Environmental Monitoring under DFO’s New Pile Driving Mitigation AdviceMay 10, 2019Jayson Kurtz, Ecofish Research Ltd.

Introduction

• Who we are:• Jayson Kurtz R.P. Bio.• Ecofish Research Ltd.

• Outline:• The environmental concern about pile driving• The regulatory context• What it takes to monitor effects

Environmental Concerns

• Fish and marine mammals• Footprint and construction activity• Loss of habitat• Behavioural disturbance• Physical injury

Disturbance and injury due to construction activity (driving piles)

Mechanism of Concern

• Exposure to underwater sound waves (pressure)• Avoidance of area• Delayed migration• Damage to auditory systems • Rupture of gas-filled organs (fish)• Interference with communication or echo location

(marine mammals)

Regulatory Context

• Fisheries Act (serious harm)• Letter of Advice• Authorization

• Species at Risk Act• CEAA/BCEAA

Regulatory Context

• Fisheries Act - Letter of Advice• Advice to avoid impacts• Often based on proponents suggested mitigation• Advice has evolved over time but typically 

referenced BMPs produced by industry

BMP

• Outlined practices by type of pile (focus on impact hammer)• Mitigation measures:

• Timing• Physical exclusion• Bubble curtain• Monitoring

• 30 kPa sound pressure threshold (209.5 dB)

Recent DFO Advice

• Based on latest scientific research on impacts• Includes fish and marine mammals• Includes impact and vibratory hammers• Includes cumulative effects monitoring• New thresholds• Exclusion zones – visual observations

New Thresholds

• Finfish peak sound pressure level (SPL): 206 dB@ 10m• Finfish cumulative sound exposure level (SEL): 187 dB re 1 μPa2s >2g• Finfish cumulative sound exposure level (SEL): 183 dB re 1 μPa2s <2g• Marine mammal exclusion zone 120 dB RMS (vibratory)• Marine mammal exclusion zone 160 dB RMS (impact)

• Confused yet?• All lower than the BMP threshold: 209.5 dB

Monitoring

Monitoring

Monitoring

What Did We Learn?

• New monitoring hardware and software is finicky• SELcum scripts from manufacturer• Stop/start measurements

• Challenges measuring background/ambient noise• Technical support

What Did We Learn?

• New peak SPL are achievable…

…with mitigation:• soft-start• bubble curtain

What Did We Learn?

• New cumulative SEL thresholds are challenging to meet• Required pausing pile driving activities • Required moving to other piles >20m apart• Similar levels for pile install and removal

What Did We Learn?

• Can predict when threshold will be reached

What Did We Learn?

• Marine mammal exclusion zone extended >1km for vibratory

• Adapted our approach for pinnipeds (seals)

Recommendations

• Plan your work• Adequately assess fish and marine mammal species in the area• Secure monitoring equipment in advance• Stagger pile locations and be prepared for time outs

Questions?