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A Model for the Space–Time Dependence of Feeding for Pelagic Fish Populations
Author(s) -
Mason Doran M.,
Patrick E. Vincent
Publication year - 1993
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(1993)122<0884:amftst>2.3.co;2
Subject(s) - alewife , pelagic zone , foraging , diel vertical migration , predation , predator , optimal foraging theory , ecology , spatial distribution , biology , statistics , mathematics
The time‐varying spatial distribution of pelagic fish is an important factor in the development of feeding rate estimates for input into bioenergetics growth models. Key issues are the degree to which fish and prey distributions overlap, the frequency and duration of such overlaps, and the effectiveness of foraging during overlaps. A model for the space and time dependences of feeding by the pelagic planktivorous alewife Alosa pseudoharengus in the Great Lakes is presented. The model combines two submodels: (1) a diffusion–taxis model of predator and prey dispersal and (2) a foraging rate model. Both models depend on environmental variables. The diffusion–taxis model is based on directional motion and random motion on the part of the fish. Directional motion is determined from a taxis function that relies on local cues for feeding rate and encounter rate with predators. The foraging model expresses the feeding rate of a predator as a function of predator and prey sizes, prey density, light level, and temperature. The diel movements, distribution, and feeding rates of alewives were simulated with these models. The model simulations successfully represented the time‐varying spatial distribution of alewives and predicted peaks in their feeding rate at dawn and dusk. The model simulations suggested a nighttime feeding rate that was less than what is known from the literature. These results suggest that many of the known features of alewife distribution can be reproduced with this class of model. Given the typically patchy distribution of predator and prey, the nonhomogeneous character of environmental conditions, and the dynamic nature of both the biological and physical components of an ecosystem, a spatiotemporal approach such as this may be necessary for modeling the feeding, growth, and production dynamics of pelagic fishes.