11
DEC
2017

Dugong (Dugong dugon) Abundance, Distribution and Its Interaction with Fisheries in the Malaysian Waters of Brunei Bay

Name: Azzakirat Raman
Course: Master of Science (Marine Sciences)

Abstract

In recent years, dugongs (Dugong dugon) has experienced an extreme population decline. However, numerous sighting have evidently confirmed the presence of dugongs in the Malaysian waters of Brunei Bay and yet, little is known about their population in Brunei Bay. This study was carried out to provide scientific information regarding the status of dugong, the interaction of dugong with the fisheries and the local’s perception towards dugong in the Malaysian waters of Brunei Bay. Interviews with 221 fishermen and one year cycle of boat surveys were carried out to fulfil the objectives of this study. Data were tested using Chi-Square test, Wilcoxon-Rank test and mapped using ArcGIS software. Based on the interview surveys, the dugong’s population was highly reported to be seen in Lawas (N=53/109, 49%) with low sighting frequency (N=66/109, 61%), small population (N=81/100, 81%) and declining sighting pattern (N=132/134, 99%). A total of six sighting of dugong were made during the boat surveys with a total sighting rate of 0.06 (100 km.hrs). Statistical test showed that dugong sighting was not influenced by months, seasons and regions (χ2=4.333, df= 2, P= 0.115). Dugong was evidently engaged with the incidental by-catch (N=53/221, 24%) with the total annual by-catch of 9.4 years-1, mostly in gillnet/trammels user (8.4 year-1) in Lawas (6.1 year-1). Interviewed fishermen gave a positive perspective towards co-habitation of dugong in their residency (N=117/221, 80%), showed evidence of a high level of awareness (N=185/221, 84%) and acknowledged the significance of dugong (N=207/221, 94%). It is recommended that an immediate, intensive and continuous attentions to be given especially to educate the local communities, monitoring the fisheries activities, enforcing legislation and most importantly, conserving the important key habitat of the dugong.

 

 

Figure1: One-to-one interviews were conducted with total participant of 221 local fisherman in the Malaysian Waters of Brunei Bay. Photo by: Azzakirat Raman

 

Figure 2: Observers scanned the entire coastline according to the designated transects using naked eyes and binocular searching for dugong in the Malaysian Waters of Brunei Bay. Photo by: Azmi Marzuki Muda

 

 

Figure 3: Map showing the Malaysian waters of Brunei Bay and surrounding area. X marked with circle indicate the locations of interviewed communities (N=16) and zig – zag lines indicate the designated boat survey routes parallel to the coastlines. Top-left is the location of Brunei Bay in Borneo map.

Figure 4: Map showing the results comparison between interview and boat surveys. The grey circles indicate the sightings reported during the interviews. Larger grey circles indicate higher sightings occurrence while smaller grey circles indicate lesser sightings. The black triangle dots indicate the sighting location of dugong during the boat surveys of April 2013 to January 2014 (N=6). The red line indicates international border between Malaysia and Brunei Darussalam, the black lines indicates national boundaries between Malaysian states of Sabah, Sarawak, and F.T Labuan. The occurrence of dugong was confirmed in the R2 and R3 region, however no similarity in sightings was found between interviews and boat surveys in the R1 region.

 

 

Figure 5: A fully adult dugong with a total length of 2.6 meter was found dead at the Mempakul Beach of Menumbok, Sabah in October 2013. Figure showed the nearby villagers tried to dig a hole to bury the stranded carcass. The internals (i.e. intestines, stomach) of the dugong was burst out of the body and there is a sign of severe haemorrhage at the genital opening and the anus. Photo by: Azzakirat Raman.

 

Figure 6: A dead dugong was found at the Mempakul Beach of Menumbok, Sabah in October 2013. Figure showed the front and back view of the dugong with a noticeable severe injuries and haemorrhage on the head, mouth and the flippers. Photo by: Azzakirat Raman.