Fish lecture Flashcards
What are the primary types of fish- and shellfish-farming systems?
Ponds (least intensive, relies on natural processes)
Cages (easy stocking and feeding but exposed to environmental risks)
Raceways (rectangular structures requiring large volumes of water)
Recirculating Aquaculture Systems (RAS) (most intensive, can be located anywhere, expensive and energy-intensive)
Offshore aquaculture and semi-closed systems
What are the key production stages in fish farming?
What is the role of the Aquaculture Stewardship Council (ASC)?
The ASC is a global certification organization that sets standards for sustainable and responsible aquaculture. They focus on improving environmental sustainability, fish welfare, and community benefits in aquaculture production.
What are Operational Welfare Indicators (OWIs) in fish farming?
OWIs are measurable parameters that provide insights into fish welfare. These indicators can be:
- Direct (outcome-based): Measures like fish behavior, growth, and physical conditions (e.g., fin condition, skin condition).
- Indirect (input-based): Environmental factors like water quality, stocking density, and feed quality.
Why does fish welfare matter in fish farms?
Fish welfare impacts stress levels, disease susceptibility, medication needs, growth rates, food conversion, and the quality of the final product. Good welfare conditions result in healthier fish, better growth, and higher-quality products.
What are the main global bodies involved in setting welfare and production standards for fish?
What is the importance of water quality in fish farming
Water quality is crucial in fish farming as it affects fish health and welfare. Parameters such as temperature, oxygen levels, ammonia concentration, salinity, and turbidity must be closely monitored to ensure a healthy environment for fish.
What are the ethical considerations in fish welfare within aquaculture?
Ethical considerations include ensuring that fish experience minimal stress and pain, maintaining biological and emotional well-being, and allowing fish to express natural behaviors. There are also concerns about how farming practices affect wild fish populations and ecosystems.
What is aquaculture
farming of aquatic organisms, including fish, molluscs, crustaceans and aquatic plants (FAO).
Describe ponds as an aquaculture production system
Enclosed water areas
Most commonly used
Least intense
Rely on natural processes
Salmonids, tilapia, shrimp/prawns, catfish
Describe cages as an aquaculture production system
Advantages:
- Easy stocking
- Easy feeding
- Easy harvest
Disadvantages:
- Little environmental control
- Susceptibility to predators
- Exposure to water borne irritants (jellyfish, plankton blooms)
- Exposure to bad weather conditions
- Shared water body – quicker disease spread
- Limited water quality control.
Salmonids, tilapia, seabass, seabream, tuna
Describe sea cages as an aquaculture production system
Much larger
More robust
“Movible”
Describe raceways as an aquaculture production system
Rectangular structures
Single pass system
Built above or below ground
Cement, fiberglass or wood
Require large volumes of water
Gravity flow
Trout, tilapia, carp, prawns
Describe RAS as an aquaculture production system
Most intensive systems
Can be located almost anywhere
Less water requirement
Signficant energy input
Required expertise
Expensive
Salmon, trout, eel, sturgeon, Artic char, yellowtail
What are the main hazards to human health on fish/selfish farms
Hazards include water quality issues, biosecurity breaches, zoonotic diseases (e.g., Aeromonas, Vibrio, Mycobacterium), and contamination with non-infectious toxins, heavy metals, and antibiotics.
What are the clinical signs of Mycobacteriosis in fish and humans
Most common “true” bacterial zoonosis
Three major species (M. marinum, M. fortuitum, M. chelonae, amongst others)
In fish: multiple internal granulomas, low but persistent mortalities, chronic presentation (“fish tuberculosis”)
In humans: superficial skin lesions (“fish handlers disease” or “fish tank granuloma”)
Immunocompromised individuals: systemic mycobacteriosis
Describe the lifecycle of Diphyllobothrium spp.
What does this fish have
Diphyllobothrium spp.
Cestode
Diphyllobothrium is killed by normal cooking & freezing.
The cysts of Diphyllobothrium are white and clearly evident on the intestine of fish.
describe the lifecycle of Anisakiasis
