Phytoplankton are the plant-like

organisms of the sea that carry out

photosynthesis and float in the upper

areas of the world’s oceans.

Most of the Most of the ocean is too ocean is too

deep for deep for plants to plants to

attach to the attach to the bottom like bottom like this Giant this Giant

Kelp off the Kelp off the coast of coast of

California.California.

Therefore, Therefore, most of the most of the

photosynthesiphotosynthesis is carried s is carried

out by out by microscopic microscopic single celled single celled organisms or organisms or

chains of chains of single cells.single cells.

These These organisms organisms often have often have

long long projections to projections to increase their increase their surface area surface area

or oils to keep or oils to keep them in the them in the photic zone.photic zone.

Diatoms are Diatoms are dominant dominant

members of members of the the

phytoplankton phytoplankton that can be that can be caught in a caught in a

net.net.

They are They are especially especially common in common in temperate , temperate , coastal and coastal and

polar regions.polar regions.

They have They have sculptured sculptured shells, or shells, or frustules, frustules,

made of silica. made of silica. Diatoms can Diatoms can

come in a come in a variety of variety of shapes.shapes.

More Diatom ShapesMore Diatom Shapes

Life Cycle of a DiatomLife Cycle of a Diatom

Fish KillerFish Killer

Some Some diatoms, like diatoms, like this one can this one can kill fish when kill fish when

found in found in large large

numbersnumbers

The glasslike The glasslike projections projections

cause mucus cause mucus to build up in to build up in the fish’s gill the fish’s gill

which can which can lead to the lead to the

fish's death.fish's death.

DinoflagellatesDinoflagellates

Dinoflagellates are Dinoflagellates are found throughout found throughout

the world’s the world’s oceans, but tend oceans, but tend to prefer warmer to prefer warmer

areas. Given areas. Given nutrients, nutrients,

dinoflagellates can dinoflagellates can bloombloom or or

explosively grow explosively grow to huge numbers to huge numbers

sometimes causing sometimes causing RED TIDESRED TIDES

Florida red tide organism: Gymnodinium breve

Dinoflagellates: red tides

Around 60 Around 60 species of species of

Dinoflagellates Dinoflagellates are known to are known to

cause red tides.cause red tides.A few species A few species

produce produce poisons that are poisons that are

among the among the most powerful most powerful natural toxins natural toxins

known.known.

During a red During a red tide, tide,

dinoflagellates dinoflagellates may poison the may poison the waters, turning waters, turning

the surface the surface into a sea of into a sea of

dead fish.dead fish.

Red tides can Red tides can also threaten also threaten

human health.human health.

Mussels, clams Mussels, clams and other and other

bivalves store bivalves store the toxins as the toxins as

they filter feed.they filter feed.

People who eat People who eat the shellfish the shellfish

can get can get Paralytic Paralytic Shellfish Shellfish

Poisoning.Poisoning.

Victims suffer Victims suffer numbness and numbness and tingling, loss of tingling, loss of

balance, balance, slurred speech, slurred speech, and in extreme and in extreme

cases, cases, paralysis and paralysis and

death!death!

Symbiotic DinoflagellatesSymbiotic Dinoflagellates

Some Some dinoflagellates dinoflagellates

like like ZooxanthellaeZooxanthellae, are symbiotic , are symbiotic with corals or with corals or

jellyfish.jellyfish.

CoccolithophoridsCoccolithophorids

CoccolithophoridCoccolithophorids are common s are common

members of the members of the nanoplankton. nanoplankton. Most are too Most are too small to be small to be taken in a taken in a

regular regular plankton net.plankton net.

Though found in Though found in coastal waters, coastal waters, they do best in they do best in open oceans open oceans where they where they

often far often far outnumber all outnumber all other types of other types of phytoplankton.phytoplankton.

These single These single celled celled

organisms organisms are covered are covered

by plates by plates made of made of calcium calcium

carbonate.carbonate.

SilicoflagellatesSilicoflagellates

Because of there Because of there small size, very small size, very little is known little is known

about about silicoflagellates silicoflagellates except that they except that they

can be very can be very important to the important to the

primary primary production in the production in the world’s oceans.world’s oceans.