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Jacob Butler Slide 2 Algal communities and diversity Trends in succession Algal toxins and toxin production Allelopathy and allelochemicals Toxic algae found in AZ Consequences of toxicity Prymnesium parvum notes and research Slide 3 Often quite diverse Many factors affect succession Temperature, pH, light, nutrient avaliability Seasonal trends, but not always Slide 4 Atypical weather Pollutants Excess nutrients And Slide 5 Inhibit growth of some taxa, eliminate others Aids in succession to dominant status Can cause formation of blooms Because of the advantage provided, toxic secondary metabolite production seen many algae Unintentional consequences Toxicity to humans, other organisms Taste, odor, aesthetic issues Slide 6 Any positive or negative effect on growth or development of biological, agricultural systems Frequent occurrence in aquatic ecosystems Ease of transmission Low cost Chemical warfare among algal species Slide 7 Slide 8 Slide 9 Many algal toxins difficult to detect, let alone quantify Production of toxins highly variable Exact mechanisms, triggers largely unknown Results of toxin production en masse often all that is seen. Slide 10 Slide 11 Anabaena Cylindrospermopsis Aphanizomenon Lyngbya Microcystis aeruginosa Prymnesium parvum Capable of producing Anatoxin-A, Saxitoxin, Cylindrospermopsin, Microcystin, Prymnesins Slide 12 Human health and water quality issues Neurotoxicity Hepatotoxicity Tastes, odors Collection in reservoirs, canals Environmental costs and alteration Slide 13 Corbicula die offs Filter feeders gone, bloom susceptibility Food web dynamics Less, different species recover Slide 14 Growth and toxicity of P. parvum likely effected by other algae present in system Cyanobacteria, Dinoflagellates most resistant Likely others follow suit Slide 15 Slide 16 Secondary metabolites of P. parvum (prymnesins), vs those produced by others (Cyanobacteria, Dinoflagellates, etc) Tied to competition with one another, plus environmental factors Slide 17 Seasonal monitoring Documentation of assemblage shifts Generation of history/database for comparison Detection of algal toxins Site specificity No succession model works everywhere Observation of potentially toxic/allelopathic algae Notes on conditions and assemblage present in field before blooms and toxic events invaluable Inferences for laboratory studies Slide 18 Laboratory experiments critical to identify and validate triggers and allelopathic interactions among algal species Highly complex, even when limited in number of species cultured Possible to find strains which are non-toxic, but suppress growth or toxin production of undesirables Findings may be used to guide management actions in affected or vulnerable water bodies. Slide 19 Algal toxins are potent and capable of massive impacts to both environments and our quality of life Allelopathy in phytoplankton is complex, but with diligent and thorough research it can be understood in much greater detail Slide 20