1) measuring bacterial activity and growth rates using molecular approaches and relating activity to the environment (see Campbell et al., PNAS, 2011); I am currently examining activity in relation to biotic and abiotic factors in estuarine and coastal environments; 2) using metagenomics/metatranscriptomics to investigate temporal bacterial community and activity changes in coastal and open ocean bacterial communities; 3) developing high-throughput sequencing approaches to investigate the presence, persistence and activity of fecal indicator bacteria and potential pathogens such as Helicobacter and Campylobacter in aquatic environments (see Twing et al., Water Research, 2011); and 4) characterizing a novel nitrogen assimilation pathway in a thermophilic deep-sea Epsilonproteobacteria isolated from hydrothermal vents as well as in human-associated campylobacters (see Campbell et al., PLoS Genetics, 2009).