碩士 / 國立臺灣大學 / 漁業科學研究所 / 96 / In shrimp ponds with highly intensive stocking density, at the middle and/or latter period, the high existing volume (biomass) of shrimp ponds, the excretion of shrimps, over-feeding and feed-corruption led to drastic changes in water quality. The slight effects are slow growing rate of shrimps, shrimp size differences, shrimp diseases and feed wasting. In some serious cases, the shrimps die partially or even completely. Therefore, in this study, the shrimp-farming management for existing capacity and high production, partial harvesting, were carried out in order to simplify the management of shrimp-farming, to increase production and to improve economic efficiency.
The results showed that as the shrimp farming period passed by, the water quality and carrying capacity got worse gradually. In Kuruma shrimp (Penaeus japonicus) pond A, after four months the harvest per hectare increased to 28 tons, due to partial harvest, with the average body-size of 18-24 grams. Similarly in Kuruma shrimp pond B, the harvest per hectare was 10 tons, and the average body-size of shrimp was 7-10 grams after three months. Due to high temperature during the farming period, the growing rate of grass shrimp(P. monodon) pond A was very quickly, and after two months the total output was 7.13 tons per hectare. Because of the operation of partial harvesting, the output increased 1.65 tons per hectare, the shrimp body enlarged and the price increased.
In addition to increase the water exchanging rate and application of biotics or water purification, the partial harvesting could maintain the production loading (carrying capacity), reduce farming risk, increase the output and benefits, simplify water quality management, increase the survival rate of shrimps and raise the growing rate of shrimps. Although the partial harvesting will increase the cost of farming, it is still worthy. Thus, the partial harvesting is one of the most effective management strategies increasing shrimp production.
| Identifer | oai:union.ndltd.org:TW/096NTU05451004 |
| Date | January 2008 |
| Creators | Shen-Chien Huang, 黃尚健 |
| Contributors | 陳弘成 |
| Source Sets | National Digital Library of Theses and Dissertations in Taiwan |
| Language | zh-TW |
| Detected Language | English |
| Type | 學位論文 ; thesis |
| Format | 64 |
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