The Pennsylvania State University The Graduate School College of Agricultural Sciences AQUATIC HABITAT CHARACTERS THAT SUPPORT BOTH THE BRIDLE SHINER (Notropis bifrenatus) AND THE IRONCOLOR SHINER (Notropis chalybaeus) A Dissertation in Wildlife and Fisheries Science by Clare William Hanson, II Captain, United States Navy (retired) 2013 Clare William Hanson, II Submitted in Partial Fulfillment of the Requirements for the Degree of Doctor of Philosophy December 2013 ii The dissertation of Clare William Hanson, II, was reviewed and approved* by the following: Jay R. Stauffer Jr. Distinguished Professor of Ichthyology Chair of Committee Dissertation Adviser Michael C. Saunders Professor of Entomology Charles A. Cole Associate Professor of Landscape Architecture and Ecology Jeanette L. Schnars Executive Director, Regional Science Consortium, The Tom Ridge Environmental Center, Erie, PA Gregory A. Hoover Senior Extension Associate, Department of Entomology Special Signatory Michael G. Messina Head and Professor, Department of Ecosystem Science and Management *Signatures are on file in the Graduate School iii ABSTRACT The endangered Bridle Shiner, Notropis bifrenatus, and endangered Ironcolor Shiner, Notropis chalybaeus, co-exist in Marshalls Creek (Delaware River drainage), Monroe County, Pennsylvania. Although both species were historically widespread, the only known extant populations where these two species occur syntopically is in Marshalls Creek. The primary research goal was to determine the unique aquatic habitat characters of Marshalls Creek that support the syntopic populations of Bridle and Ironcolor shiners. To achieve this goal, research objectives were (1) to examine and discern the aquatic habitat characters (i.e., the combination and interaction of biological, chemical, and physical habitat characters) that are coincident with these two endangered species in Marshalls Creek; (2) to determine if these aquatic habitat characters are commonly found at other historical sites for these two endangered shiners; and (3) to speculate as to why these two endangered shiners currently exist together in Marshalls Creek. A NetWeaver model was developed to examine aquatic habitat characters of Marshalls Creek research sites and other historical sites on the Atlantic seaboard. NetWeaver model network components were utilized to produce strength of evidence scores (i.e., trueness levels) to compare, contrast, and evaluate aquatic habitat characters to the reference (i.e., benchmark) aquatic habitat characters in Marshalls Creek. This study provided important data and methodology for scientists and resource managers to assess biodiversity and determine favorable habitat for these two endangered shiners, and documented important aquatic habitat character data for fisheries management personnel to manage Bridle and Ironcolor shiner populations. Key Words: endangered Bridle Shiner, Notropis bifrenatus; endangered Ironcolor Shiner, Notropis chalybaeus; Marshalls Creek; syntopically; aquatic habitat characters; biological, chemical, and physical habitat characters; biodiversity; fisheries management. iv TABLE OF CONTENTS LIST OF FIGURES ................................................................................................................. vii LIST OF TABLES ................................................................................................................... x ACKNOWLEDGEMENTS ..................................................................................................... xviii Chapter 1 Introduction ............................................................................................................ 1 Research Goal and Objectives ......................................................................................... 1 Research Model ................................................................................................................ 2 Research Hypothesis and Testing .................................................................................... 4 Research Approval ........................................................................................................... 5 Research Citations ............................................................................................................ 6 Previous Research ............................................................................................................ 6 Endangered Shiners .......................................................................................................... 6 Bridle Shiner (Notropis bifrenatus) ............................................................................ 7 Morphological/Meristic Description ................................................................... 7 Etymology ........................................................................................................... 8 Habitat ................................................................................................................. 9 Feeding ................................................................................................................ 9 Spawning/Development ...................................................................................... 10 Native Range ...................................................................................................... 11 Ironcolor Shiner (Notropis chalybaeus). ..................................................................... 13 Morphological/Meristic Description ................................................................... 13 Etymology ........................................................................................................... 14 Habitat ................................................................................................................. 14 Feeding ................................................................................................................ 15 Spawning/Development ...................................................................................... 15 Native Range ...................................................................................................... 16 Comparisons ............................................................................................................... 18 Chapter 2 Methods and Materials .......................................................................................... 20 Research Sites .................................................................................................................. 20 Marshalls Creek .......................................................................................................... 23 Other Historical Sites .................................................................................................. 27 Maryland ............................................................................................................. 27 Delaware ............................................................................................................. 28 Massachusettes .................................................................................................... 29 Pennsylvania ....................................................................................................... 30 Research Site Collections and Measurements .................................................................. 31 Biological Habitat Characters ..................................................................................... 32 Fishes .................................................................................................................. 32 Aquatic Macroinvertebrates ................................................................................ 33 Aquatic Plants/Algae........................................................................................... 34 v Chemical Habitat Characters ...................................................................................... 35 Physical Habitat Characters ........................................................................................ 36 NetWeaver Model ............................................................................................................ 37 Development and Application .................................................................................... 37 Strength of Evidence Scores ....................................................................................... 41 Biological Habitat Characters Dependency Network ................................................. 42 Fishes Dependency Network ............................................................................. 43 Aquatic Macroinvertebrates Dependency Network ............................................ 44 Aquatic Plants/Algae Dependency Network ....................................................... 45 Chemical Habitat Characters Dependency Network .................................................. 46 Physical Habitat Characters Dependency Network .................................................... 47 Aquatic Habitat Characters Dependency Network ..................................................... 48 Chapter 3 Results .................................................................................................................... 50 Research Site Collections and Measurements .................................................................. 50 Biological Habitat Characters ..................................................................................... 50 Endangered