Protists of the Ocean

"Eukaryotes that are neither Animals, Fungi, nor Plants"

Ameoba with ingested Diatoms

Paramecium

Lunch!

Plant like ProtistsAutotrophic oxygen producers

• Euglena

• Algae– Single celled

• Phytoplankton– Cyanobacteria– Diatoms– Dinoflagellates

– Multi-celled• Sea weeds

Euglena

• Has flagella• Mostly lives in fresh

water• Has light sensitive red

eyespot• Autotrophic and

heterotrophic

Phytoplankton: Ocean Food!• Derived from the Greek words phyto (plant) and plankton

(made to wander or drift), phytoplankton are microscopic organisms that live in watery environments, both salty and fresh.

• Some phytoplankton are bacteria, some are protists, and most are single-celled plants. Among the common kinds are cyanobacteria, silica-encased diatoms, dinoflagellates, green algae, and chalk-coated coccolithophores.

Algae: single celled• Prokaryotic

– Cyanobacteria• Single-celled to filamentous blue-green alga or

cyanobacterium• Photosynthetic• Produce much of the oxygen in the world

Life in a Glass House

• Diatoms– Most abundant of single celled protists– Account for 20% of photosynthesis– Silica shells make them great fossils to study

Dinoflagellates• The term "dinoflagellate" means

"whirling flagella" • Each has two flagella• Most are photosynthetic• Some are parasitic• Can cause problems with “blooms”• Red tide

– produce a neurotoxin which affects muscle function in susceptible organisms.

– Humans may be affected by eating fish or shellfish containing the toxins.

– paralytic shellfish poisoning, or PSP (from eating affected shellfish, such as clams, mussels, and oysters)

– serious but are not usually fatal.

Seaweed

• Seaweeds are algae that live in the sea or in brackish water. Scientists often call them "benthic marine algae", which just means "attached algae that live in the sea".

• There are about 10,000 species of seaweeds • three basic colors: red, green, and brown

– Red and Brown are in salt water– Green often in fresh water

Conjugation – Sexual Reproduction

Filamentous Green Alga

Colonial Algae

Multicellular Green Algae

Kelp Forestskelp forest web

cam

Detrimental Aspects of Algae

• Blooms of freshwater algae• Red tides and marine blooms• Toxins accumulated in food chains• Damage to cave paintings, frescoes, and other works of

art• Fouling of ships and other submerged surfaces• Fouling of the shells of commercially important bivalves

Red tide bloom

• Prorocentrum micans bloom

• Associated with Hurricane Floyd, which ended a dry summer

• surface of water slick with this dinoflagellate

Algal Bloom: Before and After

Red tide

Toxic Phytoplankton & Human poisoning

• Paralytic shellfish poisoning - saxitoxin• Neurotxic shellfish poisoning - brevetoxin• Ciguatera fish poisoning - ciguatoxin and

maitotoxin• Diarrhetic shellfish poisoning - okadaic acid• Amnesic shellfish poisoning - domoic acid• Cyanobacterial neurotoxins - anatoxins• Cyanobacterial hepatotoxins - microcystin,

nodularin• Dermatitis - lyngbyatoxin, aplysiatoxin

Benefits of Algae• used commercially for toothpastes, soaps, ice cream, tinned

meats, fabric printing etc, • Food for humans• Food for invertebrates and fishes in mariculture• Animal feed• Soil fertilizers and conditioners in agriculture• Treatment of waste water• Diatomaceous earth (= diatoms)• Chalk deposits• Drugs

• The total wholesale value of dried brown algae worldwide collected in the wild or cultivated is less than $100 million

dollars.

Brown Tide

• Causes:– Species: golden-brown algae

• Aureococcus anophagefferens, A. lanunensis

– Changes in groundwater, nutrients

• Impacts– Zooplankton lose their appetites and die– Reduced sunlight kills plants– Death of bivalves (mussels, scallops etc)

• What can we do?:– Less fertilizers!

Amnesic Shellfish Poisoning

• Causes– Diatoms (Pseudo-nitzschia multiseries,

Paustralis)

• Impacts– Toxin- domoic acid causes permanent loss of

short term memory and may be fatal– Shell fish, crabs, and fish may be affected– Sea lion, pelicans, and cormorants also

• What to do?

Diarrhetic Shellfish Poisoning

• Causes– Phytoplankton like Dinophysis acuminata, D. fortii,

and Prorocentrum lima

• Impacts– Toxins: lots of them– Cause nausea, vomiting, abdominal pain and diarrhea– Affect mussels, oysters, scallops and the humans and

mammals who eat them

• What to do?

Neurotoxic Shellfish Poisoning

• Causes– Dinoflagellates: Karenia brevis

• Impacts– Toxins produced brevetoxin which affects manatees,

dolphins, oysters, fish, clams, and birds and humans by consumption or breathing in the sea foam containing the toxin

– Causes diarrhea, vomiting, neurologic symptoms, and asthma-like symptoms. NO known antidote but most recover in a few days

• What to do?

Paralytic Shellfish Poisoning

• Causes– Algae Alexandrium

• Impacts– Toxin affects mussels, clams, crabs, oysters,

scallops, herring, sardines, marine mammals, and birds, and humans

– Symptoms include numbness, paralysis and respiratory failure. No known antidote and death may occur from respiratory arrest within 24 hours

• What to do?

Harmful Cyanobacterial Blooms

• Causes– Excessive growths of cyanobacteria

• Impacts– Toxins affect nerves, liver tissues in mammals, birds,

fishes and invertbrates– Humans can be affected by inhaling toxins causing

nausea, diarrhea, stomach pain, difficulty breathing, allergic reactions, skin irritation, liver damage, and neurologic symptoms

– Increased turbidity so decreased light

• What to do?

Pfiesteria piscicida

• Causes– dinoflagellate

• Impacts– Flu like symptoms, skin rashes, memory loss

in commercial fishermen and women.

• What to do?