CHAPTER 7a – TEST 5

I. Aquatic Environments:-Aquatic Life Zones = Biomes

-Organisms that are found in life zones are determined by Salinity.

1. Marine (Saltwater): • Ocean, coral reefs, coastal marshes2. Freshwater:• Rivers, lakes, streams, wetlands

A. Main Types of Organisms in aquatic life zones:

1. Plankton:-Weak swimming and free-floating

(ex: types of algae)-3 categories: Phyto(surface), Zoo,

Nano

2. Nekton:-Strong Swimming

consumer (Fish, turtles, sharks and

whales)

3. Benthos:-Bottom dwelling….(Oysters, sea star, worms,

lobster & crabs)

4. Decomposers (Mostly Bacteria):

-Break down organic compounds

1)BUOYANCY:

• Provides support • Allows vertical

movement • Reduces the need for

large supportive structures

B. Benefits of Life in the Water:

2) THERMOSTAT ACTION:

• Keeps organisms from drying out

• Protects from major temperature changes.

5)DILUSION OF TOXIC MATERIAL

• Filtering of waste

3)DISSOLVING CAPABILITY:• Dissolves nutrients and

makes them readily available.

4)UV PROTECTION: • Protects against

harmful radiation

C. Limiting Factors In Aquatic Environments:

*Factors that determine the number and types of organisms that live in certain aquatic life zones.

- Temperature - Sunlight

- Dissolved oxygen- Nutrients

2. Sunlight:-Most important at the surface,

or EUPHOTIC ZONE, where photosynthesis occurs

-The amount of sunlight can be affected by depth and excessive algal growth

1.Temperature:-Tends to have an effect on or to be

affected by all the other factors.

3. Dissolved Oxygen-The amount of oxygen

dissolved in the water.-Affected by these factors …*Temperature

-Holds more at low temperatures

*Number of Producers (add O2)*Number of Consumers

(remove O2) *Number of aerobic

decomposers* Many fish die when D.O. drops

below 5 ppm

• A Dead Zone caused by a lowering of dissolved oxygen in the water is referred to as hypoxia.

4. Nutrients:-Found in ample supplies in shallow

water-Lacking in open ocean except where

there are UPWELLINGS• Seasonal mixing of deep nutrient

waters that are brought to the surface.

II. Key Roles Of Oceans:-Oceans play many vital roles on the

planet…1. Help to regulate climate2. Greatest total amt. of productivity

across the world3. Provide a source of many natural resources & habitat for animals and plants4. Disperse/Dilute human produced wastes and has

-Two major “Ocean Life Zones”: coastal and open ocean

1. COASTAL ZONE -Nutrient rich, shallow

water -Extends from high tide mark to *CONTINENTAL SHELF

-Contains 90% of all marine species

-Most ecosystems w/in zone have high primary productivity

A. Ocean Life Zones

Costal zones can be broken into various other areas…

Estuaries and Coastal Wetlands A. Estuary- Partially enclosed area

of coastal water where sea and fresh waters mix.

B. Coastal Wetlands- associated with Estuaries that are water covered all or part of the year. Can further include INLETS,BAYS,SOUNDS,MARSHES

Chesapeake Bay Facts

• LENGTH: 200 miles.

• WIDTH: varies: 4 miles at the Bay Bridge to 30 miles at the mouth of the Potomac River.

• DEPTH: average depth is 21 feet, maximum depth is 175 feet near Bloody Point, Md.

• MILES OF SHORELINE: 11,000 miles. (The same as the distance from New York to Los Angeles and back to New York.)

• SURFACE AREA OF SHORELINE: 4,400 square miles.

• WATERSHED: 64,000 square miles in 6 states and Washington, D.C.

• The Chesapeake Bay is the largest estuary in the United States.

• There are 15,000 streams covering 100,000 miles that feed into the Bay. (That's four times around the world!)

• There are 600,000 acres of marshlands (wetlands). Marshlands and adjoining woodlands provide a natural habitat for over 2,700 species of plants and animals.

• 90% of the Bay’s fresh water comes from l0 major river systems, and 50% of it comes from the Susquehanna River. The Bay provides more blue crabs than anywhere in the world. *The industry of Chicken farming has been blamed the most in degrading the Bay*The pollution that received the most blame for the degradation of the Bay is pollution from run off within the waters that supply the bay

Functions of Estuaries and Coastal Wetlands

• Breeding ground for aquatic organisms and habitat for water fowl

• Maintain water quality by diluting and filtering

• Food Production• Recreational activities• Protects mainland from

flooding• Most coastal wetlands

that are lost are used for urban development

• Covered with mangrove forest swamps.• Mangrove tree species has the ability to live in

salt water.

Human Impacts on Estuaries53% have been destroyed in

the USACauses:• Dredging, and filling • Trap pesticides, heavy metals and

other contaminants• Sewage runoff• Dam construction and river

diversion• California and Florida have lost

most of their coastal wetlands.

C. Intertidal Zone• Area of shoreline between low and

high tides• Sometimes thought of as the SWASH

ZONE• Stressful zone to live in

- Swept away or crushed by waves

- Immersed during high tides- High and Dry during low tides- Changing levels of salinity

• Most organisms have shells, dig in or hold onto something

1. Sandy Shores vs. RockySandy Shores or Barrier Beaches

-Show a variety of plant and animal -Most animals survive under the sand-Vegetation in “levels” among sand dunes

*Sandy shores dominate the Eastern Atlantic coast.

-Subject to:Violent stormsPollution from the landOver-harvestingCoastal development

Ocean Beach

Intensive recreationno building

Primary Dune

No direct passage

or building

Trough

Limitedrecreation

and walkways

Secondary Dune

No direct passage

or building

Bay orLagoon

Intensiverecreation

Back Dune

Most suitablefor development

Grasses or shrubs Taller shrubs

Taller shrubs and trees

Bay shoreNo filling

Sand Dunes-Primary and Secondary Dunes play

and important role in protecting the land

-Development should only be behind the second strip of dunes

Rocky Shores-Characterized by pounding waves-Often numerous tidal pools containing various organisms

D. Barrier Islands-Long, thin, low offshore islands of

sediment that generally run parallel to the shore

-Helps to protect mainland estuaries and coastal wetlands by dispersing storm waves

-Constantly change shape and size

EX. Atlantic City, Miami Beach, Outer Banks

E. Coral Reefs-Second only to tropical rain forest in

biodiversity. -3 categories of organisms …

*Attached*Fish *Organisms that bore, attach, or hide

-Found only in the tropics-Usually colored by algae

- 65 countries protect 300 coral reefs as reserves/parks. Another 600 reefs have been recommended for protection.

Human Impacts on Coral ReefsEstimated that 10%

have been seriously degraded by …

• Deposition of eroded soil

• Fertilizer runoff• Chemical Pollution• Coral bleaching-the

killing of symbiotic algae(largest threat)

• Increased UV• Destructive harvesting techniques• Ecotourism damage

Coral Reefs

Gray reef shark

Green seaturtle

Sea nettle

Fairy basslet

Bluetangs

Brittle star Banded

coralshrimp

Sergeant majorParrot

fish

Hard corals Algae

PhytoplanktonSymbiotic

algae

Zooplankton

Sponges

Bacteria

Morayeel

Black basslet

Coney

Producerto primaryconsumer

Primaryto secondaryconsumer

Secondary to higher-levelconsumer

All consumer and producers todecomposers

Fig. 7.13, p. 163

2. The Open Ocean3 vertical zones based on sunlight

penetration

1. Euphotic Zone:

2. Bathyal Zone:

3. Abyssal Zone:

1. Euphotic Zone-High photosynthesis-Low nutrients-High dissolved oxygen-Large fish

2. Bathyal Zone-No/Little photosynthesis-Zooplankton abundant-Small migratory fish

3. Abyssal Zone-Low temps-Low dissolved oxygen-High nutrients

Ocean ZonesHigh tide

Low tideCoastal zone

EstuarineZone

Continentalshelf

Open SeaSea level

Sun

Euphotic Zone

Bathyal Zone

Abyssal ZoneSlope

Continental

Depth inmeters

0

50

100

200

Phot

osyn

thes

is

500

1,000

1,500

2,000

3,000

4,000

5,000

10,000

Dar

knes

s

- Salt marshes, mangrove forests, and sea-grass meadows, are being lost and degraded

-Estimated that coastal wetlands have decreased by 53% over the last century

-70% of world beaches are eroding-Bottom habitat is being degraded by trawlers +

dredging.

III. Human Impact on Marine Systems and Coastal

Biomes: