Long-term trends in the use of a protected area by small cetaceans in relation to changes in population status

  • Published source details Cheney B., Corkrey R., Durban J.W., Grellier K., Hammond P.S., Islas-Villanueva V., Janik V.M., Lusseau S.M., Parsons K.M., Quick N.J., Wilson B. & Thompson B.M. (2014) Long-term trends in the use of a protected area by small cetaceans in relation to changes in population status. Biological Conservation, 2, 118-128.


This study is summarised as evidence for the following.

Action Category

Legally protect habitat for marine and freshwater mammals

Action Link
Marine and Freshwater Mammal Conservation
  1. Legally protect habitat for marine and freshwater mammals

    A before-and-after study in 1990–2010 in an inlet of the North Sea, Scotland, UK (Cheney et al. 2014) reported that after the area was protected, the resident population of bottlenose dolphins Tursiops truncatus was estimated to be of a similar size to before protection. The total bottlenose dolphin population was estimated to be 102–157 individuals/year during the 15 years before the area was protected, and 143–178 individuals/year during the six years after, although the difference was not tested for statistical significance. Overall, the population was estimated to be stable or increasing over the entire 21-year period. In 2005, part of the bottlenose dolphin population’s range was designated as a protected area. In May–September 1990–2010, the area was surveyed during 10–39 boat surveys/year along fixed (1990–2000) or flexible routes (2001–2010). All dolphins encountered were recorded and photographs were taken of the left and right side of their dorsal fins. Annual abundance and population trends were estimated using sightings of distinctive individuals (26–92 individuals/year) and mark-recapture models.

    (Summarised by: Anna Berthinussen)

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