Water Environments - Main ideas:
 Almost ¾ of Earth is covered by water
 There are different water environments: Saltwater (or Marine), Freshwater, Brackish
 Water Environments are different in many ways:
o Salt content (biggest difference)
o Depth
o Temperature
 Sunlight: As water gets deeper, less sunlight shines through so it gets darker and colder. Water near Surface has more sunlight
shining through, and is warmer, so most water plants/animals live near surface
 Different kinds of plants and animals live in different water environments
Salt
Content
Bodies of
Water
Depth
Sunlight
Temperature
Plant/Animal Life
Very salty
Oceans, seas
cover most of
earth
Very deep
(thousands
of meters)
Dark
(deeper→
less sunlight)
 Colder as you get
deeper
 Tropical oceans
near equator stay
warm all year
 Temperate
environments –
water cold in winter
 Surface – green plants
& algae
 Deep ocean – very little
marine life
 Tropical oceans –
tropical fish (find food,
lay eggs, stay safe)
Freshwater  Almost no Lakes, ponds,
Few meters
deep
On surface,
sunlight
shines
through)
Saltwater
(marine)
salt
 Drinking
water
Brackish
rivers, streams,
ice, underground
sources
Mixture of
Where river meets
fresh and salt ocean
o Surface – green plants
& algae
o Water lilies in ponds b/c
air spaces inside leaves
helps them float
o NO tropical fish here!
Marine animals lay eggs &
raise young here