Marine EcosystemsA brief overview of different

marine ecosystems

Marine Environments and Habitats• Habitat – the place or “home” in

which an organism is typically found• Environment – the total surroundings

of living things• The oceans have many

environments, some coastal and some out at sea

• Environments have 2 components – living and nonliving

Living Components of Environments• These are the biological aspects of

environments, having to do with living things

• These things are called “biotic” things and the living things within environments are called “biota”

• For example, a coral reefs biota consists of algae, fish, crustaceans, cnidarians, sponges, bacteria, etc. Anything living that inhabits the area

Nonliving Components of Environments• The nonliving aspects of environments are

the physical and chemical parts that make up the environment

• These are the “abiotic” things• For example, the abiotic aspects of a coral

reef are the water chemistry, light, temperature, salinity, and pressure

• It is the interactions between the biotic and abiotic factors that characterize environments!

Identify Some Biotic Factors

Biotic Factors• Fish• Sea stars• Predators

Identify Some Abiotic Factors

Abiotic Factors• Salinity of the

water• Sunlight• Weather/Climate• Nutrient

availability• Waves

Different Marine Life Zones (A Review)

Life Zones Review

Sandy Beach Environment

The Sandy Beach Environment• Made up of small sand, crashing

waves and exposed to fresh water from rain and runoff

• Has distinct zonation of life, contains small organisms adapted to sandy environments (such as the mole crab and surf clam)

Video

Rocky Coasts (Ex: Our West Coast)

Rocky Coast• Greatly affected by

tides• Crashing waves• Ice in higher

latitudes• Intense sunlight in

tropic regions• Fresh water runoff

which can contain a lot of minerals and lots of dissolved gas

Rocky Coasts continued• During high tides the intertidal zone

is exposed to ocean grazers• During low tide it is exposed to

terrestrial (land) grazers• Large quantity of food available

because of the high level of nutrient availability

Barnacles!

Estuary Environments• An estuary is an area where fresh

and salt water mix (brackish – mixture of salt and fresh water)

• Usually occurs along coasts near rivers.

• Affected by tides

Birds Eye

Estuarine Salt Marshes

Estuarine Salt Marshes• Costal region that is affected by the

tides• Can potentially have extreme

temperature changes• Generally calm waters• Fresh and salt water mix in this area

Estuarine Salt Marshes Continued• Has a lot of decaying material• High primary productivity• Many marsh grasses, hermit crabs,

shrimp, eels and ducks• Act as nurseries

Mud flats

Mudflats• Characterized by dark, muddy sand

and no marsh grasses• Very little wave action so the sands

are poorly aerated

Mud flats• Decaying material tends to

accumulate – Kind of a graveyard– Causes a gross, rotten egg smell if you

disturb the sand• Home to lots of scavengers

– Mud snails, blood worms…

Mangroves

Mangrove• Found in tropical

regions• Affected by the

tides• Water may be

brackish (mixing salt and fresh water) in some mangrove environments

Mangroves Cont.• Mangrove trees are dominant

– Form an intricate system of tangled prop roots

– Serves as a nursery for fish• Lots of decaying materials• Barnacles, snails, crabs and fish are typical

of this environment

Coral Reef

Coral reefs• Found in warm environments• Clear, nutrient poor water• High wave energy environments

Corals Continued• Coral polyps

create oddly shaped crevices which fish can hide and live in– Acts a nursery

and protects them from predators

Corals Continued• Has a high

level of biodiversity (number of species)

• Parrot fish, sharks, butterfly fish and corals are typical of this environment

Brochure assignment• You will be assigned the

zone/ecosystem your group will be doing.