Do harbour porpoises target offshore installations as feeding stations?

Open Access Journal Article 2007

IADC Environmental Conference & Exhibition

Two sets of field trials were performed from offshore installations in the German Entenschnabel sector of the Dogger Bank, North Sea. Trial 1 was undertaken from the jackup drilling rig Noble Kolskaya and its support vessel Northern Seeker, at locations B4-5 and B11-4 over three discrete periods (October/November 2004 and December 2004/January 2005). The purpose of these trials was to perform measurements of acoustic noise levels generated by the rig during routine activities and to undertake preliminary passive acoustic monitoring (using T-PODs) of porpoises (Cetacea: Phocoena phocoena) around the rig. Trial 2 was a six-month study (August 2005-January 2006) using T-PODS around the A6-A gas-production platform when it was isolated, when the Noble Kolskaya was docked alongside, and after the rig’s departure. Sound levels generated by the Kolskaya were similar to previous measurements from metal-legged bottom-founded platforms, both in level (120 dB re 1μPa) and in the frequency range of dominant tonals (2-1400 Hz). Sound levels were highly variable over short periods, shifting 15-20 dB between quietest (holding) and loudest (drilling) operations. The rig was significantly quieter than its associated support vessels; rig high frequency sound levels dropped rapidly > 8 kHz. With the exception of rig-docking/rig-departure manoeuvres, porpoise activity appeared to be independent of platform/rig activity. The greatest porpoise activity was observed during the winter months; porpoise activity and feeding rates were significantly reduced in periods of heavy weather. Here we present data to suggest that harbour porpoises may be using installations in the Dogger Bank on a seasonal basis and that installations may enhance porpoise habitat by acting as artificial reefs and feeding stations, especially during the winter months. However, these are preliminary snapshot findings. To answer completely the question posed in the title of this paper, we would need to undertake baseline and controlled and replicated longer-term studies if the story of harbour porpoise usage of offshore installations is to be fully told.

Link To Publication

Similar Research

A Summary of Existing and Future Potential Treatments for Reducing Underwater Sounds from Oil and Gas Industry Activities

Pay-walled Conference 2007

OCEANS 2007

This paper summarizes the efforts undertaken by the author to identify existing and future potential methods to reduce underwater sound levels created by nearly all oil...
Read More

Influences of man-made noise and other human actions on cetacean behaviour

Pay-walled Journal Article 1995

Marine and Freshwater Behaviour and Physiology

Behavioral reactions of cetaceans to man-made noises are highly variable, ranging from attraction (e.g. bow riding by dolphins) or no response through short-term changes in behaviour...
Read More

Reactions of bowhead whales, Balaena mysticetus, to drilling and dredging noise in the Canadian Beaufort Sea

Pay-walled Journal Article 1990

Marine Environmental Research

Behavioural reactions of bowhead whales to seven 30–40 min underwater playbacks of recorded drillship and dredge noise were determined in 1982–1984. Some (but not all) bowheads...
Read More

Proximate Measurements of Acoustic Emissions Associated with the Installation and Operation of an Exploration Jackup Drilling Rig in the North Sea.

Pay-walled Peer Reviewed Publication 2012

The Effects of Noise on Aquatic Life: Advances in Experimental Medicine and Biology

Underwater sound recordings were obtained from the Noble Kolskaya jackup gas-exploration drilling rig in the North Sea on the Dogger Bank. The aim was to document...
Read More

Drilling and operational sounds from an oil production island in the ice covered Beaufort Sea

Pay-walled Peer Reviewed Publication 2004

Journal of the Acoustical Society of America

Recordings of sounds underwater and in air, and of iceborne vibrations, were obtained at Northstar Island, an artificial gravel island in the Beaufort Sea near Prudhoe...
Read More

Characteristics of oil industry dredge and drilling sounds in the Beaufort Sea.

Pay-walled Peer Reviewed Publication 1987

Journal of the Acoustical Society of America

As part of a general study of underwater industrial noises and their effects on bowhead whales, sounds from drilling and dredging operations were measured in the...
Read More

A brief review of known effects of noise on marine mammals.

Open Access Literature Review 2007

International Journal of Comparative Psychology

Marine mammals, especially cetaceans, are highly vocal and dependent on sound for almost all aspects of their lives, e.g. food-finding, reproduction, communication, detection of predators/hazards, and...
Read More

Review and Assessment of Underwater Sound Produced from Oil and Gas Sound Activities and Potential Reporting Requirements under the Marine Strategy Framework Directive.

Open Access Report 2011

Genesis Oil and Gas Consultants

Underwater sound and the potential impacts on marine life has received increased attention in recent years, with measures to assess underwater sound having been included within...
Read More

Marine Mammal Noise Exposure Criteria: Updated Scientific Recommendations for Residual Hearing Effects

Open Access Peer Reviewed Publication 2019

Aquatic Mammals

This article evaluates Southall et al. (2007) in light of subsequent scientific findings and proposes revised noise exposure criteria to predict the onset of auditory effects...
Read More

East or west: the energetic cost of being a gray whale and the consequence of losing energy to disturbance

Open Access Peer Reviewed Publication 2017

Endangered Species Research

Western gray whales (WGW) Eschrichtius robustus are considered one of the world’s most endangered baleen whale populations. Development of oil and gas fields in northeastern Sakhalin,...
Read More