MARINE ENVIRONMENTS

2014

A. Intertidal zones- between high and low tide

1. marked by strandline(seaweed and debris deposited on beach at high tide)2. organisms must be adapted to alternating periods of wet and dry.

B. Supratidal zone- above intertidal up to dunes

1. salt spray limits plant growth2. terrestrial animals and birds

c. Subtidal zone- below low tide line.1. heavy wave impact and high

turbulence2. marine life has adaptations to help cling to surfaces

I. MARINE LIFE

ZONES

METHODS OF ATTACHMENT

• Encrusting sponges

TUBE FEET USED BY SEASTARS

SNAILS AND MOLLUSKS CLING USING MUSCULAR

FOOT

MUSSELS ATTACH USING

BYSSAL THREADS

BARNACLES SECRETE CEMENT

KELP AND ROCKWEED HAVE

HOLDFASTS

FLATTENED BODIES- FLOUNDER AND SAND DOLLAR

PELAGIC ZONE-COVERS ENTIRE OCEAN OF WATER ABOVE THE

SEA BOTTOM1. Neritic zone-fewer than 200 m in depth above continental shelf

• Where most commercial fishing takes place

• Very productive because of river runoff which provides nutrients

2. Oceanic zone- open ocean

• Photic zone- light penetrates and supports life

• Disphotic zone- small amounts of light penetrate

• Aphotic zone- no light. Deep sea animals adapted to high pressure and no light. Includes ocean basin.– Ex. Deep sea fish,

worms, crustaceans

SANDY BEACH ENVIRONMENT- COMPOSED OF SAND(LOOSE SEDIMENTS EASILY SHIFTED BY WIND AND WAVE ACTION).

A. Upper Zone1. zone with most temperature change.

a. desiccation(drying out) in summer b. freezing in winter

2. limited times of water inundation means limited MARINE food sources.

3. fauna- mostly scavengers(amphipods, insects and oligochaetes). Nocturnal to avoid desiccation and predation.

a. amphipods(sand fleas)- crustaceans that crawl or hop along sand. Use gills that act similar to lungs, must stay moist but will drown if completely submerged. Can burrow up to 3 feet. Predators include shorebirds, beetles and occasional fox, raccoons etc.

b. beetles and flies c. oligochaetes (segmented worms)

B. MID ZONE- AREA BEFORE UPPER ZONE.

1. MODERATE INUNDATION TIMES SO STILL EXPERIENCES TEMPERATURE ISSUES.

2. INCREASED WAVE ACTION CAUSES RAPID SEDIMENT REMOVAL AND THEREFORE REQUIRES HIGHLY MOBILE FAUNA.

3. Fauna- isopods which are carnivorous scavengers. Will burrow approx. 1 cm near the low tide line and forage when tide comes in. Predators are mainly shorebirds.

C. SURF ZONE- REGIONS OF CRASHING WAVES

1. Constantly moving water, sand is moved by wave action.

Fauna- most be adapted to land, sea and wave action.

a. mole crab- paddle-like appendages (swimming), smooth, flattened body

b. surf clam- thick shell to resist wave action and muscular foot allows for digging (avoid predation)

II. ROCKY COAST ENVIRONMENT- SHORES MADE OF SOLID ROCK, ROCKS PROVIDE SUBSTRATE FOR PLANTS AND ANIMALS

A. Zones- Upper intertidal (splash zone)• 1.large amounts of blue- green algae• 2. dominant fauna- periwinkle snails to feed on

algae• 3. main predators are shore birds• B. Mid-Intertidal zone• a. dominant fauna – barnacles, whelk, mussels and

sea stars• b. barnacles are filter feeders when covered with

water, overlapping plates close when not covered with water to prevent desiccation.

• c. dog whelk feed on barnacles(drill though plates)• d. Mussels• e. Sea stars are predators

• C. Lower Intertidal Zone- region dominated by sea weed.

• 1. red seaweed (Irish moss) common• 2. tide pools- many types of algae,

small invertebrates and fish• D. Subtidal zone-below low tide line.• 1. sea urchins common, eats holdfast

of kelp• 2. sea stars move in with tide and

feed on mussels

III. Estuary- brackish water found at the mouth of a river, where it enters the ocean.

A. Very productive region1. called “nature’s nursery”- many

organisms lay eggs and young develop in nutrient rich waters.

2. formed by melting ice flooding the mouths of rivers.

3. found on the bay side of a barrier beach where calmer waters are found

B. Salt Marsh Community- (wetlands)1. dominant species- marsh grasses

a. cord grass (Spartina)- resistant to salt, can secrete salt crystals.

b. when the grasses die, provide nutrients

c. Phosphates and nitrates used by plankton and plankton are filtered by larger animals

d. other animals include fiddler crabs, hermit crabs and fish

C. Mud Flat Community

1. dark, muddy sand with no grassesa. very little aeration and minimal flushing action

2. nature’s graveyardsa. high amounts of decomposition

by bacteriab. Rotten egg smell from hydrogen

sulfide H2Sc. Invertebrates scavenge for food-

mud snails, sandworms and clams

D. Mangrove Community-found in tropical and subtropical regions.

1. trees are adapted to salt water. Low wave action and large exposed roots act as a nursery area for organisms lower in the food chain and protect shore from erosion.

2. dominant species- red mangrove trees

3. wildlife sanctuary- home to raccoons, snails, oysters, crabs, conchs, pelican and osprey

E. Coral Reef Environment1. stony formation built by coral polyp.2. made of calcium carbonate CaCO3.3. symbiotic algae-zooxanthellae which

give coral its color a. live inside coral polyp

4. coral featuresa. found btwn 30°N and 30°Sb. longest reef- Great Barrier Reefc. hard coral- elkhorn ,staghorn

and braind. Soft coral- sea fans, sea whipse. very fragile ecosystem

Reef inhabitants1. Butterfly fish-snout able to get prey

in small crevices2. Parrotfish- eats coral polyps and

grinds the skeleton to sand 3. many able to hide in small crevices4. colorful coral – many fish

camouflaged to blend in