Marine mammals in the waters of East Coast Johor, Malaysia

Marine mammal searches were opportunistically conducted during the East Coast Johor Scientific Expedition (ECJSE) on 21-30 May 2012, on a live-on-board (LOB) diving vessel, MV BLACK PEARL. The expedition was designed mainly to survey coral reef ecosystems and water quality. Daylight visual observations of the sea were undertaken during sailing and stopping/anchored from the most upper open-deck of the vessel. The survey resulted in two sightings of long-beaked common dolphins (Delphinus capensis), each at Pulau Aur and Pulau Tinggi. Both observations were brief (< 5 minutes) and were made when the vessel was anchored. Based on anecdotal evidences, skeletal remains and previous surveys, the vulnerable dugong, Indo-Pacific bottlenose, Indo-Pacific humpback, Irrawaddy and long-beaked common dolphins, the false killer and pygmy killer whales, and the baleen whales are known to occur in the East Coast Johor waters, at least occasionally. The low sighting rate with marine mammals during this survey is highly likely caused by the survey design and also may be due to the environmental conditions and ecological factors. Dedicated and periodical boat and aerial surveys for marine mammals need to be conducted to determine species diversity and to understand the seasonality, habitat use, and social interactions of the marine mammal populations in the area. The findings will be most useful for marine park and fisheries authorities to plan conservation management strategies for marine mammals and promote their conservation through eco-tourism activities