A previously unpublished study has found significant dolphin and whale activity around the route of the proposed Corrib gas field pipeline off the Co Mayo coast.
The study, carried out by marine scientists from University College Cork in 2001 and 2002, recorded over 220 sightings of seven whale and dolphin species.
Sightings of two seal species and marine mammals such as basking sharks and a sea turtle in Broadhaven Bay and north-west Mayo waters were also recorded.
The report said the bay was a significant breeding and rearing area for whales and dolphins, and warns that it would be "difficult" to protect such mammals from drilling and blasting works associated with a pipeline.
The study was commissioned and funded by the Corrib gas field developers, but was not submitted as part of the company's foreshore licence application. In its application, the company said there was "no evidence that Broadhaven Bay is of particular importance to cetaceans (whales and dolphins)".
The study was received by Dúchas, the Heritage Service, last month, 10 months after its completion. The Department of the Marine only recently requested a copy following inquiries by The Irish Times.
The Department said the study was not required under the company's foreshore licence application even though Irish waters are designated as a whale and dolphin sanctuary. Broadhaven Bay is a candidate Special Area of Conservation (SAC).
UCC's Coastal and Marine Resources Centre (CMRC) gathered data within the Broadhaven Bay SAC and neighbouring waters between August 2001 and October 2002.
It noted five types of dolphin, including the relatively rare Risso's Dolphin. The study notes that marine mammals are particularly vulnerable to underwater noise and pressure waves.
Consultants employed by the Department of the Marine to analyse Shell's environmental impact statement for its foreshore licence application had been critical in March 2002 of the lack of information on whale and dolphin activity in the area.
A spokeswoman for Shell said yesterday the company had not been asked by the Department for such information. It had decided to commission the scientific survey when it became aware of such marine life during preliminary survey work.
She said it intended to take the report's recommendations on board, including the need for "mitigating" factors, when carrying out offshore pipeline work.
