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USING KNOWLEDGE OF RECRUITMENT TO MANAGE HARVESTING
Author(s) -
Haydon Daniel T.,
Fryxell John
Publication year - 2004
Publication title -
ecology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.144
H-Index - 294
eISSN - 1939-9170
pISSN - 0012-9658
DOI - 10.1890/02-8001
Subject(s) - escapement , variance (accounting) , ecology , yield (engineering) , population , variation (astronomy) , environmental science , set (abstract data type) , computer science , biology , fishery , economics , demography , materials science , physics , accounting , sociology , astrophysics , metallurgy , programming language
Numerous field studies show that changing environmental conditions and ecological interactions within complex food webs can influence the dynamics of populations. Nonetheless, the potential benefit of understanding and predicting this variation to manage harvesting rarely has been considered. Here we develop analytic approximations to explore the relationship between the proportion of variation in annual recruitment that can be predicted and the expected annual harvest yield arising from fixed escapement harvesting methods. Simulations suggest that these approximations are reliable, provided that the unpredicted variance in recruitment is not large and the escapement threshold is set below carrying capacity. As an example of how these approximations may be applied, we use demographic and environmental data from a trapped population of martens ( Martes americana ) in Ontario to evaluate the effect on harvest yield of improvements in prediction of recruitment based on fluctuations in its prey base. We conclude that realistic improvements in forecasting of recruitment lead to only a modest increase in the average annual harvest and increase the variation in realized harvests, but could substantially reduce the risk of over‐harvesting when escapement levels are set low.