Atypical residency of short-beaked common dolphins (Delphinus delphis) to a shallow, urbanized embayment in south-eastern Australia
نویسندگان
چکیده
Short-beaked common dolphins (Delphinus delphis) are typically considered highly mobile, offshore delphinids. This study assessed the residency of a small community of short-beaked common dolphins in the shallow, urbanized Port Phillip Bay, south-eastern Australia. The ability to identify common dolphins by their dorsal fin markings and coloration using photo-identification was also investigated. Systematic and non-systematic boat surveys were undertaken between 2007 and 2014. Results showed that 13 adult common dolphins and their offspring inhabit Port Phillip Bay, of which 10 adults exhibit residency to the bay. The majority of these adults are reproductively active females, suggesting that female philopatry may occur in the community. Systematic surveys conducted between 2012 and 2014 revealed that the dolphins were found in a median water depth of 16 m and median distance of 2.2 km from the coast. The shallow, urbanized habitat of this resident common dolphin community is atypical for this species. As a result, these common dolphins face threats usually associated with inshore bottlenose dolphin communities. We suggest that the Port Phillip Bay common dolphin community is considered and managed separate to those outside the embayment and offshore to ensure the community's long-term viability and residency in the bay.
منابع مشابه
Mixed-species associations of striped dolphins (Stenella coeruleoalba), short-beaked common dolphins (Delphinus delphis), and Risso’s dolphins (Grampus griseus) in the Gulf of Corinth (Greece, Mediterranean Sea)
Surveys to assess cetacean presence were conducted in July 1995 and 1997 in the Gulf of Corinth, which is an almost-enclosed sea in Greece, Eastern Mediterranean. The dolphin sighting frequencies were high (0.043 sightings/km). Four dolphin species were encountered: striped dolphins (Stenella coeruleoalba), short-beaked common dolphins (Delphinus delphis), Risso’s dolphins (Grampus griseus) and...
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based on shipboard surveys off California, Oregon and Washington, 1991-96 (see Appendix 2, Figures 3-5, for data sources and information on timing and location of survey effort). No Delphinus sightings have been made off Oregon and Washington. Dashed line represents the U.S. EEZ, thick line indicates the outer boundary of all surveys combined. Revised 12/15/2000 SHORT-BEAKED COMMON DOLPHIN (Del...
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