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Aquaculture Overview

Introduction to Aquaculture

  • Aquaculture: Farming of fish, seafood, and aquatic plants in fresh or saltwater.
  • Mariculture: Aquaculture focused on marine species (saltwater).
  • Monoculture: Cultivating a single species at a time.
  • Polyculture: Raising multiple species together (e.g. finfish, shellfish, algae, crustaceans).
  • Fastest growing food sector globally, critical for food production:
    • Over 50% of aquatic foods consumed by humans are farmed (FAO, 2024).
    • Farmed fish is the most efficient source of animal protein.

Contributions of Aquaculture

  • Feeding the World:
    • Commitment to sustainable practices for 20+ years.
    • Significant number of people depend on aquaculture for livelihoods (more than 100 million).
  • Food Safety:
    • BAP certification indicates adherence to high environmental and safety standards.
  • Nutritional Benefits:
    • Fish is a rich source of essential nutrients: protein, Vitamin D, calcium, and omega-3 fatty acids.
    • Omega-3 from fish is more effective than supplements for heart health (University of Pennsylvania).

Environmental Advantages of Aquaculture

  • Lower greenhouse gas emissions compared to terrestrial livestock (e.g. 7x lower CO2 than cattle).
  • Sustainability Practices:
    • Zero bycatch; no unintentional capture of non-target species.
    • Practices improve utility of rural communities economically.

Aquaculture Farming Methods

  1. Hatchery to Natural Release:
    • Intensive farming where fish like salmon are raised in controlled environments and released into natural habitats.
  2. Life Cycle Rearing:
    • Fish are reared in controlled conditions and also held in open-ocean cages.
  3. Indoor Rearing:
    • Controlled growing environments (e.g. striped bass) with tank systems.
  4. Pond-Based Farming:
    • Extensive practices with minimal environmental control (e.g. tilapia, carp).

Successful Aquaculture Practices in Canada

  • Shellfish Farming:
    • Bivalves (oysters, mussels) thrive well due to filter-feeding mechanisms.
    • Involves rearing larvae to juveniles and then adults while avoiding the need for additional feeding.
  • Mussel Culture:
    • Certified organic blue mussels are a significant product from Newfoundland.
  • Oyster Cultivation:
    • Expanding due to the loss of natural reefs; takes 4-5 years to reach market size.
  • Shrimp Culture:
    • Focuses on species like tiger prawn, but poses disease and environmental risks.

Concerns with Aquaculture

  • Salmon Farming Issues:
    • Escape risks leading to wild stock displacement.
    • Potential disease transmission (e.g. sea lice, viral outbreaks).
  • Environmental Impact:
    • Mangrove destruction for shrimp farms and pollution from accumulated waste.
    • Nutrient loading causing eutrophication in coastal waters.

Solutions and Innovations

  • Land-Based Aquaculture:
    • Offers benefits such as reduced environmental contamination, disease control, but high costs involved.
  • Integrated Multi-Trophic Aquaculture (IMTA):
    • Combines different species to optimize space and nutrient use (e.g. salmon, mussels, kelp system).
    • Still in development stages, particularly in Atlantic Canada.

Conclusion

  • Aquaculture presents numerous opportunities to sustainably address food challenges while also raising concerns that need to be addressed through innovation and best practices.