Bell Ringer

Plankton that spend their whole lives in the plankton community are called ________. Temporary visitors are called ________.

Zooplankton: Heterotrophs

Zooplankton

• What are they?• Mass is approximately 10% that of

phytoplankton• Almost every animal group is represented

Zooplankton

• Copepods– 70% of all zooplankton– Shrimplike– Crustaceans; same family as crabs, lobsters, &

shrimp

Copepods

Zooplankton

• Macroplankton – plankton larger than 1 cm.– Jellyfish

Zooplankton

• Holoplankton – spend whole lives as plankton– Copepods, krill– Far more common

• Meroplankton – partial life spent as plankton– Juvenile stage – crabs, barnacles, clams, sea stars,

tuna

Krill

• Most important!– Keystone of Antarctic ecosystem

• Thumb-size, graze on diatoms• Eaten by seabirds, squids, fish, & whales• 500-700 million metric tons inhabit Antarctic

Krill

Krill

• Travel in large schools – several square miles– Exceed biomass of human population!

• Behave more like a school of fish• Swim horizontally, not vertically

Foraminifera

• Related to amoebas• Calcium carbonate shells– Similar to coccolithophores

Foraminifera

Oxygen minimum zone

• Oxygen is depleted by animals & not replaced by phytoplankton

• Just below well-lit area• Nightly migrations from here toward darkened

surface layer to feed on smaller organisms

Zooplankton

• Large animals (whale sharks & baleen whales) feed on zooplankton.

Larger Marine Producers

• Seaweeds -> 2%-5% primary productivity• Most are algae– Algae – possess chlorophyll, photosynthesize,

lacking vessels

Larger Marine Producers

• Unicellular algae – single-celled diatoms & dinoflagellates

• Multicellular algae – seaweeds• Angiosperms – flowering plants – sea grasses

& mangrove trees – NOT seaweeds

Algae

• Nonvascular – no vessels– Still require carbon, oxygen, sun, and water– All in one spot so no need for vessels

Algae

Algae

• Multicellular – can form forests or solitary isolation

• Largest can grow up to 62 m• Flexible, easily absorb shock, resistant to

abrasion, streamlined to reduce water drag, & very strong

Algae

• Doesn’t grow below euphotic zone – depends on photosynthesis

• Over 7,000 species identified• Covered by slick, mucilagenous material– Lubricates, keeps from drying, deters grazers