Population estimation, distribution, and habitat preference of Irrawaddy dolphins Orcaella brevirostris (Owen in Gray, 1866) in the Brunei Bay, Malaysian waters

doi:10.2981/wlb.00383

	Population estimation, distribution, and habitat preference of Irrawaddy dolphins Orcaella brevirostris (Owen in Gray, 1866) in the Brunei Bay, Malaysian waters
	Mahmud, Anisul Islam 1; Jaaman, Saifullah Arifin 2; Muda, Azmi Marzuki 2; Muhamad, Hairul Masrini 3; Zhang, Xuelei 4; Scapini, Felicita 1
刊名	WILDLIFE BIOLOGY
	2018
ISSN号	0909-6396
DOI	10.2981/wlb.00383
英文摘要	The population of Irrawaddy dolphins in Brunei Bay, Malaysia is currently under threat by anthropogenic activities. This study is aimed at contributing information on population size, group composition, spatial occurrence and habitat preferences of this dolphin species in the bay area. A total of 36 individuals (adults) of Irrawaddy dolphins were identified using dorsal fin photo match software (DARWIN) by undertaking 297.91 h of boat-based dedicated surveys (April 2013 October 2015). By using the mark-recapture open-population parameterization, the estimated population size (adult) was 33 (95% CI. 28-39) with the apparent survival rate of 0.98 (0.89-0.99, SE = 0.01). Also, the recapture rate was 0.27 (0.14-0.45, SE = 0.07) and the estimated individual entry rate from super-population was 0.15 (0.10-0.22, SE = 0.03). The estimated entire population size was 41 (95% CI = 36-49) including calves. The observed mean group size was 6 (SE = 0.66, range 1-18). Two hotspots were identified for dolphin occurrences near Lawas and Labuan Island at a sighting rate of 2.8-12.3 km(-2). The dolphins were encountered in the bay over the entire year with no seasonal differences. The observation of dolphin calves in the groups are a positive indicator that the dolphins are breeding successfully in the Bay area and provide hope that the population will remain stable or increase in number. The dolphins showed habitat preferences of sea depths (2 to 9.99 m), surface water temperature (29 to 31.99 degrees C), and coastline distance (1.5 to 4.49 km). This study provides the first detailed information about Irrawaddy dolphins in the Brunei Bay, Malaysia, and may serve as a baseline for future comparisons. It can help researchers, conservationists, local marine park managers and policy makers to propose effective conservation and management plans in the Brunei Bay area.
WOS关键词	CRITICALLY ENDANGERED POPULATION ; EAST KALIMANTAN ; MEKONG RIVER ; CONSERVATION ; ABUNDANCE ; SURVIVAL ; CETACEANS ; PATTERNS ; BEHAVIOR ; SOUNDS
WOS研究方向	Environmental Sciences & Ecology ; Zoology
语种	英语
出版者	WILDLIFE BIOLOGY
WOS记录号	WOS:000444323900001
内容类型	期刊论文
源URL	[http://ir.fio.com.cn:8080/handle/2SI8HI0U/25729]
专题	自然资源部第一海洋研究所
通讯作者	Mahmud, Anisul Islam
作者单位	1.Univ Firenze UNIFI, Dipto Biol, Via Madonna del Piano 6, I-50019 Florence, Italy 2.UMT, Inst Oceanog & Environm INOS, Kuala Terengganu, Malaysia 3.Xiamen Univ, Coll Ocean & Earth, Dept Appl Marine Phys & Engn, Key Lab Underwater Acoust & Marine Informat Techn, Xiamen, Peoples R China 4.State Ocean Adm, Inst Oceanog 1, Qingdao, Peoples R China
推荐引用方式 GB/T 7714	Mahmud, Anisul Islam,Jaaman, Saifullah Arifin,Muda, Azmi Marzuki,et al. Population estimation, distribution, and habitat preference of Irrawaddy dolphins Orcaella brevirostris (Owen in Gray, 1866) in the Brunei Bay, Malaysian waters[J]. WILDLIFE BIOLOGY,2018.
APA	Mahmud, Anisul Islam,Jaaman, Saifullah Arifin,Muda, Azmi Marzuki,Muhamad, Hairul Masrini,Zhang, Xuelei,&Scapini, Felicita.(2018).Population estimation, distribution, and habitat preference of Irrawaddy dolphins Orcaella brevirostris (Owen in Gray, 1866) in the Brunei Bay, Malaysian waters.WILDLIFE BIOLOGY.
MLA	Mahmud, Anisul Islam,et al."Population estimation, distribution, and habitat preference of Irrawaddy dolphins Orcaella brevirostris (Owen in Gray, 1866) in the Brunei Bay, Malaysian waters".WILDLIFE BIOLOGY (2018).