Finfish and Shellfish Final

Raceway Culture System

A flow-through, land-based aquaculture system with continuous water flow through long channels, used for fast-growing freshwater fish like salmonids; waste is flushed out rather than recirculated.

Smart Aquaculture System

A technology-driven system (often RAS + AI) using sensors, automation, and data to optimize water quality, feeding, energy use, and overall system management for sustainability.

Benefits of Open Ocean Aquaculture

Offshore aquaculture uses deeper water and strong natural currents, providing better water quality, reduced HABs, natural nutrient flow, lower waste concentration, and a more natural environment.

Carrying Capacity

The maximum biomass an aquaculture system or environment can support without environmental damage, determined by oxygen supply, waste removal, water flow, disease risk, and feed resources.

Functions of Restorative Aquaculture

Uses aquaculture to restore ecosystems by supporting biodiversity, filtering water (shellfish), sequestering carbon (seaweed), providing habitat, and creating community benefits.

Live Fish Transportation

Controlled movement of live fish requiring oxygenation, temperature control, low stress handling, and minimized waste buildup to maintain survival.

Conservation Aquaculture

Aquaculture used to rebuild species at risk, focusing on natural phenotypic development, genetic integrity, post-release survival, and ecological fitness.

Phenotypic Variation

Observable differences in traits caused by environment × genotype interactions; maintaining variation improves fish adaptability and conservation outcomes.

Strategies for Conservation Aquaculture

Collect gametes from wild stocks, maintain genetic integrity, use environmental enrichment, avoid domestication selection, use soft-release, and time releases based on habitat carrying capacity.

Spontaneous Autoploidy

A natural chromosome doubling event in rearing (e.g., sturgeon 8N to 12N), prevented by gentle egg handling instead of tumbling.

IMTA (Integrated Multi-Trophic Aquaculture)

System that grows fed species (fish) with extractive species (seaweed, bivalves) that absorb nutrients from fish waste, improving nutrient recycling and sustainability.

Extractive Species

Species that remove nutrients from water, such as seaweed and filter feeders like oysters and mussels, improving water quality in IMTA systems.

Definition of RAS

A recirculating aquaculture system with 10% or less daily water exchange, using mechanical filtration, biofiltration, degassing, oxygenation, and disinfection to reuse water.

Water Flow in RAS

Water moves from tanks to mechanical filters, then biofilters, then degassing, oxygenation/UV treatment, and back to tanks for continuous reuse.

Settleable Solids

Large particles (>100 microns) such as feces and uneaten feed that settle by gravity in radial flow settlers or sedimentation tanks.

Hydrocyclone Effect

Centrifugal action in a swirl tank or hydrocyclone that spins water to separate heavier solids from the water for removal.

Foam Fractionator

A device that removes very fine solids (<30 microns) and dissolved organics using fine bubbles; foam rises and carries waste away, using the Venturi effect.

Venturi Effect

A pressure drop created when water flows through a narrow pipe section, pulling air into the flow to create fine bubbles for gas exchange and foam fractionation.

Biofilter Conditioning

The process of establishing nitrifying bacteria on biofilter media (about 2 weeks at 20-25°C), often using NH4Cl or feed as an ammonia source.

Pump Material for RAS

RAS uses corrosion-resistant pump materials such as 316 stainless steel or titanium for saltwater; plastics may be used for lower cost systems.

Mechanical Filtration

Removal of solid waste (feces, uneaten feed, TSS) using drum filters, radial flow settlers, swirl tanks, sedimentation tanks, or bead filters to reduce waste load on biofilters.

Nitrifying Bacteria

Biofilter bacteria: Nitrosomonas convert ammonia to nitrite (AOB), and Nitrobacter convert nitrite to nitrate (NOB), detoxifying nitrogen waste.

PVC Parts

PVC piping components used to move water in RAS, including pipes, elbows, tees, valves, and pump connections designed to handle pressure and allow cleaning.

PVC Code

Markings on PVC indicating schedule, pressure rating, and size standards, used for selecting correct piping for aquaculture systems.

Specific Surface Area

The total surface area per volume of biofilter media (e.g., Kaldness K1), determining how many nitrifying bacteria can colonize the media and the biofilter capacity.

ASC (Aquaculture Stewardship Council)

Global sustainability certification ensuring responsible aquaculture with standards for stocking density, feed ingredients, chemical use, and environmental management.

GAA (Global Aquaculture Alliance)

Organization promoting responsible aquaculture through the Responsible Aquaculture Program, setting environmental and social standards and certification programs.

Fed Species

Species receiving formulated feed, such as finfish or shrimp.

RFS

Radial Flow Settler, a passive gravity device used to remove settleable solids from RAS water.

MBBR

Moving Bed Biofilm Reactor, a biofilter using floating K1 media that provides high surface area and self-cleaning action.

IMTA Benefit

Recycles nutrients, increases biodiversity, and improves environmental sustainability by combining fed and extractive species.