Marine Environments

What are the major life zones in the ocean and along the coast?

What is a life zone?

• A region that contains specific organisms that interact with one another and with their environment

Major Marine Life Zones

1. Supratidal zone- an area of the upper beach that gets a fine mist of salt spray from the crashing waves.

Contains beach plants, grasses, shrubs, and trees.

Supratidal Zone

2. Intertidal zone- the turbulent area between high tide and low tide. This is where clams, mussels, sea worms, and

seaweeds live.

The long line of seaweed called the strandline marks the high tide on beaches.

Intertidal Zone

3. Subtidal zone- the area below the intertidal zone. This zone includes the surf zone, an area of turbulence.

Fish , crabs, sea stars, and sea urchins live in the area.

Subtidal Zone

3. Neritic zone- lies above the continental shelf, the shallow part of the seafloor that surrounds the continents.

This is the main area for commercial fishing.

4. Oceanic zone- extends beyond the neritic zone and includes most of the open sea.

Together the neritic and the oceanic zones make up the largest marine life zone (the Pelagic zone- we went into the various pelagic zones on our ocean zonation model!!). Photic zone- closest to the surface

Aphotic zone- no light penetrates

5. Benthic zone- includes the entire ocean floor, from the intertidal zone to the ocean basin.

Organisms living here exhibit unique

adaptations to conditions on the ocean floor.

Marine Life Zones

Can you identify the zones?

The Beach

What causes the water, in the picture below, to be white?

(When waves crash, air mixes with water producing white foam)

What do we know about sandy beaches?

• Contains loose, unstable sediment which is easily

moved around by wind and water.

• Beaches that face open ocean are characterized by large surf (breaking waves).

• The surf zone (region where waves crash) is constantly moving up and down with the tide

• The surf zone is comprised of beach grasses, shrubs, trees (supratidal).

• Crabs and small fish live in the surf zone.

Florida has sandy beaches

How are marine animals adapted to life in the surf zone?

• Mole Crab (Emertia)

http://www.youtube.com/watch?v=_JgoZxjJLzI

• Lady Crab (Ovalipes)

• Silverside fish (Menidia)

http://www.youtube.com/watch?v=xqs4imGVxew

Marine animals adapted to surf zone Mole Crab:

-smooth jellybean shape helps it move through sand and water

-avoids wave impact by digging into sand with wavelike appendages

Lady Crab:

- Paddle like appendages

- Burrows in sand

Silverside fish:

- Small fish swims in schools

- Preyed upon by larger fish

What do we know about rocky beaches?

• Rocky beaches provide a more stable

environment.

• Rocky beaches contain coves, crevices, and tunnels in which marine organisms can hide.

• Rocky beaches are divided into 4 tidal zones, depending on how high or low the tides are.

• Some organisms found in a rocky coastal beach environment are: barnacles, snails, sea urchins, starfish, algae, very small fish.

Maine, California have rocky beaches

4 major rocky coast zones

1) Upper Tidal: wave splash zone, algae on rocks, periwinkle snails, limpets

2) Mid-tidal: barnacles, mussels, dog whelks

3) Lower-intertidal:, tide pools Tide pools are rocky areas on the edge of an ocean that are

filled with sea water red seaweed, starfish, sea urchins, crabs, mussel shells, etc.

Subtidal: snorkeling, sea urchins

3.4 Estuaries

You will be able to:

-Describe what an estuary is

-Explain why estuaries are important

-ID and describe the communities in the estuary

Estuary • Where the river meets the sea

• Salt and freshwater mix= brackish water

• Sediments from ocean come in with tides to form barrier beaches- long ridges

• Calm water- perfect “nurseries”

3 zones in an Estuary saltmarsh, mangroves, mudflats

Salt marsh= wetlands • Marsh grasses = Phragmites

– Tough, coarse, resistant to the killing effects of salts

– High in nutrients – When dies turns into organic

matter= detritus – the organic matter

containing nitrates and phosphates is taken up by plankton/becomes food for filter feeders

Mud flats • “graveyard” bacteria decompose and turn sand into dark mud with foul odor

• no grasses

• Mud snail (Ilyanassa), clam worm (Nereis), razor clam (Ensis), and soft-shelled clam (Mya)

• Various birds prey on these invertebrates

Mangrove swamp

• Thick tree (Rhizophora)

• Protect the shoreline from erosion and act like giant sponges absorbing the water and impact of tropical storms

Mangroves

• https://www.youtube.com/watch?v=64Gq32s4aaA