Stock Enhancement in Fisheries Management

Questions and Answers

What is a primary goal of stock enhancement in floodplains, large reservoirs, and lakes in Asia?

To increase food fish supplies (correct)

To promote aquaculture practices

To diminish the number of invasive species

To decrease the environmental impact of fishing

Which characteristic is crucial for the survival and growth of fingerlings during stocking?

Ability to thrive in saltwater

Resistance to disease

Minimum size of 100 mm (correct)

High temperature tolerance

What defines stock enhancement as a management strategy?

Achieving improvements through natural productivity (correct)

Focus solely on recreational fishing opportunities

Heavy reliance on artificial feeding methods

Use of extensive external energy inputs

What does species enhancement focus on for successful fish production from reservoirs?

Stocking the right species at appropriate proportions Signup and view all the answers

In which countries have successful stock enhancement programs primarily been associated with reservoirs?

India, Cuba, and China Signup and view all the answers

What mainly influences the effectiveness of stock enhancement practices?

The specific management options exercised Signup and view all the answers

What is the general expectation from stock enhancement practices?

To increase stock size and fish catch Signup and view all the answers

What is a key factor that distinguishes successful stock enhancement from other fisheries management strategies?

Dependence on recapturing stocked fish rather than breeding Signup and view all the answers

Which species is recommended for stocking in reservoirs primarily due to its ability to establish a breeding population?

C. catla Signup and view all the answers

What is the maximum recommended proportion of C. mrigala to be stocked in reservoirs due to harvesting difficulties?

30% Signup and view all the answers

Which characteristic is NOT essential for the selection of fish species for reservoirs?

Thermal tolerance Signup and view all the answers

What negative effect has been attributed to the stocking of H. molitrix in reservoirs?

Inhibition of catla growth Signup and view all the answers

Which of the following species is specifically suggested for utilization of molluscan fauna in reservoirs?

Puntius pulchellus Signup and view all the answers

For which region should the endemic carps’ breeding technology be perfected for regular seed supply?

Peninsular river basins Signup and view all the answers

What is a notable characteristic of the Common carp (C. carpio) regarding its suitability for stocking in reservoirs?

It is not suitable for thermally stratified reservoirs with anoxic hypolimnion Signup and view all the answers

Which attribute of reservoirs influences the combination and composition of stocks recommended?

Available food niches Signup and view all the answers

Study Notes

Stock Enhancement Overview

Stock enhancement improves both qualitative and quantitative aspects of open water ecosystems through specific management practices.
Relies largely on natural productivity, requiring minimal external feeds or energy, thus offering high returns on limited investments.
Effective strategy for boosting fish production in large reservoirs, fostering both breeding and existing fish stocks.

Success in Small Reservoirs

Culture-based fisheries in small reservoirs of India emphasize recapturing stocked fish over establishing breeding populations.
Aimed at increasing overall stock size and fish catch from reservoirs through enhanced stocking practices.

Purpose and Benefits

Serves as a primary strategy to maintain or improve fish populations in less productive water bodies.
In Asia, focus is on increasing food fish supplies; in developed countries, on enhancing recreational fisheries and conserving species.

Ideal Stocking Conditions

Fingerling stocking is most effective post-monsoon when water levels stabilize with abundant zooplankton.
Optimal fingerling size for stocking is 100 mm and above for better survival and accelerated growth.

Species Enhancement and Selection

Successful fish production in reservoirs relies on stocking appropriate fish species in proper proportions.
Selection factors include growth rates, feeding habits, market demand, food conversion efficiency, and compatibility with available natural food.

Recommended Species for Stocking in India

Indian Major Carps (IMCs) are preferred for reservoirs, especially Catla (C.catla) and Rohu (L.rohita) known for better yields and breeding success.
Catla and Rohu should comprise a high proportion of stocked species in zooplankton-rich environments.
C.mrigala should not exceed 30% of the species ratio due to harvest difficulties.

Exotic Species Considerations

Silver carp (H.molitrix) is a fast-growing candidate due to its efficient use of phytoplankton, but may compete adversely with native species like Catla.
Various other species suitable for stocking include: C.cirrhosa, L.calbasu, L.bata, and Tor spp.

Promoting Endemic Species

Endemic carps (Labeo kontius, Puntius carnaticus, Gonoproktopterus dubius, G.kolus, Tor khudree) should be stocked in Peninsular river basins to enhance genetic diversity and resilience.
Breeding technologies for endemic carps need further development for consistent seed supply.

Specific Stocking Requirements

Common carp (C.carpio) is suitable for reservoirs in Karnataka and Tamil Nadu but is not recommended for thermally stratified waters where growth is poor.
Small reservoirs should focus on developing catfish fisheries to optimize aquatic resources.

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Description

Explore the concept of stock enhancement, a vital management strategy for increasing fish production. This quiz covers the qualitative and quantitative improvements achieved through various management options in open water systems. Understand how relying on natural productivity can lead to effective and cost-efficient fish production enhancement.