TURSIOPS TRUNCATUS)IN Dolphin and Wildlife Foundation, Merchants Quay, TRALEE BAY and BRANDON BAY, CO
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Stephanie Levesque (corresponding PHOTO-IDENTIFICATION OF BOTTLENOSE author: salevesq@ gmail.com), Shannon DOLPHINS (TURSIOPS TRUNCATUS)IN Dolphin and Wildlife Foundation, Merchants Quay, TRALEE BAY AND BRANDON BAY, CO. Kilrush, Co. Clare, Ireland; Irish Whale KERRY: A CASE FOR SAC BOUNDARY and Dolphin Group, Merchants Quay, EXTENSION Kilrush, Co. Clare, Ireland; Katharina Reusch, Shannon Stephanie Levesque, Katharina Reusch, Isabel Baker, Dolphin and Wildlife Foundation, Joanne O’Brien and Simon Berrow Merchants Quay, Kilrush, Co. Clare, Ireland; Isabel Baker, Joanne O’Brien, and ABSTRACT Simon Berrow, Shannon Dolphin The Lower River Shannon is a Special Area of Conservation (SAC) with bottlenose dolphins (Tursiops and Wildlife Founda- truncatus) as a qualifying interest, and is one of only two SACs for this species in Ireland. Bottlenose tion, Merchants dolphins in the Shannon Estuary are present year-round and genetically discrete from other populations Quay, Kilrush, Co. in Ireland. They have regularly been reported from Tralee Bay and Brandon Bay, Co. Kerry, adjacent Clare, Ireland; Irish to the Lower River Shannon SAC boundary. In order to determine the provenance of these dolphins, Whale and Dolphin photo-identification data collected between 2008 and 2016 from both bays were used to identify Group, Merchants Quay, Kilrush, Co. individuals and match them to existing bottlenose dolphin catalogues in Ireland. Bottlenose dolphins Clare, Ireland; were observed on over 90% of the 13 trips carried out, with photo-identification data collected on 11 of Marine and Fresh- these trips. A total of 70 individual dolphins were identified, of which 67 have been regularly recorded water Research within the Lower River Shannon SAC, confirming them to be from this population. Shannon dolphins Centre, Galway- represented an average of 98% of dolphins photographed during each survey. Of the estimated 108 Mayo Institute of individual adult dolphins extant in the Shannon population, 62% were identified in Brandon Bay and/ Technology, Dublin or Tralee Bay during the study period. A discovery curve of individuals identified did not reach a Road, Co. Galway, plateau, suggesting that not all dolphins occurring in these bays were photographed during the study. Ireland. Results suggest that these areas are of high importance to the Shannon dolphin population and support the need to extend the current boundary of the Lower River Shannon SAC to include Brandon Bay Cite as follows: Levesque, S., Reusch, and Tralee Bay. K., Baker, I., O’Brien, J. and Berrow, S. INTRODUCTION includes bottlenose dolphins as a qualifying interest, 2016 Photo-Identifi- particularly the Shannon Estuary’s resident popula- cation of Bottlenose Bottlenose dolphins (Tursiops truncatus) are wide- tion. The West Connacht Coast SAC (Site Code Dolphins (Tursiops spread in Irish coastal waters and are particularly 002998) was designated in 2013 solely for bottlenose truncatus) in Tralee dolphins and covers an area from North Mayo to Bay and Brandon abundant along the western seaboard (Berrow et al., Bay, Co. Kerry: 2010). Three genetically discrete populations have West Galway. A Case for SAC recently been described in Ireland; one resident in SACs, which incorporate marine habitats or Boundary Extension. the Shannon Estuary, one inshore or coastal popula- species, can be considered as Marine Protected Areas Biology and tion and one offshore population (Mirimin et al., (MPAs). The International Union for Conservation Environment: 2011; Louis et al., 2014). The coastal population is of Nature (IUCN) defines an MPA as ‘a clearly Proceedings of highly mobile with resightings of the same indivi- defined geographical space, recognised, dedicated the Royal Irish Academy 2016. DOI: duals reported all around the Irish coast, including and managed, through legal or other effective means, http://dx.doi.org/ Northern Ireland (O’Brien et al., 2009), with some to achieve the long-term conservation of nature with 10.3318/BIOE.2016. individuals also reported from Scotland and England associated ecosystem services and cultural values’ 11 (Ryan et al., 2010; Robinson et al., 2012). (IUCN, 2012). In order for the MPA to be an effec- European member states under the European tive conservation tool, its boundaries must reflect the Union Habitats Directive are required to designate biological needs of the focal species (Wilson et al., Received 5 May 2016. Accepted 19 October Special Areas of Conservation (SACs) for bottlenose 2004). Managers must have a thorough knowledge 2016. dolphins to protect a representative range of habitats of a population’s entire distribution in order to allow Published 29 November used by this species. The Lower River Shannon SAC for the development of successful management and 2016. (Site Code 002165) was designated in 2000 and monitoring programmes (Hastie et al., 2003). DOI: http://dx.doi.org.10.3318/BIOE.2016.11 BIOLOGY AND ENVIRONMENT: PROCEEDINGS OF THE ROYAL IRISH ACADEMY, VOL. 116,NO. 1, 1Á10 (2016). # ROYAL IRISH ACADEMY 1 BIOLOGY AND ENVIRONMENT Monitoring programmes may assist in identify- impact on the bottlenose dolphin population (SIFP, ing distribution patterns and thus provide vital 2013). information to support and advise management Current evidence suggests that the population of decisions (Hastie et al., 2003). Furthermore, they bottlenose dolphins in the Shannon Estuary is may aid in the identification of critically important restricted to the estuary and genetically discrete habitats, which consist of ‘functioning ecological from the inshore population (Mirimin et al., 2011). units required for successful breeding and foraging’ These Shannon dolphins have rarely been recorded (Harwood, 2001) whose existence are vital for the outside of the estuary with the furthest report coming species to persist (Jax et al., 1998). In addition to key from Sauce Creek, Co. Kerry, c. 30km to the west of feeding and breeding sites, critical habitats also Kerry Head (Fig. 1) (Montagu, 1821). There are include important migration corridors and should regular reports of bottlenose dolphins to the north of be prioritised when considering the placement of the Shannon Estuary from Kilkee Bay, Doonbeg Bay MPAs (Hooker and Gerber, 2004). In more recent years, conservation efforts regarding marine species and Lahinch Bay, Co. Clare and to the south from have begun to focus more on the protection of these Tralee Bay and Brandon Bay, Co. Kerry (Fig. 1) areas (Agardy, 1994). (Berrow et al., 2010) although it is not known if these are Shannon dolphins or members of the inshore MPAs must be large enough to provide suitable population. It is essential to determine which protection for the species, yet small enough to allow population they are from and the range of the for effective management of anthropogenic activities within their borders (Ashe et al., 2010). Potential Shannon population outside the SAC boundary, threats to the species within the area must be which extends between Loop Head and Kerry Head evaluated in the initial stages of MPA development, (Fig. 1). and regulations established for how these threats will Although it is generally considered that bot- be managed (Hooker and Gerber, 2004). The tlenose dolphins in Tralee Bay and Brandon Bay in management of the Lower River Shannon SAC North Kerry are most likely from the Shannon has been successful in modifying human behaviour population, there have been no studies to validate this through requiring consent for any activity occurring hypothesis or to establish their occurrence and use of within its boundaries which may have a negative the bays. The present study used photo-identification Fig. 1 Bottlenose dolphins are seen regularly from Doonbeg Bay, Kilkee Bay and Lahinch Bay, although no studies have been done* to discern which population they are from. Some individuals seen in Brandon/Tralee were also observed as far east as Labasheeda Bay; a distance of 100 120km. Study area is shown with group sightings (black points) and survey tracklines. The black line between Loop HeadÁ and Kerry Head represents the boundary of the Lower River Shannon SAC. 2 PHOTO-ID OF BOTTLENOSE DOLPHINS (photo-ID) data to discern if dolphins occurring in calves). Due to the availability of long-term data on Brandon Bay and Tralee Bay are indeed part of the the population, all individuals in the catalogue can be Shannon population. identified when resighted as any changes in appear- Photo-ID is a non-invasive method of mon- ance have been tracked over time*a prime example itoring individuals in a wild population that relies of the value of long-term monitoring. This allows upon the presence of unique markings on the researchers to identify animals that otherwise may be animal (Wu¨rsig and Jefferson, 1990). This techni- considered too poorly marked for re-identification que has been widely used in the study of a range of and result in the loss of data on the population. cetacean species worldwide (Berrow et al., 2012) The aim of this study was to survey Tralee Bay and was first applied to bottlenose dolphins by and Brandon Bay in an attempt to locate and Wu¨rsig and Wu¨rsig (1977). Bottlenose dolphins are photograph bottlenose dolphins in order to deter- a suitable species for photo-ID as they frequently mine if they were from the Shannon population by acquire markings such as nicks and notches, located comparing them to individuals from the SDWF primarily on the dorsal fins, allowing them to be catalogue. In doing so, we hoped to provide evi- identified as unique individuals. This method allows dence that these bays are regularly used by the for individual dolphins to be monitored over time protected Shannon bottlenose dolphin population and can provide useful information regarding life and represent important habitats that should be histories, habitat preferences, distribution, move- included as part of the Lower River Shannon SAC. ments, behaviour and associations (Hammond et al., 1990; Kerr et al., 2005). MATERIALS AND METHODS The Shannon Dolphin and Wildlife Foundation (SDWF) has been collecting images of dolphins in STUDY AREA the Shannon Estuary since 1993 (Berrow et al., 1996).