**4. Threats**

Waters in peat areas are unique ecosystems and are important habitats for various types of fish. However, this ecosystem is vulnerable to various disturbances, especially from human activities. Yesi and Tantoro [26] reported that more than 90% of the area of peat swamp forest in Southeast Asia has been degraded or converted. Many peatlands have been converted into oil palm plantations, acacia plantations to provide raw materials for the paper industry, and expansion for agricultural land. The clearing of peatlands into oil palm plantations is very intensive and continues to this day, especially in Sumatra and Kalimantan. However, this does not mean that in other areas there is no conversion of peatlands into oil palm plantations. Even the opening of oil palm plantations has also penetrated the easternmost region of Indonesia [37, 38]. Conversion of peatlands into plantation areas is a serious threat to the sustainability of the fish resources in it. Land clearing will change the ecological function of the surrounding waters, including increasing sediment and turbidity levels, increasing water temperature, reducing food sources for fish from outside the waters (allochthonous), decreasing shelter for fish, and changing river currents and flows. In addition, waste from the use of weed killers and fertilizers will enter the waters of rivers, lakes, and swamps, which are important habitats for fish and other aquatic biota.

Conversion of peatlands into agricultural areas is also easy to find in Indonesia. Yesi and Tantoro [26] reported that agricultural activities on peat areas in Riau are with crop commodities such as pineapple, chili, and tomatoes. Previously, Haryono [17] reported that Central Kalimantan is a province whose peat area was once used as a million-hectare peatland development project for agricultural activities, especially for rice fields. However, the success of these activities was not as expected, so many were stopped. The impact of these activities is the number of artificial canals that change the condition of the natural waters.

The threat to the sustainability of fish resources in the waters around peatlands is forest fires. Almost every year, especially in the dry season, forest fires occur in peatland areas [19, 39, 40]. The causes of forest fires in Indonesia include land clearing, and some are unintentional. The intensity of these forest fires is very high and a concern for human health. The forest fires will have a negative impact on the sustainability of fish communities in the surrounding waters. In fact, fish whose habitat is in peatland waters have a unique pattern and color intensity, and many are endemic species [19, 41]. In addition, there are peat mining activities which are used as fuel [18].

Waters in peatland areas are also a focus for inland fishermen [13, 26]. If there is a decrease in the diversity of fish species, it will have an impact on a decrease in their income. In general, fishermen in peatland areas still catch fish using environmentally friendly tools. However, some of them use fishing gear that is not environmentally friendly, including using electric shocks, poison/tuba, and nets placed at the mouths of creeks.
