Toxic Algae: A review plus notes on Prymnesium parvum · • Observation of potentially...

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Jacob Butler

• 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

• Often quite diverse

• Many factors affect succession

• Temperature, pH, light, nutrient avaliability

• Seasonal trends, but not always

• Atypical weather

• Pollutants

• Excess nutrients

And…

• 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

• 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

• 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.

• Anabaena

• Cylindrospermopsis

• Aphanizomenon

• Lyngbya

• Microcystis aeruginosa

• Prymnesium parvum

Capable of producing Anatoxin-A, Saxitoxin, Cylindrospermopsin, Microcystin, Prymnesins

• Human health and water quality issues

• Neurotoxicity

• Hepatotoxicity

• Tastes, odors

• Collection in reservoirs, canals

• Environmental costs and alteration

• Corbicula die offs

• Filter feeders gone, bloom susceptibility

• Food web dynamics

• Less, different species recover

• Growth and toxicity of P. parvum likely

effected by other algae present in

system

• Cyanobacteria, Dinoflagellates most resistant

• Likely others follow suit

• Secondary metabolites of P. parvum

(prymnesins), vs those produced by

others (Cyanobacteria, Dinoflagellates,

etc)

• Tied to competition with one another,

plus environmental factors

• 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

• 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.

• 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