DOI: 10.5061/dryad.4ht86
title: Data from: Consumer versus resource control and the importance of habitat heterogeneity for estuarine bivalves

description: The relative influence of consumers (top down) and resources (bottom up)
 on the distribution and abundance of organisms remains a key question in
 ecology. We examined the relationships between consumer and resource
 variables along a productivity gradient for a dominant predator–prey
 interaction in a marine soft-sediment system. We 1) quantified density and
 size of the clam Macoma balthica (prey species) in six replicate sites at
 each of four habitat types (shallow mud, deep mud, muddy sand and detrital
 mud) in the Rhode River, Chesapeake Bay. We selected one habitat type of
 high food availability and clam density (shallow mud) and another of low
 food availability and clam density (muddy sand) for manipulative
 experiments. Then, we 2) measured M. balthica survival and growth through
 transplants, 3) measured food availability as sedimentary organic carbon
 content, 4) quantified predator density, and 5) calculated predator
 foraging efficiency in the two habitat types. Clam density in the four
 habitat types differed and was related to sedimentary carbon availability
 and predator density. One of the habitats, detrital mud, appeared to be a
 population sink because it only held juvenile Macoma that never survived
 to reproductive age. Macoma size and growth, and predator (mainly blue
 crab Callinectes sapidus) densities were positively correlated with
 productivity and were higher in shallow mud than muddy sand. In contrast,
 Macoma mortality, local ‘interaction strength’, and predator foraging
 efficiency were lower in the productive habitat (shallow mud). Thus,
 predation intensity was inversely correlated with productivity (food
 availability); consumer and resource effects differed by habitat type;
 and, at a relatively small spatial scale, consumer and resource forces
 jointly determined population dynamics in this soft-sediment marine
 system.
description: Data spreadsheet for
 Carbon and nitrogenData spreadsheet for
 Carbon and nitrogen ANOVA analyses and Fig. 2. Habitat 1 = shallow mud, 2
 = muddy sand, 3 = detrital mud, 4 = deep mudCHNData2.xlsxCHNData2 - Statistics for Carbon and NitrogenStatistics for Carbon and Nitrogen ANOVA analyses and Fig. 2.Habitat 1 = shallow mud, 2 = muddy sand, 3 = detrital mud, 4 = deep mudCHNData2.docxAbunVsCHN2 -data spreadsheet for regression equationData spreadsheet for regression equation of CHN vs M. balthica densityAbunVsCHN2.xlsxAbunVsCHN2 -statistics from Minitab CHN vs M. balthica densityStatistics from Minitab for regression equation of CHN vs M. balthica densityAbunVsCHN2.docxAbund&SizeSmLg_05-31-16 -Data spreadsheet Ambient clam densityAmbient M. balthica density and size Small (juvenile) and Large (Adult) and Fig. 3Abund&SizeSmLg_05-31-16.xlsxAbund&SizeSmLg_05-31-16 - Statistics for ambient clam densityANOVAs for M. balthica density and size Small (juvenile) and Large (Adult) and Fig. 3Abund&SizeSmLg_05-31-16.docxPreds2_05-31-16 - Data spreadsheet predator abundanceData for predator abundance ANOVAs, and number of clams per crab ANOVAs and meansPreds2_05-31-16.xlsxPreds2_05-31-16 - Statistics from Minitab for predator abundanceStatistics from Minitab for predator abundance ANOVAs, and number of clams per crab ANOVAs and meansPreds2_05-31-16.docxForagEff -Data spreadsheet Foraging efficiency of crabs on clamsData spreadsheet of foraging efficiency of crabs and clamsForagEff.xlsxForagEff - Statistics in Minitab of foraging efficiency of crabs on clamsStatistics in Minitab of foraging efficiency of crabs on clams, and foraging efficiency ANOVAs (log-transformed data)ForagEff.docxGrowSplitPlot - Data spreadsheet for clam growth using split plot designData spreadsheet for clam growth in caging experiment using split plot designGrowSplitPlot.xlsxGrowSplitPlot -Statistics from Minitab for clam growth from caging experimentsStatistics from Minitab for clam growth from caging experiments; stats for Table 2, growth from split plot analysisGrowSplitPlot.docxOpAmbient2 - Data spreadsheet ambient clams from experimental plotsData spreadsheet ambient clams from experimental plots; mean ambient abundance in experimental plots for Fig. 5OpAmbient2.xlsxOpAmbient2 - Statistics from Minitab mean ambient clam abundanceStatistics from Minitab; mean ambient clam abundance in experimental plots for Fig. 5OpAmbient2.docx