Plankton Notes

Question 1

What are plankton?

Answer 1

Free floating organisms with a weak swimming ability
Are at the mercy of the movement of water
Base of all marine food webs
Live in the top layer of the ocean (epipelagic zone)

Question 2

Phytoplankton

Answer 2

Plants
Photosynthesize and produce about 70% of the oxygen in Earth’s atmosphere
Are considered plankton for whole life
Can be found in:
- High altitudes, cold water
- Shallow areas
- Areas of upwelling
- Plenty of light

Question 3

Zooplankton

Answer 3

Animal
Many animals start as larvae and are considered plankton during this time, until they fully mature

Question 4

Major Plankton Groups

Answer 4

Phytoplankton
- Diatoms
- Dinoflagellates

Zooplankton
- Copepods
- Krill

Question 5

Plankton Adaptations

Answer 5

Plankton are more dense than seawater, so they have several adaptations to help them stay afloat and in the photic zone
- Small size
- Extensions like spines to increase surface area
- Incorporate oil to lower density, employing gas filled floats
- Reducing weight through osmosis
- Forming spiral chains that allow them to zigzag through water

Question 6

Anti-Predator Mechanisms

Answer 6

Phytoplankton are eaten by zooplankton
Both phyto and zooplankton incorporate mechanisms to protect against predators
- Spines and elongation of cell
- Chain formation and colonization
- Toxins
- Jumping

Question 7

Algae (Seaweeds)

Answer 7

Considered to be a “plant-like protist”
NOT a true plant

Question 8

Phaeophyta

Answer 8

Brown algae
EX. Kelp, Sargassum

Question 9

Rhodophyta

Answer 9

Red algae
EX. Ceramium, polysiphonia

Question 10

Chlorophyta

Answer 10

Green algae
EX. Sea lettuce, codium

Question 11

Krill

Answer 11

Largest zooplankton
Backbone of Antarctic food web
Whole ecosystem would crash without this