Cycling of carbon, sulfur, oxygen and nutrients in a microbial mat

Microbial mats are among the most productive aquatic ecosystems on Earth, yet, in many cases, the waters from which they grow are depleted in the basic nutrient elements. How, then, are nutrients cycled to allow for such high rates, and what ultimately controls these rates? To begin to address these issues, the cycling of carbon, oxygen, sulfur and nutrients has been explored over several years in Microcoleus chtholoplastes-dominated cyanobacterial mats from the hypersaline salt ponds in Guerrero Negro, Baja California Sur, Mexico (D’Amelio et al. 1989; Canfield and Des Marais 1993).