Fishwelfare

FISH WELFARE
2010
RUBY PIZARRO
AQUA 1042 Aquaculture Research Project
6/15/2010

Contents

Abstract 4
Introduction 5
WATER QUALITY 6
Oxygen 6
Carbon Dioxide 7
Temperature 7
Suspend Solids 8
STOCKING DENSITIES 10
FEEDING 12
Meal frequency 12
Feed Rate 12
Influential Pointin the Welfare fish 13
FISH GRADING 14
Purpose 14
Disadvantages 14
RESULTS 15
REFERENCES 16

Abstract
The objective of this project was to research the most influential points in the welfare of Atlantic salmon in their freshwater phase. Among the main factors impacting on the welfare of Atlantic salmon farming is the water quality, fishdensity, diet and the process by which are classified according to the size of the fish. The conditions to which fish are subjected depends much of its production and final quality. Importantly, the interaction of these factors is key to the effectiveness of salmon farming systems and the contribution to the protection of the marine species. The objective of any commercial fish farming is toobtain economic returns in the production of fish, as high as possible. This performance is directly proportional to production, and this depends crucially on good fish. A stock of fish with a low level of welfare, shows a low yield (low growth, high feed conversion rates, mortality above normal) and not commercial interests. Therefore, most of the recommendations made to respect the welfare of fish,are absolutely in line with recommendations on how to achieve maximum performance of a stock of fish in culture. The welfare of the culture can have positive effects on resistance to diseases. Improved management is key to not only increasing production but also guarenting a higher quality and safer product for consumption.

Introduction
The following report describes four factors thatinfluence the welfare of the fish. When any one of these factors is at a disadvantage from the rest or fails, the welfare of fish is affected automatically. According to literature based on raising hatchery salmon we can find step by step how to carry out an adequate production of fish. However, the secret is in knowing how to interpret correctly physiological and behavioural changes of fish. Thebiggest challenge in raising fish is to preventing the spread of disease which leads to an imbalance in the production, i.e., loss of fish affected by the disease, time required for fish to recovery after disease, investment in medicine, labour and more. International institutions such as EFSA (European Food Safety Authority) with project Welfare Quality has shown that improving the welfare ofculture can have positive effects on resistance to diseases and illnesses. Fish welfare is an important issue for the industry, not just for public perception, marketing and product acceptance, but also often in terms of production efficiency, quality and quantity

Are water quality, stocking densities, feeding and grading adequate measure fish welfare?

WATER QUALITY
“Water quality determines toa great extent the success or failure of a fish culture operation. Physical and chemical characteristics such as suspended solids, temperature, dissolved gases, pH, mineral content, and the potential danger of toxic metals must be considered in the selection of a suitable water source”. (Piper, R., McElwain, I., Orme, L., McCraren, J., Fowler, L. & Leonard, J. 1982). Water quality is one ofthe most important factors contributing to the welfare of the fish as it is the environment where they live and develop all phases of life. Based on this, we find that different parameters need to be measured to maintain a good check of the water quality.
Oxygen
Many experts conclude that oxygen is one of the most important parameters in the life of the fish. It was established that the...