The dependence of marine biofouling -- the accumulation of a dense community of plants and animals on the hulls of ships, docks and pilings, and in pipes submerged in the sea --on marine biofilms is well established. Multi-species biofilms provide the stimuli for recruitment of larvae and spores of the eukaryotic members of biofouling communities. We investigate the bacterial-larval interactions underlying recruitment of a ubiquitous warm-sea fouling organism, the tube worm Hydroides elegans. These interactions include: (1) a dependence on living bacteria; (2) some biofilm bacteria, in monospecific films, stimulate massive settlement of H. elegans, while others release low percentages or no larval to settlement; (3) biofilms increase the strength of larval attachment to surfaces; (4) in broth culture, biofilm bacteria that typically stimulate larval settlement produce no settlement-stimulus; (5) soluble bacterial products from biofilms are not responsible for the stimulus; (6) bacterial species may be stratified in biofilms, effectively separating some from the surface where larvae may contact them; and (7) genetic differences among larvae appear to predict settlement response to different bacterial species. Larvae of different animal species and phyla join the fouling community at predictably different times in its development, indicating that the surface bacterial community undergoes successional changes to produce a predictable and complex community of prokaryotic and eukaryotic organisms in 4 to 6 months in warm-water ports. No other known complex biological community develops with such speed or with such dependence on bacteria to stimulate assembly of its components.
Presenter:
Michael G. Hadfield, Ph.D.
Department of Zoology
College of Natural Sciences
University of Hawaii, Manoa
Thursday December 2, 2004
11:00 a.m.
Pacific Ocean Science & Technology Building, 723
Refreshments will be served after the seminar in POST 121
The Pacific Research Center for Marine Biomedicine (PRCMB) is a newly established center at the University of Hawaii dedicated to trans-disciplinary research designed to gain new knowledge about the profound impacts of the ocean on human health. The Center is funded by the National Science Foundation and the National Institute of Environmental Health Sciences.
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