ABSTRACT
CONTENTS Introduction ............................................................................................................................................ 111 Biofilm Ecology..................................................................................................................................... 112 Biofilms as Estuarine Indicators............................................................................................................ 114 Sampler Design...................................................................................................................................... 114 Estuarine Periphyton as an Environmental Diagnostic Indicator ......................................................... 115 Analysis of Spatial Patterns of Biofilm Growth ................................................................................... 117 Molecular Approaches ........................................................................................................................... 119 Summary ................................................................................................................................................ 122 Acknowledgments.................................................................................................................................. 122 References .............................................................................................................................................. 122
Recognition of correlations between the occurrence of microbial organisms and various environmental conditions is as old as microscopy (Dobell, 1958). Formalization of the concept as a biological indicator also has a long history. The Saprobic (Saprobien) system represents an early European effort to standardize this type of approach (Kolkwitz and Marsson, 1908). Ruth Patrick in the United States established periphyton analysis as a standard for freshwater work (Patrick et al., 1954; Patrick, 1967; Weitzel, 1979), and the dominance of diatoms within open-water biofilms has led to the description of these films as “periphyton.” The autotrophic component is, however, only part of the entire community structure. These surface films are composed of bacteria, microalgae, protists, and small metazoans in a polymer matrix (Figure 9.1), making the term aufwuchs technically more correct, and inclusive of biofilms occurring in light-limited conditions. Efforts to tap these communities as indicators of water quality have focused on both the algal and protist components (Stewart et al., 1985; Foissner et al., 1992; Eaton et al., 1995; Foissner and Berger, 1996; U.S. EPA, 1997; FDEP, 1998; Kanhere and Gunale, 1999; Madoni and Bassanini, 1999; Wu, 1999). Analysis of the prokaryotic portion of environmental microbial biofilms to define environmental conditions has been a more recent approach (Guckert et al., 1992; Mohamed et al., 1998; Manz et al., 1999; Piceno and Lovell, 2000).
