title: Maximum sustainable yields from a spatially-explicit harvest model.
abstract: Spatial heterogeneity plays an important role in complex ecosystem dynamics, and therefore is also an important consideration in sustainable resource management. However, little is known about how spatial effects can influence management targets derived from a non-spatial harvest model. Here, we extended the Schaefer model, a conventional non-spatial harvest model that is widely used in resource management, to a spatially-explicit harvest model by integrating environmental heterogeneities, as well as species exchange between patches. By comparing the maximum sustainable yields (MSY), one of the central management targets in resource management, obtained from the spatially extended model with that of the conventional model, we examined the effect of spatial heterogeneity. When spatial heterogeneity exists, we found that the Schaefer model tends to overestimate the MSY, implying potential for causing overharvesting. In addition, by assuming a well-mixed population in the heterogeneous environment, we showed analytically that the Schaefer model always overestimate the MSY, regardless of the number of patches existing. The degree of overestimation becomes significant when spatial heterogeneity is marked. Collectively, these results highlight the importance of integrating the spatial structure to conduct sustainable resource management.
authors.affiliation: Department of Biology, Faculty of Sciences, Kyushu University, 6-10-1, Hakozaki, Fukuoka, 812-8581, Japan. Electronic address: nao.takashina@gmail.com.
authors.forename: Nao
authors.initials: N
authors.lastname: Takashina
authors.affiliation: Department of Biological Science, Faculty of Life and Environmental Science, Shimane University, Nishikawatsu-cho 1060, Matsue 690-8504, Japan. Electronic address: amougi@gmail.com.
authors.forename: Akihiko
authors.initials: A
authors.lastname: Mougi
mesh_terms: D000818:Animals; D017753:Ecosystem; D005398:Fisheries / Q000379:methods; D005399:Fishes / Q000502:physiology*; D008954:Models, Biological; D011157:Population Dynamics; D062206:Spatial Analysis
keywords: Maximum sustainable yields; Resource management; Schaefer model; Spatially-explicit model