Chap 6- Fishery Managemen Flashcards
What is fishery management?
The rational exploitation of aquatic resources in such a way that they are maintained on a sustainable yield basis
How does FAO define a fishery?
A fishery is defined by the people involved, species of fish, area of water/seabed, method of fishing, class of boats, purpose of activities, or a combination of these features
What are the two main categories of fish production in Nigeria?
Capture fishery and culture fishery
What is capture fishery?
The catching of fish from open water; more like hunting than stock raising
What is culture fishery?
The rearing of aquatic organisms in controlled or semi-controlled environments; also known as aquaculture
What are the three types of aquatic environments in Nigeria?
Marine, brackish, and freshwater environments
What distinguishes different aquatic environments?
Their level of salinity (saltiness)
What is the salinity level of marine water?
Greater than or equal to 35 parts per thousand
What is the salinity level of brackish water?
Between 1-34 parts per thousand
What is the salinity level of freshwater?
Less than 1 part per thousand
What is monoculture in fish farming?
The culture of a single species of fish
What is polyculture in fish farming?
The culture of more than one species of fish in a pond
What is integrated aquaculture?
The rearing of fish alongside other forms of agriculture, where resources are efficiently utilized and recycled
What is cage culture?
The rearing of fish in cages in open waters such as rivers lakes reservoirs and large ponds
What percentage of Earth’s surface is covered by marine ecosystems?
71% of Earth’s surface
What percentage of Earth’s surface is covered by freshwater ecosystems?
0.80% of Earth’s surface
What percentage of known fish species inhabit freshwater ecosystems?
41% of the world’s known fish species
What are the main advantages of integrated aquaculture?
Optimal resource utilization, higher return on investment, reduced production costs, and reduced environmental pollution
What is the main disadvantage of monoculture?
If there is a disease outbreak the entire fish population can die
What are the conditions for selecting a suitable aquaculture site?
Good quality water supply, water-retaining soil, gently sloping topography, free from pollution, accessible by road
What are the conditions for selecting fish suitable for culture?
Must reproduce under culture conditions, be temperature tolerant, accept artificial feed, be disease resistant, be consumer-accepted, have fast growth rate
What are external factors affecting fish growth?
Temperature, quantity and quality of food, water quality, necessary amount of space
What are internal factors affecting fish growth?
Heredity, feed conversion ratio, resistance to diseases
What are the major problems of aquaculture development in Nigeria?
Insufficient quality fish seed, inadequate genetically improved fish seed, inadequate cost-effective feed, faulty data collection, poor marketing structure, poaching
What is the difference between passive and active fishing gears?
Passive gears remain fixed while fish move into them; active gears are moved about during operation to catch fish
Name five examples of passive fishing gears
Traps, gill nets, drift nets, hooks and lines, trammel nets
Name five examples of active fishing gears
Pole and lines, cast nets, clap nets, beach seine, drag nets, trawl nets
What is fish processing?
Any modification to fish that changes texture, taste, and physical appearance to slow deterioration
What are organoleptic characteristics in fish processing?
Flavor, taste, texture, and appearance
What is fish preservation?
Maintaining fish in its fresh state without changes to texture, taste, or physical appearance
List common fish preservation methods
Icing, freezing
List common fish processing methods
Smoking, salting, canning, drying, frying, fish protein concentrate, fish meal, fish silage
What percentage of Earth’s water is contained in marine ecosystems?
97% of the planet’s water
Why is polyculture sometimes preferred over monoculture?
Better utilizes natural food in the pond as fish feed at different trophic levels, and fish are more resistant to disease outbreaks
What are the main divisions of capture fishery?
Artisanal fishery (coastal and brackish water) and Industrial fishery (onshore and offshore)
What are common examples of brackish water environments?
Estuaries and lagoons
What are common examples of freshwater environments?
Lakes, rivers, streams, and springs
What is the purpose of fisheries management according to FAO?
To ensure continued productivity of resources and accomplish fisheries objectives through information gathering, analysis, planning, consultation, and implementation of regulations
Name three commonly cultivated catfish species in Nigeria
Clarias gariepinus, Heterobranchus bidorsalis, Heterobranchus longifilis
What is the scientific name for Nile Tilapia?
Oreochromis niloticus
What is the scientific name for African bony tongue fish?
Heterotis niloticus
What is the scientific name for Giant River Prawn?
Macrobrachium macrobranchion
Why should heavily wooded vegetation be avoided when constructing fish ponds?
To reduce cost of construction
What are the key benefits of fishery to Nigeria’s economy?
Provides cheap protein source, employment opportunities, foreign exchange earnings, recreation opportunities, raw materials for food manufacturing
