2022 Early Hearing Detection & Intervention Virtual Conference
March 13 - 15, 2022
6/06/2017 | 12:15 PM - 12:30 PM | RISE AND FALL OF TOXIC BENTHIC FRESHWATER ANABAENA: BUOYANCY AND DISPERSAL | 306B
RISE AND FALL OF TOXIC BENTHIC FRESHWATER ANABAENA: BUOYANCY AND DISPERSAL
Freshwater benthic cyanobacteria in rivers produce cyanotoxins and affect aquatic food webs, but knowledge of their ecology lags behind planktonic cyanobacteria. The buoyancy of benthic cyanobacterial mats was studied to understand implications for dispersal and the spread of harmful algal blooms in the Eel River, California. Field experiments were used to investigate the effects of oxygen bubble production and dissolution on the buoyancy of benthic algal mats dominated by Anabaena in response to light and dark exposure. Floating and sinking occurred within minutes and were driven by photosynthesis, rather than intracellular changes in carbohydrates or gas vesicles. Light experiment results showed that in a natural light regime, mats remain floating for at least 4 days, while in the dark mats begin to sink in <24 hours. Floating Anabaena samples were collected from 5 sites in the watershed and found to contain the cyanotoxins anatoxin-a and microcystin, with higher concentrations of anatoxin-a than microcystins. Maintaining buoyancy for days, the presence of bubbles in Anabaena mats will markedly increase their downstream dispersal distances over negatively buoyant taxa, threatening human and animal public health in rivers where cyanotoxin producing Anabaena mats occur.
- C01 Algae
- C13 Ecotoxicology
- S20 Understanding physical controls on cyanobacteria dominance: toward prediction and prevention
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Presenters/Authors
Keith Bouma-Gregson
(), University of California, Berkeley, kbg@berkeley.edu;
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Mary Power
(), University of California, Berkeley, mepower@berkeley.edu;
Dr. Mary E. Power is Professor in the Department of Integrative Biology at the University of California, Berkeley. She was awarded an honorary doctorate by Umea University, the Kempe Medal for distinguished ecologists, and the Hutchinson Award from the American Society of Limnologists and Oceanographers. She is a member of the California Academy of Science, the American Academy of Arts and Sciences, and National Academy of Sciences, USA. She has served on the Editorial Board of PNAS (2014 to present) and Science (2006-2009). Mary also served as President of the American Society of Naturalists, and of the Ecological Society of America. Since 1988, she has been the Faculty Director of the Angelo Coast Range Reserve, (one of the UC Natural Reserve System sites, a 3500 ha reserve protected for university teaching and research). She has studied food webs in temperate and tropical rivers, as well as linkages of rivers, watersheds and near-shore environments. Focal organisms include cyanobacteria, algae, invertebrates, fish, estuarine crustaceans and terrestrial grasshoppers, spiders, lizards, birds and bats. By studying how key ecological interactions depend on landscape and temporal contexts, her group hopes to learn how river-structured ecosystems will respond to changes over space and time in climate, land use, and biota. Her group also collaborates closely with Earth and atmospheric scientists in site-based research to investigate linkages among riverine, upland, and near-shore ocean ecosystems.
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Myriam Bormans
(), University of Rennes, myriam.bormans@univ-rennes1.fr;
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