Ch. 2: Adaptations in Water Environments
Water Environments

¾ of planet covered by water

Differences:
o SALT content
o Depth
 measures distance from water’s surface to floor
 oceans VERY deep (thousands of meters)
 ponds are few meters deep
 surface is where most water plants/animals live
o Sunlight
 Surface – sunlight shines through water, so green plants
and algae have enough sunlight to grow
 As water gets deeper, less sunlight can shine
 Deep water – dark, and few animals live here
o Temperature
 Equator – tropical waters stay warm all year
 Temperate environments – water cold in winter
 Water depth affects temperature.
 Surface water warmer b/c much sunlight heats
 Deep water colder b/c little sunlight
1. Saltwater / Marine
o VERY salty water
o Oceans and seas
o Covers most of the earth
2. Freshwater
o almost NO salt
o Drinking water
o Lakes, ponds, rivers and streams
o Ice and underground sources
3. Brackish
o MIXTURE of Fresh and Salt water
o Where a river meets the ocean
o Marine animals lay eggs & raise young here
See Chart
OCEAN LIFE
 The ocean is the earth’s LARGEST environment
 5 oceans: Atlantic, Pacific (largest and covers 1/3 of planet), Indian, Arctic
and southern oceans
 Almost all ocean life (billions of living things) lives in SHALLOW waters
(100 meters/328 feet or less)
 Ocean plants and animals have adaptations that help them survive in this
saltwater environment
OCEAN PLANTS:
 Eelgrass is true plant – it is a flowering plant often mistaken for algae
 Algae - not a true plant; they are plant-like living things which use water,
carbon dioxide gas and sunlight to make their own food, and then give us
oxygen.
 Two kinds of algae found in ocean:
1. Ones with rootlike structures that attach to ocean floor. Live in
shallow water to get sunlight to grow
2. Ones without roots. Drift near sunlit surface
 Both types of ALGAE have own adaptations
 Kelp Forest
o Groups together
o Grows to huge sizes (30 meters or almost 100 feet)
o Adaptations: Leaflike structures take in sunlight to grow,
Balloonlike structures called air bladders to help them float
o Grow in clear, shallow water
o Home to sea urchins and sea otters
OCEAN ANIMALS:
 Fish are the most numerous animals in the ocean.
 Coral reef – shallow waters are warm and clear, and host colorful fish,
sponges and other forms of ocean life
 Ocean animals have adaptations:
o Breathing – fish need oxygen. Have gills on both sides to take in
oxygen as water passes out.
o Moving – body shaped to glide through water, strong tails to propel,
fins to steer
o Staying Safe – larger fish prey on smaller fish. Camouflage (ex.
Stingray skin matches color of sand)
THE WETLANDS
 Environments where water covers the soil for most of the year, so the soil
does not hold much oxygen
 Usually form along the edge of a water body where land and water meet.
 The water here may be salt water, fresh water, or a mixture of salt and
fresh water.
 How Wetlands help the environment:
1. Plants and soil act like sponges that absorb water so when oceans,
rivers, ponds or lakes overflow, the extra water is absorbed by a
wetland
2. The grasses and plants of a wetland help filter and clean the water
that passes through. They absorb the harmful fertilizers and
chemicals (from farming) that can leak into water. As water flows
through the wetlands, it is filtered by plants and soil naturally.
 Found all over the world, except Antarctica
 Different Kinds of Wetlands:
1. Marshes
o where grasses and reeds grow, NO TREES
2. Swamps
o have TREES (cypress and willow trees) and shrubs.
o Mangroves = swamp trees that have giant, woody roots that
grow above water line.
3. Bogs
o Freshwater wetlands.
o Filled with moss and rich soil.
o Wet, spongy ground covered in moss.
 Each type has different wetland plants.
 Many animals, birds and wildlife live in wetlands:
o Amphibians – spend time in water and on land. Ex: frog
 With little oxygen in soil, plants and animals have adaptations to survive in
wetlands
o Mangrove roots above water line take in oxygen
o Frogs breathe through their wet skin
o Herons – hunting by standing motionless and waiting for prey,
then attacks with long beak to catch frogs, insects, mice, lizards
o Walking catfish use fins as legs to move to another body of water
when ponds evaporate, and also uses a special body part that
holds air to breathe on land for short periods of time
Each plant/animal has adaptations that can help it survive in
their water environments
 Water lily lives in freshwater ponds b/c air spaces help them float,
and roots are buried in muddy soil below.
 Ocean plants and animals have special adaptations that help them
survive in SALT WATER
 algae – kelp has leaflike structures to take in sunlight and air
bladders to float
 many kinds of fish live in sunny, shallow water in coral reefs.
Tropical fish can find food, lay eggs, stay safe.
 stingray has camouflage skin
 fish have gills to get oxygen from water, body shape to glide, fins
to steer, tails to propel
 viperfish – giant eyes to find food in dark, deep ocean bottom,
opens jaw wide to capture fish swimming by
 giant squid – big eyes (like volleyballs) to see in deep ocean
 angler fish – lighted “fishing pole” to attract prey
 tubeworms have hard-shelled tube to protect from predators
 Wetland plants and animals have adaptations that help them survive
in WET environments
 some marsh plants have special tubes in their stems which carry
oxygen from leaves to the roots
 Mangrove trees which live in swamps have roots above water line
to take in oxygen from the air
 Frogs adapt to wetlands by breathing through their wet skin
 Herons adapted to hunt in wetlands. Excellent eyesight, stands
motionless and waits for prey, then attacks with long beak to catch
frogs, insects, mice, lizards
 Walking catfish use fins as legs to move to another body of water
when ponds evaporate, and also uses a special boy part that holds
air to breathe on land for short periods of time