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Gain in Weight per day as a Measure of Production in Fish Rearing Ponds
Author(s) -
Meehean O. Lloyd
Publication year - 1943
Publication title -
transactions of the american fisheries society
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.696
H-Index - 86
eISSN - 1548-8659
pISSN - 0002-8487
DOI - 10.1577/1548-8659(1942)72[220:giwpda]2.0.co;2
Subject(s) - acre , productivity , zoology , environmental science , body weight , mathematics , fishery , biology , agronomy , economics , macroeconomics , endocrinology
The variation in production due to ecological factors, some of which are beyond the control of the operator, is demonstrated for largemouth black bass ponds. A comparison of effectiveness is made between inorganic and organic fertilizers on the basis of survival and weight of fish per acre, which are ordinarily used as a measure of productivity. Data are presented to show how survival and yield per unit area may be affected by manipulation and intentional interference by the operator. The gain in weight per acre per day is calculated to show that number or weight of fish per acre is not a reliable measure of the effectiveness of fertilizers. Information on gain in weight per acre per day is presented on other waters in two series of experiments to demonstrate the applicability of this measure in comparing the productivity of different waters or various combinations of fertilizers.