Bellringer

• Describe the different plants and animals in the salt water aquarium show in the picture.

• What requirements do the fish in the aquarium need to survive?

• What would happen if a fish from a local Alabama river was added to this salt water aquarium? WHY?

Aquatic EcosystemsChapter 7

Objectives:1. Describe features of freshwater

and marine ecosystems.2. Describe threats to freshwater

and marine ecosystems.

Aquatic Ecosystems

• How many aquatic ecosystems can you name?

• What are the differences between them?

I. Freshwater Ecosystems• Organisms are grouped by location and

adaptations:– Plankton – float near the surface of the

water• Phytoplankton – microscopic plants• Zooplankton – microscopic animals

– Nekton – free-swimming (fish, turtles, whales)

– Benthos – bottom-dwellers (mussels, worms, barnacles)

A. Lakes and Ponds

• Littoral zone– nutrient-rich area near shore– variety of plant and animal life

• Benthic zone– Bottom of a pond or lake– Inhabited by decomposers, insect larvae, and clams

• Eutrophication – – more nutrients = more plants = more decomposers

using oxygen = less oxygen for other organisms– Can be caused by runoff of sewage, fertilizers,

animal waste

B. Wetlands• Marshes (Ex: The Everglades)

– Contain non-woody plants (reeds, rushes, cattails)

• Swamps (Ex: Louisiana swamps)– Contain woody plants or water-loving trees

Functions of Wetlands• Trap sediments, nutrients, and

pollutants, keeping them from lakes, reservoirs, and oceans

• Buffer shorelines against erosion• Protect against flooding• Provide spawning grounds and habitats• Recreational areas (fishing, bird-

watching, hiking, canoeing, photography)

Human Impact on Wetlands

• Were drained and filled for farming and residential and commercial development

• Pollution

C. Rivers

• Swift-moving• Home to strong swimming fish and

organisms with adaptations to cling to rocks

• Polluted by – human sewage and garbage– runoff from the land

• Drained by industries

#41 - Concept Map1. Freshwater wetlands 2. Decomposers3. Lakes 4. Phytoplankton5. Littoral zone 6. Zooplankton7. Freshwater ecosystems 8. Runoff9. Eutrophication10. Traps and filters pollutants11. Benthic zone12. Buffers shorelines

II. Marine Ecosystems

• Mainly in coastal areas and the open ocean

A. Coastal Wetlands• Coastal areas covered by salt water at least

part of the time1. Estuaries – where fresh river water and

salty ocean water mix• Constant source of fresh nutrients supplied by

the river• Nutrients fall to the bottom (“nutrient trap”)• Provide harbors protected from open ocean –

site of major ports• May be used as dumping sites for sewage,

industrial waste, and agricultural runoff

Coastal Wetlands (cont.)2. Salt marshes

– Develop in estuaries– Found along the Gulf Coast

Coastal Wetlands (cont.)3. Mangrove swamps

– Found along the coast in tropical and subtropical zones

– Dominated by mangrove trees

Coastal Wetlands (cont.)4. Rocky and sandy shores

– Rocky shores have more plants and animals (Why?)

– Barrier islands run parallel to the shore and protect the mainland and coastal wetlands.

Barrier Islands

B. Coral Reefs

• Limestone ridges made of the skeletons of animals called coral polyps

• Found in shallow, tropical seas with clear, warm salt water and lots of light

• Disappearing coral reefs:– Damaged by oil spills, sewage, and runoff– Overfishing– Damaged by anchors, divers, shipwrecks

C. Oceans

• Plankton on the ______; decomposers and filter feeders on the ________.

• Threats to the ocean:– Pollution from land activities– Overfishing

• Arctic and Antarctic ecosystems:– Nearly all food in the arctic ecosystem comes

from the ocean; land is frozen, so plants don’t grow well.

Assignment

• Compare and contrast1. Salt marshes (p.182) and freshwater

marshes (p.176)2. Mangrove swamps (p.182) and freshwater

swamps (p.177)