General Information
The İznik Dereköy Trout Farm is a facility located in İznik district of Bursa province that applies conventional methods in rainbow trout production. Structurally, it adopts the classic flow-through production model and uses primarily U.S.-origin eggs. Instead of a complete hatchery cycle, the farm operates under an “intermediate production” system; in other words, it purchases juveniles at a certain weight and grows them to marketable sizes. While this model supports domestic production capacity, it also increases dependency on external sources. The facility is an important example for small- and medium-scale producers in the region, ensuring continuity of trout supply. Figure 1 shows images of the facility.
3.2. Water Source
A key feature of the facility is its exclusive use of natural spring water. The water is directed straight from the source to the ponds without filtration or treatment and without recirculation. This provides a continuous supply of fresh water for the fish but leads to very high consumption volumes. As in many conventional trout farms in Turkey, the natural flow and oxygen levels of the water have been found sufficient for production. However, as recirculating systems become widespread globally, such “flow-through” systems are known to be inefficient in terms of water use. Figure 2 illustrates the facility’s water source and distribution.
3.3. Production Stages and Equipment
Production starts with obtaining fry that have completed the hatchery process from U.S.-origin eggs. The facility raises juveniles of 5–10 grams in ponds and grades them until they reach marketable sizes of 100–250 grams. The ponds are reinforced concrete and designed according to the classical surface flow system. Equipment includes feeding units, net scoops, and manual measuring devices. Advanced automation or biofiltration technologies are not present at the facility. Production relies mostly on manual labor, which increases operating costs but contributes to employment.
Water Quality and Analyses
Because the source water is used directly, its physical and chemical parameters are highly suitable for production. Average temperature ranges between 8–12 °C throughout the year, and dissolved oxygen levels are around 9 mg/L. Teams from the Ministry of Agriculture and Forestry (Türkiye) regularly take samples from the water and conduct necessary analyses. At least once a year, fish samples are examined in university laboratories for food safety. However, the facility lacks an automatic sensor system for continuous water-quality monitoring, which is considered a shortcoming compared with international sustainability standards.
Chemical Use
One of the most critical findings is the manual injection of medication into juvenile fish of 5–10 grams under veterinary supervision to protect fish health. This increases labor demand and raises questions about fish welfare. Apart from this, disinfection or antibiotic use at the facility is negligible. Chemicals are limited to disease treatment, and feed additives are minimal. Although usage volumes are lower than those under EU aquaculture regulations, they lag behind the “zero-chemical” approach seen in modern RAS facilities.
Suppliers
Eggs used at the farm are mostly of U.S. origin. Some of the juveniles raised are sourced from local facilities in Bursa and Kütahya. Feed supply is provided through international brands operating in Turkey. This leaves the enterprise dependent on external sources and under cost pressure. Nevertheless, cooperation with local suppliers contributes to the regional economy. Such partnerships are particularly important for enabling small producers to remain in the sector.
Waste and Waste Management
Wastewater management is simple, as in conventional systems: water leaving the ponds is discharged directly into the stream. The organic load consists of fish feces and feed residues. Since there are no pre-treatment structures such as settling ponds, the effects of this water on the ecosystem pose potential risks. Solid waste arises mainly from kitchen and daily operations and is regularly disposed of thanks to municipal collection services. Compared with good practices in Europe, there is significant room for improvement in waste management at this facility.
Cost Items
The main costs of the facility include egg imports, feed expenses, water and land rent, and labor costs. Especially the increase in feed prices linked to foreign exchange rates poses a serious burden. Land rent is also higher than in other regional facilities. In contrast, product sales prices remain low, narrowing profit margins. The average cost per fish is 25 TL, while revenues remain at the same level. Therefore, the enterprise’s sustainability largely depends on restaurant sales and tourism activities.
Challenges
Over the years, the facility has been affected by fluctuations in feed prices, disease risks, and regulatory restrictions. During the 2001 economic crisis, feed prices increased fourfold, severely straining operations. Additionally, legal processes regarding land use under Forest Law No. 6831 have been problematic, and operating a restaurant alongside production has been subject to litigation. Labor needs vary seasonally, and manual interventions against fish diseases increase the workload. These challenges make it difficult for the enterprise to take steps toward modernization.
Innovation
The level of innovation at the facility is limited. In the past, small-scale feed production trials were conducted to reduce feed costs, and the installation of a hydroelectric power plant provided energy savings. Beyond this, there are no modern RAS, sensor systems, or automation applications. The innovative approach has been more about cost reduction during crisis periods. While global trends today move toward bio-integration, aquaponics, and zero-waste systems, this facility continues to operate with a more traditional production mindset.
Employees
Because the production process requires intensive labor, the workforce is a key element. Typically, there are 8–12 employees at the facility, with the number exceeding 20 in summer due to seasonal workers. Most workers are men performing pond-side tasks, while women are mainly employed in kitchen and service areas. Ages range from 18–60. Work is organized in a double-shift system, and most of the workforce comes from the local community.
Recommendations
A series of recommendations have been developed to enhance the facility’s sustainability. First, partial transition to recirculating water systems would improve water-use efficiency. Replacing manual injection with automatic dosing or bath treatments would reduce labor and improve fish welfare. In waste management, settling ponds and biological filtration systems should be installed to limit the organic load discharged into receiving waters. Additionally, cooperation with domestic feed producers should be increased to reduce feed costs, and the facility should be included in R&D projects. Table 1 presents a summary of information about the İznik Dereköy Trout Farm.
Table 1. Summary of information about the İznik Dereköy Trout Farm
|
GENERAL |
|
| Facility Area | Located in İznik district, Bursa province. |
| Water Source | Natural spring water. |
| Water Quality Characteristics | Average temperature 8–12 °C year-round, dissolved oxygen about 9 mg/L. Samples are taken regularly from the water source for monitoring. |
|
ECONOMY |
|
| Income/Expenses | Average cost per fish is 25 TL, while sales revenues remain at the same level. The enterprise’s sustainability largely depends on restaurant sales and tourism activities. |
| Suppliers | Eggs used at the farm are mostly of U.S. origin. Some juveniles are sourced from local facilities in Bursa and Kütahya. Feed supply is provided through international brands operating in Turkey. |
|
SOCIAL |
|
| Number of Employees | Typically 8–12 employees, exceeding 20 in summer with seasonal workers. |
| Age Distribution | 18–60 |
| Work Areas | Male workers handle pond-side tasks; female workers are mainly employed in kitchen and service areas. |
| Work Arrangement | Double-shift system. |
|
ENVIRONMENT |
|
| Energy Use Areas: | – |
| Energy Produced | – |
| Generated Waste | Wastewater containing fish feces and feed residues, as well as solid waste from kitchen and daily operations. Solid waste is regularly disposed of through municipal collection services. |
|
INNOVATION |
|
| Implemented Practices | Past trials of small-scale feed production to reduce costs; installation of a hydroelectric power plant for energy savings. |