Although infectious disease risk from recreational exposure to waterborne pathogens has been an active area of research for decades, beach sand is a relatively unexplored habitat for the persistence of pathogens and fecal indicator bacteria (FIB). Beach sand, biofilms, and water all present unique advantages and challenges to pathogen introduction, growth, and persistence. These dynamics are further complicated by continuous exchange between sand and water habitats. Models of FIB and pathogen fate and transport at beaches can help predict the risk of infectious disease from beach use, but knowledge gaps with respect to decay and growth rates of pathogens in beach habitats impede robust modeling. Climatic variability adds further complexity to predictive modeling because extreme weather events, warming water, and sea level change may increase human exposure to waterborne pathogens and alter relationships between FIB and pathogens. In addition, population growth and urbanization will exacerbate contamination events and increase the potential for human exposure. The cumulative effects of anthropogenic changes will alter microbial population dynamics in beach habitats and the assumptions and relationships used in quantitative microbial risk assessment (QMRA) and process-based models. Here, we review our current understanding of microbial populations and transport dynamics across the sand-water continuum at beaches, how these dynamics can be modeled, and how global change factors (e.g., climate and land use) should be integrated into more accurate beachscape-based models.
Bibliographical noteFunding Information:
E.M.S. was supported by the U.S. National Science Foundation (U.S. NSF) , grant OCE-1566562 .
Financial support from CESAM ( UID/AMB/50017-POCI-01-0145-FEDER-007638 ), via FCT / MCTES , from national funds (PIDDAC) , co-funded by FEDER , (PT2020 Partnership Agreement and Compete 2020).
This work is dedicated to Dr. Huw Taylor, a son of Wales, who was never happier than when involved in a project to improve the human condition. Thank you, Huw, for inspiring so many of us to altruism and a higher purpose, and for always helping us find the lighter side of even the darkest situation. E.M.S. was supported by the U.S. National Science Foundation (U.S. NSF), grant OCE-1566562. Financial support from CESAM (UID/AMB/50017-POCI-01-0145-FEDER-007638), via FCT/MCTES, from national funds (PIDDAC), co-funded by FEDER, (PT2020 Partnership Agreement and Compete 2020). The authors would like to thank Megan Smith, Jingru Chen, and Michael Winikoff at the University of Minnesota BioTechnology Institute for their kind help in developing illustrations. We would also like to thank Meredith Nevers for her insight and help in developing many of the ideas presented here.
- Climate change
- Water quality