Look How people are ignoring the extinction of Batak fish

• Batak fish (Neolissochilus thienemannie) is an increasingly rare fish endemic to Lake Toba. The IUCN red list includes it in the endangered category. Decree of the Minister of Maritime Affairs and Fisheries Number 1/2021 includes it as a protected fish.
• Factors causing the Batak fish population in the Lake Toba area to decrease are environmental changes, namely declining water quality, agricultural waste around the lake entering the waters, overfishing, introduction of introduced fish species, and fishing gear that are not environmentally friendly.
• Anthropologist Robert Sibarani said the traditional ceremony in the ancestral tradition of the Toba Batak tribe is closely related to Batak fish. However, due to its scarcity, it is now increasingly shifting and being replaced with carp as well as buffalo and pork.
• Sekar Larashati, a Limnologist and Water Resources expert at BRIN, said that habitats in rivers and lakes, especially in mountainous areas, would be suitable for Batak fish cultivation and conservation.

Since hundreds of years ago the Batak tribe who live around the shores of Lake Toba have an attachment to the native fish species that exist in the waters of the lake. It is Batak fish ( Neolissochilus thienemannie ), a type of fish that is often used in traditional rituals and ceremonies, as well as for traditional culinary delights.

Environmental degradation and the introduction of foreign fish species such as tilapia and tilapia are increasingly marginalizing their existence. Due to its rarity and on the verge of extinction, the Batak fish is protected as a protected fish species based on the Decree of the Minister of Maritime Affairs and Fisheries Number 1 of 2021.

"The introduction of fish species that are not native to their natural habitat has become a competitor for the Batak fish," Sekar Larashati, a Limnologist and Water Resources expert at National Agency for Research and Innovation, told Mongabay via telephone interview.

According to him, the causes of the decreasing Batak fish population in the Lake Toba area are environmental change factors such as declining water quality, the entry of agricultural waste into Lake Toba waters, overfishing, and fishing gear that are not environmentally friendly.

As an example of the fishermen in Bakkara, Humbang Hasundutan now admits that he has never found Batak fish in the catchment area anymore. There are only tilapia and small fish that are not native to the waters of Lake Toba.

In 2016 the LIPI Limnology and Water Resources Research Center Team examined the presence of Batak fish in the Bonan Dolok River, Samosir Regency, which is the Lake Toba Watershed.

"The type of N was not identified at that time. thienemanni there. People know that the Batak fish is like the Jurung fish, indeed at a glance they are similar," said Sekar.

The Batak fish is indeed different from the genus Tor fish or what is commonly called the Jurung fish or Dewa fish. This type of tor is found in rivers in Sumatra.

As for the type N . theimemanni have a flat, silvery elongated body, with 10 scales on the front of the dorsal fin and 26 along the lateral line. There are 10 rows of irregular pores on the sides of the muzzle and under the eyes. The back groove down to the lower lip is cut off in the middle.

This fish in the Cyprinidae family is an omnivorous fish and lives in fast and clear rivers. In 2020 the IUCN Red List declared N. Thienemannie an endangered species.

Rachmad, Sihombing and Sabariyah in their research published in the journal Applied Maritime Affairs and Fisheries (2019) found 25 male and 13 female Batak fish with a length of about 16 cm - 41.9 cm in three rivers in three districts in North Sumatra.

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The function of Batak fish from an anthropological perspective

Then how can Batak fish be preserved? Robert Sibarani, Professor of Anthropology at the University of North Sumatra said that the local wisdom of local people can be an alternative for saving.

“In the past, all ceremonial activities used fish, starting from the cycle of birth to death. The Batak people use Batak fish as a dish at parties," he explained.

In the Horja Mangupaupa or Batak Toba traditional wedding ceremony, the bride's family presents this fish to the groom. Instead the groom gave an offering in the form of buffalo meat.

The philosophy is that Batak fish is a symbol of Boru Muli, the bride (oroan) , and giving Batak fish to men is called Ulu ni Dekke Mulak.

“Nowadays Batak fish are scarce, the price per head reaches millions of rupiah, so the ceremony using Batak fish is slowly being abandoned, replaced by goldfish, buffalo meat or pork. This shift has been going on since 70-80 years ago,” said Robert.

In traditional ceremonies, Batak fish is served in the form of arsik' , which is a dish of yellow seasoned fish mixed with spices.

The myth that has developed in the residents of Bonan Dolok Village, Samosir believes that Batak fish only comes out at certain times. For those who see the fish will get fortune or luck.

His arrest should not be arbitrary. It is only consumed to treat certain diseases, through prayers and ceremonies at the location where the Batak fish was caught.

“Fish that are near the banyan tree should not be taken or caught carelessly. If fish are caught on purpose, cooked for 7 days and seven nights, the fish will not be cooked. There will be reinforcements for those who eat them,” said Robert.

He considered such myths to be an alternative in preserving Batak fish in their natural habitat and reducing overfishing. Robert also mentioned the need for cultivation efforts so that future generations can get to know Batak fish.

Cultivation location

To find a location for cultivation that is in accordance with the suitability of its natural habitat, it is necessary to have a flow of water that is still natural, clear and rich in oxygen.

Sekar Larashati suggested a location in the waters of Bonan Dolok Village. As a primary division freshwater fish group, these fish are suitable for habitat in rivers and lakes in mountainous areas. "The village of Bonan Dolok has the potential to be developed into a Batak fish conservation area," said the graduate of the Danish Technical University doctoral program.

Bonan Dolok in Sianjur Mulamula District, Samosir is a village on the edge of Lake Toba. It has a good landscape, surrounded by hills, traditional rice fields, and there is a waterfall.

The water flows all year round, and the upstream is still natural forest," he continued.

He believes that conservation of the Batak fish habitat will protect other biota that live around it, such as snails and worms.

If Bonan Dolok is made into a conservation area, there are things that need attention, for example disposal of domestic (household) waste, industrial waste, and mining activities. In addition, the government needs to cooperate with local communities to protect the ecosystem so that it has a positive impact on downstream water quality (Lake Toba).

“Conservation efforts must be based on study and research. Local residents also need to be involved and supported and become a priority program for the local government," he concluded.