Podcast
Questions and Answers
What percentage of world fish production was attributed to aquaculture in 2020?
What percentage of world fish production was attributed to aquaculture in 2020?
- 40%
- 50% (correct)
- 60%
- 25%
Which of the following is a consequence of inappropriate fishing methods?
Which of the following is a consequence of inappropriate fishing methods?
- Enhanced biodiversity
- Increased fish populations
- Habitat destruction (correct)
- Growth of aquaculture
What type of fishing targets species that live near the seabed?
What type of fishing targets species that live near the seabed?
- Commercial fishing
- Pelagic fishing
- Demersal fishing (correct)
- Drift fishing
Which seabird species has benefited from bycatch according to the content?
Which seabird species has benefited from bycatch according to the content?
Which fishing method involves the use of traps?
Which fishing method involves the use of traps?
What characterizes pelagic fisheries?
What characterizes pelagic fisheries?
What was the breeding range situation of the Northern Fulmar until the late 19th century?
What was the breeding range situation of the Northern Fulmar until the late 19th century?
Why is bycatch difficult to avoid in commercial fishing?
Why is bycatch difficult to avoid in commercial fishing?
What is the primary reason sea fisheries and aquaculture are important globally?
What is the primary reason sea fisheries and aquaculture are important globally?
Which of the following species is NOT mentioned as a commonly landed pelagic species?
Which of the following species is NOT mentioned as a commonly landed pelagic species?
Where are the most productive fishing areas typically found?
Where are the most productive fishing areas typically found?
What impact has advanced technology had on fishing practices?
What impact has advanced technology had on fishing practices?
How do modern fishing methods differ from traditional methods?
How do modern fishing methods differ from traditional methods?
What role does bycatch play in modern fishing practices?
What role does bycatch play in modern fishing practices?
In what way is fishing seen as a less complex method of food acquisition compared to farming?
In what way is fishing seen as a less complex method of food acquisition compared to farming?
Which factor does NOT significantly contribute to fish biomass in productive areas?
Which factor does NOT significantly contribute to fish biomass in productive areas?
At what size do fish begin to be commonly caught in trawl nets?
At what size do fish begin to be commonly caught in trawl nets?
What is the length a cod typically reaches maturity?
What is the length a cod typically reaches maturity?
Which characteristic is NOT associated with the European plaice?
Which characteristic is NOT associated with the European plaice?
Where are plaice commonly found in the North Sea?
Where are plaice commonly found in the North Sea?
What time of year is the quality of plaice typically poor?
What time of year is the quality of plaice typically poor?
What is the primary method used to catch plaice?
What is the primary method used to catch plaice?
In which areas does spawning occur for plaice?
In which areas does spawning occur for plaice?
During which months does spawning primarily occur for plaice?
During which months does spawning primarily occur for plaice?
What is the primary dependence of the larva immediately after hatching?
What is the primary dependence of the larva immediately after hatching?
At what size does the cod typically reach by the end of the first 6 months in the North Sea?
At what size does the cod typically reach by the end of the first 6 months in the North Sea?
During the planktonic phase, which organisms are the main food for young cod?
During the planktonic phase, which organisms are the main food for young cod?
What physical change occurs in young fish when transitioning from a planktonic to a demersal lifestyle?
What physical change occurs in young fish when transitioning from a planktonic to a demersal lifestyle?
What is a significant prey for adult cod while hunting?
What is a significant prey for adult cod while hunting?
What happens to the young cod when they reach the end of their planktonic phase?
What happens to the young cod when they reach the end of their planktonic phase?
How does the growth rate of cod differ in various geographical locations?
How does the growth rate of cod differ in various geographical locations?
What are cod fry often preyed upon by during their early stages?
What are cod fry often preyed upon by during their early stages?
What primarily affects the timing of fish migrations in the discussed regions?
What primarily affects the timing of fish migrations in the discussed regions?
What type of environment do overwintering fish primarily inhabit?
What type of environment do overwintering fish primarily inhabit?
During which part of their migration do fish begin to form surface shoals?
During which part of their migration do fish begin to form surface shoals?
What food sources are working as the primary diet for overwintering fish?
What food sources are working as the primary diet for overwintering fish?
Following spawning, where do fish that spawned in the Celtic Sea typically migrate?
Following spawning, where do fish that spawned in the Celtic Sea typically migrate?
What is the primary movement pattern of fish that overwintered in the Irish Sea at the start of spring?
What is the primary movement pattern of fish that overwintered in the Irish Sea at the start of spring?
Where do fish that spawn in the central North Sea primarily return to post-spawning?
Where do fish that spawn in the central North Sea primarily return to post-spawning?
What role do cascade currents play in the local ecosystem for overwintering fish?
What role do cascade currents play in the local ecosystem for overwintering fish?
What does the equation $S2 = S1 + (A + G) - (C + M)$ represent?
What does the equation $S2 = S1 + (A + G) - (C + M)$ represent?
In what situation is a fishery considered 'stabilized'?
In what situation is a fishery considered 'stabilized'?
What is the biological optimum fishing rate?
What is the biological optimum fishing rate?
Which of the following factors is NOT considered when determining the optimum yield?
Which of the following factors is NOT considered when determining the optimum yield?
What happens during overfishing, according to the passage?
What happens during overfishing, according to the passage?
Which statement best reflects the relationship between fishing, stock, yields, and profitability?
Which statement best reflects the relationship between fishing, stock, yields, and profitability?
What does the term 'natural yield' refer to?
What does the term 'natural yield' refer to?
Why is it necessary to regulate fishing activity?
Why is it necessary to regulate fishing activity?
Which factor has contributed to the impressive expansion of fulmars in the 20th century?
Which factor has contributed to the impressive expansion of fulmars in the 20th century?
What is indicated as a likely cause for the decline in the number of breeding pairs of fulmars since the 21st century?
What is indicated as a likely cause for the decline in the number of breeding pairs of fulmars since the 21st century?
What type of fishing vessel is described as capable of processing its catch on board and freezing it?
What type of fishing vessel is described as capable of processing its catch on board and freezing it?
Which of the following best describes the current understanding of fulmar diets?
Which of the following best describes the current understanding of fulmar diets?
Which fishing methods are mentioned as contributing factors to the population changes in fulmars?
Which fishing methods are mentioned as contributing factors to the population changes in fulmars?
What is implied about the relationship between fishing activities and bird populations like the fulmar?
What is implied about the relationship between fishing activities and bird populations like the fulmar?
How is the size of industrial fishing vessels characterized in the passage?
How is the size of industrial fishing vessels characterized in the passage?
What factor in the North Sea is mentioned as changing due to climate change, affecting the fulmar's food sources?
What factor in the North Sea is mentioned as changing due to climate change, affecting the fulmar's food sources?
What is a significant consequence of overfishing?
What is a significant consequence of overfishing?
Why are lower limits imposed on the size of fish that can be caught?
Why are lower limits imposed on the size of fish that can be caught?
How did advancements in technology impact fishing practices after Huxley's statement in 1883?
How did advancements in technology impact fishing practices after Huxley's statement in 1883?
What was E.S. Russell’s conclusion about the state of fisheries in northwest European waters?
What was E.S. Russell’s conclusion about the state of fisheries in northwest European waters?
What did Huxley mistakenly believe about the fisheries he addressed?
What did Huxley mistakenly believe about the fisheries he addressed?
What has been observed in areas of intensive fishing in the northeast Atlantic since Huxley’s prediction?
What has been observed in areas of intensive fishing in the northeast Atlantic since Huxley’s prediction?
What does overfishing primarily result from?
What does overfishing primarily result from?
Which of the following is NOT a reason that traditional fishing methods became less common?
Which of the following is NOT a reason that traditional fishing methods became less common?
What type of fish primarily becomes sexually mature during their fourth year?
What type of fish primarily becomes sexually mature during their fourth year?
Which environmental condition contributes to a rich plankton supply for fish?
Which environmental condition contributes to a rich plankton supply for fish?
Which of the following species is an example of anadromous fish?
Which of the following species is an example of anadromous fish?
What characterizes catadromous fish species?
What characterizes catadromous fish species?
What happens to many Pacific Sockeye Salmon after spawning?
What happens to many Pacific Sockeye Salmon after spawning?
What is a primary factor that affects the fat content of fish flesh?
What is a primary factor that affects the fat content of fish flesh?
How do young Atlantic Salmon behave before migrating to the ocean?
How do young Atlantic Salmon behave before migrating to the ocean?
What physiological adaptation is critical for fish that migrate between freshwater and ocean environments?
What physiological adaptation is critical for fish that migrate between freshwater and ocean environments?
What has been the impact of bottom trawling on Atlantic cod populations?
What has been the impact of bottom trawling on Atlantic cod populations?
How much did the world catch of Atlantic cod reach in 2018?
How much did the world catch of Atlantic cod reach in 2018?
What is the typical depth at which Atlantic cod are predominantly found?
What is the typical depth at which Atlantic cod are predominantly found?
What percentage of Atlantic cod stocks is currently reported to be in a poor state?
What percentage of Atlantic cod stocks is currently reported to be in a poor state?
Which of the following regions is NOT mentioned as a part of the Atlantic cod's distribution?
Which of the following regions is NOT mentioned as a part of the Atlantic cod's distribution?
What has been a major technological change in fishing since the late 1940s?
What has been a major technological change in fishing since the late 1940s?
What caused the initial perception that Atlantic cod could not be overfished?
What caused the initial perception that Atlantic cod could not be overfished?
What is indicated by the current status of Atlantic cod fisheries as rated by the Marine Conservation Society?
What is indicated by the current status of Atlantic cod fisheries as rated by the Marine Conservation Society?
What has caused the saturation of fish catches at a particular level since around 1970?
What has caused the saturation of fish catches at a particular level since around 1970?
In what temperature range is Atlantic cod most abundant?
In what temperature range is Atlantic cod most abundant?
How has the transition from steam to diesel power affected fishing vessels?
How has the transition from steam to diesel power affected fishing vessels?
What is a consequence of fishing occurring too early in the fishes’ life cycle?
What is a consequence of fishing occurring too early in the fishes’ life cycle?
What role do modern navigation systems like GPS play in fishing practices?
What role do modern navigation systems like GPS play in fishing practices?
What has been the average annual increase in world landings of fish from 1948 to 1968?
What has been the average annual increase in world landings of fish from 1948 to 1968?
What is indicated by the flattening of the catch curve despite increased fishing efforts?
What is indicated by the flattening of the catch curve despite increased fishing efforts?
What is the impact of fishing vessels equipped with refrigeration systems?
What is the impact of fishing vessels equipped with refrigeration systems?
What is a significant factor in the slow recovery of Atlantic Cod stocks?
What is a significant factor in the slow recovery of Atlantic Cod stocks?
How did war affect the fish stocks in the northeast Atlantic during the 20th century?
How did war affect the fish stocks in the northeast Atlantic during the 20th century?
What type of fishing approach is increasingly being understood as necessary for fisheries management?
What type of fishing approach is increasingly being understood as necessary for fisheries management?
What has been the state of cod stocks in relation to their population size since the 1960s?
What has been the state of cod stocks in relation to their population size since the 1960s?
What ecological impact does seabed trawling have on cod populations?
What ecological impact does seabed trawling have on cod populations?
Which of the following best explains the concept of 'motherfish' in relation to cod recovery?
Which of the following best explains the concept of 'motherfish' in relation to cod recovery?
What does the significant decline in haddock landings during the 1930s illustrate about fisheries?
What does the significant decline in haddock landings during the 1930s illustrate about fisheries?
What evolutionary pressure may result from constant heavy fishing on cod populations?
What evolutionary pressure may result from constant heavy fishing on cod populations?
Flashcards
Sea Fisheries
Sea Fisheries
Fishing activities in the ocean, targeting various marine species for food, employment, or income.
Aquaculture
Aquaculture
The farming of aquatic organisms like fish.
Fishing Impact
Fishing Impact
Human fishing activities can have substantial effects on fish populations and ocean ecosystems.
Global Fish Landings
Global Fish Landings
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Pelagic Species
Pelagic Species
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Bycatch
Bycatch
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Fishing Areas
Fishing Areas
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Fishing Methods
Fishing Methods
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Aquaculture's role in fish production
Aquaculture's role in fish production
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Inappropriate Fishing Methods
Inappropriate Fishing Methods
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Demersal Fishing
Demersal Fishing
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Pelagic Fishing
Pelagic Fishing
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Active Fishing Methods
Active Fishing Methods
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Passive Fishing Methods
Passive Fishing Methods
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Keystone Species
Keystone Species
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Cod Larval Diet
Cod Larval Diet
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Planktonic Phase
Planktonic Phase
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Demersal Cod
Demersal Cod
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Demersal Diet Change
Demersal Diet Change
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Cod Nursery Areas
Cod Nursery Areas
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Adult Cod Diet
Adult Cod Diet
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Cod Growth Rate Variation
Cod Growth Rate Variation
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Yolk-Sac Absorption
Yolk-Sac Absorption
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Cod Maturity Size
Cod Maturity Size
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Cod Maximum Size
Cod Maximum Size
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European Plaice Habitat
European Plaice Habitat
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Plaice Fishing Methods
Plaice Fishing Methods
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Plaice Spawning Time and Locations
Plaice Spawning Time and Locations
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Plaice Migration
Plaice Migration
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Plaice Growth Limit
Plaice Growth Limit
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Plaice Fishing Season
Plaice Fishing Season
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Overwintering shoals
Overwintering shoals
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Migration timing shift
Migration timing shift
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Food sources during overwintering
Food sources during overwintering
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Diurnal vertical movement
Diurnal vertical movement
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Surface shoals formation
Surface shoals formation
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Spawning migration paths
Spawning migration paths
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Spawning areas convergence
Spawning areas convergence
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Russell's Equation (1942)
Russell's Equation (1942)
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Natural Yield
Natural Yield
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Equilibrium Catch
Equilibrium Catch
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Stabilized Fishery
Stabilized Fishery
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Biological Optimum Fishing Rate
Biological Optimum Fishing Rate
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Economic Optimum Fishing Rate
Economic Optimum Fishing Rate
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Optimum Yield
Optimum Yield
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Fish Stock Composition
Fish Stock Composition
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Fulmar Expansion
Fulmar Expansion
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Fulmar Diet Shift
Fulmar Diet Shift
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Fulmar Decline
Fulmar Decline
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Fishing Vessels
Fishing Vessels
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Supertrawlers
Supertrawlers
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Reproductive Strategies
Reproductive Strategies
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Life History Parameters
Life History Parameters
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Fisheries Management
Fisheries Management
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Atlantic Cod's Importance
Atlantic Cod's Importance
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Cod's Distribution
Cod's Distribution
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Cod's Temperature Preference
Cod's Temperature Preference
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Cod's Life History
Cod's Life History
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Cod Fishing Impact
Cod Fishing Impact
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Cod Management
Cod Management
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Cod's Close Relative
Cod's Close Relative
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Cod's Role in the Food Chain
Cod's Role in the Food Chain
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Overfishing
Overfishing
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Immature Fish
Immature Fish
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What is a fishing limit?
What is a fishing limit?
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Huxley's Prediction
Huxley's Prediction
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Evidence of Overfishing
Evidence of Overfishing
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Russell's Overfishing Statement
Russell's Overfishing Statement
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Overfishing Consequences
Overfishing Consequences
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Sustainable Fishing
Sustainable Fishing
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Herring Oiliness
Herring Oiliness
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Herring Maturity
Herring Maturity
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Anadromous Fish
Anadromous Fish
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Catadromous Fish
Catadromous Fish
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Atlantic Salmon Spawning
Atlantic Salmon Spawning
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Pacific Sockeye Salmon
Pacific Sockeye Salmon
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Food and Herring Oiliness
Food and Herring Oiliness
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Fish Shoals
Fish Shoals
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Trawling Impact
Trawling Impact
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Cod Dependence
Cod Dependence
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Slow Recovery
Slow Recovery
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Motherfish Importance
Motherfish Importance
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Fishing Pressure Impact
Fishing Pressure Impact
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Evolutionary Pressure
Evolutionary Pressure
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War's Impact on Fisheries
War's Impact on Fisheries
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Haddock Recovery
Haddock Recovery
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Fishing Impact on Population
Fishing Impact on Population
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Fishing Innovations
Fishing Innovations
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World Fish Landings
World Fish Landings
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Fish Stock Limits
Fish Stock Limits
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Fishing and Size Composition
Fishing and Size Composition
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Light Fishing
Light Fishing
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Study Notes
Human Impacts on Sea Fisheries and Aquaculture
- Sea fisheries and aquaculture are significant topics, encompassing various books and scientific papers. Fishing is essential to feeding the global population, providing nourishment, employment, and income.
- Fisheries and aquaculture play crucial roles in global food and nutrition needs.
- Advanced technology now allows fishing almost anywhere and at greater depths than previously possible, leading to increased species variety in catches. This is evident in fish markets—with more unusual species being targeted.
- Bycatch, including species like Frilled Sharks, is a result of fishing methods targeting different species (and also invertebrates and marine mammals).
- Key pelagic species, such as Peruvian Anchovy, Alaskan Pollock, Chilean Jack Mackerel, Atlantic Herring, and Chub Mackerel, account for a substantial portion of global landings (around 15%).
- Productive fishing areas are typically located over continental shelves and upwelling zones due to higher primary production levels and subsequently higher fish biomass.
- Inappropriate fishing methods and overfishing threaten entire ecosystems through habitat destruction and removal of keystone species.
- Efficient fisheries need to avoid bycatch; sometimes offal and bycatch can indirectly benefit other marine species.
- Northern Gannets (Morus bassanus) populations have increased in some areas due to scavenging bycatch.
Reproductive Strategies and Life Cycles
- Fishing management requires an understanding of a species' life history and reproductive strategies. Two main strategies, r- and K-strategists, exist.
- R-strategists produce large numbers of offspring, with little effort in supporting offspring survival, while K-strategists ensure few, but well-supported offspring.
- Different environments will cause species to have unique life histories.
- Many ray-finned fish (Actinopterygii) lay large numbers of small eggs, broadcast into the water and externally fertilized, illustrating an r-strategy.
- Some examples of r-strategists that contribute significantly to global fish landings are those mentioned above as key pelagic species.
- Other species display K-strategists strategies—with examples like sharks, rays, and chimaeras which produce fewer young but invest more resources in their offspring's survival.
Fisheries Components and Issues
- Fisheries are divided into demersal (bottom-dwelling) and pelagic (water-column).
- Demersal fisheries target species like cod, flatfish, rays, and Orange Roughy.
- Pelagic fisheries target shoals like herring.
- Inappropriate fishing methods, including overfishing, threaten entire ecosystems through habitat destruction and removal of keystone species.
- Efficient fisheries need to avoid bycatch; sometimes discards and bycatch can indirectly benefit other marine species.
- Northern Gannets (Morus bassanus) populations have increased in some areas due to scavenging bycatch.
Fulmars
- Northern Fulmars (Fulmarus glacialis) demonstrate a close connection between fishing activities and non-target species.
- Historically, their populations were limited, but expanded notably during the 20th century due likely to a food source coming from fisheries discards.
- Recent declines may be linked to reduced discards and other regulatory changes.
Example Fish Life Histories
- Atlantic cod (Gadus morhua) is important, historically abundant, but now overfished in many areas.
- Cod life history involves migration between spawning and feeding grounds, with a long lifespan and slow growth.
- Cod primarily feed on smaller organisms near the seabed.
European Plaice (Pleuronectes platessa)
- It is important commercially and demonstrates a typical life history.
- Plaice (Fig. 8.2, page 396) spawn in the North Sea, English Channel, and Irish Sea during the winter months, with juveniles commonly found in shallow, coastal nursery areas.
Atlantic Herring (Clupea harengus)
- Herring are pelagic and migrate for spawning, feeding, and migration, showing remarkable movements and migrations based on their lifespan.
- Herring feed primarily on plankton in the open ocean, particularly during the spawning process.
Anadromous and Catadromous Species
- Salmon (Salmonidae), shads, and some lampreys (Petromyzontidae) are anadromous migrating from ocean to freshwater to spawn.
- Freshwater eels (Anguilla spp.) are catadromous.
Stock Assessment Methods
- Stock assessment aims to evaluate ongoing fishery implications for a stock, for example, to identify overfished stocks, and to estimate sustainable fishing rates.
Overfishing
- Overfishing depletes fish populations, hindering restocking rates.
- The effects of overfishing include dramatic population declines, like those seen in Cod.
- Often, overfishing coincides with other environmental concerns such as climate change.
Fishery Management and Regulations
- Fishery management often involves setting quotas, establishing protected areas or restricted time frames for fishing (closed season).
- Implementing rational fishing methods is necessary to avoid overfishing and negative ecosystem consequences.
- Overfishing dramatically impacts fish populations and can cause ecosystem collapse, as demonstrated in the Grand Banks cod fishery collapse.
Aquaculture
- Aquaculture is becoming a vital protein source, particularly for high-value species like salmon and sturgeon.
- Aquaculture methods vary widely, from simple pond culture of herbivorous fish to more sophisticated systems like tanks or cages (sea-cage farming).
- Aquaculture faces challenges, such as pollution from waste products, escapes of farmed fish into wild populations, which can compromise local wild fish genetic lines.
- Aquaculture also relies on feeding the fish for optimal growth; this can present challenges for sustainability.
- Seaweed farming makes use of natural processes and can serve as an alternative to traditional fish farming regarding certain sustainability claims.
- Stocks used for aquaculture feed often rely on wild-caught fish and crustaceans
- In many cases, Aquaculture production exceeds Wild capture fisheries
- Aquaculture developments in some regions are more sustainable than others
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Test your knowledge about aquaculture and fishing practices in this quiz. Explore key concepts such as bycatch, fishing methods, and the ecological impact of fishing technologies. Perfect for students studying marine biology or environmental science.
