2015 GSA Annual Meeting in Baltimore, Maryland, USA (1-4 November 2015)

Paper No. 207-17
Presentation Time: 9:00 AM-6:30 PM

ANTHROPOGENIC MACRODEBRIS AND MICROPLASTICS FROM BEACHES OF SOUTHERN LAKE MICHIGAN


GARCIA, Cesar A., KOSTRO, Patricia and KILIBARDA, Zoran, Geosciences, Indiana University Northwest, 3400 Broadway, Gary, IN 46408, cesgarci@iun.edu

The objective of this study is to determine the amount and types of macrodebris and microplastics found in the strand line along six Indiana beaches of southern Lake Michigan before and after storm activity. Anthropogenic debris was collected after storms from specific sites (5m long section) at six beaches - Whihala Beach, Marquette Park, Portage Lakefront and Riverwalk, Porter Beach, Dunbar Beach and Central Avenue Beach. The anthropogenic debris collected was sorted into 8 major categories, following classification used in Europe (Laglbauer et al., 2014). A storm at the end of October 2014 brought a high amount of macrodebris to four of the beaches, while two of the beaches, Whihala and Central, experienced heavy damage and were closed to the public. The amount of anthropogenic debris ranged from 511.2 g (Dunbar Beach), to 46.4 g (Porter Beach). Various plastic materials (bags, smoking related material, bottle caps, and miscellaneous) were the primary type of anthropogenic debris found on all of the beaches. Historical data for each of the aforementioned beaches, obtained from the Alliance for the Great Lakes, revealed a similar type of anthropogenic debris, but it differed in the relative amount of total debris collected. This discrepancy in relative amount of debris is due to the limited number of sampling dates, and collecting methods. We will use density liquids to separate microplastics from natural sediment and then examine microdebris with petrographic and fluorescent microscope.