EFFECT OF WATER PARAMETERS ON THE BEHAVIOUR OF INDO-PACIFIC HUMPBACK AND IRRAWADDY DOLPHINS IN COWIE BAY, SABAH, MALAYSIA

ABSTRACT. Many dolphin species around the world are found generally in coastal areas and may be affected by water parameters. Of particular attention are two species of dolphin inhabiting the Cowie Bay on the eastern coast of Sabah; the Indo-Pacific Humpback (Sousa chinensis) and Irrawaddy (Orcaella brevirostris) dolphins. The objective of this study is to determine effects of water parameters (sea surface temperature (SST), salinity and turbidity) on the behaviour (feeding, socializing and travelling) of the two dolphin species. A boat-based survey was conducted monthly from April 2008 to March 2009 (one year) during spring and neap tides. There were 47 surveys conducted for both species. Irrawaddy dolphins were found in 43 surveys (91.5%). The feeding and socializing behaviour of Irrawaddy dolphins were positively correlated with SST and negatively correlated with turbidity. None of the water parameters affected dolphins’ travelling behaviour. The behaviour of the Irrawaddy dolphin was not correlated with salinity. Indo-Pacific humpback dolphins were found only in 41 surveys (87.2%) where its behaviour did not correlate with any water parameters. The socio-economic activities such as logging, agriculture and fisheries highly contribute to suspended sediment and also contribute to high water turbidity in the bay. These are possible causes for the changing of water parameters and may affect the food chain of vast marine life including dolphins. As a recommendation, those activities should be controlled and an the application of sustainable development practices in order to sustain the dolphin population in the bay.

KEYWORDS. Behaviour, Cowie Bay, Indo-Pacific humpback dolphin, Irrawaddy dolphin, water parameters

Download Full Paper Here (right click and save as)

DIVERSITY OF MANGROVES ECOSYSTEM IN SEMPORNA MANGROVE FOREST

ABSTRACT. The aim of this study is to determine the diversity and density of mangrove tree species as well as to compare the diameter distribution of mangrove species in Semporna mangrove area. Two types of study area were compared the non-disturbed and disturbed mangrove areas in Semporna. The non-disturbed mangrove areas that were selected were distant from local settlements namely Sg. Sipit, Sum-sum, Tong Tabataba, Hampalan, Bantau-bantau and Sg. Gajah. While Kalumpang, Kg. Tanjung Kapur, Kg. Salimbangun, Kg. Parang Tangah, Pangkalangan, Labuan Senang and Proboscis monkey area were selected as disturbed mangrove areas due to their location close to settlements. A total of 30 rectangular plots were established randomly, each measuring 20 x 10 m. Each site consists of 3 separate plots and the minimum sampling area was 0.6 ha. From the findings, 26 species were identified at both disturbed and non-disturbed mangrove area. The mean diameter at breast height (DBH) at disturbed mangrove area ranges from 10-20 cm, as compared to 20-35 cm in non-disturbed mangrove area. Besides, the value of the mangrove species diversity in non-disturbed mangrove area is less diverse with Shannon-Weiner (H’) = 0.711 as compared to disturbed mangrove area which has a higher value with H’ = 1.725. The diameter distribution graph indicated both areas show an inverse J-curve shape which represents an even-aged tree stand structure. However, the graph showing disturbed mangrove area revealed more scattered and randomly distributed tree stands. This is due to local community activities in that area such as collection of wood and fire wood for personal use. The species Rhizophora apiculata is the most common species counted in most of the disturbed mangrove area with the highest Important Value Index (IVI) value of 173.6, as opposed to Rhizophora mucronata which is most dominant in nearly all of the non-disturbed mangrove area. The results show that the disturbed mangrove area has higher tree diversity and the tree stands are less dense as compared to non-disturbed mangrove area. It is recommended that more similar studies and longtime monitoring should be conducted in these areas in the future.

KEYWORD. Density, diversity, diameter distribution, disturbed mangrove area, non-disturbed mangrove area, species composition

Download Full Paper Here (right click and save as)

METHOD TO ESTIMATE THE LAND LOSS FROM SEA LEVEL RISE DUE TO GRADUAL WARMING IN KOTA KINABALU, SABAH

ABSTRACT. Debates have been going on for several years regarding the issue of global warming and subsequent sea level rise. Are humans one of the contributing factors to the warming of the Earth’s temperature? Or is it just a natural phenomenon and there is nothing to be worried about? Whatever it is, global warming, the increase of average global air temperature, is one of the most talked about and of high concern issues today, not just amongst the scientists, but also the general public. The rise of air temperature and subsequent increase in sea surface temperature (SST) will raise the sea level due to thermal expansion. These changes in water temperature could affect the health of many aquatic species, in addition to causing land loss and beach erosion. For the past 10 years (2000 until 2009), the average air temperature change in Kota Kinabalu, Sabah is approximately 0.10°C and according to these trends for the next eleven years (until 2020), the projection of air temperature change will be approximately0.21°C. When this happens, average sea surface temperature (SST) will also increase due to the relationship between air temperature and water temperature, though the change in SST may not be as large as the air temperature increase. The empirical relationship obtained in this study for air temperature and SST is SST = 0.241T + 22.6, with air temperature, T. As a rule of thumb, an increase of 1°C in SST can raise sea level by approximately 1 cm.. Using the SST data for the last eleven years, the change of SST is also calculated, as well as the projected SST changes for the next decade. Based on the last decade’s data, SST in Kota Kinabalu has increased 0.26 °C and it will increase another 0.24 °C by 2020. Sea level in Kota Kinabalu has also increased by 2.6 mm inthe last 11 years. Projections show that sea level in Kota Kinabalu will increase another 2.4 mm by 2020. Using the estimated value of sea level rise due to SST increase, land loss is also estimated for the coastal areas in Kota Kinabalu and the calculation is explained.

KEYWORDS. Air temperature, beach angle, beach loss, sea level rise, sea surface temperature

Download Full Paper Here (right click and save as)

HUMAN INTERVENTION ON MANGROVE AREA IN AMBONG BAY, KOTA BELUD, SABAH

ABSTRACT. Mangrove is one important coastal vegetation that provides natural habitat for much marine life and serves as protection to the shoreline. Most mangrove areas in Kota Belud are located in the southern part (Kuala Abai and Ambong Bay) of this district. However the mangrove along the shoreline of Ambong Bay belongs to the Sabah state government. High demand of the mangrove area for personal use and exploitation of the resource have contributed to the destruction of mangrove ecosystem and its function as shoreline protection. The objectives of the study are to identify the change of mangrove cover and to identify the dependency level, human impact and conservation knowledge of local communities on mangroves along the shoreline of Ambong Bay, Kota Belud. The evaluation of spatial and temporal changes in mangrove areas were conducted based on Landsat TM imagery in 2001 and 2005. The data was analysed by using Erdas Imagine 9.1 version software. Field trips were conducted for ground checking and questionnaires were randomly distributed at 3 villages to assess their dependence on and conservation knowledge of mangrove. Small changes of mangrove cover can be seen from satellite images however ground checking indicated that this area was highly exploited by the local community for human settlement, conversion to paddy fields and aquaculture activities. During high tide and heavy rain, some areas are flooded which affects the human activities along the roads. Most of the respondents were unaware of the importance of the mangrove as shoreline protection, source of food and habitat for marine life. The local communities are keen to participate in any mangrove conservation activities but so far no related programme has been conducted in that area. Therefore, an awareness programme and sustainable management of the remaining mangrove should be implemented. Strong support from government and local authorities are also needed to ensure the success of the programme.

KEYWORDS. Mangrove changes, human interference, conservation knowledge, Ambong Bay

Download Full Paper Here (right click and save as)

IDENTIFICATION OF MARINE SAND-DWELLING DINOFLAGELLATES IN DINAWAN ISLAND, SABAH

ABSTRACT. Identification of marine sand-dwelling species is important due to the toxin-producing abilities of some species that may harm human beings. In this study, sand samples were collected for 12 months at Dinawan Island, Sabah. Samples were identified using light microscopy (LM) and Scanning Electron Microscopy (SEM). Sixteen dinoflagellates species have been identified including 4 potential toxic species i.e. Prorocentrum arenarium, P. lima, P. rhatymum and Amphidinium carterae. Prorocentrum norrisianum is morphologically very similar to P. cassabicum. List of sand-dwelling dinoflagellates species especially toxic species provides important knowledge for monitoring and management of harmful algal bloom.


KEYWORDS.
Dinoflagellates, Dinawan Island, marine sand-dwelling, toxin

Download Full Paper Here (right click and save as)

POSITIVE IMPACTS OF TYPHOON [CASE STUDY ON TYPHOON KETSANA IN THE SOUTH CHINA SEA: SEPTEMBER 2009]

ABSTRACT. This brief study depicts the changes of water properties (temperature and salinity profile) after Typhoon Ketsana passed over the South China Sea and the benefits contributed to marine life as well as human being. Argo float data near the typhoon track before and after Typhoon Ketsana, available from GODAE website was analyzed in this project. Cooling of sea surface temperature (SST) about 1 to 3 °C was recorded in the study area. Typhoon Ketsana had removed about 250 to 380 MJ of heat from a surface area of 1 m². Sea surface salinity was observed to be increased about 0.2 to 0.4 pss after the typhoon. In addition, thermocline and halocline depths have deepened about 7.8 to 12.6 m and 10.3 to 12.9 m respectively due to the increase of surface layer depth. Even though the lifespan of Typhoon Ketsana was short, it brought several positive impacts: removed heat from the tropic regions in order to maintain moderate temperature, increased the concentration of nutrients due to the increases of salinity thus enhancing phytoplankton bloom in the ocean. Furthermore, the typhoon changed the ocean structure by deepening the thermocline and halocline depths. This affects the behavior of marine organisms that perform vertical migration. From the rough estimation, if the heat energy removed by Ketsana could be harnessed and converted into electricity, it would support the electrical usage in Malaysia for many years. Therefore, this study may cause some people to change their perspective on typhoons. In fact typhoons causes not just destruction and tragedy they also bring positive benefits to human kind and marine environment.

KEYWORDS. Halocline, SST, SSS, thermocline, typhoon

Download Full Paper Here (right click and save as)

POPULATION ECOLOGY AND POTENTIAL FOOD SOURCES OF THE SALTWATER CROCODILES IN KAWANG RIVER, SABAH

ABSTRACT. Kawang River is one of the remaining habitats for Crocodylusporosus (saltwater crocodile) on the west coast of Sabah. The objectives of this study are to find the current abundance of C. porosus, to obtain their historical background, list fish and invertebrates that could be their food sources, and potential human-crocodile conflict (HCC) issues in the Kawang River. Spotlight surveys to search for crocodiles and interview surveys were conducted to obtain more information on their historical background and HCC issues. Two fishing trips were also made to investigate the potential food sources (fish and invertebrates) of C. porosus in the river. Results from three spotlight surveys showed 36 C. porosus were recorded. The average calculated density of C. porosus was 2.73 crocodiles km-1andthe value has appeared to increase marginally from 2.11 crocodiles km-1 but statistical analysis showed that there was no significant mean difference of density of the C. porosus between the past and current study. From the 18 local people interviewed, 15 claimed that they have seen crocodiles in the Kawang River with high proportion (50% of different crocodile sizes estimated by the interviewees) of immature crocodiles. The results from fishing trips identified seven species of fish and two species of invertebrates as potential food sources. Interview results showed that the awareness of the local people towards HCC was low in the Kawang River, altogether with poor livestock management and human encroachment into crocodile habitats, these factors can trigger HCC in the future.

KEYWORDS. Abundance, human-crocodile conflict, interview surveys

Download Full Paper Here (right click and save as)

SILENT TURTLE DWELLERS: BARNACLES ON RESIDENT GREEN (CHELONIA MYDAS) AND HAWKSBILL TURTLES (ERETMOCHELYS IMBRICATA) OF MABUL AND SIPADAN ISLANDS

ABSTRACT. Barnacles are sessile organisms that attach themselves permanently to the surface of hard or living substrates. Marine turtles are one example of living substrates colonised by barnacles. A survey was conducted from August 2010 to February 2011 to observe the barnacles on resident green (Chelonia mydas) and hawksbill turtles (Eretmochelys imbricata) of Mabul and Sipadan Islands, located on the East Coast of Sabah. This survey intended to produce a list of barnacle species occurring on turtles in these islands and the specific location of the barnacles on the bodies of turtles. One barnacle species, Chelonibia testudinaria (diameter 20.11 ± 8.15 mm from 291 specimens) was identified from 64 turtles – 2 hawksbills and 62 greens. The colonisation site for most of the barnacles was on the plastron of the turtles. From the observation in present study, turtles were cleaned by dusky surgeonfish, Acanthurus nigrofuscus and striated surgeonfish, Ctenochaetus striatus in two dive sites (Staghorn Crest and Barracuda Point) of Sipadan Island. Turtles inhabit and forage near to these turtles cleaning stations consequently having smaller number of barnacles while turtles inhabiting non-cleaning station environments have larger numbers of barnacles.

KEYWORDS. Turtles, barnacles, surgeonfish, Mabul, Sipadan

Download Full Paper Here (right click and save as)

IMPACTS OF RAINFALL, TEMPERATURE AND RECENT EL NIÑOS ON FISHERIES AND AGRICULTURAL PRODUCTS IN THE WEST COAST OF SABAH [2000 – 2010]

ABSTRACT. The impacts of El Niño Southern Oscillation (ENSO) phenomenon on rainfall and temperature as well as the relationships between rainfall, temperature and ENSO phenomenon on fish landings and production of palm oil Fresh Fruit Bunch (FFB) along the West Coast of Sabah during the last 10 years have been examined. Rainfall, temperature, Southern Oscillation Index (SOI) values, fish landings and production of FFB from available local departments have been studied and analyzed for the past 10 years. On the whole, there is significant positive correlation between rainfall and temperature on fish landings. The correlation coefficient between rainfall and fish landings is +0.74 with fish landings leading by 2 months. Also, fish landings and temperature are directly correlated with correlation coefficient of +0.83 with no time lag. However, a negative correlation between SOI values on fish landings is observed whereby 1 month before fish landings increase, the SOI values become low or negative. Analysis of production of palm oil on the same meteorological parameters show that there is significant positive correlation between rainfall on production of FFB, monthly temperature on production of FFB and SOI values on production of FFB for the 6-year study period. When rainfall is considered, the production of FFB is correlated with rainfall at +0.83 with rainfall leading by 3 months. The correlation coefficients between temperature and production of FFB is +0.87 with temperature leading by 4 months. Also, when SOI values are considered, production of FFB leads SOI by 3 months with the correlation coefficient of +0.62. Fish landings along the West Coast of Sabah are enhanced during El Niño periods while production of palm oil FFB is favoured during La Niña periods although floods are not desirable. By understanding the ENSO phenomenon and the subsequent changes in rainfall and temperature, preparations are most needed in order to sustain and promote the fisheries and agricultural products for sustainable development in the economy of Sabah.


KEYWORDS.
ENSO, fish landings, FFB, rainfall, temperature

Download Full Paper Here (right click and save as)

A PRELIMINARY STUDY OF POPULATION DYNAMICS OF GREEN TURTLES (Chelonia mydas) OF SIPADAN, MALAYSIA

ABSTRACT. A study was conducted to observe the population dynamics of residential green turtles, Chelonia mydasin Sipadan Island located off the east coast of Sabah, Malaysia. Three field trips (3 days in each trip) were conducted from August till December 2010. Green turtles were caught from 10 selected dive sites, and were brought into upon the boat for morphometric measurements and tagging using inconel tags from Sabah Parks. At the end of this study, 147 individuals with a mean straight carapace length (SCL) of 652.9 (± 124.2) mm were caught. From the results, 77 individuals were juveniles, 28 were sub-adults, and 42 were adults with mean straight carapace lengths of 557.7 (± 70.5) mm, 690.2 (± 40.7) mm, and 802.8 (± 60.6) mm, respectively. During this study, 20 adult female and 22 adult male were caught with mean straight carapace lengths of 811.1 (±59.2) mm and 795.1 (±62.6), respectively. In our study area, juvenile green turtles were the most abundant as compared to sub-adults and adults. This finding is fundamental in estimating the population of resident green turtles in Sipadan Island and also contributes to better management and conservation of this marine protected area.


KEYWORDS.
Green turtles, Chelonia mydas, population dynamics, Sipadan Island, Malaysia

Download Full Paper Here (right click and save as)