Understanding Marine Biocorrosion: Experiments with Artificial and Natural Seawater

For many years there has been a debate over the preferred laboratory medium for studying marine corrosion, i.e., natural or artificial seawater Dexter, 1988 . It is generally recognized that seawater surrogates do not approximate the complexity of natural seawater. The dilemma is whether to start with a well-characterized controlled synthetic medium that may not replicate any natural environment or with a natural environment that cannot be thoroughly characterized, varies with collection location and changes over time. That debate has continued and has become more complicated in the study of microbiologically influenced marine corrosion MIMC and the consideration of nutrients for microorganisms. Recent MIMC investigations have included natural seawater with its endogenous microbial population Lee et al ., 2004 Lee et al ., 2005 Jeffrey and Melchers, 2003, augmented natural seawater Chang et al ., 2009 Dinh et al ., 2004 , artificial seawater to which microorganisms have been added Venzlaff et al ., 2013 and inoculated synthetic media Zegeye et al.,2007. Some investigators defined synthetic seawater as a certain salt concentration, e.g., 0.6 M NaCl Vargas-Avila et al ., 2009. However, in many cases the term synthetic seawater refers to commercially available carbonate-buffered salt solutions that mimic the composition of seawater.