English - Caribbean Environment Programme

West ScotlandNumerous studies over a long time period have noted high relative abundance of white-beakeddolphins for the northern Hebrides, particularly the northern Minch 345 . There are fewer dataavailable for the winter months but it appears that white-beaked dolphins use this area throughoutthe year. The waters north of here, extending east to Orkney, along with the western Sea of theHebrides, also have reportedly high relative abundance of white-beaked dolphins although thereare fewer data available 346 . Studies in The Minch have reported calves to be present in 60% ofgroups in the summer months 347 , indicating the area provides calving and nursing habitat forwhite-beaked dolphins.Based on the reports of some sightings surveys, and on strandings records, it has been suggestedthat there has been a decrease in abundance of white-beaked dolphins for the west coast ofScotland 348 . A decrease has not been conclusively proven yet, and some recent surveys havecontinued to record high encounter rates and abundance for white-beaked dolphins in this area 349 .This suspected decrease has coincided with an apparent increase in recent years of commondolphin sightings in the region. Common dolphins are typically a warmer water species, andthese observations have led to the suggestion that these may be changes linked to risingsea temperatures 350 .Studies looking at the pattern of white-beaked dolphin strandings for the whole of the UK suggestchanges may be occurring over a wider area than the west of Scotland, with an apparent northwardshift in the location of strandings 351 . Decreases in the number of reported strandings have beennoted for all regions except the north east of Scotland 352 .Longer-term monitoring of distribution and abundance will be needed to confirm the statusof white-beaked dolphins and to determine the nature of any possible shifts in distribution.East ScotlandA seasonal inshore movement of white-beaked dolphins has been suggested for the summermonths 353 . There appears to be evidence of this for the east coast 354 , and particularly offAberdeenshire 355 where studies have shown strong seasonality with peaks in the summer months.Recorded white-beaked dolphin strandings also peak during the summer months 356 suggesting aninshore movement of animals at this time of year. More in-depth analysis of strandings data suggeststhat females move into inshore waters first, to be followed later by males 357 . This earlier peak infemale strandings coincides with a peak in calf strandings and this has led to the suggestion thatfemales make this movement to inshore waters to give birth 358 . The later increase in strandings ofmale white-beaked dolphins may signify their arrival into the area in order to breed with femalesthat have calved 359 .Sightings records of calves in UK waters support this timing, with studies reporting their presenceonly in the summer months 360 . As with most cetacean species, data on calf presence are generallyscarce and hindered by difficulties in sighting them. However, a study in Aberdeenshire coastalwaters reported calves to be present in 32% of groups in the summer months 361 . This furtherindicates that this area provides calving and nursing habitat for white-beaked dolphins.The observed summer peaks in sighting frequencies and possible inshore movement could also berelated to changes in prey distribution and abundance. White-beaked dolphins take a wide varietyof fish but cod, haddock, whiting and hake have been found to be the predominant species in thestomachs of stranded animals 362 . The North Sea provides habitat including spawning grounds formany of these fish species 363 and their distribution and abundance will in turn affect that ofwhite-beaked dolphins. Anecdotal evidence has been put forward suggesting white-beakeddolphins follow mackerel or herring into inshore waters 364 but so far, no particular movements orconcentrations of favoured prey species have been correlated with the observed distribution andincreased sighting frequencies of white-beaked dolphins 365 .46345Reid et al, 2003; Northridge et al, 1995; Evans et al, 2003; MacLeod, 2001; Pollock et al, 2000; Weir et al, 2009;Shrimpton and Parsons, 2000; Gill et al, 1997; Boran et al, 1999346Reid et al, 2003; Northridge et al, 1995; Evans et al, 2003; MacLeod, 2001; Pollock et al, 2000; Shrimpton andParsons, 2000; Boran et al, 1999347Weir, 2008348MacLeod et al, 2005; Evans, 1992349Weir, 2008; SCANS II, 2006350MacLeod et al, 2005; Weir et al, 2009351Canning et al, 2008; Jepson, 2006 (in JNCC, 2007)352Canning et al, 2008353Evans, 1992354Reid et al, 2003355Canning et al, 2008; Weir et al, 2007; Evans et al, 2008356Canning et al, 2008357Ibid358Ibid359Ibid360MacLeod, 2001; Weir et al, 2007; Pollock et al, 2000; Canning et al, 2008361Weir et al, 2007362Reid et al, 2003; Canning et al, 2008363CEFAS, 2001364Weir et al, 2007; Canning et al, 2008; Evans, 1980365Canning et al, 2008