Grade 10 marine and fisheries technology – 3.1 Fundamentals of Capture Fisheries Quiz

Capture fisheries refer to catching wild fish from natural habitats (rivers, lakes, and the sea). Fish farming in ponds is aquaculture, not capture.

Inland fisheries take place in freshwater bodies such as Lake Victoria and rivers, while marine fisheries take place in the ocean along Kenya's coast.

Seine nets (e.g., purse seines) are used to encircle schools of pelagic fish. Trawling drags a net along the bottom, longlining uses baited lines, and gillnets entangle fish by their gills.

Bycatch includes species that are not the intended target and are caught accidentally during fishing operations.

Appropriate mesh size lets undersized fish escape, reducing capture of juveniles and helping maintain sustainable fish populations.

Stock assessment uses data to estimate population size, trends, and fishing effects to inform sustainable management.

CPUE (catch divided by effort like hours or nets) is a common indicator of fish abundance; declining CPUE may indicate reduced stocks.

MPAs protect critical habitats, helping fish reproduce and grow, which supports long-term fisheries and biodiversity.

Protecting juveniles and spawning adults ensures enough young fish survive and are produced to maintain the population (recruitment).

Gear selectivity refers to matching gear type and mesh to capture desired species/sizes and reduce bycatch and juvenile catches.

Closed seasons temporarily stop fishing during spawning times, allowing fish to reproduce and support future stock abundance.

Overfishing often leads to smaller fish (younger ages) and reduced catches, indicating the stock is being depleted.

Mangroves are vital nursery habitats for many coastal species, increasing survival of juveniles and supporting fisheries productivity.

Artisanal fisheries are small-scale, often community-based; industrial fisheries involve larger vessels and commercial operations with greater capacity.

Bottom trawling drags heavy nets across the seabed, causing habitat damage and high bycatch of non-target species.

Recruitment refers to young fish surviving past early life stages to become part of the population available to fisheries.

Data on catch and effort allow assessment of stock trends and inform management measures to ensure sustainability.

Many species feed at specific times (dawn, dusk, night), and knowing these patterns helps choose effective fishing times.

Rapid cooling and proper handling preserve fish quality, reduce spoilage, and improve value at market.

Minimum landing sizes prevent capture of immature fish, allowing them to grow and reproduce, aiding stock sustainability.

Flag color does not influence fish abundance; habitat, fishing pressure, and water quality directly affect fish populations.

Spawning aggregations are critical for reproduction; targeting them can severely reduce reproductive output, so managers may protect them.

Lake Victoria supports large artisanal fisheries and biodiversity; other listed waters do not have the same scale of capture fisheries.

Small-mesh gillnets trap undersized fish and non-target species, harming future stocks and ecosystem balance.

Climate change alters ocean and lake conditions, affecting where and when fish feed and spawn, which affects fisheries.

Community-managed rules (seasonal closures, gear limits, habitat protection) can be effective and practical for sustainable fisheries.

Capture fisheries means taking fish from their natural environments (rivers, lakes and the ocean). Aquaculture (raising fish) and processing or selling fish are different parts of the value chain.

Kenya has many small-scale (artisanal) fishers who work from beaches and boats on Lake Victoria, Lake Turkana and the Indian Ocean coast. Pond farming and hatcheries are aquaculture activities, not capture fisheries.

Bottom trawling uses heavy trawl nets that are dragged along the seabed to catch species living near or on the bottom. Handlines, basket traps and cast nets are not trawling gear.

Bycatch refers to species caught unintentionally while targeting other species. It can include juveniles, protected species and unwanted fish, and is a major conservation concern.

KMFRI carries out research on marine and freshwater fisheries in Kenya and provides scientific advice for management and development of fisheries.

Closed seasons protect fish during critical life stages like spawning so that populations can reproduce and maintain sustainable levels.

A fish stock is a group of fish of the same species that live in a defined area and are managed together for conservation and harvesting.

Gear selectivity describes how well gear targets desired sizes or species, reducing bycatch and protecting juveniles by allowing them to escape.

MSY is a fisheries concept describing the highest long-term average catch that can be taken from a stock while keeping the population productive.

Cooling with ice and traditional preservation (smoking, salting) slow down spoilage and are commonly used to keep fish safe and marketable after capture.

Recruitment is the process by which juvenile fish survive and grow to sizes that are susceptible to capture and considered part of the stock available to fishers.

Mangroves provide sheltered, nutrient-rich habitat that protects juveniles and supports many species early in their life cycle, making them important nurseries.

Bottom trawling drags heavy nets across the seabed, destroying habitats like seagrass and corals and harming species that live on the bottom.

Accurate catch records (who caught what, where and how much) are crucial for scientists and managers to estimate stock status and make decisions to prevent overfishing.

Explosives and poisons are illegal and highly destructive fishing methods that kill many non-target organisms and damage habitats.

CPUE (catch per unit effort) is a simple index showing how much catch is obtained for a given effort (e.g., hours fished), helping indicate changes in stock abundance.

Fish life typically progresses from egg to larva, then juvenile and adult. Larvae are the young, free-swimming stage after hatching.

Appropriate mesh sizes prevent capture of undersized fish, helping protect juveniles so they can reproduce and support sustainable fisheries.

Lake Victoria supports important fisheries including Nile perch and Nile tilapia. Lake Magadi is saline and not known for these freshwater fisheries.

Fish move between areas to feed, follow seasonal changes, or reach spawning grounds where conditions are suitable for reproduction.

Licences are used to regulate effort, ensure compliance with laws and provide data for management; they do not guarantee catches or provide free supplies.

Smoking is a common traditional method that reduces moisture and slows bacteria growth, extending shelf life when refrigeration or ice is not available.

Selecting the right mesh size and placing nets where target species are most abundant (and bycatch least) reduces accidental capture of non-target and juvenile species.

Overfishing reduces stock size and often results in smaller average fish and falling catches per unit effort, showing that the fishery is being over-exploited.

Quick cooling and proper handling reduce bacterial growth and physical damage, preserving fish quality for sale and consumption.