Sea Life Surveys Research

 

Sea Life Surveys has been conducting cetacean surveys in the Scottish coastal waters of the Isle of Mull since 1990. The waters to the north and west of Mull contain an ecologically diverse marine life. Regularly sighted cetaceans include minke whale (Balaenoptera acutorostrata), harbour porpoise (Phocoena phocoena), Risso's Dolphin (Grampus griseus), common dolphin (Delphinus delphis), and killer whale (Orcinus orca). The regular sightings of minke whale in this area provides an excellent opportunity for the behavioural and ecological study of this species, the behaviour of which is virtually unknown in the Eastern North Atlantic. The results of such a study could have important implications for the management of minke whales if commercial hunting were to resume in the eastern North Atlantic.

 

Recording Sightings

 

In 1992 a new computer program called LOGGER was provided by The International Fund for Animal Welfare (IFAW) for the collection of sightings and environmental information during our surveys. Data is collected on board using the laptop computer which is linked to other instruments on the boat. During a trip, LOGGER is constantly collecting data, recording our survey route and environmental data such as water temperature, depth and wind conditions. Other information such as weather, sea conditions, number of passengers etc. is fed in manually. When whales and dolphins are encountered the species, number and behaviour is recorded. A comprehensive update on our sightings can be read here. This project has resulted in a database of over 5000 sightings and supporting environmental information. This data is then analysed to investigate how the whales and dolphins are distributed throughout the survey area and to highlight important areas for feeding and breeding. Constant monitoring of our survey area is essential for conservation. It provides information required for protecting animals and habitats against harmful activities such as pollution.

 

The laptop computers have been donated by The International Fund for Animal Welfare and Aberdeen Computer Services.

 

Minke Whale Photo-Identification

 

In collaboration with the Hebridean Whale and Dolphin Trust, Sea Life Surveys have been conducting a photo-identification study of minke whales since 1990. Over 60 whales have been identified and catalogued, many having been seen year after year.

 

Photo-identification is a technique used to recognise individual whales and dolphins. Every whale and dolphin encountered is photographed and these photographs are analysed for identifying features such as notches and scars on the dorsal fins or bodies of the animals.

 

Minke whales migrate to warmer waters in the winter months but return to the coastal waters of West Scotland every summer to feed on the plentiful fish. The results of this study have shown that many whales return specifically to the coastal waters of Mull each year and appear to be seasonally resident in the area. This highlights the importance of this area for the minke whale.

 

This project is also gathering evidence that suggests that marine litter is a real cause of concern for our local whales. Nine of the catalogued whales have encountered marine litter. Two of the whales have plastic strapping wrapped around their rostrums. The looped plastic straps have become trapped in the baleen plates of the whales and are cutting into the flesh on the rostrums. This could affect feeding behaviour since the baleen plates are used to sieve prey from the water.

 

Globally, an estimated one million birds and 100,000 marine mammals and sea turtles die each year from entanglement in, or ingestion of plastics. Plastics pose a particular threat to the marine environment because they float on the surface of the sea or within the water column. Plastics can be transported for miles across the sea and will remain in the marine environment for many years.

 

Minke Whale Surfacing Behaviour

 

One of the few behaviours that can be collected quantitatively in the field are surfacing rates. Whales and dolphins breathe air and so must come to the surface regularly. The rate at which they surface represents their respiration rate which depends on their levels of activity. Surfacing patterns give us clues as to what the whale is doing - travelling, resting or feeding. Measuring surfacing rates could be particularly useful in assessing whether or not whales are being disturbed. Data on surfacing patterns is also essential for correctly interpreting many types of visual surveys such as those conducted by the International Whaling Commission to estimate minke whale populations. Precise recordings of surfacing rates have been collected from individual minke whales off Mull since 1989 by Sea Life Surveys.

 

Harbour Porpoise Research

 

The harbour porpoise, one of our most frequently encountered species, is particularly susceptible to entanglement in fishing nets both around the UK coastline and worldwide. Increasing concern over this problem has led to the development of pingers (Acoustic Alarms), which make nets more 'visible' to porpoises. For the past two years we have been assisting with research into the effects of these pingers on porpoise behaviour and monitoring porpoise distribution using porpoise click detectors (PODs).

 

Acoustic Work

 

Sea Life Surveys has been studying whale and dolphin acoustics for a number of years. By making underwater recordings, we aim to look at the acoustic behaviour of cetaceans and investigate the level of noise pollution in the area. The recordings are made using underwater microphone called hydrophones. Sounds that have been successfully recorded include those of Risso's dolphins, common dolphins and killer whales which were highly vocal when encountered. Minke whales have proved more difficult to document, with only two recordings of minke whales having been made which capture very prominent repetitive sounds. The vocal repertoire of minke whales is virtually unknown and so we will continue to attempt more recordings of this species.

 

Reports and Publications

 

Spatial and temporal distribution of the minke whale (Balaenoptera acutorostrata) in relation to undersea topography and seabed sediment off the Isle of Mull, Scotland. Macleod, K., Fairbairns, R.S., Gill, A., Fairbairns, B.R., Gordon, J., Blair-Myers, C. (2001). Paper SC/53/E10 presented to the IWC Scientific meeting 2001.

 

Effects of the diel and seasonal cycles on the dive duration of the minke whale (Balaenoptera acutorostrata). Stockin, K., Fairbairns R.S, Parsons, E.C.M., Sims, D. J. Mar. Biol. Ass. U.K. (2001), 81, 189-190.

 

Photographic and strandings data highlighting the problem of marine debris and creel rope entanglement to minke whales (Balaenoptera acutorostrata) and other marine life in Scottish waters. Gill, A., Reid, R.J. and Fairbairns, B.R. 2000. European Research on Cetaceans 14 (ed. P.G.H. Evans, R. Pitt-Aiken & E. Rogan), pp. 173-178. Cork: European Cetacean Society.

 

Some observations of the minke whale (Balaenoptera acutorostrata) feeding behaviour and associations with seabirds in the coastal waters of the Isle of Mull, Scotland. Gill, A., Fairbairns, B.R. and Fairbairns, R.S. 2000. European Research on Cetaceans 13 (ed. P.G.H. Evans, J. Cruz & J.A. Raga), pp. 61-64. Valencia: European Cetacean Society.

 

Photo-Identification of the Minke whale Balaenoptera acutorostrata off the Isle of Mull, Scotland. An update. Gill, A. (2000). Report to the Hebridean Whale and Dolphin Trust.

 

The use of geographical information systems to investigate the spatial and temporal relationships between minke whales (Balaenoptera acutorostrata) distribution and seabed topography/sediment type off the Isle of Mull, Scotland. Bowe, S. 1997. M.Sc. Thesis. Department of Zoology, Aberdeen University. 75pp.

 

Assessment of relative abundance and distribution of the minke whale (Balaenoptera acutorostrata) using data collected from a whale watching operation. Fairbairns, R., Gordon, J., Hiby, A., Leaper, R., Lovell, P. and Papastavrou, V. 1997. European Research on Cetaceans 10 (ed. P.G.H. Evans), pp. 154-158. Kiel: European Cetacean Society.

 

Investigating the feasibility of a long-term ecological study of the minke whale (Balaenoptera acutorostrata) on the west coast of Scotland. Gill, A. 1997. Hebridean Whale and Dolphin Trust, Mull. 43pp.

 

Analysis of data collected from a whale-watching operation to assess relative abundance and distribution of the minke whale (Balaenoptera acutorostrata) around the Isle of Mull, Scotland. Leaper, R., Fairbairns, R., Gordon, J., Hiby, A., Lovell, P. and Papastavrou, V. 1997. Reports of the International Whaling Commission 47: 505-511

 

Respiration rates of minke whales (Balaenoptera acutorostrata) on the west coast of Scotland. Leeming, G. 1997. Undergraduate Thesis. Royal Veterinary College, London. 61pp.

 

Photo-Identification of the Minke whale Balaenoptera acutorostrata off the Isle of Mull, Scotland. Gill, A. and Fairbairns, R. 1995. In Whales, Seals, Fish and Man (ed. A.S. Blix, L.Walloe and O. Ulltand), pp. 129-132. Elsevier Science, Netherlands.

 

Range tracking of the minke whale Balaenoptera acutorostrata, off the Isle of Mull 1994. Fairbairns, R., Gill, A. and Sargent, T. 1994. Report to the Hebridean Whale and Dolphin Trust. 52pp.