Who’s Who in the Water Algae, Vascular Plants And HABS · The aquatic fern Azolla is the only...

WhoWho’’s Who in the Waters Who in the WaterAlgae, Vascular PlantsAlgae, Vascular Plants

And HABSAnd HABS

Water BiologyPHC 6937

Andrew S. Kane, Ph.D.University of Florida

Environmental Health Program, PHHPCenter for Environmental and Human Toxicology

Emerging Pathogens Institute

WATER QUALITYWATER QUALITY FACTORSFACTORS

Aquatic plants & nutrientsAquatic plants & nutrients

Effects of nutrient loading:Increased 1˚ productivity, clogging ofwaterways, hypoxia, degradation ofalgae and aquatic plants imparts anearthy, musty taste and odor todrinking water due to the productionof volatile organic molecules.

Habitats and samplingHabitats and sampling

plankton tows plant or macroscopic algae samples rock or log scrapings

Aquatic Vascular PlantsAquatic Vascular Plants

• Vascular plants have a more complex structurethan macroscopic algae, including tube-like vascularbundles for nutrient transport.

• Often classified based on physical relationshipwith water:

• Floating unattached• Floating attached• Submersed• Emergent

Types of Vascular PlantsTypes of Vascular Plants

Emergent plants:

• Roots and basal portions grow beneath the surface ofshallow water; leaves and stems mostly above thewater surface.

• Common species in this group include cattail,pickerelweed, and many species of sedges.

• Found primarily in shallow littoral areas of lakes andalong banks of slow moving streams.


Pickerel WeedPontederia


CattailTypha latifolia


Sedge Marsh

Aquatic Vascular PlantsAquatic Vascular PlantsFloating unattached plants:•Float with most of the plant body above the water'ssurface.

•If there are any roots present, they hang free in thewater and are not anchored to the bottom.

•These plants move about with wind and water currents.•Common floating unattached plants includewater lettuce, water hyacinth, and duckweed.

The aquatic fern Azolla is the only fern that can fix nitrogen. It does so viasymbiotic association with a cyanobacterium (Anabaena azollae). Azolla is foundworldwide and is sometimes used as a valuable source of nitrogen foragriculture. The plants shown here are each about 2 cm across. The pale yellowplant has been deprived of cobalt (essential for the cyanobacterial symbiont)and thus is showing typical signs of N deficiency.



Floating attached plants:

• Leaves floating on the water's surface but roots anchored tothe bottom substrate.

• The leaves are connected by flexible petioles (long, thin,fibrous stems), or by a combination of petioles and stems.

• May have underwater leaves in addition to floating leaves.

• Common example: water lilies.


Submersed plants:

• Usually anchored to substrate; vegetative parts do notreach surface. Flowers may be above the water forbetter dispersal by both wave action and wind.

• Dependent upon water clarity and light penetrationthroughout the water column.

• Common examples include watermilfoil, elodea, wildcelery, coontail, and various other pondweeds.


Coontail, Hornwort(Ceratophyllum)

Water milfoil; Parrotfeather(Myriophyllum)

Anacharis = Elodea

Hydrilla (left) can be distinguished from Elodea by its sharplyserrated leaf margins, spinous midrib & rough texture


Eurasian milfoil: AN INVASIVE SPECIES

Introduction to the algaeIntroduction to the algae

* BACILLARIOPHYTA (diatoms)

* CHLOROPHYTA (green algae)

* CHRYSOPHYTA (golden algae)

* CYANOBACTERIA (blue-green algae)

* DINOPHYTA (dinoflagellates)

* PHAEOPHYTA (brown algae)

* RHODOPHYTA (red algae)

•Eucaryotic; unicellular, planktonic, freshwater &marine species

•Lack flagella (except for gametes) but can locomoteby chemical secretion

•Silica frustules -> diatomaceous earth; used forfiltration, absorbancy, abrasives, component of TNT

•Most autotrophic; some obligate heterotrophs (mustabsorb organic carbon because lack chlorophyll)

•Estimated to contribute to 45% of total oceanicprimary production

•Indicator species (present and historic)

•Many beautiful species; some HAB/toxin producers (eg:Pseudo-nitzchia)

BACILLARIOPHYTA (diatoms)

BacillariophytaBacillariophyta:: DiatomsDiatoms

Unicellular or can exist as colonies in the shape of filaments,Unicellular or can exist as colonies in the shape of filaments,ribbons, fans, zigzags and ribbons, fans, zigzags and stellate stellate coloniescolonies

BacillariophytaBacillariophyta:: DiatomsDiatoms

CHLOROPHYTA (green algae)

•Eukaryotes

•Unicellular, filamentous, colonial,sheets

•Most aquatic; some terrestrial, onsnow, trees, symbionts

•Green color associated 1˚ withchlorophyll

•Calcified green algae (eg Halimeda)important as contributors of marinesediments

•Freshwater HABs associated withnutrient loading -> hypoxia

Chlamydomonas

Spirogyra

Volvox

CHLOROPHYTA (green algae)

Hydrodictyon

Halimeda

Ulva

CHRYSOPHYTA(golden algae)

•Eukaryotic; may be unicellular,filamentous, branched, amoeboid

•Typically flagellated (1 or 2 flagella) inmotile stage

•Abundant in freshwater and marineenvironments

•Chlorophylls a and c often masked byaccessory carotenoid pigment,fucoxanthin

•Formerly included diatoms and brownalgae; includes Rhaphidophytes

DinobryonDinobryon

UroglenaUroglena

ChrysopyxisChrysopyxis

CHRYSOPHYTA(golden algae)

•Raphidophytes are a small class of mainly marine, planktonicChrysophytes. Single-celled, naked flagellates (lack cell walls).

•Heterosigma and Fibrocapsa species have been associated with‘red tide’ blooms off the coasts of Japan and New England. Fishkills have occasionally been observed related to the species.

•Can produce brevetoxin-like toxins.

•In Delaware during 2000, a fish kill was associated with a toxicbloom of Chattonella verruculosa.

ChattonellaFibrocapsaHeterosigma

CYANOBACTERIA (blue-green algae)

•Prokaryotic; lack the organized chloroplasts of eukaryotes; theirphotosynthetic apparatus distributed peripherally in cytoplasm.

•Instead of bacteriochlorophylls found in purple and green bacteria,blue-greens contain chlorophyll a (as in eukaryotic phototrophs),and produce free 02 as a product of photosynthesis.

•Phycobilins are major light-gathering pigment bound to proteingranules (phycobilisomes).

•Large blooms of freshwater blue-greens may produce toxins:anatoxin-a, anatoxin-as, aplysiatoxin, cylindrospermopsin, domoicacid, microcystin LR, nodularin R, or saxitoxin

•Others grown commercially and marketed as high-protein dietarysupplement (eg Aphanizomenon flos-aquae and Arthrospiraplatensis (Spirulina)).

•Believed important in genesis of Earth’s oxygen atmosphere inProterozoic Era (0.5-2.5 bya)

Left: Free-living colonies ("balls") of Nostoc in a fresh water pond. Eachball is about 0.5 to 1.0 cm in diameter. Note small Pacific chorus frog.

Right: Micrograph of Nostoc filaments with specialized nitrogen-fixingcells known as heterocysts.


Microcystis bloom


•One of the largest and oldest groups of algae

•Mostly multicellular, marine species (“seaweeds”)

•Many species are coralline algae that secreteCaC03, hence important for development andstability of coral reefs

•Variety of species food items and source of agarand carrageenan

RHODOPHYTA RHODOPHYTA (Red algae)(Red algae)

Phymatolithon purpureum


Chondrus crispusPalmaria palmata

Porphyra


Nori

PHAEOPHYTA PHAEOPHYTA (Brown algae)(Brown algae)

•Kelps; “seaweeds”

•Many forms: filamentous, macroscopic/microscopic; encrusting; largefronds

•Critical role in shallow marinehabitats and in Sargasso Seafor food and shelter

•Commercial harvest for food

MacrocystisAscophyllum Fucus


A variety of fishes, including filefishes andtriggerfishes, reside in and among the brownSargassum.

LaminariaLaminaria holdfast communityholdfast community


DINOPHYTA DINOPHYTA ((dinoflagellatesdinoflagellates))

CeratiumGymnodinium

Cystodinium

•• Flagellated; unicellular; common marineFlagellated; unicellular; common marineand freshwater planktonand freshwater plankton

•• Most photosynthetic. SomeMost photosynthetic. Some species arespecies arezooxanthellaezooxanthellae, , endosymbionts endosymbionts of marineof marineprotozoa; critical role in coral biology.protozoa; critical role in coral biology.

•• Some parasitic (Some parasitic (eg eg OodiniumOodinium, , PfiesteriaPfiesteria))

•• Blooms can have concentrationsBlooms can have concentrationsof >10of >1066/mL/mL

•• Some species produceSome species produceneurotoxinsneurotoxins

When algaeWhen algae go bad:go bad: ……HARMFUL ALGAEHARMFUL ALGAE

Dead fish from aKarenia brevis bloom.

Seaweeds (i.e., macroalgae) can alsocause harm. Expansive blooms ofCaulerpa off the Florida coast havetransformed some reefs into“Caulerpa meadows” where more than70% of the coral surface is nowdominated by these macroalgal HABspecies.

When shellfish accumulate dangerous toxins afterfiltering algae, public health is at risk. State andfederal agencies monitor these shellfish forbiotoxins and close affected areas, posting signslike this. Note that although the water appearsclear, there is a danger present.

Domoic Domoic Acid: ASPAcid: ASPPseudo-nitzchia (diatom)

• Amnesic shellfish poisoning (ASP) caused by consumptionof domoic acid bioaccumulated from shellfish.

• DA acts as a neurotoxin; symptoms include vomiting,diarrhea, and in some cases, there followed confusion,loss of memory, disorientation and even coma. In humans maycause permanent short-term memory loss, brain damage, and deathin severe cases.

• Toxicity to nervous system is believed to occur on excitatoryamino acid receptors and on synaptic transmission.

Domoic Domoic Acid: ASPAcid: ASP

• Although human illness due to domoic acid has only been associatedwith shellfish, the toxin can bioaccumulate in many marine organismsthat consume phytoplankton, such as anchovies, and sardines.

• Intoxication by domoic acid in non-human organisms is frequentlyreferred to as "domoic acid poisoning" or "DAP."

• 2007 blooms off California coast resulted indeaths of grebes, gulls, cormorants, Americanavocets and loons. Mammals affected includedsea lions, dolphins and whales

SaxitoxinSaxitoxin: PSP: PSP

STX: neurotoxin produced by some species of marinedinoflagellates (Alexandrium, Gymnodinium, Pyrodinium)and some cyanobacteria (Anabaena, Aphanizomenon,Cylindrospermopsis, Lyngbya).

The term saxitoxin originates from the butter clam (Saxidomusgiganteus) in which it was first recognized.

In the US, paralytic shellfish poisoning is limited to New England andthe West Coast. The dinoflagellate Pyrodinium bahamense is the sourceof STX found in Florida.

STX block voltage-gated sodium channels; produces a flaccid paralysisthat leaves its victim calm and conscious through the progression ofsymptoms. Death often occurs from respiratory failure.

PSP toxins have been implicated in various marine animal mortalitiesinvolving trophic transfer of the toxin from its algal source up the foodweb to higher predators.

One dramatic incident occurred in 1990 when six fishermen almost died from eatingmussels during a fishing trip on Georges Bank, a productive offshore finfish andshellfish area 100 miles east of Cape Cod, MA. After a hard day of fishing, thefishermen settled down in the ship's galley to eat a pot of steamed mussels that theyhad inadvertently caught in their nets. The Captain, who had joined the meal laterthan the rest of the crew, witnessed his fellow fishermen become incapacitated dueto the paralytic effects of the toxin. He himself also became ill, but was capable ofsending an urgent radio message to the US Coast Guard. The Coast Guard airliftedthe men to the nearest hospital located on Nantucket Island, MA where they weretreated using respiratory therapy to sustain their breathing and prevent them fromdying due to paralysis of the lungs. Fortunately, all the men recovered and were backfishing within a few weeks. The event, presumably caused by a massive Alexandriumbloom transported offshore from areas along the northeast coast, closed the surfclam industry on Georges Bank to further harvest. Georges Bank is an offshore areatoo vast to monitor and is outside the states' jurisdiction, so theUS government maintains jurisdiction and currently bans theharvest of surf clams which are known to retain the toxinsfor many years.

Refer to Wang 2008. Neurotoxins from Marine Dinoflagellates.

SaxitoxinSaxitoxin: PSP: PSP

SaxitoxinSaxitoxin

Pyrodinium bahamense

Puffer fish have been determined to be a hazardousreservoir of STXs, and the dinoflagellate Pyrodiniumbahamense is thought to be the toxin source.

CiguatoxinCiguatoxin: CFP: CFP

Gambierdiscus toxicus:an armored dinoflagellate

• CFP is most commonly reported marine toxin disease in the world;associated with consumption of contaminated reef fish such asbarracuda, grouper, and snapper. Second-most problematic HABspecies in Florida.

• Ciguatoxin is lipid soluble.

• MOA of CFP based due to opening of voltage-dependant sodiumchannels in cell membranes, inducing membrane depolarization. Thedepolarizing action associated with selective increases in sodiumpermeability in nerve cells and striated muscle. The respiratoryarrest induced by a lethal dose results mainly from depression ofthe central respiratory center.

• Ciguatera presents primarily as an acute neurologic diseasemanifested by a constellation of gastrointestinal (diarrhea,abdominal cramps and vomiting), neurologic (paresthesias, pain inthe teeth, pain on urination, blurred vision, temperaturereversal) and cardiovascular (arrhythmias, heart block). Signsand symptoms within a few hours of contaminated fish ingestion.Hot/cold temperature reversal is pathneumonic, although not allpatients report this.

• Under-diagnosis and under-reporting common; CDC and othersestimate that only 2-10% of Ciguatera cases are actuallyreported in the US.

• Like many naturally and artificially occurring toxins,ciguatoxin bioaccumulates in lower-level organisms,resulting in higher concentration of the toxin athigher levels of the food chain, an example ofbiomagnification.

CiguatoxinCiguatoxin: CFP: CFP

Gambierdiscus toxicus

Fish vectors of ciguatera toxinsFish vectors of ciguatera toxins

• PbTx is a group of neurotoxins isolated from the marine dinoflagellate Karenia brevis(formerly Gymnodinium breve; Ptychodiscus brevis)

• Fish, birds and mammals are all susceptible to the brevetoxins.

• Found along Florida’s coastlines and in the Gulf of Mexica;, similar species occur throughout theworld. Observed during Florida’s red tides in the late summer and autumn months almost everyyear with massive fish and bird kills. Fish kills associated with these red tides have beenestimated up to 100 tons of fishes per day.

• These HABs are believed to be increasing in incidence, time length and geographic spread.Although the possibility of anthropogenic influences such as nutrient run-off is being investigated,it should be noted that these red tides in Florida occurred even prior to significant pollution fromhuman population.

• K. brevis relatively fragile organism; ruptured by wave action to release toxins. During anactive in-shore red tide, the aerosol of contaminated salt spray will contain the toxins andorganism fragments both in the droplets and attached to salt particles; this can be carriedinland depending on wind and other environmental conditions.

• The brevetoxins are lipid soluble polyethers with molecular weights around 900. Thesetoxins are depolarizing substances that open voltage gated sodium ion channels in cell walls,leading to uncontrolled Na+ influx into the cell.

• Respiratory, nasal and conjunctival irritation. Coughing, bronchoconstriction. Somereports of dizziness, tunnel vision, paraesthesia, skin rashes.

BrevetoxinBrevetoxin: NSP: NSP

BrevetoxinBrevetoxin: Affects on wildlife: Affects on wildlife

CyanophytesCyanophytes::MicrocystisMicrocystis

Hepatotoxic; hepatic tumorpromotor in animal models

By using amino acid single lettercode classification, eachmicrocystin is designated a namedepending on the variable aminoacids which complete theirstructure. For instance, one of themost common toxins found in watersupplies around the world,microcystin-LR contains the aminoacids Leucine (L) and Arginine (R) inthese variable positions.

This cyanobacterial bloomhas the typical appearanceof a thick layer of greenpaint. The bloom was foundto consist of toxic speciesin the genus Microcystis.

Freshwater HABS: Freshwater HABS: Lyngbya Lyngbya ((CyanophytaCyanophyta))

Lyngbya normally grows in dense,filamentous mats at the bottoms ofnutrient enriched lakes and springfed systems. These mats producegasses during photosynthesis thatoften causes the mats to rise to thesurface. At the surface, winds pilethe algal mats against shorelines orin navigation channels; these matscan be several acres in size.

In Florida, Lyngbya smotherseelgrass, a food of the endangeredWest Indian manatee.

Some Lyngbya species have beenlinked to the production of a skinirritant leading to "swimmers' itch".

Ichetucknee

Freshwater HABS: Freshwater HABS: ((CyanophytaCyanophyta))Anabaena is a genus of filamentous cyanobacteria, or blue-green algae, found as plankton.It is known for its nitrogen fixing abilities, and some species form symbiotic relationshipswith certain plants, such as the mosquito fern. They are one of four genera ofcyanobacteria that produce neurotoxins (Anatoxin-a, saxitoxins), which are harmful tolocal wildlife, as well as farm animals and pets.

Under nitrogen-limiting conditions, vegetative cells differentiate into heterocysts atsemi-regular intervals along the filaments. Heterocysts are cells that are terminallyspecialized for nitrogen fixation.

Aphanizomenon Anabaena planktonica

• Diarrhetic Shellfish Poisoning (DSP)is a gastrointestinal illness withoutneurologic manifestations reportedworldwide. Stomach pains, vomiting anddiarrhoea, typically pass after a few days.

• DSP is caused by the consumption of shellfish that have bioaccumulatedtoxin-producing, marine dinoflagellate, Dinophysis. Thesedinoflagellates are widely distributed, but do not always form red tides.The associated toxins produced by the Dinophysis dinoflagellates areokadaic acid and its derivatives; there are at least 9 total toxinsproduced by these dinoflagellates.

• Okadaic acid is lipophilic and is a potent inhibitor of proteinphosphorylase phosphatase 1 and 2A in the cytosol of the mammaliancells that dephosphorylates serine and threonine. It probablycauses diarrhea by stimulating the phosphorylation thatcontrols sodium secretion by intestinal cells similar toVibrio cholerae, although by a different mechanism.

DINOPHYTA: DINOPHYTA: dinoflagellatesdinoflagellates

Dinoflagellata Life Cycle. 1-Binary fission,2-Sexual reproduction, 3-planozygote,4-hypnozygote, 5-planomeiocyte.


Dinophysis

Amyloodinium ocellatum

Swelling, erosion and fusion of gill respiratory lamellae.


““Red TidesRed Tides””

This massive “red tide” of the dinoflagellate Noctiluca stretched formore than 20 miles along the southern California coast. Non-toxicblooms such as these can cause extensive mortalities of plants andanimals in shallow waters when the bloom biomass decays, strippingoxygen from the water.

Noctiluca scintillans in New Zealand.

Red Tides: Red Tides: Karenia brevisKarenia brevis

Red Tide Blamed ForMore Sea Turtle DeathsTuesday, December 11,2007 [News Channel 13]

Red Tides: Red Tides: Karenia brevisKarenia brevis

Mid-Atlantic Region of US: 1997Mid-Atlantic Region of US: 1997““Mutifactorial Mutifactorial nature of ulcerative lesionsnature of ulcerative lesions””

Pfiesteria piscicidaPfiesteria piscicida

Photo: J. Burkholder et al., NCSUPhoto: J. Burkholder et al., NCSU

Photo: J. Burkholder et al., NCSUPhoto: J. Burkholder et al., NCSU

Other factors associated with ulcersOther factors associated with ulcers

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