Seismic Survey

Seismic surveys are carried out in the United Kingdom Continental Shelf (UKCS) in the search for, and managing of, oil and gas reserves. Modern large-scale surveys are conducted using a towed array of 'airguns' – cylinders of compressed air. The array, typically containing tens of such cylinders, is discharged simultaneously, to generate a pressure pulse which travels downwards into the seabed. The pulses, reflected back from the seabed and underlying strata, are recorded, interpreted and plotted. As the survey proceeds, the airguns are continually fired and recharged with compressed air at intervals of approximately every ten seconds, the timing dependent on the objectives of the survey.

 

The extent to which seismic disturbance from airguns affects cetaceans is not well known for all species due to the limited research carried out to date. Seismic surveys at sea do not necessarily constitute a threat to marine mammals, if care is taken to avoid situations which could potentially harm the animals.

 

Under the EU Habitats Directive 92/43/EEC Article 12 – member states are required to establish a system of strict protection for the animal species listed in Annex IV which include all cetaceans. The Offshore Petroleum Activities (Conservation of Habitats) Regulations 2001 implements the EU Habitats Directive for all oil and gas activities within the UKCS. As part of these regulations any company wishing to carry out a seismic survey must apply for consent from the Department for Business and Regulatory Reform (BERR) (formerly the DTI). The JNCC are consulted on whether consent should be granted for each individual seismic survey and if a consent is granted, a standard condition is that the JNCC Guidelines for minimising acoustic disturbance to marine mammals from seismic surveys are always followed.

 

Amendments to the Habitats Regulations for England and Wales and the new Offshore Marine Conservation (Natural Habitats, &c.) Regulations 2007 came into force on the 21^st August 2007. Both Regulations revised the definition of deliberate disturbance of European Protected Species (cetaceans, turtles and the Atlantic sturgeon). In the document  "The deliberate disturbance of marine European Protected Species - Interim guidance for English and Welsh territorial waters and the UK offshore marine area",the JNCC provides initial guidance in interpreting the law from the point of view of nature conservation, so that developers in the marine environment can assess the likelihood of committing an offence and how offences can be avoided, and if a wildlife licence is required. 

 

Another condition of a consent being granted to carry out a seismic survey is that a report is submitted to the JNCC for each individual survey detailing how the JNCC Guidelines were implemented, the marine mammals sighted, the methods used to detect them and any problems encountered. A series of standard forms for recording this data have been developed (see below). The data from these forms is analysed by the JNCC and a series of reports have been produced entitled 'Marine Mammal Observations during seismic surveys for the years 1996 to 2000' with the publication of the 2001and 2002 reports progressing.

 

For a copy of the BERR regulations please visit the BERR website at: http://www.og.dti.gov.uk/

 

The following documents are for download