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Primary Productivity and Fish Harvest in a Small Desert Impoundment

 

作者: WilliamJ. McConnell,  

 

期刊: Transactions of the American Fisheries Society  (Taylor Available online 1963)
卷期: Volume 92, issue 1  

页码: 1-12

 

ISSN:0002-8487

 

年代: 1963

 

DOI:10.1577/1548-8659(1963)92[1:PPAFHI]2.0.CO;2

 

出版商: Taylor & Francis Group

 

数据来源: Taylor

 

摘要:

Centrarchid harvest was compared to gross photosynthesis in a small desert impoundment. Average annual gross photosynthesis for benthic plants and plankton was equal to 14,100 pounds per acre (1.6 kg/m2) of oxygen or primary photosynthate over a 3-year period. Average annual harvest of centrarchids (largemouth bass and black crappie) was 138 pounds per acre live weight, which is equal to 0.98 percent of gross photosynthesis. Considered as dry biomass, centrarchid harvest equaled 0.15 percent of gross photosynthesis. When examined with regard to degree of habitat exploitation by centrarchids, fishing intensity, population turnover, competition from other fish, and cycles of recruitment, harvest of centrarchids was judged to be near the potential maximum. By the same standards, however, channel catfish production and harvest were judged to be considerably lower than what might be achieved with more effective recruitment and fishing. For the foregoing reason the relation between total fish harvest (channel catfish plus centrarchids) and gross photosynthesis was not considered to be valid for making total harvest predictions based on knowledge of gross photosynthesis. Possible effects on interpretation of gross photosynthesis of photic depth, organic import, dominant producer of plants, and deferred entry of plant forage into the food chain are discussed. Precision of estimate of major elements used in computing the harvest/photosynthesis ratio is also considered.

 

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