Sustaining freshwater cage aquaculture amid climate change

In recent years, freshwater cage aquaculture in rivers and reservoirs has become an important livelihood for many households in Dak Lak Province. In addition to making effective use of water surface areas, this production model has created jobs and increased incomes for communities living around reservoirs. However, increasingly extreme weather conditions and the impacts of climate change are posing significant challenges to cage aquaculture, highlighting the need for appropriate management measures and production practices.

Proactive adaptation

According to the Department of Agriculture and Environment of Dak Lak Province, the prolonged El Nino event in recent years has caused water levels in many rivers and reservoirs to decline significantly, directly affecting aquaculture environments. At the same time, environmental monitoring results from farming areas across the country indicate that several water-quality indicators have exceeded permissible thresholds, increasing the risk of disease outbreaks among aquatic species.

Particularly during seasonal transitions, sharp fluctuations in temperature, rainfall and water quality are common. These factors can cause fish to experience environmental stress, weaken their immune systems and even result in mass mortality if not monitored and addressed promptly.

In response, the Department of Agriculture and Environment of Dak Lak Province has requested the Sub-Department of Fisheries and Islands Affairs, along with communes and wards where freshwater cage aquaculture is practiced, to direct relevant agencies and fish-farming establishments to implement measures aimed at minimizing losses for farmers and promoting the sustainable development of cage aquaculture in rivers and reservoirs.

In a directive on strengthening the management of freshwater cage aquaculture in response to climate change, Mr. Nguyen An Phu, Deputy Director of the Department of Agriculture and Environment of Dak Lak Province, called on local authorities to review and reorganize cage systems in accordance with approved planning schemes, ensuring appropriate stocking densities and minimizing adverse impacts on water quality. Farmers are also encouraged to use fingerlings with clear origins and proper quarantine certification to reduce disease risks from the outset of the production cycle.

Given increasingly unpredictable weather conditions, feed management and fish husbandry practices have also been emphasized. Aquaculture operators are advised to use quality feed and supplement fish diets with vitamins and minerals to improve disease resistance. During periods of adverse weather or deteriorating water conditions, feeding should be reduced or temporarily suspended to lessen stress on the fish’s digestive system.

Farmers are further encouraged to prepare essential support equipment, such as water pumps, oxygen generators, and aeration systems, to respond quickly to environmental fluctuations. Regular monitoring of environmental indicators in the early morning and late afternoon is recommended to detect abnormalities early and enable timely intervention.

For high-risk areas, technical authorities advise farmers to reinforce protective measures around cages and, where necessary, relocate cages to more suitable locations to minimize potential losses.

Alongside technical measures, stricter control of production inputs is also being strengthened. The Department of Agriculture and Environment of Dak Lak Province has urged local authorities to strictly prevent the use of veterinary drugs of unknown origin, prohibited substances and products not approved for aquaculture use.

Towards sustainable value creation

According to the Department of Agriculture and Environment of Dak Lak Province, localities should promote the development of reservoir aquaculture products that meet high-quality standards such as VietGAP, GlobalGAP, Aquaculture Stewardship Council or equivalent certification schemes. This is considered an important solution for enhancing product value and meeting the increasingly stringent demands of both domestic and international markets.

In addition to standardizing production processes, the Department of Agriculture and Environment encourages farmers to maintain detailed production records and retain documentation on fingerlings, feed, veterinary drugs and water-treatment products. These records provide an important basis for traceability, enhance transparency and strengthen consumer confidence.

Dak Lak Province is also promoting the development of cooperatives, cooperative groups, and value chain linkages in cage aquaculture. Through production and marketing partnerships, farmers can reduce input costs, improve market access and become more resilient to price fluctuations.

Environmental monitoring and early-warning systems will continue to be strengthened across the province. The relevant authorities plan to increase the frequency of water sampling and quality monitoring during sensitive periods such as seasonal transitions, prolonged heatwaves and storms, enabling timely advisories to be issued to fish farmers.

At the same time, aquaculture operations will be subject to regular inspections and supervision to ensure compliance with regulations on food safety, traceability, seed quality and environmental protection.

In this regard, Mr. Nguyen An Phu, Deputy Director of the Department of Agriculture and Environment of Dak Lak Province, called on the Sub-Department of Fisheries and Islands Affairs to strengthen oversight of the quality of aquatic seed stock, aquaculture feed and environmental treatment products. He also urged the agency to conduct inspections of compliance with aquaculture regulations and to strictly handle any violations discovered, while publicly disclosing enforcement results in accordance with the law.