Aquaculture 314

Question 1

What issues limit the development of Aquaculture?

Answer 1

• Pollution

1. Nitrogen input
2. Sedimentation
3. Eutrophication
4. Disease
5. Fouling

• Genetic issues
• Biosecurity
• Aesthetics
• Social licence

Question 2

What is the issue with recent implications (2014) for resource consent applications?

Answer 2

Limitations of getting concent in areas of outstanding natural landscape and outstanding natural character.

Question 3

• What are the three biggest threats aquaculture could create?

Answer 3

1. Bio-invasion of marine farms or cultured stock
2. Bio-invasion of the environment or wild populations
3. Impacts of invasive species

Question 4

Name five ways an aquaculture site can be infected

Answer 4

1. Infected culture related feed
2. Infected culture related stock transfer
3. Infected culture related equipment transfer
4. Infected culture related vessel movement
5. Non aquaculture source of pests (natural dispersal or vessls or activities)

Question 5

How can water transfer play a role in infecting an aquaculture site

Answer 5

• 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)

Question 6

What is stock transfer?

Answer 6

Stock infected with parasites or pathogens

Question 7

How can equipment vessel transfer infect a finfish culture site

Answer 7

• external fouling
• ballast water
• bilge water
• anchors
• ropes
• deck spaces
• nets
• buoys

Question 8

What are some non-aquaculture sources of pests that can infect an aquaculture site?

Answer 8

• natural dispersal
• From adjecent marine farms
• From natural habitat
• wild fish to caged transfer of pathogens or parasites
• non aquaculture vessels
• recreational fishing

Question 9

What is susceptibility to disease caused by?

Answer 9

High stocking densities

Question 10

What parasite causes soft flesh syndrome in salmon?

Answer 10

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

Question 11

What is one of the common parasites causing damage to salmon aquaculture?

Answer 11

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

Question 12

How can pests from marine farms be spread to the environment?

Answer 12

• Natural planktonic dispersal
• Active migration by mobile species
• Detachment passive or active defouling

Question 13

What killed 28.000 tonnes of pilchards in OZ in 1998?

Answer 13

A herpes-like virus introduced in imported baitfish

Question 14

What is Abalone Viral Ganglioneuritis (AVG)?

Answer 14

• 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

Question 15

What are the clinical signs of AVG?

Answer 15

• 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

Question 16

What are the origins of AVG?

Answer 16

Cultured abalone are the likely source of virus infection into wild abalone stocks

Question 17

What are the three introduced species with the highest risk?

Answer 17

• Undaria (sea weed)

prolific fouler of salmon and mussel farm

drag + current =breakages

• Styela (Tunicate)

prolific fouling and crop losses in shellfish culture

problematic on coromandel mussel farms

• Sabella (tube worm)

prolific fouler of artificial structures

Question 18

What does the future hold for aquaculture in the Hauraki Golf?

Answer 18

• Thriving aquaculture economy worth about $60m/yr, 900+ Jobs
• Sentinels for water quality
• Research neded to assess cost/benefits
• Better regulation and certainty needed; effected planning
• Need to spatially plan to minimise any environmental effects
• Need to spatially plan to accomodate other gulf uses
• Need to consider invasive species risk
• Need to consider environmental footprint, sedimentation, hydrodynamics, lice (fish)

Question 19

How can a sustainable aquacultur economy be created in NZ?

Answer 19

A sustainable future for New Zealand Aquaculture will come about with diversification of targets and informed spatial planning. Important is the social license to operate