Cladophora and the Beach: Implications for Public Health Colleen McDermott, D.V.M., Ph.D.

1. Cladophora and the Beach: Implications for Public Health Colleen McDermott, D.V.M., Ph.D. Department of Biology and Microbiology University of Wisconsin - Oshkosh Oshkosh, WI 54901 Phone - (920) 424-1102 Fax - (920) 424-1101 E-mail –mcdermot@uwosh.edu

2. Implications for Public Health? • What effect does Cladophora have on beach health and the status of swimming at many Wisconsin beaches?

3. Freshwater Cladophora Ecology • Filamentous, branched green algae • Often form large mats • Mainly grows attached to hard surfaces • Mats can break off and float distances • Highest abundance found in shallows of highly eutrophic bodies of water • Although recent study found that increased P & N not associated with increased Cladophora mats

4. Freshwater Cladophora Ecology • Rarely found pure in natural systems • Commonly found in communities with diatoms and other green algae • Mats resemble grey wool when dead or dying • Odorous • Harbor unwanted microorganisms

5. Scale Low Cladophora minimally present in patches on the beach. Cladophora Distribution Study Ranked the presence of Cladophora on the beach on a scale of: None (0) Low (1) Moderate (2) High (3) Moderate Cladophora noticeably present on the beach and a nuisance. High Cladophora covers beach in wind rows. Slide adopted from WI DNR 2004.

6. Door County • Out of 30 (3 inland and 27 LM) beaches monitored most had observable Cladophora at some point during 2004. • Used DNR criteria (none, low, medium, or high) for observable Cladophora and BEACH data collected on the same day to conduct a preliminary examination of a relationship between Cladophora and E.coli.

7. 2004 Observations n=2100+ E.coli samples

8. Beach Percentage of 2004 sampling affected by moderate to high Cladophora accumulations Murphy Park 76% Newport Bay 78% Nicolet Bay 43% Otumba Park 14% Portage Park 28% White Fish Dunes 53% Table 2: Extent of Cladophora accumulation at selected Door County beaches for Summer 2004.

9. The Issue • Recent research indicates: • Cladophora extracts may be able to sustain E.coli and other ‘indicator organism’ growth in recreational water. • Mats of Cladophora harbor very high levels of E.coli • Cladophora are present at many WI beach sites. • Many questions to be asked and answered for beach managers…….

10. Growth of E. coli in Cladophora leachate Byappanahalli et al. 2003

11. Bacteria found in Cladophora mats in southern Lake MichiganFrom Whitman et al., 2003

12. E. coli as an Indicator Organisms • Intended to indicate recent fecal contamination in natural waters • Indicator organisms can enter water from several sources (human, cattle, birds, domestic pets) and the source can tell you something about the risk to human health. • Commensal organisms of intestines of warm-blooded animals. • Most are not pathogenic

13. Host Environment — Primary Habitat • Host provides: • Warm, stable temperature • High nutrient concentration • Doubling time = 12-48 hours

14. Sunlight Low nutrients Variable temperature, pH and moisture Predation Outside the Host — Secondary Habitat • A battle for survival • Low rate of survival • Low probability of colonizing a new host MAMMALIAN HOST EXTERNAL ENVIRONMENT Adapted from Winfield and Groisman. 2003.

15. E. coli as an Indicator Organism • It is intended to indicate recent fecal contamination in natural waters • Chosen because: • Found in feces in high numbers • E. coli generally will survive longer in the environment than pathogens • But-should not survive for extended periods • More easily detected than pathogens Warns us of the potential of GI tract pathogen presence

16. Salmonella • Hearty as far as pathogens go. • Relatively difficult to find in the environment. • Many sources including avian and human. • Require greater nutrients than E.coli.

17. Shigella • Does not survive very long…less than Salmonella or E.coli • Higher requirement for nutrients • Primarily from human sources

18. Campylobacter sp. • Survival characteristics not well studied. (Nov. 2004 AEM study) • From avian, bovine, and human (sometimes) sources • Ubiquitous in some areas

19. Norovirus • Survival is very limited once outside the primary host. • Implicated in several outbreaks. • Human or bovine.

20. Sunlight Low nutrients Variable temperature, pH and moisture Predation PotentialCladophora help to E.coli Survival • Block UV light • Increased nutrients • Moisture retention • More stable microbial community • Changes the minimum at each site to favor growth and survival! MAMMALIAN HOST EXTERNAL ENVIRONMENT Adapted from Winfield and Groisman. 2003.

21. 2004 Observations n=2100+ E.coli samples

22. In the ‘Mats’ Data Courtesy of: Richard Whitman, USGS

23. Laboratory Studies

24. Grow Light ( 24” 20W) Open Container w/H2O, rock, & Cladophora 2005 Lab Microcosm Study • Uses lake water and Cladophora from local lake • Looks at specific influence on E.coli and pathogens in a controlled setting. • Will assist in moving to field studies.

26. Pathogens in Cladophora • Spike Cladopha mats with: • Spike lake water with: • Salmonella • Shigella • Plesiomonas • E. coli • Count organism numbers over time • Replication? Survival? Death?

27. Salmonellasurvival in Cladophora mats

28. Field Work for 2005 • Use Ozaukee, Kewaunee, and Door County beaches as a study site. • Look at spatial and temporal effects of Cladophora mats on E.coli over the summer and specific 24 hour periods. • Evaluate the genetic diversity of the E.coli isolates recovered to determine if they are transient or stable (or replicating) during the swimming season. • Evaluate any pathogens associated with the mats and at the beaches at large. • Evaluate nutrient levels and effects.

29. Future Work • Submitted WI Sea Grant to study Cladophora 2006-2009 • Effects of Cladophora mats on beach closures • Spatial effects • Replication of E. coli in mats • Pathogens in mats • Study sites Door County and Racine, WI • Collaboration between • UW-Oshkosh • University of Minnesota • USGS • City of Racine Health Department • Door County Soil & Water Department

30. Implications…. Cladophora mats could allow for replication ofindicator organism, E. coli, without concurrent replication of pathogens Premature, inappropriate beach closures? Is E. coli a suitable indicator? Cladophora mats could allow for replication of pathogens Public health concern Management issues

31. Acknowledgements • UW-Oshkosh “Beach Group” • Door County Soil and Water Conservation Department • Door County Health Department • Ozaukee County Health Department • Vilas County Soil and Water Conservation Department • Vilas County Health Department • WI DNR • WI Bureau of Communicable Disease • USGS

32. Thank You!

34. Door County SWCD Preliminary Data 12-7-04

35. Cladophora

36. 2004 Observations n=2100+ E.coli samples

37. Pathogens

39. Post Rainfall

49. Spatial Sampling