Meeting Abstract

S10.10  Wednesday, Jan. 6  Ecosystem engineers in the plankton - habitat alteration by species from microbes to jellyfish BREITBURG, DL; Smithsonian Environmental Research Center

Ecosystem engineers are species that alter the physical environment in ways that create new habitat or change the suitability of existing habitats for themselves or other organisms. In marine systems, much of the focus has been on species such as corals, oysters and macrophytes that add physical structure to the environment. But planktonic organisms ranging from microbes to jellyfish and finfish alter the chemical and physical environment both within the water column and on the benthos. By causing hypoxia, changing light regimes, and influencing physical mixing, these organisms may have as strong an effect as species that fall more clearly within the classical category of ecosystem engineer. In addition, planktonic species such as jellyfish may indirectly alter the physical environment through predator-mediated landscape structure. By creating spatial patterns of habitats that vary in their rates of predation mortality, planktonic predators may control spatial patterns and abundances of species that are the direct creators or modifiers of physical habitat.