Disease in aquatic Flashcards
how much has demand for fish or shellfish grown over the last few decades?
9% - expected to reach more than 180 million tonnes by 2020, majority will have come from farmed fish - as majority of wild fisheries will be stagnant or overfished
how do fishing contribute to the Welsh economy?
fisheries contribute more 30 million a year to rural and coastal economies - aim is to increase aquaculture by 2020
what are the main challenges facing aquaculture?
reduce ecological footprint
reduce DISEASE risk
prevent introduction of invasive species
who are the main parasites of fish species?
mainly microparasites, however there are, obvious ones such as sea lice
very common, liquid a good transfer for parasites
co evolution dating back up to 350 mya
high host levels and stress in aquaculture environments
what is gyrodactus salaris?
small ectoparasitic worm
secondary infections result in death of host
£320 million loss to Norwegian salmon industry
what is the issue relating to the impact of fish farms on wild stocks?
FARM ESCAPEES: 33 tonnes on one occasion in Norway - contribute to disease spreading
Interbreeding between farmed and wild fish can influence disease resistance
Endemic parasites have become pathogens within aquaculture - SEA LICE
What are sea lice?
crustaceans,
cost scottish Salmon industry £30 million/year to contain
high host densities and protected coastal waters so ideal conditions for lice
Single host with eight life stages
how many sea lice be treated?
medicinal control via feed or bath e.g. paramove and salmosan
wrasse and lumpsuckers natural predators of ectoparasites on fish and their use active in biological farms
what fish diseases are transferrable to man?
parasitic worm infections have decreased worldwide accept where consumption of pickled fish is traditional
Coombs and Crompton (1971) 76 human pathogens that have fish hosts:
Anisakiasis
Tapeworm
Bacterial infections - fish TB
