Over-Winter Mortality Of Gizzard Shad (Dorosoma Cepedianum) In Oneida Lake, New York

Winter limits resource availability in temperate lakes, exerting a strong influence on the northern distributions of many temperate species by altering the recruitment of age-0 fishes. Recently, there has been growing concern that projected climate change could alter over-winter survival of many fish species and have ecosystem-level effects on all trophic levels of aquatic ecosystems. Oneida Lake has been the focus of a long-term data set across several trophic levels and provides the ideal location to study over-winter mortality in fishes. In Chapter 1, I provide a review of current methods used throughout the literature to address questions involving over-winter mortality in fishes. Specifically, I address methods used, their pros and cons, and what has been learned by the application of each method. Common methods evaluated include experiments, field observations, experiments and field observations, and analysis of long-term data sets. Given that mortality is commonly driven by complex interactions between multiple factors, I suggest researchers use multiple approaches to study fish over-winter mortality. In Chapter 2, I conducted a series of experiments and field sampling to develop a conceptual model of gizzard shad over-winter mortality in Oneida Lake. Gizzard shad exhibited high mortality rates as water temperatures declined prior to ice formation and are highest at temperatures less than 4o C. Habitat sampling demonstrated that shad congregate in high densities in Oneida Lake marinas, which provide a nearshore temperature refuge but may become anoxic during years with consistent ice cover. Within any given year, shad survival is likely a function of length entering winter, rate of temperature decline preceding ice-on, and ice duration. BIOGRAPHICAL SKETCH William was born on August 30, 1982 in Brookfield, Wisconsin to Frank and Sandie Fetzer. He grew up in Nashotah, Wisconsin, where he learned to love the outdoors and appreciate the value of nature through his experiences hunting and fishing on the Rupnow Farm with his family, especially his father, brother and godfather Keith Marshall. William graduated from Arrowhead Union High School in 2001 and enrolled at the University of Wisconsin-Madison to pursue a degree in Wildlife Ecology. During his first two years, he took many different environment-related classes, and decided teaching high school biology would allow him to pass his interest in the natural world to other inquiring minds. In 2003, he applied to and was accepted into the program for secondary education in the School of Education. Prior to enrolling within the program, he received an NSF-REU to work with Dr. Jake Vander Zanden at the Center for Limnology for the summer of 2003. Through his research project, he spent countless hours near or on lakes Mendota and Monona collecting, processing and analyzing samples to establish the pre-zebra mussel food web structure of these lakes. The epiphany that he could have a career studying how lakes work forever change the course of his life. After the summer, he switched majors to Zoology, focused his coursework on aquatic ecology, and continued working for Dr. Vander Zanden. Over the next two years, he become embedded within the social and scientific community at the Center for Limnology, working on a variety of projects, including documenting invasive rusty crayfish distributions in Wisconsin, assisting graduate students with stable isotope processing, and a global meta-analysis of aquatic food-chain-length. In 2005, William graduated with honors from the University of WisconsinMadison with a degree in Zoology and enrolled in a MS/PhD program at Cornell iii University in Natural Resources. Cornell University and specifically the Cornell Biological Field Station provided the ideal setting for him to pursue his ever-growing list of questions.