Edexcel IGCSE Biology 复习笔记 5.1.6 Fish Farming

Benefits of fish farming

• Most fish are still caught in the wild (i.e. in the open ocean or in freshwater rivers and lakes)
• However, overfishing has lead to dramatic declines in many fish populations
• Fish farms are ways of raising large numbers of fish in a small space to provide food (protein) for humans
• This has several advantages over wild-caught fish, including:
  • The ability to selectively breed fish to ensure high quality, fast-growing fish
  • The ability to protect against predators
  • The ability to control water quality (many wild-caught fish have significant levels of pollutants such as mercury in their flesh)
  • The ability to control feeding to ensure rapid growth

   

Methods used in fish farms to ensure high yield

• Within fish farms, large numbers of fish are kept in freshwater or seawater enclosures and are carefully monitored and controlled in many different ways
• This helps to ensure high yields (fast growth of healthy fish)
• The methods used include:
  • The control (and maintenance) of water quality
  • The control of intraspecific predation
  • The control of interspecific predation
  • The control of disease
  • The control (and removal) of waste products
  • The control of the quality and frequency of feeding
  • The use of selective breeding

   

Fish Farming Methods Table

转载自savemyexam