Identifying the origin of waterbird carcasses in Lake Michigan using a neural network source tracking model

Journal of Great Lakes Research
By: , and 

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Abstract

Avian botulism type E is responsible for extensive waterbird mortality on the Great Lakes, yet the actual site of toxin exposure remains unclear. Beached carcasses are often used to describe the spatial aspects of botulism mortality outbreaks, but lack specificity of offshore toxin source locations. We detail methodology for developing a neural network model used for predicting waterbird carcass motions in response to wind, wave, and current forcing, in lieu of a complex analytical relationship. This empirically trained model uses current velocity, wind velocity, significant wave height, and wave peak period in Lake Michigan simulated by the Great Lakes Coastal Forecasting System. A detailed procedure is further developed to use the model for back-tracing waterbird carcasses found on beaches in various parts of Lake Michigan, which was validated using drift data for radiomarked common loon (Gavia immer) carcasses deployed at a variety of locations in northern Lake Michigan during September and October of 2013. The back-tracing model was further used on 22 non-radiomarked common loon carcasses found along the shoreline of northern Lake Michigan in October and November of 2012. The model-estimated origins of those cases pointed to some common source locations offshore that coincide with concentrations of common loons observed during aerial surveys. The neural network source tracking model provides a promising approach for identifying locations of botulinum neurotoxin type E intoxication and, in turn, contributes to developing an understanding of the dynamics of toxin production and possible trophic transfer pathways.

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Additional publication details

Publication type Article
Publication Subtype Journal Article
Title Identifying the origin of waterbird carcasses in Lake Michigan using a neural network source tracking model
Series title Journal of Great Lakes Research
DOI 10.1016/j.jglr.2016.02.014
Volume 42
Issue 3
Year Published 2016
Language English
Publisher International Association for Great Lakes Research
Contributing office(s) Upper Midwest Environmental Sciences Center
Description 12 p.
First page 637
Last page 648
Country Canada, United States
Other Geospatial Lake Michigan
Online Only (Y/N) N
Additional Online Files (Y/N) N
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