https://vital.seals.ac.za/vital/access/manager/Index ${session.getAttribute("locale")} 5 https://vital.seals.ac.za/vital/access/manager/Repository/vital:3093 Wed 12 May 2021 19:08:01 SAST ]]> https://vital.seals.ac.za/vital/access/manager/Repository/vital:31382 Wed 12 May 2021 18:52:00 SAST ]]> https://vital.seals.ac.za/vital/access/manager/Repository/vital:2237 Wed 12 May 2021 18:33:18 SAST ]]> https://vital.seals.ac.za/vital/access/manager/Repository/vital:31213 Thu 29 Sep 2022 14:24:30 SAST ]]> https://vital.seals.ac.za/vital/access/manager/Repository/vital:73556 Thu 20 Jun 2024 14:52:27 SAST ]]> https://vital.seals.ac.za/vital/access/manager/Repository/vital:3167 Thu 13 May 2021 08:18:01 SAST ]]> https://vital.seals.ac.za/vital/access/manager/Repository/vital:38512 Thu 13 May 2021 08:11:03 SAST ]]> https://vital.seals.ac.za/vital/access/manager/Repository/vital:698 Thu 13 May 2021 06:20:58 SAST ]]> https://vital.seals.ac.za/vital/access/manager/Repository/vital:28752 Thu 13 May 2021 05:59:30 SAST ]]> https://vital.seals.ac.za/vital/access/manager/Repository/vital:28354 Thu 13 May 2021 04:49:59 SAST ]]> https://vital.seals.ac.za/vital/access/manager/Repository/vital:8628 Thu 13 May 2021 04:49:56 SAST ]]> https://vital.seals.ac.za/vital/access/manager/Repository/vital:28035 Thu 13 May 2021 04:13:28 SAST ]]> https://vital.seals.ac.za/vital/access/manager/Repository/vital:34197 70% of total counts) of sightings were made inside the MPAs. Short-term boat-based surveys were conducted three times a year between June 2014 and December 2016, contributing to a total of 47 days of surveys divided into three locations: Amathole, Hluleka, and Pondoland, each containing a MPA. Density and group size data were analyzed for both species and photographic identification analysis was performed for photographs of bottlenose dolphin dorsal fins. Results indicate that animal and sighting density did not differ temporally (bottlenose dolphin: sighting density – p=0.398, individual density –p=0.781; common dolphin: sighting density –p=0.472, individual density – p=0.204). Environmental factors (sea surface temperature, depth, substrate, and distance from shore) appeared to have limited effect on individual and sighting density and group size for both species (p>0.05). Photographic identification of bottlenose dolphins resulted in 2149 individuals, with a 11.8% resighting rate, with the highest resighting rate within the Pondoland MPA (16.1%). The resighting count did not differ temporally between monthly survey based on generalized linear models (p=0.866), but did differ between study areas (p<0.0001). These results provide the first evidence of the occurrence of both species of dolphin off the Wild Coast, as they were sighted in this region in all survey months. There was no trend in density based on temporal or environmental factors, which suggests other factors are influencing their occurrence. Resightings of bottlenose dolphins within the area suggest that there is some degree of residency, though the majority of animals were only sighted on a single occasion and there was no plateau in the discovery curve. A total of 256 biopsy samples (bottlenose dolphins =128; common dolphins=128) were collected during boat-based surveys. Bottlenose dolphin samples were also collected from adjacent areas to the southwest (Algoa Bay, n=22) and northeast (KwaZulu-Natal (KZN), n=20) of the Wild Coast to investigate similarities and differences between these areas. Despite a high degree of niche overlap between the two species (41%), common dolphins fed with a broader niche (standard ellipse area probability 0.89) than bottlenose dolphins in the summer and a narrower niche in the winter (probability 0.94). There was a clear spatial variation in the diet of bottlenose dolphins along the coast, with individuals from Algoa Bay and Amathole demonstrating 0% niche overlap with individuals from KZN, but the mechanism for these differences remains unclear as other species from South African waters demonstrate a strong southwest to northeast gradient in nitrogen for the Eastern Cape coastline. This research provides valuable baseline information regarding dolphins off the Wild Coast of South Africa, which remained largely unknown. My results indicate that bottlenose dolphins may be more resident in the Wild Coast than previous predicted, and confirm that common dolphins are highly mobile in this area.]]> Thu 13 May 2021 03:09:09 SAST ]]> https://vital.seals.ac.za/vital/access/manager/Repository/vital:28417 Mon 22 May 2023 15:47:55 SAST ]]>