1. Rod 2. Trawling 3. Netting 4. Spear diving 5. Potting (shellfish)

Week 11: Marine resources Flashcards by Alex Dench

5 Artisanal fisheries characteristics

Focused on target species
Little by-catch
Few steps from fiher to consumer
Little waste
Managed locally, few central controls

How well did you know this?

Not at all

Perfectly

5 Recreational fisheries charcteristics

Local
Low by-catch
Managed by size limits and take
Increasing take
Low waste, direct return

How well did you know this?

Not at all

Perfectly

5 Industrial fisheries characteristics

Large scale
High by-catch
High waste
High transport costs
Centrally managed

How well did you know this?

Not at all

Perfectly

How has industrial fishing been further industrialised over time

Refridgeration
Exclusive economic fishing zones
GPS location
Trawling and netting methods

How well did you know this?

Not at all

Perfectly

Small scale fisheries employ

More people, cost less, use less fuel, and have less impact on the environment

How well did you know this?

Not at all

Perfectly

5 Methods of fishing

Rod
Trawling
Netting
Spear diving
Potting (shellfish)

How well did you know this?

Not at all

Perfectly

There is a global slowdown in _____ fisheries

Marine capture

How well did you know this?

Not at all

Perfectly

Marine fish stocks are

Declining

How well did you know this?

Not at all

Perfectly

Due to depletion in fish stocks, fishermen are having to

Fish deeper

How well did you know this?

Not at all

Perfectly

3 primary impacts of fishing

Population effects
Ecosystem effects
Human impacts

How well did you know this?

Not at all

Perfectly

How does fishing have an effect on population

Populations collapse and loss of large individuals

How well did you know this?

Not at all

Perfectly

How does fishing have an effect on ecosystem

Fishing down the food web 2. Loss of large predators
Habitat destruction
Bycatch

How well did you know this?

Not at all

Perfectly

How does fishing have an effect on human impacts

Subsistence and Economic value

How well did you know this?

Not at all

Perfectly

BOFFFF

Big old fat fertile female fish

How well did you know this?

Not at all

Perfectly

BOFFFF are important for

Maintaining a large population of fish

How well did you know this?

Not at all

Perfectly

Removing a fish species results in a term known

Fishing down the food web

How well did you know this?

Not at all

Perfectly

Habitat modification from fishing pattern

Damage via fishing gear to habitat = Reductions in stock due to habitat loss = Reduced harvest

How well did you know this?

Not at all

Perfectly

Bycatch means

Non targeted organisms

How well did you know this?

Not at all

Perfectly

Discards mean

Animals that are thrown back into the sea

How well did you know this?

Not at all

Perfectly

Unused or unmanaged species account for

38.5 million tonnes or 40.4% of estimated total marine catch

How well did you know this?

Not at all

Perfectly

Mariculture means

Cultivation of species in open ocean or enclosed areas of the ocean

How well did you know this?

Not at all

Perfectly

Ocean ranching means

Juveniles reared in hatcheries and released into the ocean without further intervention

How well did you know this?

Not at all

Perfectly

Integrated multi-trophic aquaculture (IMTA) means

System in which different trophic levels are farmed together so wastes of one species = food of the other

How well did you know this?

Not at all

Perfectly

Feed conversion ratio (FCR) means

Ratio of inputs (ie feed) to outputs (food grown). Measure of efficiency

How well did you know this?

Not at all

Perfectly

Water based systems in aquaculture

1. Freshwater and saltwater (Mariculture / Ocean ranching) 2. Cages, pens, ropes, floats 3. Can be offshore/inshore 4. Species include seaweeds, invertebrates (e.g oysters) and vertebrates (e.g salmon)

Land based water systems in aquaculture

1. Freshwater and saltwater 2. Ponds, tanks, raceways 3. Re-circulating or flow through 4. Species include vertebrates (e.g trout, paua)

Integrated systems in aquaculture

1. Agriculture-Aguaculture systems 2. Integrated Multi-trophic Aquaculture 3. By-product of one system becomes input (food) of the other

Marine aquaculture is dominated by

Low trophic levels

Marine aquaculture by volume

Fish = 9% Molluscs and Crustaceans = 43% Seaweeds = 46%

Which country has the largest aquaculture production

China

How can aquaculture solve the global requirements for food

1. Abundance (Global production = 130.9 m t per annum) 2. Worth $281.5 b USD 3. 40% of seafood eaten worldwide 4. May provide 60% of global protein in 50 years 5. Approx 90% comes from Asia 6. > 300 species excluding seaweed

Farmed animal with the largest feed conversion rate

Cow with 6-10:1 (unideal)

Farmed animal with the lowest feed conversion rate

Carp with 0:1 (very ideal)

Restoration potential means

1. Restoration of depleted or endangered species 2. Restoration of habitat

Restoration of habitat will result in

1. Reduced preesure on wild stocks 2. Increased catch and improving fishing opportunities

Fundamental issue for sustainability in aquaculture

Bacteria and predation

Issue with farmed marine organisms in aquaculture

1. Creatures attached to surfaces (oysters) have to eat whatever floats by 2. Mobile fish require protein and oils

What is required for omega-3-rich farmed fish

Fish oil from fish meal

Aquaculture expansion is limited by dependence on

Fish oil and fish meal

Issues for overstocked farms in shallow water with poor water flow

Nutrient pollution and contaminants

Nutrient pollution, organic matter and suspended solids enriches

Discharge

Eutrophication equals

Increase in nutrient availability

Contaminents in aquaculture include

1. Persistent Organic Pollutants (POPs) 2. Antibiotics (veterinary drug residue)

Farmed species can ______ contaminants

Bio-accumulate

Habitat modification can be defined as

Physical alteration from infrastructure installation

Types of habitat modification

1. Localised organic enrichment of the seabed 2. Biofouling (accumulation of organisms) 3. Seabed shading 4. Entanglement 5. Noise disturbance

Habitat modification has the potential to

Facilitate establishment and spread pests and diseases

Advantages of enclosed/recirculating systems over Flow through systems

1. Use less water 2. Can regulate enviromental parameters 3. Prevents escape 4. Aerated settling tanks or (bio)filters minimise nutrient discharge 5. Requires high initial investment (disadvantage)

Integrated (multi-trophic) aquaculture involves

1. Two + species belonging to different trophic levels in the same system 2. Waste of one species converted to products with an economic value

Adverse environmental impacts of farming high trophic level species balanced by

Low trophic level species

Improvements to feed formulations for feed management to reduce

FO, FM, N and P, and meet the nutritional needs of aquaculture species

Substitution of natural food i.e plankton to

Supplement artificial diets

What determines the species selection that focus on lower trophic levels in aquaculture

1. Food 2. High value gels 3. Medicinal values 4. Cleans the water

Site selection and design is determined by

1. Placement (well flushed, deep productive sites, away from migratory animals) 2. Orientation to prevailing current directions 3. Stock density of farms 4. Cage design and orientation

Aquaculture in New Zealand dominated by

Mussels, salmon and oysters

Aquaculture needs clean water so

Self preservation can retain the health of marine populations

Wild capture fisheries cannot sustain demand for

Protein

The solution for a demand for protein is to turn to

Aquaculture

Aquaculture has a number of risks and challenges including

Feed, Escapees, Pollution, Habitat modification

Ways to manage the risks and challenges created by aquaculture

1. Recirculting/integrated systems 2. Feed management 3. Focusing on the right species 4. Being sensible