Unit 4 Topic 2 Managing fisheries Flashcards
Types of fishing (3)
Commercial Fishing
-The activity of catching fish and other seafood for commercial profit mostly from wild fisheries (Demersal trawl, prawn trawl)
Recreational fishing
-Sportfishing for pleasure and competition (rod, reel, and hooks)
Artisinal fishing
-Various small scale, low technology, low capita fishing practices undertaken by individual fishing households (fishing traps and beach seine)
Importance of wild-caught fisheries
A major source of protein to oceanic countries. Is useful for small countries without the land for traditional farming
How fishing data is reported
- Fishermen send catch data to government authorities
- Scientist is placed on a vessel to conduct a personal investigation (Age, size, length, and maturity level
- Scientists conduct personal research on a vessel
- Stock assessment is created
- Data is published by FAO
Fish population distribution is influenced by
The amount of food in an area is determined by the amount of phytoplankton in the area. Phytoplankton are located in areas with sufficient nutrients such as
- Dissolved Nitrogen
- Dissolved phosphate
- Dissolved iron
- Silica
Rugosity is
An index that measures habitat complexity and is expressed as a number from 0-3
-The higher the number the higher the fish diversity
Fish diversity is measured through
- Species richness
- Species diversity
- Simpsons diversity index
- functional diversity
Bioaccumulation
- The accumulation of substances such as pesticides, heavy metals, or other organic chemicals
- Bioaccumulation occurs when a substance is absorbed faster than it is excreted
- Bioaccumulation occurs when with the repeated consumption of contaminated lower-order consumers overtime
Bioaccumulation and bioindicators
Some organisms accumulate the chemical in their body to a concentration that is several orders of magnitude higher than the surrounding water and can represent the level of pollution (muscles and mudskippers)
Input and control outputs
Input
-Limitations on the amount of fishing effort or restrictions on aspects of a vessel (vessel, gear size and time of fishing)
Output
-Limitations of the weight of the catch (quota) or allowable size, sex or reproductive condition
Fishing technology
- Sonar
- Navigation gear
- More effective boats
Tagging limitations
- May affect growth and survival
- Impact behavior and swimming/hiding performance
- Fouling of tags
- Tag loss
- Tag entanglement with fishing supplies
Lincoln Index formula
N= M x n/m N = Stock size M = number tagged n = second catch m = recaptures
CPUE
Catch per unit effort
Methods to test fisheries data
- E-monitoring
- Vessel monitoring (VMS)
Lincoln index assumptions
The method assumes that tagging does not affect survival, nor the probability of recapture. It also assumes that no migration occurs
Methods scientists use to measure the amount of fish present
- Lincoln Diversity index
- Underwater visual census (Baited remote camera)
- Acoustic methods (fishfinder, sonar)
- Egg production method (density of eggs in water)
- Depletion method (CPUE)
- Portside sampling (fish frames, otoliths)
- Marketplace data
Factors that determine the reliability of fisheries population data (fish behavior)
- Schooling
- Spawning
- Diel migration
How are the high seas managed
Through commissions or Regional Fisheries Management Organisations (RFMOs) that are born from international agreements (formalised by the signing of a convention or treat
RFMO
- Regional fisheries management
- An international organisation made up of countries that share a practical or financial interest in managing and conserving fish stocks
Maximum sustainable yield (MSY)
MSY is the largest average catch (or yield) that can be continuously taken from a stock under existing environmental conditions.
Fishing effort
The amount of effort to find and catch fish
Maximum economic yield (MEY)
MEY is the point at which a fishery (as a whole) maximises its economic potential
Unintended outcomes of MSY models
- Bycatch
- Habitat destruction
- Deterioration of trophic levels
EBFM
- Ecosystem-based fisheries management
- EBFM is essentially reversing the order of management priorities so that management starts with the ecosystem rather than a target species
EBFM tools
- Bycatch reduction devices
- Marine protected areas
Value of non take MPAs
- The spillover effect
- Larval export
- Fishery recovery and sustainability
- Reduced bycatch, discards, and ghost fishing
- Habitat protection
- Fisheries research
- Fisheries induced evolution (FIE)
Australian Fishing Zone (AFZ)
- AFZ declared in 1979
- 3-200 nautical miles from the coast of Australia
- Covers 8 million square kilometers
Maritime zones
Territorial sea
-The Territorial Sea is a belt of water not exceeding 12M
Contiguous sea
-The Contiguous Zone is a belt of water contiguous to the territorial sea, the outer limit of which does not exceed 24M
Exclusive ecanomic zone
-(200 nautical mile limit) is an area beyond and adjacent to the territorial sea
Continental shelf
-Is the area of the seabed and subsoil which extends beyond the territorial sea to a distance of 200M
Science-based management
Fisheries management decisions that are made based on the best available science
Management framework and tools include
- Harvest strategy
- Ecological risk assessment
- Sustainable catch limits
The rule of law
The rules set out to control fishing
Good governance
The process of decision making and the process of implementing decisions
Australian seafood imports/exports
- Australian seafood imports mainly consist of frozen fillets, frozen prawns, and canned fish
- Exports lobster to China 80$ a kg and salmon
Why Australia imports
Cheaper to import aquaculture based seafood than wild-caught
TAC
Total allowable catch
Quota
A quota unit is not a fixed weight of fish -it is a fixed percentage of fish
ITQ
Individual transferable quota
Spatial management strategies
-2003 status quo
the level of the annual quota is dictated by a total allowable catch (TAC) estimate calculated from the catch trend
-Enhanced quota management
All species in the area are protected
-Integrated management
in this strategy, regional quotas are set for 17 key target groups and groups of conservation concern
-Conservation dominated management
Stringent restrictions on vessel size and power are introduced to constrain effort, although gear restrictions
Precautionary principle
when an activity raises threats of harm to human health or the environment, precautionary measures should be taken even if some cause and effect relationships are not fully established scientifically
Food security
when all people at all times have access to sufficient, safe, nutritious food to maintain a healthy and active life
Aquaculture definition
The farming of aquatic organisms including fish, molluscs, crustaceans, and aquatic plants with some sort of intervention in the rearing process to enhance production, such as regular stocking
Stages of aquaculture
- Hatching
- Nursery operation
- Grow out operation
- Harvesting
Desirable attributes of aquaculture organism
- Rapid growth with high yield
- Can be feed commercial grain and pellets
- High tolerance to disease and temperature
- Non-aggressive nature
- Easy to harvest
- Easy to market and transport live
What determines carrying capacity in aquaculture
- Size of species
- Requirements of species
- Life cycle of species
- Pond/tank size
- Farming technique
- Nutrient supply
- Stock density
- Other environmental factors
- Water quality
Types of aquaculture farming
Open system
-Open systems culture generally refers to fish farming in natural water bodies such as oceans, bays, estuaries, coastal lagoons, lakes, or river
-Limitations: hard to control water quality, salinity, nutrients
Closed system
-Closed systems are those where the water is reconditioned and recirculated to the culture unit
-Limitations: less land and water to use, water quality management, tank cleaning, and filters
Aquaculture issues
- Output pollution
- Waste removal
- Biosecurity
- Feed protection
