019-01-18.csv” Five columns = MMMSI.x, DATE.TIME.x, Deployment.number, BOAT.LATITUDE, BOAT.LONGITUDE. MMMSI.x is the unique 9 digit vessel identifier. DATE.TIME.x is the time of the vessel detection. Deployment.number is the CPOD deployment to which that vessel detection refers. BOAT.LATITUDE is the latitude in decimal degrees for that vessel detection. BOAT.LONGITUDE is the longitude in decimal degrees for that vessel detection.

Graham_BOWL_cMMMP_5min_boat_withineach_1kmCPODbuffer_data_2019-01-18.csv



Data on AIS detections within 500m of CPODs

Data on the number of AIS vessel detections within 500m of each CPOD. Raw AIS data for 2017 for the Moray Firth were supplied to BOWL by Astra Paging Ltd., Sliven, Bulgaria. This AIS data consisted of the location (latitude and longitude) of each AIS vessel at 5 minute intervals. These data were processed in R to select only AIS vessel locations within 500 m of each CPOD when the CPOD was operational (i.e. deployed and recording data). Filename = “Graham_BOWL_cMMMP_5min_boat_withineach_500mCPODbuffer _data_2019-01-18.csv” Five columns = MMMSI.x, DATE.TIME.x, Deployment.number, BOAT.LATITUDE, BOAT.LONGITUDE. MMMSI.x is the unique 9 digit vessel identifier. DATE.TIME.x is the time of the vessel detection. Deployment.number is the CPOD deployment to which that vessel detection refers. BOAT.LATITUDE is the latitude in decimal degrees for that vessel detection. BOAT.LONGITUDE is the longitude in decimal degrees for that vessel detection.

Graham_BOWL_cMMMP_5min_boat_withineach_500mCPODbuffer_data_2019-01-18.csv



Data on the predicted received sound exposure levels

Data on the predicted received sound exposure levels (SEL; dB re 1 µPa^2 s), single pulse for an impact strike with the maximum hammer energy for that piling location, depth averaged for each CPOD sampling sites. Filename = “Graham_BOWL_cMMMP_Received_noise_levels_18pilinglocations_allCPODlocations_data_2019-05-01.csv” Six columns = Deployment_number, Turbine, Unweighted_SS_SEL, NOAA_SS_SEL, Southall_SS_SEL, Aud_SS_SEL. Deployment_number is the CPOD deployment number for that location. Turbine is the piling location. Unweighted_SS_SEL is the unweighted the predicted received sound exposure level (SEL; dB re 1 µPa^2 s), single pulse for an impact strike with the maximum hammer energy for that piling location, depth averaged for that CPOD site. NOAA_SS_SEL is the predicted SEL frequency weighted by the generalised weighting function for high frequency cetaceans proposed by NOAA (2016 & 2018: see methods in paper for references). Southall_SS_SEL is the predicted SEL frequency weighted by the high-frequency cetacean weighting function proposed by Southall et al. (2007: see methods in paper for reference). Aud_SS_SEL is the predicted SEL frequency weighted by a harbour porpoise specific audiogram from Kastelein et al. (2010: see methods in paper for reference).

Graham_BOWL_cMMMP_Received_noise_levels_18pilinglocations_allCPODlocations_data_2019-05-01.csv



R code to analyse porpoise responses to construction activity

R code to analyse porpoise responses to pile-driving, acoustic deterrent device (ADD) use and vessel activity. Filename = "Graham_BOWL_cMMMP_R_code_to_analyse_porpoise_responses_2019-01-18.R"

Graham_BOWL_cMMMP_R_code_to_analyse_porpoise_responses_2019-05-01.R



Data on porpoise responses (from CPODs) for analyses of responses of porpoises to piling, acoustic deterrent device use and vessel activit

Filename = “Graham_BOWL_cMMMP_Porpoise_responses_to_construction_data_2019-05-01.csv” Twenty-four columns = dep_no, turbine, dph24, dph12, base24, base12, prop24, prop12, resp24_50, resp12_50, location, distance, vessels24_1km, vessels12_1km, vessels24_500m, vessels12_500m, duration, piling_order, ADD, pod, Unweighted_SS_SEL, NOAA_SS_SEL, Southall_SS_SEL, Aud_SS_SEL. dep_no is the CPOD deployment number. turbine is the piling location. dph24 is the number of detection positive hours in the 24-hour period from the end of piling. dph12 is the number of detection positive hours in the 12-hour period from the end of piling. base24 is the number of detection positive hours in the 24-hour baseline period. base12 is the number of detection positive hours in the 12-hour baseline period. prop24 is (dph24 – base24)/base24. prop12 (dph12 – base12)/base12. resp24_50 is the 24-hour porpoise response coded as 0 or 1: if prop24 <= -0.5, response = 1. resp12_50 is the 12-hour porpoise response coded as 0 or 1: if prop12 <= -0.5, response = 1. location is the numeric identifier for the location at which that CPOD was deployed. distance is the distance to piling (km). vessels24_1km is the number of AIS vessel detections in the 24-h response period within 1km of the CPOD. vessels12_1km is the number of AIS vessel detections in the 12-h response period within 1km of the CPOD. vessels24_500m is the number of AIS vessel detections in the 24-h response period within 500m of the CPOD. vessels12_500m is the number of AIS vessel detections in the 12-h response period within 500m of the CPOD. duration is the duration of active piling in hours. piling_order is the order in which locations were piled, equivalent to the cumulative number of locations piled at the end of piling at that location. ADD is whether or not ADD mitigation was used prior to piling, coded “Y” (Yes) or “N” (No). pod is the CPOD number. Unweighted_SS_SEL, NOAA_SS_SEL, Southall_SS_SEL, Aud_SS_SEL are the predicted received sound exposure levels as above for data file 8.

Graham_BOWL_cMMMP_Porpoise_responses_to_construction_data_2019-05-01.csv



Data on predicted porpoise responses for the model of 24-h response with distance

Data on predicted porpoise responses for the model (24-h response ~ log(distance)*piling order + no. vessel locations_1km; see Table 1, Model a) used in the R code in the ESM to calculate the number of individuals displaced using behavioural-response curves. Filename = “Graham_BOWL_cMMMP_bootstrapped_predictions_m8_24_data_2019-05-01.csv” Six columns = distance, zorder, zvessels_1km, fit, lci, uci distance is the distance to piling (km). zorder is the standardised value of piling order (order in which the locations were piled): values were standardised by subtracting the mean piling order and dividing by the standard deviation of the mean. zvessels_1km is the standardised value of the number of AIS vessel detections in the 24-h response period within 1km of the CPOD: values were standardised by subtracting the mean number of AIS vessel detections and dividing by the standard deviation of the mean. fit are the predicted values of the probability of response estimated using bootstrapping. lci are the predicted values of the lower 95 % confidence interval of the probability of response estimated using bootstrapping. uci are the predicted values of the upper 95 % confidence interval of the probability of response estimated using bootstrapping.

Graham_BOWL_cMMMP_bootstrapped_predictions_m8_24_data_2019-05-01.csv

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