Effects of Non-Point Nutrient Loading on Planktonic Community Structure and Function in a Great Lakes Coastal Wetland

A thesis presented to the faculty of the College of Science and Technology at Morehead State University in partial fulfillment of the requirements for the Degree of Master of Science in Biology by Brian M. Binion on July 26, 1995

Data from: A spatial kernel density method to estimate diet composition of fish

We present a novel spatially-explicit kernel density approach to estimate the proportional contribution of a prey to a predator’s diet by weight. First, we compare the spatial estimator to a traditional cluster-based approach using a Monte Carlo simulation study. Next we compare the diet composition of three predators from Pamlico Sound, North Carolina to evaluate how ignoring spatial correlation affected diet estimates. The spatial estimator had lower MSE values compared to the traditional cluster-based estimator for all Monte Carlo simulations. Incorporating spatial correlation when estimating the predator’s diet resulted in a consistent increase in precision across multiple levels of spatial correlation. Bias was often similar between the two estimators but when it differed it mostly favored the spatial estimator. The two estimators produced different estimates of proportional contribution of prey to the diets of the three field-collected predator species, especially when spatial correlation was strong and prey were consumed in patchy areas. Our simulation and empirical data provide strong evidence food habits data should be modeled using spatial approaches and not treated as spatially-independent

Cross Validation using Optimization

R code for cross validation using an optimization routine

Creating S Predict Grids

R code for generating

s_predict

Locations for s, needed when estimating the diet using the spatial estimator and for simulating diet data across the Pamlico Sound surface

Estimating Diet using Spatial Estimator (SDKE)

R code for estimating predator diet composition using the spatial estimator

Pamlico_Waters_Extended_wgs

Pamlico_Waters_Extended_wg

Bhattacharyya Distance

R code for calculating Bhattacharyya Distance

spot_trawl

Data used for estimating Spot diet using the spatial and non-spatial estimators