Ecology Chapter 7

Aquatic Ecosystems

Standard 5 - BiomesExamine the major freshwater and marine ecosystems

{CLE 3255.5.3,.4,.5}

Obj:

Describe the factors and characteristics that determine each water biome and the organisms that live there

Freshwater Biome*

Sec. 1: Freshwater Ecosystems

Wetland - land that is periodically under water

Factors that determine which organisms live in an area are:

salinity, temperature, oxygen, sunlight, and nutrients

Include: lakes, ponds, swamps, and marshes

Types of Organisms

Plankton: float near the surface

2 Types:

1.) Phytoplankton - microscopic plants;

2.) Zooplankton - microscopic animals

Nekton: free swimming organisms - fish, turtles, whales, etc.

Benthos: bottom dwellers - muscles, worms, bacteria, etc.

Lakes and Ponds

Lakes, ponds, wetlands, rivers, streams

2 Zones:

1.) Littoral - near the shore;

2.) Benthic - bottom of the lake or pond - decomposers, insect larvae, and clams

Eutrophication - increase in the amount of nutrients in an aquatic ecosystems

Can cause damage to the lake and life

Swamps and Marshes

Swamps: dominated by woody plants such as trees and shrubs

Occur on flat, poorly drained land often near streams

Variety of plant and animal life exists

Swamp

Marshes

Contain non-woody plants such as cattails

Florida Everglades is the largest freshwater wetland in US

Occur in low, flat lands and have little water movement

Several kinds of marshes each with it’s own characteristics and salinity

Freshwater Marsh

Rivers

Most originate from snow melt in mountains

Changes with the land and climate through which it flows

Runoff effects the growth and health of the water and organisms

Life adapts to the different parts of the river (flow, temp, etc.)

Standard 5 - BiomesExamine the major freshwater and marine ecosystems

{CLE 3255.5.3,.4,.5}

Obj:

Describe the factors and characteristics that determine each water biome and the organisms that live there

Marine Biome*

Sec. 7-2: Marine Ecosystems

Located mainly in coastal areas and in the open ocean

Organisms in coastal areas adapt to changes in water level and salinity

In open ocean they adapt to temperature, amount of sunlight and nutrients

Coastal Wetlands

Covered by salt water for all or part of the time

Estuaries, Marshes, and Swamps

Provide habitat and nesting for many fish and wildlife

Absorb excess rain, protects areas from flooding

Estuaries

An area in which fresh water from rivers mixes with salt water from the ocean

Very productive ecosystems because they constantly receive fresh nutrients

Estuaries: Plants and Animals

Receives lots of sunlight and plenty of nutrients for plants and animals

Provide protected harbors and access to the ocean, and connection to the river

Threats to Estuaries

In populated areas, used as places to dump wastes

Pollutants can destroy; breaks down over time, but estuaries cannot cope with the amounts produced by large human populations

Salt Marshes

Develop in estuaries where rivers dump mineral rich mud

Breeding ground for clams, fish, birds, shrimps, and crabs

Absorb pollutants and protect inland areas

Mangrove Swamps

Located along coastal areas of tropical and subtropical zones

Mangrove trees dominate these areas

Grow partly submerged in warm shallow waters

Help protect the coastline from erosion and reduce damage from storms

Rocky and Sandy Shores

Rocky shores have more plants and animals than sandy shores

Rocks provide anchors and protection to the organisms

Sandy shores often dry out and organisms get stranded

Coral Reefs

Built by tiny coral animals that secrete limestone which slowly accumulate to form the coral reef

Live only in clear and warm salt water with sunlight for photosynthesis

Among the most diverse ecosystem on Earth

Two types of CoralsHard Coral

Brain Coral and elkhorn coral

Build coral reefs

Soft Coral

Sea fingers and sea whips

Do not build coral reefs

Types of Reefs

Fringing reefs are reefs that form along a coastline. They grow on the continental shelf in shallow water.

Barrier reefs grow parallel to shorelines, but farther out, usually separated from the land by a deep lagoon.

Coral Atolls are rings of coral that grow on top of old, sunken volcanoes in the ocean.

Humans and coral reefs

Fragile ecosystem

27% of coral reefs in the world are in danger of destruction from human activities

Oil spills, sewage, pesticides, and silt runoff have been linked to coral reef destruction

Human interaction (cont.)

Over fishing can deplete fish populations and upset the reefs balance

Reefs grow slowly so may not be able to overcome repair the damage

Oceans

Sunlight that is usable only goes to about 100m (330ft) into the ocean before the sunlight is absorbed

Much of the oceans life is concentrated in the shallow, coastal waters

Seaweed and algae grow anchored to rocks, phytoplankton float near the surface, invertebrates that feed on these are also concentrated near the shore

Plants and Animals of the Ocean

In open ocean; least productive of all ecosystemsPhytoplankton only grow in area where there is enough sunlightZooplankton live near the surface with the phytoplankton they feed onThe larger organisms come closer to the surface to feed on these organismsDecomposers, filter feeders that do not depend on sunlight dwell in the depths

Sunlit zone or the Euphotic zone

Plants

Primary ProducersFree-floating algae -- often called seaweed

Red algae

Green algae

Brown algae

Phytoplankton -- tiny, one-celled photosynthetic plankton like diatoms, dinoflagellates,

Animals

include most ocean fishincluding:

sharks and rays, man-o'-war, jellyfish, sea turtles, seals, coral, and zooplankton

Intertidal zone: where the land and sea meet

Threats to Oceans

Steadily becoming polluted

Most pollution come from activities on land due to runoff

Over-fishing and certain fishing methods also destroying fish populations

Nets can drown or strangle animals that must return to the surface to breathe when they get caught in them

Artic & Antartic Ecosystems

Artic Ocean gets nutrients from the surrounding land masses

Supports whales, seals, ocean birds, polar bears, and provide food for people

Antartic only continent never colonized by humans - used mainly for research

Only a few plants grow

Artic plankton feed the fish, whales, and penguins that live there