Guardians of the blue: MareCet’s quest to save Malaysia’s marine mammals

We couldn’t believe the incredible opportunity we got when being invited to join the MareCet team on their January dolphin survey on the west coast of Malaysia. Two days out on the waters on a small vessel of discovery and conservation, on a mission to monitor the dolphins of the productive coastal waters of Matang, Perak with a team of amazing experts in marine conservation – what can be better than this? 

Dolphins, whales, porpoises and dugongs call Malaysia’s waters their home and play crucial roles in maintaining the ecological balance of their marine habitats. However, like many marine mammals worldwide, Malaysia’s wild marine sentinels face a myriad of threats ranging from habitat degradation to pollution and entanglement in fishing gear. MareCet is the first and only non-profit grassroots NGO in Malaysia dedicated to the research and conservation of marine mammals in the country, and with them we could finally dip our toes into marine surveys and conservation, something very different to the terrestrial conservation we have been active in throughout our careers.

Many people admire these animals that live in a world where humans will always only be visitors, but most don’t know how important they really are for the marine ecosystem. As apex predators or filter feeders, dolphins and whales or scientifically called cetaceans, help regulate the populations of prey species, contributing to the overall health and resilience of marine ecosystems. Similarly, the herbivorous dugongs are ecosystem engineers. As they graze on seagrass beds, they help maintain the health and productivity of these vital habitats. 

Marine mammals also serve as indicators of ocean health. Their presence, abundance, and behaviour provide valuable insights into the condition of marine environments, helping scientists monitor changes and assess the effectiveness of conservation efforts. And with at least 27 species of dolphins, whales, porpoises and dugongs present in Malaysia, we have come to just the right place to learn about their conservation. Indo-Pacific humpback dolphins, Irrawaddy dolphins, Indo-Pacific finless porpoises, Spinner dolphins, Dugongs, Long-beaked common dolphins, Bryde’s whales (Eden’s and Indo-Pacific bottlenose dolphins are just a few of the species that can be found in this biodiverse country.

Call of the sea

Finally, the morning comes where we meet the group and share breakfast while we wait for the high tide. For the MareCet team, the day starts like any other out on sea. Under the leadership of Dr. Vivian Kuit, scientific officer, the team consisted of Kelly, Chris, Jean, Jeba, Emily, and Lokkaman – employees and volunteers of MareCet plus us two, as well as our skipper, Herry. After we pack the survey gear into the boat, the team quickly gets to work, everybody smoothly taking their roles onboard. There are three observers in the front of the boat, and Vivian quickly explains some boat basics to us. That one observer stays at the bow (front of the vessel) while one each remains on the port (left hand side) and starboard (right hand side), always looking out for dolphin signs on each side. 

Getting ready for a day out at sea with the MareCet team. The mornings are smooth sailing – as soon as we get on board, everybody takes their place and role.

Vivian tells us that we are going to survey along transects, which are straight lines that cut through a natural landscape to enable standardised observations and measurements. Every two months over the course of a week, the MareCet team surveys the same transects to monitor dolphin abundance and environmental factors. Lokkaman and Emily start their shift in the back of the boat and show us the form they use to note down all human activity around as well as water salinity, temperature and water depth in the beginning and end of every transect.

Water salinity, temperature and water depth are logged in the ‘effort log’ in the beginning and end of every transect. The observers keep a lookout for dolphins, while all human activity is recorded as well.

“We can expect to see Indo-Pacific humpback dolphins, Irrawaddy dolphins as well as Indo-Pacific finless porpoises in this area,” Vivian tells us, while we set off to start our first transect. The goal of the Matang Dolphin Research Project, MareCet’s second cetacean research project, is to assess population abundance of the cetaceans in the Matang and Pangkor Island area, as well as understand their distribution, habitat use, behaviour, diet and overlaps in human-dolphin interactions. This is why the team puts a lot of effort into conducting interviews with local fishermen, aiming to learn about their fishing activities, their perception about cetaceans and encounters with them, especially cases of entanglements in fishing nets.

In 2019, based on research data of MareCet, the IUCN Marine Mammal Protected Areas Task Force recognised the waters around Matang and its adjacent coasts as part of the Matang Mangroves and Coastal Waters Important Marine Mammal Area (IMMA).

Fishers and dolphins

Fishers often encounter dolphins because they are both searching for large schools (or groups) of fish in coastal waters. While some interactions are peaceful, others can lead to conflicts or unintended harm to dolphins. Dolphins may become accidentally entangled in fishing gear such as gillnets, trawls, or longlines. This unintentional capture, known as bycatch, can result in injury or death of the dolphins. Vivian explains that the accidental capture of dolphins in fishing gear poses a significant threat to their populations, which is exactly why MareCet aims to work together with fishers and government agencies to raise awareness about the importance of dolphin conservation and promote the adoption of dolphin-friendly fishing practices.

MareCet has introduced several measures to reduce the risk of dolphin bycatch. They give out pingers – high frequency sound emitters – for free to fishers, which attached to boats keep dolphins away. “Especially purse seine boats are very dangerous to dolphins, there are specifically many cases of bottlenose dolphins being caught in their nets,” Vivian tells us. All they ask in return is data. A purse seine is an expansive wall of netting set up to encircle either a designated area or a group of fish. When a school of fish is identified, the boat manoeuvres around them with the net, while a lead line is gradually drawn in, effectively “closing” the net at the bottom. Once the netting has been closed, encircled dolphins cannot escape and can become stressed, entangled and even injured. Fishermen usually try to push out the dolphins from the net before hauling it up, in which case they are usually released alive and okay, however, they are not always successful.

A purse seine boat in action. Photo on the right by NOAA fisheries.

Historically, dolphin pods (groups of dolphins) were even used as a natural cue visually leading purse seine boats toward areas of abundant schooling fish. “One pinger costs about 80 USD, and although the battery lasts for about one year for drift nets (nets not anchored down), unfortunately the battery of the model for Purse seine boats only lasts for about 2-3 months. Pingers also seem to work well for humpback dolphins but not for bottlenose dolphins,” reveals Vivian. 

MareCet gives out free pingers to fishers, which are high frequency sound emitters, which attached to boats keep dolphins away.

In some communities, fishers view dolphins as competitors for fish resources or even as pests that interfere with fishing activities. Some fishers would throw explosives into the water to chase them away. Once caught in the net, most of them would throw the dolphin back, but some fishers would kill or eat the animal. However, for other communities in Malaysia, dolphins are also revered or viewed as auspicious animals. Some fishers believe that encountering dolphins is a sign of good luck or signifies abundant fish stocks, and killing bycatch will bring bad luck. However, all in all according to Vivian, the survival rate after bycatch is only about 50% for humpback dolphins, while a little bit lower for Irrawaddy dolphins. This is why it’s particularly important to engage with local communities, fisherfolk, and stakeholders to foster the stewardship of marine resources.

Spot the fin

While moving along the transects, often catching a glimpse of flying fish, we spot several big and small fishing boats. The team also explains that increased maritime traffic and underwater noise pollution disrupts dolphin communication, navigation, and feeding behaviours, further compromising their survival. That is why noting down all human activity in the survey site is so important. All of us are busy staring into the horizon, when suddenly, we see several fins. Herry, our skilled skipper, immediately stops the boat, and we all stare in the same direction. Vivian quickly picks up her camera and starts taking photographs of the animals. We are all in awe, while her main goal is to capture good photos of the Irrawaddy dolphins’ dorsal fins for identification.

The Irrawaddy dolphins recorded during the January 2024 survey. After taking enough photos, Vivian immediately records all details in the effort log. Left photo by: The MareCet Research Organization.

The rest of the team lowers underwater sound recording devices into the water to collect acoustic data. Dolphins are very audio-focused animals, they use a lot of vocalisations in their everyday lives like whistles, squeaks and echolocation signals such as clicks, to communicate, navigate and forage. “Irrawaddy dolphins are generally more elusive, so we have less recordings of their vocalisations compared to humpback dolphins” Vivian explains.

As we learn, the dorsal fin is the most important identification key for humpback dolphins, while regarding the Irrawaddy dolphin, photo identification is much harder. MareCet already has an extensive catalogue of about 450 humpback dolphins, which means that this many individuals were identified using just photos of their dorsal fins. Differentiating marks can be pigmentation (the older an individual gets, the more pigmentation it loses and so there appears to be more pink on its fin), as well as scars, nicks – smaller cuts – and notches – V-shaped cuts – present on the leading and trailing edges of the dorsal fin, many acquired during the dolphin’s lifetime. After each survey, the MareCet team goes through each photo and identifies as many formerly catalogued individuals as possible. Surely a herculean task, but it is fascinating to learn that just like a human fingerprint, no two dorsal fins are the same. 

The dorsal fin is the most important identification key for humpback dolphins, and no two dorsal fins are the same. Humpback dolphin photos provided by: The MareCet Research Organization.

A Call to arms: a shared responsibility

We spend two very interesting days at sea with MareCet. We learn that on a survey, there is so much more to do on the boat, than just keeping a lookout for dolphins. Additionally, focusing on detecting even the slightest movement in the expansive sea while being exposed to sun and weather all day long is more than exhausting. But at the same time, it is a lot of fun to be together on the boat and such a survey makes you appreciate the true power of teamwork, while all are dedicated to unravelling the mysteries of marine life and identifying their conservation needs. 

A team of happy dolphin enthusiasts. Photo by: The MareCet Research Organization.

MareCet also wants to encourage young and old to train and be active in the protection of marine mammals. They organise various outreach programs and educational initiatives, to inspire a new generation of ocean stewards. And with the increasing development of dolphin-watching tourism in the west coast of Malaysia, MareCet aims to provide constructive input for the industry, and they offer anyone the opportunity to see what dolphin research is like through educational dolphin edu-tour trips

Asked about MareCet’s plans for the next decade, Vivian says they hope to reach even more success in bycatch mitigation, and they dream of contributing to the establishment of  dugong sanctuary for the now less than 100 dugongs found in Johor, on the south-eastern side of Peninsular Malaysia.

“We also hope to improve Malaysia’s stranding network so that we have more trained personnel along the coastline that are able to respond faster to marine mammal stranding calls.”

Dr. Vivian Kuit, scientific officer of MareCet

As we navigate the complexities of marine conservation, it is evident that the protection of dolphins and other marine mammals requires collective action. Governments, NGOs, communities, and individuals must work together to address the root causes of threats and implement sustainable solutions. In Malaysia, MareCet exemplifies the power of collaboration and dedication in safeguarding marine biodiversity. Through their tireless efforts, MareCet inspires hope for a future where dolphins, whales and dugongs continue to thrive in Malaysian waters, enriching our lives and ecosystems for generations to come.