EVSC Topic 6

Aquaaculture: why do we farm aquatic organisms

what is aquaculture

the cultivation of aquatic organisms mainly for food

what is fisheries

catching aquatic organisms from the wild

why aquaculture

growing world population, growing per capita seafood consumption, increase demand

how many people rely on seafood for protein

3 billion

when did aquaculture surpass fisheries for production

2022

problem with fisheries

94% at capacity or overfished, unsustainable, cannot expand, no selective breeding

benefits of aquaculture

reduce fisshing pressure, ecosystem service, sustainable, low FCR, selective breeding, price range

what is the range of products for aquaculture

food, nonedible for pharmaceuticals, aquarium trade, juvenilles restock fisheries

challenges of aquaculture

pollution, antibiotics, escapes (impact environmnet)

diversity of aquaculture - approx how many species

>300

what are the diversity of aquaculture

different taxa, trophic levels, environments

compare fish farming to poultry commercially

fish over 30 species, poultry only 1

what does diversity of aquaculture mean

diversity of production methods

which type of aquatic organisms does inland aquaculture have more of

fish

which type of aquatic organisms does coastal aquaculture have more of

algae

which continents dominantes aquaculture

asia, with consistent growth

how much of aquaculture production in oceania is responsible by australia

more than half

trends in aquaculture

rapid and consistent growth

how much is aquaculture weigh in australia’s fisheries and aquaculture production combined

40%

what are key aquaculture species in australia

fin fish eg. barramundi with salmoids great majority, crustaceans, molluscs

what is the largest contributor to Ausatralia aquaculture production

Tasmanian salmond fishing

what do different states produce in Austraila

very differetn species

what are the economic values of Australia’s aquaculture

58% of sea food production value

what is the highest gross value species in australia aquaculture

salmonoid

what is key about australia aquaculture production

contributes small global production volumes but process high value aquaculture products

what are unique points of organisms growing in water

energy efficency meaning difference in feed, disease management, feeding practises, water quality and management

what is special about the anatomy of aquatic organisms, and what does it impact

they are distantly related, anatomy, phsiology, immune differ, so impact management

which type of aquatic organism is fed

mainly fish and crustaceans including herbivore, carnivore and omnivores

what type of aquatic organsim is not fed

filter feeders, detrivores, aquatic plants

what are the three classifications of inputs

extensive, semiintensive, intensive

what is extensive aquaculture and for what organisms

complete reliance on natural fertility, seaweed, shellfish, crustaceans, fish

what is semi-intensive aquaculture and for what organisms

some improvements to natural fertility, shellfish, crustaceans, fish

what is intensive aquaculture and for what organisms

complete reliance on external feed input, crustaceans, fish

what are the 3 classification of species

monoculture, polyculture, integrated multiculture

what is monoculture

1 species

what is polyculture

2 or more species

what is intergated multiculture

multiple species from multiple trophic levels

what are the 3 classifications of control

open, semi-closed, closed

what is open system

minimal control over water quality and inputs

what is semi-closed system

partial control over water quality and inputs eg. ponds and raceways

what is closed system

full control over water quality and nutrinets eg. RAS

what are aspects of the closed control system

decrease dependence on local ecosystem services, but increase material and energy input

what are the 5 different aquaculture systems

line, cage, pond, tank based, flow through

what classification is line system

extensive, open

what is line system and what is it for

long ropes anchored to sea floor and suspended with floats, for shellfish and seaweeds

what is the process of line system

larvae grown in hateries intensively, settle on subtrate, moved into line

what classification is caged system

semi-intensive, open

what are cage systems

floating net pens for fish in freshwater, brackish or marine

what are drawbacks of cage systems

offshore ones are costly, difficult to manage water quality and disease, feed wastage = high FCR

classification of pond system

extensive to intensive, semiclosed or closed

what are pond system

ponds for fish/crustaceans, need clean water input and waste removal, easier to control and monitor, costs depening on intensification

classification of tank based systems

intensive, closed

what is the most common tank based system

recirculating aquaculture system (RAS)

what is aqauponics

RAS and hydroponics

what classification is the flow through system

semi-intensive or intensive, open

flow through system characteristics

continuous supply of water and may include ponds, tanks, raceways, requires a lot fo clean water, can support high stocking densities, limited control over water

examples of challenges to aquaculture

pollution, antibiotics, diversity means we cannot group problem

where does most challenges to aquaculture come from

poor planning, wrong system in the wrong place —> important to recognise and actively make it more sustainble

myths about aquaculture - read this

Aquaculture is a major source of pollution	Not inherently
Aquaculture destroys the environment	Generalisation → comparing production systems or chicken vs. 50 fish
Aquaculture uses more wild fish than it produces	Depends on species and feeding choices
Escapes from farms ruin wild populations	Only with poor management
Farmed fish are pumped full of antibiotics	Outdated
Aquaculture reduces biodiversity	Not directly → but only when done irresponsibly
Farmed fish suffer and have poor welfare	Welfare is valid, but depends on management

why do we need to work on making aquaculture more sustainable

aquaculture is not optional, it will continue to increase due to large role in global food, if no aquaculture, wild stocks will be pressured, increasing food security

what is Biofloc

using bacteria to turn toxic waste into nutrition

what is IMTA aquaculture

intergrated multitrophic aquaculture

what are 2 examples of IMTA aquaculture

fish waste filtered by shellfish, fish waste absorbed by seaweeds

what are the methods to make aquaculture more sustainable

1. Recognise the diversity of seafood → sustainability strategies must reflect different in species requirements 

2. Match species to right environment and system → eg. no carnivores in extensive systems 

3. Follow regulations and best practises → water quality, biosecurity, welfare, environment and labor regulations → decrease chance of unsustainable 

4. Tailor farming systems to local conditions

5. Close nutrient loops eg. integrated or multitrophic systems 

6. Optimise production systems for energy and waste efficiency eg. increase water reuse 

7. Prioritize renewable and low impact inputs 

8. Use alternative and low impact feed ingredients eg. insects to reduce pressure on wild stocks 

9. Put food security outcomes at the core 

10. Design for resilience for climate variability

11. Assess environmental impacts using science based tools → informed 

12. Support regulations that are guided by scientific data