There are a number of potential issues affecting the populations of cetaceans living in or using UK waters. Without knowing the distribution and abundance of these animals the ability to assess how any of these issues could be affecting UK cetaceans are limited.
The area of sea, or range, specifically used by each cetacean species is an important factor when looking at issues such as Marine Renewable developments. If a development site falls within the natural range of a cetacean species, that species may be likely to be present and therefore collection of baseline data is of vital importance. However, the definition of a natural range, and whether a particular species is likely to be present at a particular site, is not straightforward as cetaceans may only be present at a site seasonally or sporadically because of their wide ranging movements.
There are a wide variety of techniques developed to explore the issue of animal range but not all of these may be suitable for cetaceans, and for some there are not adequate data. Further research will be necessary to ascertain whether there is enough existing cetacean sightings data to explore the utility of some of the measures that have been devised, and therefore to find a model that best serves the need to define the ‘natural range’ of these animals both within the context of the Habitats Directive and any other legislative obligations.