Boat Effects on the Behaviour of Indo-Pacific Humpback (Sousa chinensis) and Irrawaddy Dolphins (Orcaella brevirostris) in Cowie Bay, Sabah, Malaysia

A series of boat surveys were conducted from April to September 2008. This work evaluated the effects of boats on Indo-Pacific Humpback and Irrawaddy dolphins. The types of boats, dolphins’ interactions towards various types of boat and vessel-dolphin distance under different intensities were measur...

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Main Authors:	Nur Azeyanti Nor Hashim, Saifullah A. Jaaman
Format:	Article
Language:	English
Published:	Universiti Kebangsaan Malaysia 2011
Online Access:	http://journalarticle.ukm.my/3139/ http://journalarticle.ukm.my/3139/ http://journalarticle.ukm.my/3139/1/08_Nur_Azeyanti.pdf

id	ukm-3139
recordtype	eprints
spelling	ukm-31392016-12-14T06:33:43Z http://journalarticle.ukm.my/3139/ Boat Effects on the Behaviour of Indo-Pacific Humpback (Sousa chinensis) and Irrawaddy Dolphins (Orcaella brevirostris) in Cowie Bay, Sabah, Malaysia Nur Azeyanti Nor Hashim, Saifullah A. Jaaman, A series of boat surveys were conducted from April to September 2008. This work evaluated the effects of boats on Indo-Pacific Humpback and Irrawaddy dolphins. The types of boats, dolphins’ interactions towards various types of boat and vessel-dolphin distance under different intensities were measured. The absence of boats sailing in the bay was considered as control situation. There was a highly significant difference in the response of Indo-Pacific Humpback (x2 = 97.1, df = 8, p = 0.000) and Irrawaddy (x2 = 52.4, df = 8, p = 0.000) dolphins to different classes of boats. Analyses showed that positive behaviour was the most observed behaviour towards trawlers for both dolphin species. However, Indo-Pacific Humpback (H = 3.107, p = 0.540) and Irrawaddy (H = 4.208, p= 0.379) dolphins independently associated with negative behaviour while interacting with all boat classes. Irrawaddy dolphin tend to avoid boats using outboard <40 hp engine compared to Indo-Pacific Humpback dolphin (Z = -2.023, p = 0.043). In this study, these fast moving vessels often caused immediate stress and behaviour disruption on dolphin’s community especially on Irrawaddy dolphin. On the other hand, Indo-Pacific Humpback and Irrawaddy dolphins showed a high rate of neutral response towards trawlers. Even though there was no stress involved in slow moving vessels especially trawlers, there is still concern on how it will affect the animal’s feeding behaviour, as dolphins always show approaching behaviour during the presence of trawlers. Universiti Kebangsaan Malaysia 2011-12 Article PeerReviewed application/pdf en http://journalarticle.ukm.my/3139/1/08_Nur_Azeyanti.pdf Nur Azeyanti Nor Hashim, and Saifullah A. Jaaman, (2011) Boat Effects on the Behaviour of Indo-Pacific Humpback (Sousa chinensis) and Irrawaddy Dolphins (Orcaella brevirostris) in Cowie Bay, Sabah, Malaysia. Sains Malaysiana, 40 (12). pp. 1383-1392. ISSN 0126-6039 http//:www.ukm.my/jsm/
repository_type	Digital Repository
institution_category	Local University
institution	Universiti Kebangasaan Malaysia
building	UKM Institutional Repository
collection	Online Access
language	English
description	A series of boat surveys were conducted from April to September 2008. This work evaluated the effects of boats on Indo-Pacific Humpback and Irrawaddy dolphins. The types of boats, dolphins’ interactions towards various types of boat and vessel-dolphin distance under different intensities were measured. The absence of boats sailing in the bay was considered as control situation. There was a highly significant difference in the response of Indo-Pacific Humpback (x2 = 97.1, df = 8, p = 0.000) and Irrawaddy (x2 = 52.4, df = 8, p = 0.000) dolphins to different classes of boats. Analyses showed that positive behaviour was the most observed behaviour towards trawlers for both dolphin species. However, Indo-Pacific Humpback (H = 3.107, p = 0.540) and Irrawaddy (H = 4.208, p= 0.379) dolphins independently associated with negative behaviour while interacting with all boat classes. Irrawaddy dolphin tend to avoid boats using outboard <40 hp engine compared to Indo-Pacific Humpback dolphin (Z = -2.023, p = 0.043). In this study, these fast moving vessels often caused immediate stress and behaviour disruption on dolphin’s community especially on Irrawaddy dolphin. On the other hand, Indo-Pacific Humpback and Irrawaddy dolphins showed a high rate of neutral response towards trawlers. Even though there was no stress involved in slow moving vessels especially trawlers, there is still concern on how it will affect the animal’s feeding behaviour, as dolphins always show approaching behaviour during the presence of trawlers.
format	Article
author	Nur Azeyanti Nor Hashim, Saifullah A. Jaaman,
spellingShingle	Nur Azeyanti Nor Hashim, Saifullah A. Jaaman, Boat Effects on the Behaviour of Indo-Pacific Humpback (Sousa chinensis) and Irrawaddy Dolphins (Orcaella brevirostris) in Cowie Bay, Sabah, Malaysia
author_facet	Nur Azeyanti Nor Hashim, Saifullah A. Jaaman,
author_sort	Nur Azeyanti Nor Hashim,
title	Boat Effects on the Behaviour of Indo-Pacific Humpback (Sousa chinensis) and Irrawaddy Dolphins (Orcaella brevirostris) in Cowie Bay, Sabah, Malaysia
title_short	Boat Effects on the Behaviour of Indo-Pacific Humpback (Sousa chinensis) and Irrawaddy Dolphins (Orcaella brevirostris) in Cowie Bay, Sabah, Malaysia
title_full	Boat Effects on the Behaviour of Indo-Pacific Humpback (Sousa chinensis) and Irrawaddy Dolphins (Orcaella brevirostris) in Cowie Bay, Sabah, Malaysia
title_fullStr	Boat Effects on the Behaviour of Indo-Pacific Humpback (Sousa chinensis) and Irrawaddy Dolphins (Orcaella brevirostris) in Cowie Bay, Sabah, Malaysia
title_full_unstemmed	Boat Effects on the Behaviour of Indo-Pacific Humpback (Sousa chinensis) and Irrawaddy Dolphins (Orcaella brevirostris) in Cowie Bay, Sabah, Malaysia
title_sort	boat effects on the behaviour of indo-pacific humpback (sousa chinensis) and irrawaddy dolphins (orcaella brevirostris) in cowie bay, sabah, malaysia
publisher	Universiti Kebangsaan Malaysia
publishDate	2011
url	http://journalarticle.ukm.my/3139/ http://journalarticle.ukm.my/3139/ http://journalarticle.ukm.my/3139/1/08_Nur_Azeyanti.pdf
first_indexed	2023-09-18T19:37:59Z
last_indexed	2023-09-18T19:37:59Z
_version_	1777405399484334080

Boat Effects on the Behaviour of Indo-Pacific Humpback (Sousa chinensis) and Irrawaddy Dolphins (Orcaella brevirostris) in Cowie Bay, Sabah, Malaysia

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