Expert say the occurrence of stranding is an alarm. While Indonesia still lacks resources to conduct further research into the cause of cetaceans stranding.
Residents of Lembata Island, East Nusa Tenggara, always look forward to the year’s final quarter. As the wind blew cooler, a light rain began to fall. Ampupu—a tree species in the eucalyptus family—leaves began to grow after months of falling, adjusting to the high soil water evaporation during the long dry season in eastern Indonesia.
One afternoon Waienga Bay, a calm watery basin in Watodiri Village, northwest of Lembata Island, was suddenly visited by many people of various ages from not-so-near villages. It was October 2014, recalls Paulus Igo, 40. “When I received a call from an environmental activist. There are five blue whales stranded in Watodiri,” he said.
It didn’t take long for Igo to contact members of Gema Putra-Putri Lembata (Gempita), a group of nature lovers that Igo had also founded. Arriving at Waienga Bay, one of the five blue whales was dead. At about 21 meters long, it was the smallest of the five, and he assumed it was a calf. When they arrived, part of the calf’s body was left with only a skeleton. Several residents had cut the calf’s body parts to be consumed at home.
Visitorus Agustinus Huar, or Tinus, 38, one of Gempita’s members, recalled the bustling afternoon in the bay. He said the largest whale was about 35 meters in length. It “spouted water many times. Like a water fountain. It was deafening.”
The other four whales were seen circling the bay basin, trying to find their way back to the junction between the Flores Sea—to the north of Lembata—and the Savu Sea—which stretches to the south of the island and at first glance looks like a soaring bird. While about a kilometer from them, “the sonar of the rescue team detected the undersea movement of the orcas.”
“Orcas won’t hesitate to attack an adult blue whale, the planet’s largest creature,” said Amang Raga, an ethologist who led the evacuation. He suspected the four blue whales “didn’t want to leave the bay basin because their sonar detected orcas at close range.”
Traditional and scientific knowledge
On the third day, the four whales were trapped in the bay. Igo mobilized and guided several Gempita members in the evacuation process. He took the initiative to rent a sampan—a relatively flat-bottomed wooden boat—so they could get closer to the whales. “The five of us boarded the sampan while carrying items that could make a loud sound,” said a man who identified himself as a descendant from the indigenous ancestral Wuwur Branior tribe.
The items Igo was referring to included iron rods. The plan was to hit an iron rod with a fork or a motorbike key—whatever they carried was easy to find and capable of making noise underwater in the Waienga Bay basin. This method was expected to disturb the whales so they could get out of the basin into deeper waters.
The plan never materialized. The sampan barely left the shore when it suddenly capsized. The five passengers—as well as the equipment they had prepared—sunk into the shallow water. They didn’t need to swim; all they had to do was walk through the water’s surface to reach the onshore.
They had to go home soon. Changing clothes which, apart from being wet, “were also rancid from the carcass of the smallest whale,” said Ambrosia Paulina Peni Lamak. She was the only Gempita woman participant in the evacuation process.
They went back to the bay the next day. The 30-year-old Ani, her nickname, remembered how she and her friends from the edge of the fishing boat tried to drop parts of their body into the water, ringing an iron bar and a fork or a motorbike key. “We were trying to ‘repel’ the whales for them to turn back and find the way out,” said Ani.
They tried for days, but the four whales were still at the basin. One afternoon, they gathered on the shores of Waienga Bay, as Ani recalled. The then marine mammals program coordinator at the non-profit organization Jakarta Animal Aid Network, Amang Raga, said: “Isn’t the moon about to enter its full phase soon? That means that sea levels will rise. They [the four whales] may make their way out of the bay basin.”
Amang may not be too far off. The four whales found their way back into the deep waters on the full moon night. They were returning to the vast open sea of Savu while the villagers and most of the evacuation team members were asleep, leaving a long silence along Waienga Bay.
An altered acoustic communication
The Kupang Marine Protected Area (BKKPN Kupang) divided the migration section of whales along the Savu Sea into five periods. It happens in April-June, June-August, August-September, September-October, and October-January. Between January and June, they migrate from the Great South Australian Coastal Upwelling System (GSACUS) area to the north. They will return to the GSACUS between August and October, foraging and breeding there.
Waienga Bay is not adjacent to the Savu Sea. It consists of basins with narrow trenches, with only one exit to the Flores Sea to the north. To return to the Savu Sea, a whale must swim in an inverted U-shape to the south.
“We need to update the migration patterns through the tagging process. Not to mention several cases of cetaceans stranding occurred far off the Savu Sea,” said Imam Fauzi, the head of BKKPN Kupang. Besides, “a more in-depth study is needed on the factors that cause them to swim away from the migration corridors.”
Amang said that some veterinarians managed to take samples from the smallest blue whale’s stranded body before residents in Watodiri cut it in pieces. Still, the cause of five blue whales stranding in the last quarter of 2014 has not been determined. Neither have the exact causes of the stranding of whales and other cetaceans until May 2022 in East Nusa Tenggara.
“Thus far, we have only been able to state the ‘suspected cause’ instead of the ‘definite cause,'” said Imam. He said later that some of the whales that died stranded, “we investigated further through the necropsy method, in collaboration with independent veterinarians.”
A necropsy is a post-mortem conducted to pinpoint the cause of death—and in this case, how they get stranded. “From the necropsy, we found various materials in the whale’s body. For example, plastics, materials for fishing, and debris that is thought to be part of a ship,” said Permana Yudiarso, Head of the Denpasar Marine and Coastal Resources Management Agency. The institutions led by Permana and Imam are both under the auspices of the Ministry of Maritime Affairs and Fisheries.
In addition to plastic, the hearing organs and echolocation organs were found damaged. Odontocetes or toothed whales—sperm whales, orcas, and dolphins—rely on echolocation organs to find their way to orient themselves and, in the end, find prey. Parts of the body that support echolocation are around the odontocetes’ head, such as the internal ear, lower jaw, and melon. Meanwhile, the baleen whales—such as blue whales, humpback whales, and fin whales—communicate by producing sounds at low frequencies.
Physical damage is caused by “a variety of underwater noise sources such as body tissues resembling decompression sickness and auditory damage,” wrote Compton et al. in their findings. Auditory damage “is the physical reduction in hearing sensitivity due to exposure to high-intensity sound and can be either temporary or permanent, depending on the exposure level and duration.”
The physical damage “possibly caused them to fail to have knowledge of surrounding contours before entering a narrow trough or receding water surface with lack of food. Swimming weary, they could end up stranded somewhere,” Amang said.
The syntax of marine mammals, especially whales, is more complex than humans. They have a very diverse calling code. Imagine when a complex communication is interrupted by anthropogenic factors,” said Susilo Hadi, a bioacoustics researcher from Gadjah Mada University in Yogyakarta. The anthropogenic factors referred to by Susilo Hadi include the sound of ship engines, ship propellers, and seismic airguns.
Cetaceans have “acoustic-based communication methods.” Susilo said, “and seismic survey methods affect these acoustic-based creatures at close range.” Seismic survey, he continued, “make noises that the cetaceans don’t want to hear.” Like being in front of a music concert stage, “they will be ‘stuck’ in the middle of various frequencies colliding. The frequency of the stage speakers, the voices of the audiences and their own voice.”
The Ministry of Energy and Mineral Resources does not possess detailed seismic survey data from several companies. On the time marker regarding the seismic surveys conducted in the Savu Sea, “we only have data on a yearly- instead of monthly-basis,” Eko Budi Lelono, the Head of Geological Agency of the Ministry of Energy and Mineral Resources, said.
The last seismic survey conducted in the Savu Sea “was held in 2007. That is, again, according to the data that we have.s
Seismic survey and stranding occurrence
Danielle Kreb was never a part of the necropsy team in cetacean stranding incidents in East Nusa Tenggara. But she spent more than 20 years in marine mammal research to study the migration routes of cetaceans in eastern Indonesia. Speaking from a bay in East Kalimantan, the Scientific Program Advisor of the non-profit organization RASI Conservation Foundation said that, in general, there is possible damage caused by a seismic survey to the echolocation sensing organ.
In the research findings by Compton et al., she continued, “we can say that one of the stranding factors may be related to underwater seismic survey activities.” But, again, “as written by Compton, the causal link between cetacean stranding and seismic survey is disputed due to lack of clear data.”
In Indonesia, it’s a different story. Jaya Ratha, a veterinarian and a trainer with a community that tracks and maintains a database of marine mammal stranding events in the archipelago Whale Stranding Indonesia, said that “we really can’t confirm because the human resources and equipment are not sufficient, so we can’t do further research.”
At the same time, “there is a kind of tug-of-war between related agencies regarding further post-mortem investigation on cetaceans that died stranded in the Savu Sea,” said Permana. He did not specify the agencies.
Kreb prompted that the occurrence of cetaceans stranding is one of the crucial signs of the importance of a more coordinated policy in Indonesia’s marine protected area. “The occurrence of the stranding is an alarm. This is an important ocean issue that must be tackled together,” said the member of the International Union for Conservation of Nature (IUCN) Cetacean Specialist Group.
The most recent stranding occurrence in East Nusa Tenggara was in May 2022, according to data provided by Kupang Marine Protected Area and Whale Stranding Indonesia. That was when a sperm whale was stranded alive in East Flores Regency before its body parts were cut to be consumed at local people’s homes.
Currently, “less than 1 percent of high seas waters are highly protected,” wrote Pew Trusts quoted Bethan C. O’Leary et al. These 99 percent of areas without any flag “are not immune to the impacts of climate change.” At the same time, the cumulative effects of pollution, noise from oil, gas, mineral exploration, shipping, and other human activities “now affect 66 percent of the ocean.”
For cetaceans, “these overlapping stressors in their key habitats are impacting the recovery of some populations and driving severe declines in others,” wrote World Wide Fund for Nature (WWF) in their global report.
Indonesia does not have regulations explicitly regulating noise pollution in its territorial waters. Thus, a 1999 Government Regulation about Control of Marine Pollution or Destruction defines marine pollution as follows: “Sea pollution is the inclusion of living things, substances, energy or other components by human activities into the sea that reduce the function of the marine environment.”
In early August, Permana had, for five days, intensely shared information about a sperm whale that was stranded in Banyuwangi, East Java. In the middle of the shared updates, Permana wrote through an online chat application, “Hopefully this [necopsy results on the sperm whale] can encourage better policies in our seas.”
Better sea policy
It was Sunday, August 21, when Permana came to a story of the necropsy development on a sperm whale stranded in Banyuwangi. “We haven’t received the necropsy results,” said Permana. The results usually will come out before two months.
However, he said, “our initial assumption is that the sperm whale’s navigation system was damaged somewhere so that it entered Banyuwangi waters. That could be considered an anomaly.” Referring to the tagging on different whales a few years back, “there was no indication that they migrated into the waters of Banyuwangi.”
According to the tagging, whales swam from the Australian continent to the Savu Sea or further east, to the Banda Sea or the Arafura Sea. “Let us wait for what the team found in the necropsy,” said Permana. What is clear, he said on a separate occasion, “that there’s a lot of problems in the Savu Sea, one of the largest contributors to the marine conservation areas in Indonesia.”
Indonesia’s marine conservation areas reached 28 million hectares in 2021, or 7.12 percent of its territorial waters. Of the total marine conservation area, 3.35 million hectares are in the Savu Sea, according to a document provided by BKKPN Kupang.
Indonesia has at least 14 marine-related institutions, said I Made Andi Arsana, a geodetics engineering lecturer and researcher at Gadjah Mada University in Yogyakarta. Having expertise in maritime boundaries, Andi recognizes the complexity of managing policy coordination between these government institutions in Indonesia’s territorial seas.
“To be honest, there are countless theses that have emerged from the sectoral ego between these dozens of institutions,” Andi said. “The Indonesian government often establishes new institutions which, they hope, will be able to strengthen the coordination,” he said.
But, instead of strengthening coordination, these new institutions complicate the collaboration needed from the marine-related institutions. In practice, these institutions need constant affirmation about each other’s jurisdictions, Andi said. The absence of these clear-cut limits “allows anyone to argue that their activities do not enter the Savu Sea’s cetaceans conservation area,” he said.
Andi, who in 2008 was assigned as a marine mammal observer aboard a seismic survey vessel in the Indian Ocean, encouraged parties involved in initial offshore oil and gas exploration to “at the very least conduct seismic surveys outside the months of cetaceans migration in the Savu Sea.”