A SURVEY OF MUSSEL MIDDENS ON THE ST. CROIX AND KETTLE RIVERS AT ST. CROIX STATE PARK (MN)

Lindsay E. Fulton, Student, Edgewood High School (Madison, WI)
Bethany A. Walker, Student, Edgewood High School (Madison, WI)
Mekel A. Wiederholt Meier, Director, Advanced Environmental Field Education, Edgewood High School, 2219 Monroe Street, Madison, WI 53711

Mussel middens were surveyed along the banks of the St. Croix and Kettle River in St. Croix State Park in spring, 2008. More middens were found along the banks of the St. Croix River than the Kettle River indicating that the St. Croix is a better habitat for muskrats. Middens along the St. Croix indicate a more diverse mussel population than the Kettle River. The most common species of mussels found at both sites were the Mucket (Actinonaias ligamentina) and Fat Mucket (Lampsilis siliquoidea), at 29.95% and 23.05% on the St. Croix and 8.42% and 21.98% on the Kettle River, respectively. Also common at both sites was the Spike (Elliptio dilatata) species, at 21.88% on the St. Croix and 5.13% on the Kettle River. Mussels found on both rivers in small numbers were the Round Pigtoe (Pleurobema coccineum) and Pink Heelsplitter (Potamilus alatus), at 2.73% and 0.91% on the St. Croix and 0.73% and 0.35% on the Kettle River. Mussels found only on the St. Croix River were the Wabash Pigtoe (Fusconaia flava), Pimpleback (Quadrula pustulosa pustulosa), Giant Floater (Pyganodon grandis), and Hickorynut (Obovaria olivaria).