title: A field-based population model for the sediment toxicity test organism Leptocheirus plumulosus: I. Model development.
abstract: We describe the development of a stage-structured population matrix model for the estuarine amphipod Leptocheirus plumulosus, a sediment toxicity test organism, based on regular sampling of a natural population for approximately 2 years. Annual population dynamics were characterized by abundance peaks in the spring and fall, and low densities in the summer and winter. We use a sequence of seasonal projection matrices to capture these qualitative patterns in population dynamics. We compare two methods for estimating transition probabilities: multiple regression and truncated singular value decomposition (SVD). Overall, SVD gave more realistic parameter estimates than regression, although fecundity estimation was problematic. There were predictable trends in growth, survival and fecundity within years. The SVD-derived model provides a framework for assessing the population-level effects of contaminants on Leptocheirus.
authors.affiliation: Applied Biomathematics, Setauket, NY 11733, USA. ms379@cam.ac.uk
authors.forename: M
authors.initials: M
authors.lastname: Spencer
authors.forename: B L
authors.initials: BL
authors.lastname: McGee
mesh_terms: D000818:Animals; D003445:Crustacea / Q000187:drug effects* / Q000502:physiology; D005260:Female; D005298:Fertility; D019015:Geologic Sediments / Q000737:chemistry*; D008018:Life Cycle Stages; D008297:Male; D008954:Models, Biological; D011157:Population Dynamics; D012621:Seasons; D012989:Soil Pollutants / Q000633:toxicity*
chemical_list: D012989:Soil Pollutants