A stream of sea traffic makes the sea channel off Northport, Port Klang, a busy shipping route. Each day, huge ships, tankers, barges and tugboats ply this narrow sea passage. The water is murky and often, topped with an oily sheen and patches of flotsam.
It is not exactly a place where one would expect to see wildlife. So it certainly was a treat for marine mammal scientist Dr Louisa Ponnampalam when she spotted the uncommon Irrawaddy dolphins there in February. And it was not just one or two animals, but a group of 12 or more, with at least one calf.
“We were heading back to the port when we saw them in the middle of the channel. They then moved towards the mangroves (across from the port) and hung around there,” she says.
Ponnampalam and her assistant had hopped along when a group of Malaysian Nature Society members took a boat out for a bird survey of the islands off Port Klang. She was actually on the lookout for Indo-pacific humpback dolphins which were recently seen there. But spotting the Irrawaddy dolphins instead was a welcome discovery for until now, no one could say for sure that they could be found off the Selangor coast since no detailed study has been done.
Nevertheless, Ponnampalam is not exactly surprised at the sighting. “Finding them there is not unexpected as mangroves and mudflats are typical waddies habitats,” she says, using the abbreviated name commonly used for the dolphin. Also, past cases of strandings of these species along the Straits of Malacca indicate their presence off the Peninsular Malaysia west coast.
The mangrove islands off Port Klang are interspersed by an intricate network of water channels. “It is this complex environment that allows the dolphins to still be there because they can go into areas that have less or no shipping activities. So there is still some refuge for them even in this busy shipping area,” explains Ponnampalam, a research fellow at the Institute of Ocean and Earth Sciences in Universiti Malaya.
Where waddies roam
Marine mammals are little known in Malaysia. To counter this, Ponnampalam and another marine scientist had set up a non-profit called MareCet, focusing on research and conservation of marine mammals. They started studying these animals in Langkawi in 2010 and later, along the Perak coastline. With these ongoing projects, as well as another one on dugongs in Johor taking up her limited resources, Ponnampalam has no immediate plans for a research project on the dolphins in Port Klang.
Nonetheless, that sighting adds to current knowledge about waddies. They are already known from parts of Sabah and Sarawak but for the longest time no one knew how well distributed they are in Peninsular Malaysia due to a dearth of studies.
From MareCet’s work, we now know that waddies inhabit the waters off Kuala Kedah, Kuala Perlis, Perak, Johor and now, Port Klang in Selangor. Other cetacean experts have seen them off Malacca and Penang.
Ponnampalam believes they occur all along the west coast as the habitat here is mostly mangrove-lined shores and mudflats, which are essentially Irrawaddy dolphin grounds.
So far, her work has determined three main coastal cetacean species in the west coast: the Indo-pacific humpback dolphin, Irrawaddy dolphin and Indo-pacific finless porpoise. (The cetacean family includes whales, dolphins and porpoises.)
The finless porpoise tends to occur further offshore and is the most common species in Langkawi. The other two species prefer coastal and mudflat environments, which are highly productive ecosystems with lots of food.
Ponnampalam says based on reports and sightings, all three species are also found in the east coast but in smaller numbers.
Dolphins in Perak
News about dolphin sightings in Kuala Sepetang, near Taiping in Perak, prompted a research project there in 2013. Fishermen have encountered the dolphins in the river and off the fishing village, as have visitors on boat tours to see mangroves. From photographs provided by the locals, Ponnampalam identified them to be humpback dolphins.
But when surveys started, she discovered Irrawaddy dolphins to be there too. Unlike the humpback dolphins, they do not come upriver but stay further offshore, so they pretty much went unnoticed.
The researchers spotted waddies throughout their survey of the Perak coastline, from Kuala Gula near Bagan Serai to Kuala Sangga in Matang, Kuala Larut, Kuala Trong and Kuala Jarum Mas, north of Lumut. The humpback dolphins on the other hand, have a patchy distribution in the same survey area and tend to hug the coast and enter into estuaries.
Kuala Sepetang now has a thriving nature tourism industry. Villagers offer boat tours to see mangroves and pink dolphins, the local name for the humpback dolphin, which is also how they are called in Hong Kong.
Calves are born dark grey and the skin lightens as they mature. But while adult humpback dolphins in Hong Kong turn completely pink, the ones here turn 80% pink and retain some grey mottling. There may be species variations but globally, they are all known as Sousa chinensis. The taxonomy of the species is now under review and Ponnampalam will contribute tissue samples for genetic studies.
Threats from humans
Apart from the dolphins’ distribution and abundance, the research also covers their diet, behaviour, movement patterns and use of the habitat, such as for feeding or nursing ground. The researchers also look at whether human activities can affect the dolphins’ habitat and if so, will make recommendations on managing the habitat to minimise risks to the dolphins.
Because the dolphins inhabit an intensely fished area, they might be hit by boats or trapped in trawl nets. Marine pollution is another threat. A Universiti Malaya study found pathogenic bacteria in the waters of Kuala Sepetang, believed to be from discharges of raw sewage, aquaculture waste and open garbage dumps. The pollutants were detected in water and sediment samples in the Sepetang, Sangga Besar and Selinsing rivers. The study, published in 2014, warned of a potential public health risk if contaminated fish, prawns and cockles were consumed.
Ponnampalam’s team has seen dolphins with lesions and growths on their bodies, possibly triggered by a contaminated environment. “Pollution doesn’t necessarily kill an animal but reduces its resilience to disease and its overall health,” she says.
Health of the sea
She considers marine mammals as flagship species for ocean preservation. “Where there is food, they are there. They’re a sign that a place is still viable. If animals start declining or moving out of the area, we need to ask why. Did they die of disease or net entanglement or that habitat is no longer able to support them as resources have been depleted?”
The International Union for Conservation of Nature has listed waddies as vulnerable to extinction and has noted its decreasing trend, while the humpback dolphin is near-threatened.
Ponnampalam says Bangladesh, with 5,000 animals in the Sundarban wetlands, has the world’s largest population of waddies. “Outside of that, most populations are highly threatened or teetering. Because waddies share their habitat with areas of high human activities, the pressure is pretty intense.”
The population in the Mekong River is critically endangered, their future threatened by 11 proposed hydro-power dams. In the Cambodian part of the Mekong, waddies number only 80 while in Laos, only four are left.
No one knows how big our waddies population is. “In Kuala Sepetang, fishermen say they used to see them a lot more often. Whether the population has moved away or declined, we don’t know as there is no baseline data,” says Ponnampalam.
“I can’t say if our dolphins are endangered or critically endangered. But definitely, the threats to their survival are huge. Everywhere, human impact on ecosystems is increasing. With that, you can expect these animals to live in a more stressed environment. Given the pressures facing the marine environment, our animals are not out of the danger zone.”
As our dolphins populations are not large, Ponnampalam advises caution. “All over Malaysia, we have small localised populations of coastal cetaceans. Some may be more endangered that others, we don’t know. So we need to be careful in managing their habitats and our habits on land.”