1. Door County Avian Waste Survey and Bird Count Colleen McDermott, D.V.M., Ph.D. University of Wisconsin Oshkosh Oshkosh, WI 54901 Phone: (920) 424-1102 FAX: (920) 424-1101 Mcdermot@uwosh.edu

2. Sources of E. coli at Recreational Beaches Human waste Agricultural runoff Domestic pets Avian waste –Gulls –Ducks –Geese –Others

3. Door County While all sources are possible, avian waste has been suggested as important source Large numbers of gulls and geese at some beaches –E.g. Whitefish Dunes & gulls –E.g. Otumba Park & Geese

6. Avian Waste Contains: –3.7 X 10 8 fecal coliforms/gram feces (Alderisio & DeLuca, 1999) –E. coli (indicator organism of fecal contamination) -Potential pathogens Salmonella Campylobacter –Avian waste as source of E. coli may have lower potential to cause disease in humans than other sources

7. Ways to ID Source of Contamination Many have been suggested –DNA fingerprinting (E. coli & other fecal organisms) –Antibiotic Sensitivity Profiles –Caffeine concentrations –Etc. None are easy or definitive Often bird counts at beaches have been used to determine impact of avians on beach health –Once/day snapshot count –Longer term counts

8. Other Ideas? Quantify amount of avian waste on beaches, rather than bird numbers Summer 2004 –Counted and classified avian waste “droppings” – 10 Beaches in Door County – Each beach was counted 1X/week for 14 weeks –Used random grid counting method

9. Method Sampler throws square grid (1.5 m 2 ) in transect zone along swash zone Counts waste within grid and classifies type of bird waste Moves to next location 45.5 m along swash zone Throws grid again and counts Repeats for a total of 9 sampling plots

10. Figure 1: Sampling scheme for avian waste enumeration (Fish Creek, WI)

12. Table 1: Pearson Correlations for Avian Waste and Bird Counts with E. coli

13. Table 1: Proportions of bird types in Door County, WI Summer 2004 BeachGulls as percent of total birds present Geese as percent of total birds present Mean log 10 E. coli concentration Baileys Harbor78%21%1.44 Egg Harbor53%43%1.45 Ellison Bay41%27%1.65 Ephraim61%27%1.05 Fish Creek36%30%1.58 Newport88%4%0.79 Otumba18%73%1.68 Sister Bay67%7%1.30 Sunset78%18%1.79 Whitefish Dunes100%0%1.17

14. Summary Avian waste counts do not correlate with bird numbers nor with E. coli concentration in beach water At a few beaches bird counts do correlate with E. coli concentrations in beach water Proportions of gulls vs. geese does not seem to affect E. coli concentrations in beach water

15. Future Work In Summer 2005 we will expand project –Count avian waste and bird numbers at 13 beaches in Door County –Add numbers to ensure our statistics are powerful –Continue to collect avian waste samples for E. coli isolations, DNA fingerprinting, antibiotics sensitivity profiles

16. Thank you Questions?