Effect of water quality on rainbow trout performance : Water oxygen level in commercial trout farm “Kala ja marjapojat”
Avkhimovich, Dmitry (2013)
Mikkelin ammattikorkeakoulu
2013
All rights reserved
Julkaisun pysyvä osoite on
https://urn.fi/URN:NBN:fi:amk-201305025924
https://urn.fi/URN:NBN:fi:amk-201305025924
Tiivistelmä
Water quality is a combination of chemical, physical and biological parameters that affect the growth and prosperity of cultured fish. The success of a commercial aquaculture activity depends on the op-timal environment conditions for accelerated growth at the lowest cost of resources. Water quality affects the general condition of the cultured body as it determines the conditions of health and growth of the cultured fish. The water quality is, therefore, an essential factor to consider when planning a high aquaculture production.
Although the environment of fish aquaculture is a complex system, consisting of some water quality variables, only few of them play a crucial role. Critical parameters are temperature, suspended solids and dissolved oxygen, nitrite, ammonia, alkalinity and carbon dioxide. However, the dissolved oxygen is the most important parameter, requiring continuous monitoring in aquaculture production systems, because fish aerobic metabolism requires dissolved oxygen. In this work the most significant changes in the quality of the water environment are described.
The range of environmental impact depends on the amount of wastes produced by the studied cages, and is evaluated by the stocking density, amount and type of feed, feed composition, size of granules and the physicochemical conditions where cages are located. The level of fish production that would be sustained in an area is variable depending on different impacts.
It was observed that the trout farm effluents had no significant impact on the water quality. There were no significant differences in most of water physicochemical factors between cages and the water nearby cages. The results suggest that oxygen saturation levels affect both feed conversion ratio and growth performance of the rainbow trout. The highest growth rate and lowest feed conversion ratio in cages can be found at higher oxygen saturation levels, between 80 - 100 %. However, more research is necessary in order to know at which saturation point the growth is maximized. The water temperature varied greatly. Also this factor influenced the fish growth extremely. The feeding tables presented incorrect coefficients for feeding the fish.
Although the environment of fish aquaculture is a complex system, consisting of some water quality variables, only few of them play a crucial role. Critical parameters are temperature, suspended solids and dissolved oxygen, nitrite, ammonia, alkalinity and carbon dioxide. However, the dissolved oxygen is the most important parameter, requiring continuous monitoring in aquaculture production systems, because fish aerobic metabolism requires dissolved oxygen. In this work the most significant changes in the quality of the water environment are described.
The range of environmental impact depends on the amount of wastes produced by the studied cages, and is evaluated by the stocking density, amount and type of feed, feed composition, size of granules and the physicochemical conditions where cages are located. The level of fish production that would be sustained in an area is variable depending on different impacts.
It was observed that the trout farm effluents had no significant impact on the water quality. There were no significant differences in most of water physicochemical factors between cages and the water nearby cages. The results suggest that oxygen saturation levels affect both feed conversion ratio and growth performance of the rainbow trout. The highest growth rate and lowest feed conversion ratio in cages can be found at higher oxygen saturation levels, between 80 - 100 %. However, more research is necessary in order to know at which saturation point the growth is maximized. The water temperature varied greatly. Also this factor influenced the fish growth extremely. The feeding tables presented incorrect coefficients for feeding the fish.