Recent and Ongoing Seismic Operations West of Shetland

Seismic surveys are best conducted in calm seas conditions, during the period April to September. Historically, upon the award of a licence for oil exploration purposes, the Government attatched constraints to the licence in terms of the activities allowed on that block, which often related to the possible effect of seismic operations on fish on the advice of the Scottish Office Agriculture and Fisheries Department (SOAFD). Seismic surveys have been blamed as one of the reasons for reduced seasonal fish catches from the North Sea. Known effects on fish include damage to fish and eggs and displacement of fish (Turnpenny and Nedwell 1994).

In the past, cetaceans were not considered in the licence conditions. However, increasing attention has been focused on the potential effects of seismic operations on cetaceans. The UKOOA have recently sponsored a review of the effects of underwater sounds from seismic surveys on cetaceans (Evans and Nice 1996). This concluded:

1. The choice of when to conduct a seismic survey should be dictated by the relative vulnerability of the species present. For example for minke and fin whales, the period of least impact would be November to March (the worst period for seismic surveys)
2. Cetaceans are difficult to detect even at short distances less than 1km and yet the zone of influence of seismic sound will exceed this.
3. Baleen whales, such as minke whales are likely to be silent for long periods of time (possibly May to September) and thus could escape acoustic detection. A combination of visual and acoustic monitoring is advisable.
4. Where possible, direct measurements of recieved sound pressure levels from the siesmic arrays at varying distances and in different directions should be made, in order to better predict likely impacts upon wildlife in the future.

1. Keeping a log of all visual cetacean sightings (to be forwardeed to the JNCC on completion of a survey)
2. Utilising a slow start procedure for the source array (gradually stepping up the power output over 20 minutes to, in theory, allow cetaceans time to swim away.
3. Delaying the start of survey lines if cetaceans are spotted within 500m of the source by waiting 20 minutes to ensure that animals are clear of the survey area

In the West of Shetland area, environmental issues are being evaluated and managed by all operators jointly, led by Shell. Environmental initiatives include improved cetacean monitoring capability (including visual and acoustic monitoring) as part of seismic surveys and, a major research project sponsored by a consortium of 14 oil companies, through JNCC and Cornell University. This project is aimed at monitoring and tracking large cetaceans in the Atlantic (and West of Shetland) using redundant US naval hydrophones, the so-called SOSUS sound surveillance system chain).

There has been a good deal of survey activity in the waters west of Shetland over the summer, and in the next few months, the results of several surveys for cetaceans in the area may (or may not) become available. These include:

1. A new JNCC report, currrently at the printers, containing JNCC data on cetaceans up to March 1996 (contact: Phil Bloor, Seabirdds at Sea Tel: 01224 655707)
(According to the seismic testing guidelines, see above, seismic vessels should keep a log of cetacean sightings to be forwrded to the JNCC. It is not clear whether this data is to be added to the JNCC SAST database)
2. Surveys from the NERC RV Charles Darwin, coordinated by JNCC (?) (vessel chartered by an oil company).
3. North Atlantic Sightings surveys (NASS-95), co-ordinated by Niels Oien/Per Berregren and led by G. Desportes (Museum of Natural History, Futalag 40, FR-100 Torshavn, Faroe Islands).
4. Cetacean monitoring surveys (visual and acoustic) from a seismic survey guard vessel, sponsored by Shell. Research was conducted through Birmingham University (headed by Prof. R. Coates).
NB. Unfortunately the report was unavailable at the time of writing.
5. Results of cetacean research undertaken by Dr. Chris Clark, of Cornell University, under contract to JNCC (?) and a consortium of 14 oil companies. This is utilising acoustic information from SOSUS arrays in the waters west of Shetland.

Contact for Chris. W. Clark:
Cornell Laboratory of Ornithology
Bioaccoustics Research Program,
159 Sapsucker Woods Road
Ithaca, NY,
USA 14850. tel: 607 254 2405

Chris Clark is involved with acoustic research using SOSUS data in other parts of the world e.g Pacific Ocean. Some of this has been published (some papers are included with the other references pertaining to this report).

Other researchers/contacts working on/in the area include:
Alison Gill and Tim Atkinson
The Risso's Dolphin Project
PO Box 9902
Stornaway
Isle of Lewis
HS2 0HQ
(see also Gill and Atkinson 1996). These researchers are currently seeking funding to continue the project, which had minimal funding for the pilot stage from WDCS and the Mammal Conservation Trust. Peter Evans is involved in an advisory capacity.

Simon Boxall
Department of Oceanography,
Southampton Oceanagraphic Centre
Maritime Way
Southampton
This group have been involved with research in the area west of Shetland (particularly deep sea biology, I think).

Mr. John Shears (British Antartic Survey/ Some responsibility for Oil spills and EIA's off Shetland. Tel: 01223 251400.

John Goold
University of Wales Bangor
School of Oceanic Sciences
Menai Bridge
Anglesey, LL59 5EY
e-mail: oss123@sos.bangor.ac.uk

I have been in contact with John Goold, who is concerned about the sheer numbers of sperm whales washing up off Scotland, and also about potential damage to sperm whales from seismic testing. His request for research funds from the DTI to continue the work he was doing of the coast of Wales was rejected.
NB. It would be interesting to try and find out whether the stranded sperm whales had their ears examined.

I have been advised that the JNCC Coastal Directories are useful and pertinent to this subject, giving detailed descriptions for each area of coast. Peter Evans has been contracted to write the 'Cetacean' sections, and the Shetland area is currently at proof stage.

I have contacted the DOE wildliffe division (Bristol) to obtain recent details of the Natural History Museum's strandings project. Unfortunately I did not recieve information in time for inclusion in this report.

Vassili Papastvrou (IFAW) has a broad collection of refernces relating to cetaceans around the UK and whaling earlier this century.