Toxic Algae: A Review P lus N otes on Prymnesium parvum

1. Toxic Algae: A Review Plus Notes on Prymnesium parvum Jacob Butler

2. Overview • 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

3. Algal Communities and Diversity • Often quite diverse • Many factors affect succession • Temperature, pH, light, nutrient avaliability • Seasonal trends, but not always

4. Deviations From Succession Patterns • Atypical weather • Pollutants • Excess nutrients And…

5. Algal Toxins and Succession • 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

6. Allelopathy • 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

7. Allelochemicals

8. Allelochemicals Continued From Legrand et al. 2003 (42)

9. Only the beginning… • 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.

10. Fish Kills

11. Toxic Algae in the Salt River Reservoirs • Anabaena • Cylindrospermopsis • Aphanizomenon • Lyngbya • Microcystis aeruginosa • Prymnesium parvum Capable of producing Anatoxin-A, Saxitoxin, Cylindrospermopsin, Microcystin, Prymnesins

12. Consequences of Algal Toxins • Human health and water quality issues • Neurotoxicity • Hepatotoxicity • Tastes, odors • Collection in reservoirs, canals • Environmental costs and alteration

13. Environmental Alteration • Corbicula die offs • Filter feeders gone, bloom susceptibility • Food web dynamics • Less, different species recover

14. Prymnesium Parvum • Growth and toxicity of P. parvum likely effected by other algae present in system • Cyanobacteria, Dinoflagellates most resistant • Likely others follow suit

15. Interactions and Connectivity

16. Understanding Toxic Algae • Secondary metabolites of P. parvum (prymnesins), vs those produced by others (Cyanobacteria, Dinoflagellates, etc) • Tied to competition with one another, plus environmental factors

17. Connecting the Dots • 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

18. Research • 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.

19. Conclusion • 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

20. Questions?