Aquatic Systems

All freshwater comes from two sources: Water that seeps below ground Some is taken up and used by plants Large amounts found in underground rock formations called aquifers Lakes, ponds, rivers, and streams…ALL water above ground Most urban areas rely on surface water Supply resources and allow for travel/trade GROUND WATER SURFACE WATER

Surface water movement: Water Cycle Earths water supply is constantly recycled

Surface Water Movement 1) Runoff Water flowing down slope along Earth’s surface or seep into the ground Run off speed determined by slope of the hill Ends up in a stream or lake, evaporate, or accumulate into puddles

Movement Seep into ground Evaporate Ground must have large enough pores – loose soil Evaporate

Fate of water: Run off or Seep Certain characteristics will determine whether not water will either seep into or become runoff 1) Vegetation Vegetation allows for loose soil Loose soil allows water to enter ground Gardeners do not pack their soil

Fate of water 2) Rate of precipitation Heavy: Light: soil clumps together closing pores Fills up ground to quickly and water becomes runoff Light: allows water to gently slide through Less erosion

Fate of Water 3) Soil Composition Effects the waters holding capacity Decayed organic matter (humus) Creates the pores in soil – Increases retain ability Minerals Clay – fine mineral which clump together Few Spaces Sand – large pores

Fate of Water 4) Slopes Steep: allows for high runoff & little absorption Little: low runoff and high absorption

Formation of Stream systems Runoff Surface water flows in thin sheets and eventually collects in small channels Runoff increases, channels widen and become deeper and longer Channels fill up again each time with rain Channel can become a stream

Water sheds: Divide drainage basin Land where all water drains into High land area that separates watersheds

Mississippi Watershed

Floods Water fills over the sides of a stream banks Floodplain: broad flat area of land that extends out from streams for excess flooding

Aquatic Ecosystems Objectives: Describe features of freshwater and marine ecosystems. Describe threats to freshwater and marine ecosystems.

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 Benthic zone Eutrophication – 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) Swamps (Ex: Louisiana swamps) 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

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 time 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.