TULUNGAGUNG – The risk of mass fish deaths in Tulungagung is rising as the seasonal transition, known locally as pancaroba, brings extreme temperature changes. These conditions are starting to affect fish farming across the region.
The Tulungagung Fisheries Agency has asked fish farmers to stay alert. Officials want them to take preventive steps to reduce the risk of large-scale fish deaths during unstable weather.
Dedy Azhar, Head of Aquaculture at the local fisheries office, said sudden changes in water temperature are the main cause of fish stress. He urged farmers to monitor pond conditions regularly and watch for early warning signs.
“Fish under stress usually move more slowly, stay away from their group, and show pale body colors instead of bright ones. These are early warning signs before disease attacks,” he said.
Dedy explained that temperature differences between day and night can reach 10 to 12 degrees Celsius during the transition season. This forces fish metabolism to work harder and weakens their immune systems.
As a result, fish become more vulnerable to bacterial infections and fungal diseases. Harmful bacteria can enter through small wounds or through the gills when fish are weak.
“This is what often leads to mass fish deaths,” he explained.
To prevent losses, the fisheries office encourages fish farmers to apply simple but effective solutions. One important step is keeping pond water temperature stable during the day.
Farmers can use shade protection such as paranet nets or banana leaves. These methods help reduce direct sunlight and prevent sudden temperature changes.
“The main point is to prevent drastic temperature changes in the water. Temperature stability is very important for fish health,” he added.
The agency also recommends giving supplements such as vitamin C to improve fish immunity. However, farmers should not force feeding when fish already show signs of illness.
If fish refuse to eat, leftover feed will settle at the bottom of the pond. It can then turn into ammonia, which creates another serious danger for fish survival.
“If the feed is not eaten, it will become ammonia and harm the fish,” Dedy stressed.
The Fisheries Agency continues to coordinate with the Meteorology, Climatology, and Geophysics Agency (BMKG). This helps officials monitor weather changes and provide updates to fish farmers.
Through field extension officers, the agency keeps sharing warnings and preventive advice. Officials hope these efforts will protect fish harvests and prevent economic losses during the seasonal transition.

