To scare away predators
Just for fun
To attract a mate
To see in the dark
aquatic (water-living)
microscopic
plants
drifting or wandering
the ocean
zooplankton
prokaryotes
algae
phytoplankton
eukaryotes
Millions of cells
Thousands of cells
A few dozen cells
Hundreds of cells
All plankton are microscopic (too small to see without a microscope).
Zooplankton are tiny animals.
it makes the water more acidic.
it kills large predators like sharks.
it makes the water saltier.