Concepts of spawning targets

Environment Agency (2000) Concepts of spawning targets. Environment Agency North West, 23pp.

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Abstract

This report discusses the concepts of spawning targets. Spawning target setting is based on the fact that the number of smolts produced by any given river is constrained by habitat availability. This means smolt numbers depend on spawner numbers up to a point, but thereafter smolt production reaches a ceiling. It has been shown, in some rivers at least, that the relationship between egg deposition and smolt production may approximately be described by a mathematical equation. The equation will vary between rivers and there is uncertainty over its exact form. The concept of Maximum Gain (MG) is explained and its application in fisheries management discussed. The author also critically examines the concept of Density Independent Mortality (DIM).

Item Type: Monograph or Serial Issue
Title: Concepts of spawning targets
Corporate Creator/Author: Environment Agency
Number of Pages: 23
Date: 2000
Publisher: Environment Agency North West
Funders: Environment Agency Archives North West
Contact Email Address: dis@fba.org.uk
Issuing Agency: Environment Agency, UK (Freshwater Biological Association)
Additional Information: No date on publication. Date given is estimation. Environment Agency internal report, includes "Response to Dr Milner's targets"
Uncontrolled Keywords: Salmo salar; Salmo trutta; Salmon fisheries; River fisheries; Spawning populations; Spawning; Fishery management; Smolts; Stock assessment; Stocks
Subjects: Ecology
Fisheries
Limnology
Item ID: 8086
Depositing User: Hardy B Schwamm
Date Deposited: 01 Mar 2012 17:32
Last Modified: 01 Mar 2012 17:32
URI: http://aquaticcommons.org/id/eprint/8086

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