Aquaculture 314 Flashcards
What issues limit the development of Aquaculture?
- Pollution
- Nitrogen input
- Sedimentation
- Eutrophication
- Disease
- Fouling
- Genetic issues
- Biosecurity
- Aesthetics
- Social licence
What is the issue with recent implications (2014) for resource consent applications?
Limitations of getting concent in areas of outstanding natural landscape and outstanding natural character.
- What are the three biggest threats aquaculture could create?
- Bio-invasion of marine farms or cultured stock
- Bio-invasion of the environment or wild populations
- Impacts of invasive species
Name five ways an aquaculture site can be infected
- Infected culture related feed
- Infected culture related stock transfer
- Infected culture related equipment transfer
- Infected culture related vessel movement
- Non aquaculture source of pests (natural dispersal or vessls or activities)
How can water transfer play a role in infecting an aquaculture site
- Planktonic dispersal phase (e.g. invertebrate larvae)
- Fragments of colonial organisms (e.g. sea squirts, sponges)
- HAB species and holoplankton (e.g. comp jelly)
- Infected water (pathogens)
What is stock transfer?
Stock infected with parasites or pathogens
How can equipment vessel transfer infect a finfish culture site
- external fouling
- ballast water
- bilge water
- anchors
- ropes
- deck spaces
- nets
- buoys
What are some non-aquaculture sources of pests that can infect an aquaculture site?
- natural dispersal
- From adjecent marine farms
- From natural habitat
- wild fish to caged transfer of pathogens or parasites
- non aquaculture vessels
- recreational fishing
What is susceptibility to disease caused by?
High stocking densities
What parasite causes soft flesh syndrome in salmon?
Salmon kudoa -> breaks down muscle fibre in fish
- Turns flesh to a jelly-like consistency making it commercially worthless.
- No known cure.
- Kudoathyristescontamination is usually first detected when salmon are slaughtered and processed.
- Kudoaparasite affects 20–50 percent of all salmon produced in British Columbia,
- Costing the industry in B.C. is at least $30 to $40 million annually
What is one of the common parasites causing damage to salmon aquaculture?
Salmon lice Lepeophtheirus salmonis
- Parasitic copepod
- Infestations in Canada, Norway, Scotland and Ireland
- Lice chew on salmon creating open lesions
- Open wounds create pathways for other pathogens
How can pests from marine farms be spread to the environment?
- Natural planktonic dispersal
- Active migration by mobile species
- Detachment passive or active defouling
What killed 28.000 tonnes of pilchards in OZ in 1998?
A herpes-like virus introduced in imported baitfish
What is Abalone Viral Ganglioneuritis (AVG)?
- A herpes like virus
- First detected in wild abalone in May 2006 (Taylor Bay)
- Spread along coast at a rate of 5-10km per month
- By 2007 infected 200km of Victoria coastline
- affects nervous system
- affects al age classes
- transmission through direct contact with infected animals or waste
- High mortality
What are the clinical signs of AVG?
- Swollen and protruding mouth parts
- Protrusiun if the radula
- Reduced activity of the pedal muscle
- Edges of the foot curl inwards
- Inability to self right or adhere to substraten
