Fish Farming Flashcards
why is fish farming now meeting a shortfall in fish?
stocks in the wild have been depleted
what are the most commonly farmed fish?
salmon and trout
what do farmers feed fish to promote rapid growth?
high lipid and protein food - regular feeding with small amounts to ensure it gets eaten
what happens if you put several species in one pond?
interspecific competition - different species will compete for food and some species may be wiped out
predation - carnivorous species will prey on other fish
what is the solution to interspecific competition and predation?
place different species in different ponds, tanks etc - use nets to seperate species and wild/farmed populations
how can farmers prevent predation from birds?
by placing a cover/net over the ponds
what happens if you put too many individuals in one pond?
intraspecific competition - larger individuals will out compete smaller individuals for food or larger individuals may prey on smaller individuals
infectious diseases - parasites and pathogens spread quickly if the fish are too close together
what is the solution to intraspecific competition and infectious diseases?
seperate fish by age and size - remove dead or infected fish quickly and add antibiotics to the water to kill bacteria and antifungals or chemicals to kill parasites
how do fish farms affect the environment?
- fish may escape and out compete or interbreed with local species reducing biodiversity and upsetting the local ecosystem
- parasites or pathogens can be introduced into ecosystems by farmed fish
- excess feed and waste from fish can cause eutrophication and a reduction in oxygen concentrations in the water (reduced by limiting feed, clearing waste and bubbling oxygen through water)
