The first decade of 'Aquatic Microbial Ecology' (1995-2005): evidence for gradualism or punctuated equilibrium?

Abstract

Aquatic Microbial Ecology (AME) celebrates its first 10 years of publication. AME began in 1995 and soon became the companion journal to Marine Ecology Progress Series (MEPS). It is the successor to Marine Microbial Food Webs (MMFW), which first appeared in 1985. Between a decade of MMFW and a decade of AME an entire generation of microbial ecologists has come of age. Was the field fundamentally altered by the advent of molecular biology? Have there been sudden shifts or rather gradual changes in focus and methodology? We attempt to answer these questions by looking at the most cited articles published. MMFW came into existence when the field of microbiology was taking center stage in aquatic ecology. While the existence of large quantities of bacteria, flagellates and ciliates in aquatic systems had been known since the early 1900s (e.g. Beers 1982), their importance was largely ignored until the 1980s. Aquatic microbial ecology became a focal point of research following 5 key discoveries: (1) A large portion of primary production is attributable to small size-classes, too small for typical metazoan grazers (e.g. Malone 1980). (2) Ciliates can attain a considerable biomass and are capable of consuming a large part of the primary production (e.g. Rassoulzadegan 1978, Heinbokel & Beers 1979). (3) Phytoplankton excretes a significant fraction of the carbon fixed as dissolved organic matter (e.g. Sharp 1977). (4) Fluorochrome dyes reveal that bacteria are very abundant, much more so than previously assumed (e.g. Hobbie et al. 1977). (5) Despite relatively constant concentrations, heterotrophic bacteria are continually dividing and producing a considerable biomass (e.g. Fuhrman & Azam 1980). Thus, it became clear that very significant ecological activity occurs among the microbes (Azam et al. 1983). A review of the most cited articles published in MMFW provides a good idea of the key topics from 1985 to 1994 (Table 1). The most cited titles reflect the importance accorded to trophic relationships: who eats whom or what? A recurring topic (1986, 1993 and 1994) is the relationship between metazoans (copepods and daphnids) and microbial populations. The focus of food web analyses progressed from stock estimates, to qualitative studies of the relationships between the stocks, followed by attempts to quantify these relationships (i.e. to quantify fluxes).