Marine Mammal Commission

Stages of Offshore Oil and Gas Development and Potential Effects on Marine Mammals

Exploration

Locate and characterize geological structures that may contain hydrocarbon reserves

  • Acoustic disturbance/potential injury from seismic sound source
  • Disturbance from vessel and aircraft activity
  • Collisions with survey and support vessels

Coring or sampling of surface and subsurface sediments to determine geophysical properties

  • Physical alteration or disturbance of bottom habitat

Provide imagery of the sub-seafloor to locate and characterize geological features and hazards, biologically sensitive areas, and archaeological resources

  • Acoustic disturbance from sound source
  • Disturbance from vessel activity
  • Collisions with survey and support vessels

Confirm presence of hydrocarbons; characterize physical properties of reservoir to determine economic feasibility

  • Disturbance from vessel and aircraft activity
  • Collisions with support vessels
  • Physical alteration or disturbance of bottom habitat
  • Chemical alteration and/or contamination of water or bottom habitat (from drilling muds and waste)
  • Pollution from trash and debris
  • Oil and gas spills and leaks

Determine the structure of a particular petroleum-bearing zone

  • Acoustic disturbance/potential injury from seismic sound source
  • Collisions with survey and support vessels

Temporary or permanent capping and abandonment of exploratory well

  • Oil and gas spills and leaks

Construction and Installation of Platforms, Pipelines, and Other Equipment

Provide imagery of the sub-seafloor to locate and characterize geological features and hazards, biologically sensitive areas, and archaeological resources

  • Acoustic disturbance from sound source
  • Disturbance from vessel and aircraft activity
  • Collisions with survey and support vessels

Install and anchor drilling platform and equipment to seafloor to support long-term hydrocarbon production, storage, and offloading

  • Acoustic disturbance/potential injury from pile driving or platform construction
  • Disturbance from vessel and aircraft activity
  • Collisions with support vessels
  • Physical alteration or disturbance of bottom habitat
  • Discharges prior to a disposal well being serviceable
  • Pollution from trash and debris
  • Oil and gas spills and leaks

Locate and avoid bottom hazards, bottom-set fishing gear, biologically sensitive areas, and archaeological resources

  • Acoustic disturbance
  • Disturbance from vessel and aircraft activity

Install pipeline for transport of hydrocarbons to an onshore facility port or refinery

  • Acoustic disturbance/potential injury from pile driving (where applicable)
  • Disturbance from vessel and aircraft activity
  • Physical alteration or disturbance of bottom habitat or ice and mobilization of sediments (and potentially toxins) into the water column
  • Pollution from trash and debris
  • Oil and gas spills and leaks

Production and Transport of Hydrocarbons

Monitor distribution, volume, and pressure of the reserve during extraction

  • Acoustic disturbance/potential injury from seismic sound source
  • Disturbance from vessel and aircraft activity
  • Collisions with survey and support vessels

Extraction of oil and gas reserves for refinement and commercial sale

  • Disturbance from vessel and aircraft activity
  • Collisions with support vessels
  • Physical alteration or disturbance of bottom habitat
  • Chemical alteration and/or contamination of water or bottom habitat (from drilling muds and waste)
  • Pollution from trash and debris
  • Oil and gas spills and leaks
  • Artificial reef effects of platforms (e.g., attraction of certain fish and other species, changes in community composition and dynamics)

Transport of hydrocarbons to port or processing site via pipelines or tankers

  • Disturbance from vessel activity (tankers)
  • Oil and gas spills and leaks (tankers and pipelines)
  • Invasive species from tankers

Decommissioning and Site Clearance

Remove structures or equipment from seafloor

  • Acoustic disturbance/potential injury from explosives
  • Disturbance from vessel and aircraft activity
  • Pollution from trash and debris
  • Oil and gas spills and leaks

Remove structures or equipment from seafloor

  • Disturbance from vessel and aircraft activity
  • Pollution from trash and debris
  • Oil and gas spills and leaks

Permanent capping and abandonment of well

  • Oil and gas spills and leaks

Convert obsolete or non-productive platforms to artificial reefs

  • Artificial reef effects of platforms (e.g., attraction of certain fish and other species, changes in community composition and dynamics)