Plankton

Plankton

• General term to describe organisms with limited mobility who rely on water currents to get around

Plankton

Phytoplankton• Free-floating• Capable of

photosynthesis• Usually

microscopic

Zooplankton• Free-floating• Heterotrophic

Phytoplankton

• Microscopic algae• Chief producers• Basis of almost all marine food chains• Restricted to upper surface water• Distribution is patchy and varies seasonally

with light, salinity, temperature, nutrient availability, grazing by zooplankton

Harmful Algal Blooms

Harmful algal blooms are caused by species of tiny plants—phytoplankton—some of which produce potent chemical toxins. Fueled by periodic abundances of nutrients in the ocean, these algae multiply and proliferate until they can cover tens to hundreds of miles of coastal ocean. (Photo by D. Anderson)

Algal Blooms

Red Tide

Dead Fish

Foam

Harmful Algal Blooms (HABs)• A spectacular “red tide” bloom (non-toxic) of Noctiluca scintillans in New

Zealand. (Photo by M. Godfrey)

• Dead fish from a Karenia brevis bloom in Texas. At high concentrations, toxins produced by this organism can cause massive fish kills. (Photo by Brazosports)

• An example of foam produced during a Phaeocystis bloom in the North Sea. This material is unsightly and bothersome to coastal residents, but it also can coat fishermens nets, causing fish avoidance.

Ocean Phytoplankton

• Some common types– Diatoms– Dinoflagellates– Blue-green algae– Coccolithophores

Diatoms – Golden Algae• Unicellular & eukaryotic• Enclosed in glass (silica) “pill-

box” cell wall• No visible means of locomotion• Contain chlorophyll but appear

golden due to a pigment called fucoxanthin

• Most abundant & important algae

• Silica shells create diatomaceous earth when algae dies

Diatoms • Make most of world’s O2

• Major food source• As a filter:• syrups, alcoholic and nonalcoholic drinks, medicines, solvents and chemicals. • As a filler:• paper, paint , ceramics, and detergent. • As Insulation:• high-temperature insulation, including fire doors; sound insulation. • As a Mild Abrasive:• the oldest use of diatomaceous earth. Metal polish and toothpaste. I can't find a toothpaste

that is using diatomaceous earth any more; Tom's of Maine is switched to calcium carbonate. • For Optical Image Quality:• another very old use of diatoms. Because of a regular, gridlike patterning of areolae in some

species, diatoms may be used to measure the resolving power and contrast of light microscopes.

Interesting!!!!!• DE is nitroglycerin acid is made more stable if it is absorbed in diatomite. You can

safely transport the nitroglycerin if it is mixed with diatomite. Alfred Nobel discovered this in 1866 and in 1867, he got a patent for the mixture of diatomite and nitroglycerin that he named as dynamite.

Diatomaceous earth is mostly used as an insecticide. The dust of diatomaceous earth has razor-sharp edges that are lethal to the insects. The insects are killed because the sharp edges of Diatomaceous earth cut through them when it is sprayed on them.

Diatomaceous earth is used to kill intestinal worms in cats and dogs. You can mix one teaspoon of DE with the cat or dog feed. In large dogs, give approximately 1 tbsp. The fact is diatomaceous earth grinds a worm to death. The silicon content in diatomaceous earth dissolves in the mouthparts of the worm and kills it.

Dinoflagellates – Fire Algae

• Unicellular & eukaryotic• Cell wall of cellulose

plates• Use 2 whip-like flagella

for movement• Contain chlorophyll but

appear red/orange due to pigment

Dinoflagellates

• Second most important algae • Add O2 to atmosphere and are food source• High populations of some types are

responsible for red tides, where surface water takes on red/brown color

• Contain & secrete toxins which can kill fish, birds and other animals including humans (paralytic shellfish poisoning)

Interesting!!!

• Some dinoflagellates are bioluminescent

• Some species, called zooxanthellae, are endosymbionts of marine animals and play an important part in the biology of coral reef

Coccolithophores

• Unicellular & eukaryotic• Smallest phytoplankton

in ocean• Move by 2 flagella• Protected by calcium

carbonate shell called coccolith

Coccolith

Coccolithophores

• Most common in warm oceans• Important food source for filter feeding

zooplankton and animals• In areas with trillions of coccolithophores, the

waters will turn an opaque turquoise from the dense cloud of coccoliths.

Coccolithophore Bloom in Tasmania

Blue-green Algae - Cyanobacteria

• Unicellular & prokaryotic

• No nucleus or organelles

• Surrounded by a stiff cell wall

• Contain blue and green pigments, but can also have red pigments

Cyanobacteria

Blue-green Algae

• Present on Earth for as long as 4 billion years. Played a pivotal role in changing the composition of the planet's atmosphere.

• Can often form blooms which can be toxic and have the appearance of green scum

• Toxins can kill fish and animals which drink the water

• Some can fix atmospheric nitrogen and make it available to other algae and marine plants