NECO 2023 FISHERIES ESSAY AND OBJ ANSWERS – EXAMKING.NET

(1aii)
– Aquaculture: Aquaculture refers to the cultivation and breeding of aquatic organisms, such as fish, shellfish, and aquatic plants, under controlled conditions.
– Aquariculture: Aquariculture involves the cultivation and maintenance of aquatic organisms, primarily for ornamental purposes, in aquariums or controlled aquatic environments.

(1bi)
– Salting: In salting, fish is preserved by applying dry salt directly to the fish surface. It dehydrates the fish, inhibiting bacterial growth and enzyme activity.
– Brining: Brining involves soaking fish in a saltwater solution (brine). It not only dehydrates the fish but also imparts flavor and can enhance the texture.

(1bii)
Both salting and brining are methods of fish preservation that involve the use of salt to extend the shelf life of the fish. They both work by reducing the water content, creating an inhospitable environment for bacterial growth.

(1ci)
(i)Water Filtration: The system includes mechanical and biological filters to remove waste and maintain water quality.
(ii)Oxygenation: Oxygen is added to the water to support the respiration of fish and other aquatic organisms.
(iii)Water Reuse: The system recirculates and treats the water, reducing the need for large water volumes and promoting sustainability.

(1cii)
(i)Cost-effectiveness: Earthen ponds are generally more economical to construct and maintain compared to concrete ponds.
(ii)Natural environment: The earthen ponds provide a more natural habitat for fish, which can positively impact their growth and health.
(iii)Nutrient recycling: The pond’s soil can act as a source of nutrients, fostering the growth of natural food organisms, reducing the need for supplemental feeding.
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(2ai)

(2aii)
(i)Natural bodies of water like rivers, lakes, or ponds.
(ii)Groundwater from wells or boreholes.
(iii)Rainwater harvesting through ponds or reservoirs.

(2aiii)
Barrage Pond is a type of fish pond constructed by blocking a stream or river’s flow with a dam or barrage, creating an enclosed area for fish farming. The water level in the pond is regulated by controlling the gates in the dam, allowing for fish rearing in a controlled environment.

(2aiv)
(i)Both are popular fish species for aquaculture due to their fast growth rates and adaptability to different environmental conditions.
(ii)They are omnivorous, meaning they can eat both plant-based and animal-based food, which makes them relatively easy to feed and manage in fish farming systems.

(2bi)
Quality parameters refer to specific measurable factors used to assess the suitability or condition of a system, product, or environment.

(2bii)
(i)Aeration: Installing aerators or diffusers to introduce air into the water and increase oxygen levels.
(ii)Water circulation: Implementing systems to promote water movement, which enhances oxygen exchange at the water’s surface.
(iii)Reducing stocking density: Avoiding overcrowding of fish in the pond to prevent excessive oxygen consumption.
(iv)Vegetation management: Ensuring proper aquatic plant growth and management to maintain oxygen balance through photosynthesis.

(2biii)
(i)Definition:
– Polyculture: Polyculture refers to the practice of rearing multiple species of fish together in the same pond to utilize different ecological niches and resources efficiently.
– Integrated fish farming: Integrated fish farming involves the combination of fish farming with other agricultural activities like poultry, livestock, or crop farming to create a symbiotic system with waste recycling and resource utilization.

(ii)Focus:
– Polyculture: The main focus is on optimizing the interactions between different fish species for efficient resource utilization and reducing competition.
– Integrated fish farming: The main focus is on integrating fish farming with other agricultural components to create a self-sustaining and environmentally friendly system with multiple outputs.
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(4ai)
Fishing is the activity of catching, harvesting, or capturing fish and other aquatic organisms from their natural habitats, usually for commercial, recreational, or subsistence purposes.

(4aii)
(i)Fishing Nets
(ii)Fishing Hooks and Lines
(iii)Fishing Traps

(4aiii)
To calculate the area of the pond in square meters (m^2), We use the formula: Area = Length × Breadth

Given:
Length = 50,000 cm
Breadth = 25,000 cm

First, convert the measurements to meters:
Length = 50,000 cm ÷ 100 cm/m = 500 meters
Breadth = 25,000 cm ÷ 100 cm/m = 250 meters

Now, calculate the area:
Area = 500 meters × 250 meters = 125,000 square meters (m^2)

(4bi)
– Endo-parasite: An endo-parasite is a parasite that lives inside the host’s body, such as in organs, tissues, or blood vessels.
– Ecto-parasite: An ecto-parasite is a parasite that lives on the host’s body surface, such as the skin, fins, or gills.

(4bii)
(i)Weight loss and reduced growth rate.
(ii)Increased mucus production and skin irritation.
(iii)Abnormal swimming behavior, such as flashing or rubbing against objects.
(iv)Fins clamping or fin erosion.
(v)Presence of visible parasites on the fish’s body or gills.

(4biii)
(i)Install a strong and secure fence around the pond to prevent alligator access.
(ii)Implement regular monitoring and surveillance to detect any alligator presence early and take appropriate action.
(iii)Educate and inform people in the area about alligator behavior and safety measures to prevent future incidents.

(4c)
(i)Both are passive fishing gears that rely on fish swimming into them to be captured.
(ii)They are widely used in commercial fishing to catch a variety of fish species and are designed to be efficient in their respective fishing environments.
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(5ai)
Fish preservation involves methods of preventing or slowing down the spoilage of fish after harvest. This can be done through methods like chilling, freezing, salting, smoking, drying, and canning.

Fish processing, on the other hand, involves the transformation of fish into forms that are ready for consumption or further processing. This includes methods like filleting, skinning, deboning, mincing, and grinding.

(5aii)
(PICK ANY 4 ONLY)
– Refrigerators or freezers
– Coolers or ice boxes
– Salt
– Smokehouses
– Drying racks

(5aiii)
– Refrigerators or freezers operate by using a circulating refrigerant gas that absorbs heat from the fish and expels it outside. This leads to a reduction in temperature, which helps to slow down bacterial growth and preserve the fish.
– Salt is used as a preservation method primarily for fish that are to be cured or dried. The fish is coated with salt, which draws out moisture and creates an environment that is not conducive for microbial growth.
– Smokehouses are used for smoking fish, which involves exposing it to smoke from burning wood chips. This imparts a distinctive flavor and color to the fish, and also helps to preserve it by slowing down the growth of bacteria and parasites.

(5bi)
– Moringa: This is a plant that is commonly used in traditional medicine and as a food source in many parts of the world. The leaves of the moringa tree can be dried and ground into a powder, which can be added to fish feed to boost its nutrient content. Moringa is rich in vitamins, minerals, and protein, and has antioxidant properties that help to improve fish health and growth.
– Soybean: Soybean meal is a popular ingredient in fish feed due to its high protein content and amino acid composition. Soybean is a plant-based protein source that is easily digestible by fish, and can be used as a substitute for fishmeal, which is a finite resource.

(5bii)
– Manual method of fish feeding involves hand-feeding fish at regular intervals. This is usually done in small-scale fish farms or recreational ponds, where the number of fish is manageable. The feed can be delivered directly to the water surface, or scattered over the pond.
– Feeding frequency refers to the number of times per day that fish are fed. This can vary depending on the species of fish, their age and size, and the conditions of the pond. Generally, fingerlings and juveniles require more frequent feeding than adult fish. Overfeeding can lead to water pollution and disease outbreaks, while underfeeding can result in stunted growth and poor health.