The Distribution Of Aquatic Mammals In The Waters Of Penang Island, Malaysia, With A Focus On The Ecology And Conservation Of The Irrawaddy Dolphin Orcaella Brevirostris (Owen In Grey, 1866)
| dc.contributor.author | Rodríguez Vargas, Luz Helena | |
| dc.date.accessioned | 2016-09-27T04:06:07Z | |
| dc.date.available | 2016-09-27T04:06:07Z | |
| dc.date.issued | 2015-10 | |
| dc.description.abstract | The current status of aquatic mammals in Penang Island, Malaysia, has largely been undocumented. Threats such as coastal development, tourism, fishing, and boating activities are increasing. Additionally, there is evidence of unregulated dolphin watching and incidental catches of cetaceans in fishing gears, which could be affecting the local populations of these animals. This research aimed to obtain information on the species of aquatic mammals, their distribution, frequency of occurrence, group size, strandings, and interactions with boats, with a focus on the ecology and behaviour of the Irrawaddy dolphins (Orcaella brevirostris) in Penang. An aquatic mammal community-based monitoring programme was carried out in north and west Penang, by conducting interview surveys every three months, from December 2012 to December 2013. Using an artisanal fishing boat, photo-identification, and behavioural studies of Irrawaddy dolphins were conducted from January to November 2013 in west Penang. Five species of aquatic mammals were confirmed in the island, namely the Indo-Pacific Humpback dolphin (Sousa chinensis), the Irrawaddy dolphin, the Finless porpoise (Neophocaena phocaenoides), the Indo-Pacific Bottlenose dolphin (Tursiops aduncus), and the Smooth-coated otter (Lutrogale perspicillata). The Humpback and the Irrawaddy dolphins were sighted more frequently in northwest and west Penang, respectively. Based on the monitoring programme and personal observations, entanglement in fishing nets was identified as a threat to all the species, but Humpback dolphins are more prone to collisions with boats. Using mark-recapture analysis, the estimated resident population of Irrawaddy dolphins in west Penang was between 32 and 51 individuals. The mean group size was 5 ± 0.5 (SE), and most of the groups were found closer to shore during high tide throughout the period of the study. Sixteen mother-calf associations were observed. Most of the sightings of this species were recorded between Sungai Pinang and Sungai Burung rivers mouth no farther than 3 km from shore in shallow waters (<6 m depth). Based on the statistical analysis, the environmental parameters such as sea surface temperature, salinity, turbidity, depth and tide were not correlated with the presence of the dolphins. Feeding was the most common behaviour, and a specific pattern in which the animals swim creating loops within the same spot was observed several times during this activity. As a result, some conservation actions recommended to protect these threatened species endemic to the region are: the continuation of the monitoring programme, the creation of an action plan for aquatic mammals, and the implementation of co-managed marine protected areas. | en_US |
| dc.identifier.uri | http://hdl.handle.net/123456789/2609 | |
| dc.language.iso | en | en_US |
| dc.publisher | Universiti Sains Malaysia | en_US |
| dc.subject | Aquatic mammals in Penang Island | en_US |
| dc.title | The Distribution Of Aquatic Mammals In The Waters Of Penang Island, Malaysia, With A Focus On The Ecology And Conservation Of The Irrawaddy Dolphin Orcaella Brevirostris (Owen In Grey, 1866) | en_US |
| dc.type | Thesis | en_US |
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