Distribution of small cetaceans in the nearshore waters of Sarawak, East Malaysia

Gianna Minton

doi:10.15468/fcntwp

Distribution of small cetaceans in the nearshore waters of Sarawak, East Malaysia

Citation

Minton, G. 2011. Distribution of small cetaceans in the nearshore waters of Sarawak, East Malaysia. Data downloaded from OBIS-SEAMAP (http://seamap.env.duke.edu/dataset/744) on yyyy-mm-dd. https://doi.org/10.15468/fcntwp accessed via GBIF.org on 2024-12-11.

Description

Original provider: The Sarawak Dolphin Project, Institute of Biodiversity and Environmental Conservation Dataset credits: The Sarawak Dolphin Project, Institute of Biodiversity and Environmental Conservation, Universiti Malaysia Sarawak, 94300 Kota Samarahan, Sarawak Abstract: Between June 2008 and September 2009, 56 days of small boat surveys were conducted off the coast of Sarawak, Malaysia with the aim of recording cetacean distribution. These surveys, which focused on the Miri, Bintulu-Similajau and Kuching regions, comprised 173 hours of survey effort and covered 2851 km of pre-determined systematic tracks. Surveys were clustered into three sets of seasonal snapshots: June-July, September-October and March-April. A total of 115 cetacean sightings were made, of which 65 were on-effort and used in analyses of cetacean encounter rates in relation to habitat characteristics. Species observed included (in order of frequency) Irrawaddy dolphins (Orcaella brevirostris), finless porpoises (Neophocaena phocaenoides), Indo-Pacific bottlenose dolphins (Tursiops aduncus) and Indo-Pacific humpback dolphins (Sousa chinensis). One hundred and ten of 115 sightings were made in less than 10 m water depth, highlighting the importance of nearshore coastal habitats for these species. Despite an apparent overlap in habitat, Irrawaddy dolphins showed a statistically significant affiliation with areas of shallower depth and closer proximity to shore and river mouths than finless porpoises or bottlenose dolphins. This preference for nearshore areas renders the species vulnerable to threats such as fisheries by-catch and habitat degradation from coastal development. Irrawaddy dolphins were more frequently encountered in Kuching, while the highest encounter rate for finless porpoises was in the Bintulu-Similajau region. The highest encounter rates in both Kuching and Similajau occurred in areas that are destined for major coastal developments. Purpose: A series of small boat surveys was conducted in three locations along Sarawak’s coastline with the aims of: 1) assessing more accurately the species composition, distribution and habitat requirements of coastal cetaceans in the region; 2) collecting baseline data on dolphin distribution and habitat use; and 3) facilitating management and conservation efforts. The results of these surveys should enable managers and researchers to identify areas of key importance for future conservation and research efforts and lay the foundation for more detailed and targeted study both within Sarawak and in other parts of the species’ range. Supplemental information: Effort data are available through request from the original data providers.

Purpose

A series of small boat surveys was conducted in three locations along Sarawak’s coastline with the aims of: 1) assessing more accurately the species composition, distribution and habitat requirements of coastal cetaceans in the region; 2) collecting baseline data on dolphin distribution and habitat use; and 3) facilitating management and conservation efforts. The results of these surveys should enable managers and researchers to identify areas of key importance for future conservation and research efforts and lay the foundation for more detailed and targeted study both within Sarawak and in other parts of the species’ range.

Sampling Description

Study Extent

NA

Sampling

NA

Method steps

NA

Additional info

marine, harvested by iOBIS

Taxonomic Coverages

Scientific names are based on the Integrated Taxonomic Information System (ITIS).

Delphinidae
common name: dolphins rank: family
Neophocaena phocaenoides
common name: Finless Porpoise rank: species
Orcaella brevirostris
common name: Irrawaddy Dolphin rank: species
Sousa chinensis
common name: Chinese white dolphin rank: species
Tursiops aduncus
common name: Indian Ocean bottlenose dolphin rank: species

Geographic Coverages

Sarawak,South China Sea,Malaysia

Bibliographic Citations

Contacts

Gianna Minton
originator
position: Primary contact
Sarawak Dolphin Project
email: gianna.minton@gmail.com
homepage: http://www.ibec.unimas.my/SDP2008

OBIS-SEAMAP
metadata author
Marine Geospatial Ecology Lab, Duke University
A328 LSRC building
Durham
27708
NC
US
email: seamap-contact@duke.edu
homepage: http://seamap.env.duke.edu

OBIS-SEAMAP
distributor
Marine Geospatial Ecology Lab, Duke University
A328 LSRC building
Durham
27708
NC
US
email: seamap-contact@duke.edu
homepage: http://seamap.env.duke.edu

Gianna Minton
owner
position: Primary contact
Sarawak Dolphin Project
email: gianna.minton@gmail.com
homepage: http://www.ibec.unimas.my/SDP2008

Gianna Minton
administrative point of contact
position: Primary contact
Sarawak Dolphin Project
email: gianna.minton@gmail.com
homepage: http://www.ibec.unimas.my/SDP2008