Risso’s dolphins in North Wales, UK

Risso's leap
Risso's leap
This project seeks to establish population size, distribution and habitat use, as well as the behavioural characteristics of Risso’s dolphins and other cetacean species of principal importance under the Natural Environment and Rural Communities Act 2006 (NERC Act), around the Llyn Peninsula in North Wales using land- and boat-based survey methodologies.

Risso’s dolphins are a section 42 species of principal importance in Wales under the NERC Act 2006. However, they remain poorly known. Lack of data hampers the development of effective conservation management strategies for them and other cetaceans in Wales, and also makes an assessment on whether or not their conservation status can be seen as ‘favourable’, as laid out under the Habitats Directive, impossible.

In order to monitor the status of the ‘Pen Llŷn a’r Sarnau’ Special Area of Conservation (SAC) in the northern part of Cardigan Bay, and to inform management decisions, the Bardsey Island Cetacean Survey by WDC has focused on the distribution of dolphins and porpoises in this area since 1999. The surveys have indicated that the waters around Bardsey Island encompass a number of important habitats for small cetaceans, most notably harbour porpoises (Phocoena phocoena), Risso’s dolphins (Grampus griseus) and common bottlenose dolphins (Tursiops truncatus).

Risso's encounter

Fine-scale monitoring of small inshore cetacean populations in these UK coastal waters is necessary to conserve ecologically important sites for animals that exclusively use particular habitats. The results of this work are therefore be central to the development and subsequent implementation of local management policies/conservation initiatives for the protection of these and other coastal cetacean species in the UK.

The aim of the survey is to generate baseline data on the abundance and distribution of small cetaceans around Bardsey Island.  

The objectives of the project are to:

  1. Characterise temporal and spatial habitat use by small cetaceans;
  2. Study the presence and distribution in particular of mother-calf pairs of dolphins and porpoises;
  3. Investigate the site fidelity of individual Risso’s dolphins;
  4. Examine the relationships within Risso’s dolphin schools by monitoring individual dolphins;
  5. Examine the relationship between Risso’s dolphins seen in these waters and those in adjacent waters;
  6. Monitor boat traffic and interactions between cetaceans and different types of boats.
Relevant publications:

De Boer, M. 2009. Risso’s dolphins off Bardsey Island. WDCS Science Report. 4pp.

Eisfeld, S., Simmonds, M. 2011. Bardsey Island Cetacean survey 2011. In: Bardsey Island Bird Observatory Reports. (Steve Stansfield, ed.).

Hoyt, 2011. Marine Protected Areas for Whales, Dolphins and Porpoises: A world handbook for cetacean habitat conservation and planning. Second Edition. Earthscan: London and New York.

WDCS. 2002. Bardsey Island Cetacean Survey 2002. A WDCS report. 30pp.

WDCS. 2003. Bardsey Island Cetacean Survey 2003. A WDCS report. 46pp.

WDCS. 2004. Bardsey Island Cetacean Survey 2004. A WDCS report. 77pp.

WDCS. 2005. Bardsey Island Cetacean Survey 2005. A WDCS report. 70pp.

WDCS. 2006. Bardsey Island Cetacean Survey 2006. A WDCS report. 27pp.

WDCS 2012. Welsh whales and dolphins – A field guide to the most commonly seen cetacean species in Welsh waters. WDCS dual-language laminate. 

Wharam, J. and Simmonds, M. 2008. Risso’s Dolphin Conservation Plan for waters west of the UK. WDCS Science Team Report.