title: Novel molecular approach demonstrates that turbid river plumes reduce predation mortality on larval fish.
abstract: Turbidity associated with river plumes is known to affect the search ability of visual predators and thus can drive 'top-down' impacts on prey populations in complex ecosystems; however, traditional quantification of predator-prey relationships (i.e. stomach content analysis) often fails with larval fish due to rapid digestion rates. Herein, we use novel molecular genetic methods to quantify larval yellow perch (YP) in predator stomachs in western Lake Erie to test the hypothesis that turbidity drives variation in larval predation. We characterize predator stomach content DNA to first identify YP DNA (single nucleotide polymorphism) and then quantify larval YP predation (microsatellite allele counting) in two river plumes differing in turbidity. Our results showed elevated larval YP predation in the less turbid river plume, consistent with a top-down impact of turbidity on larval survival. Our analyses highlight novel ecological hypothesis testing using the power of innovative molecular genetic approaches.
authors.affiliation: Biological Sciences, University of Texas at Brownsville, One West University Boulevard-LHSB 2.816, Brownsville, TX, 78520, USA.
authors.forename: Lucia B
authors.initials: LB
authors.lastname: Carreon-Martinez
authors.forename: Kyle W
authors.initials: KW
authors.lastname: Wellband
authors.forename: Timothy B
authors.initials: TB
authors.lastname: Johnson
authors.forename: Stuart A
authors.initials: SA
authors.lastname: Ludsin
authors.forename: Daniel D
authors.initials: DD
authors.lastname: Heath
mesh_terms: D000818:Animals; D001492:Bass; D020387:Food Chain; D005766:Gastrointestinal Contents; D005838:Genotype; D007814:Larva; D018895:Microsatellite Repeats; D008969:Molecular Sequence Data; D010471:Perches / Q000235:genetics; D020641:Polymorphism, Single Nucleotide; D011235:Predatory Behavior; D045483:Rivers; D017422:Sequence Analysis, DNA; D014872:Water Movements
keywords: Perca flavescens; foraging; recruitment; stomach content DNA; survival; turbidity