Risso’s Dolphin Grampus griseus is a large animal, with adults measuring 2.6-3.8 metres in length with a prominent dorsal fin, a blunt head and frequently extensive scarring on the body, predominantly caused by other Risso’s Dolphins (Carwardine, 1995). This is another species that could well be responsible for reports of Orca Orcinus orca in our region; a large animal with a prominent dorsal fin and often richly patterned flanks seems a very realistic identification mistake, especially as Risso’s Dolphin is a species that is unknown to the majority of visitors to the coast.
This is primarily a warm-water pelagic species and the JNCC Atlas (Reid et al, 2003) unsurprisingly shows that Risso’s Dolphins were rare off northeast England and in the wider central North Sea over the period 1990-2002. The subsequent pattern of occurrence in the North East’s waters described below was interpreted by the media as yet more evidence of global warming causing increasing sea surface temperatures and leading to the loss of our “native” cold water species such as White-beaked Dolphin Lagenorhynchus albirostris, and seeing them replaced with species from warmer climes.
There were six sightings of 20 animals between 2003 and 2009 recorded in the North East Cetacean Project’s (NECP) casual sightings dataset for Northumberland, including a group of four around the Farne Islands in September 2006. Risso’s Dolphins were also recorded around the Farne Islands in late September 2007, when two adults and a calf were seen in a mixed pod with White-beaked Dolphins, and again in late September 2009 when three animals were seen. There was a further sighting around the Farne Islands in July 2011. Land-based sightings have included one off Cullercoats in June 2007, three off Blyth in October 2007 and six in Alnmouth Bay in May 2008. There have also been several sightings from Whitburn, in June, August and September 2007, June and July 2009 and August 2010. A male was recorded as a tideline corpse in Cullercoats Bay in June 2007.
Given that the first observed record for the English east coast was of four animals breaching near the Crumstone (Farne Islands) as recently as 1996 (Foster-Smith, 2000), the recent run of sightings clearly suggest that this species is increasing in the North East’s waters. Furthermore, a survey of local skippers undertaken by Newcastle University (Stockill, 2006) indicated that Risso’s Dolphins accounted for 12% of cetacean sightings by fishermen in 2004. It seems likely that this recent addition to our marine megafauna is a regular, if scarce, visitor to the waters of the North East during the months from May to October, although particularly from June to September. Whitburn and the Farne Islands seem to be good locations to search for this spectacular animal.
Written by Martin Kitching (last updated Nov 12)