2Aquatic Biomes Water covers more than 70% of the Earth’s surface Aquatic habitat: one in which organisms live in or on waternot grouped geographicallydifficult to show on a mapoften determined by depth rather than location
3Land vs. Aquatic BiomeTemperature and rainfall are important factors when distinguishing one land biome from another.Temperature in large bodies of water are relatively stable.Rainfall has less effect on aquatic biomes because organisms are already underwater.
4Important FactorsSalinity: The amount of dissolved salts in a sample of water. Measured in parts per thousand (# units of salt in a thousand units of water)Aquatic biomes can be divided into two main groupsSaltwater (30 parts/1000)Freshwater (0.5 parts/1000)Brackish water > saline than fresh, < saline than ocean water
5Important FactorsDepth – directly related to the amount of sunlight that reaches the bottom of the body of water.Sunlight determines the types and amounts of plants that can grow. (Remember – plants are producers, and the base of the food web)
6Photic zone: top layer of sunlight that receives enough sunlight for photosynthesis to occur. Aphotic zone: below the photic zone. Sunlight does not reach this zone.Benthic zone: the floor of a body of water
7Question BreakWhat characteristic distinguishes the photic zone from the aphotic zone?SunlightHow is salinity measured?Parts per thousand (# units salt/1000 units of water)
8Standing-water Ecosystems The most common types of standing-water ecosystems are lakes and ponds.Also includes wetlands (bogs, swamps, etc.)While there is no flow of water in and out of most standing-water ecosystems, there is a circulation of water throughout the system.Review question: How does this circulation occur? What causes the circulation?
9Types of Standing-Water Ecosystems Abiotic FactorsBiotic FactorsDeepest type of standing water;may have an aphotic zone; may befed by aquifersFloating algae in the photic zone,plants along shoreline, complexfood websLight reaches benthic zone; fed byrainfall – may be seasonalMain producers – plants and algaethat grow on bottom; food websimpler than lakesPlants have roots under water,leaves above water; grasses,cattails; ducks and waterfowlVery shallow water, land occasion-ally exposed; saturated soil; FloridaEverglades largest freshwater marshLand soaked due to poor drainage;usually along low streambeds andflat landLarge trees and shrubs; cypresstrees in south, willow and dogwoodin northInland wetland; soil is acidic; decayis slowSphagnum moss dominant organ-ism, partly decayed moss accumu-lates as peatLakePondMarshSwampBogTypes of Standing-Water Ecosystems
10Standing-Water Organisms Several levels of habitatPlankton communityPlankton: microorganisms that float on the surface of the waterPhytoplankton: carry out photosynthesis. Main producers in most aquatic biomesZooplankton: do not carry out photosynthesis. Include microscopic animals and protozoans. Consumers – feed on phytoplanktonBig fish feed on little fish, little fish feed onplanktonBenthic communityScavengers, depend upon a steady rain of organic material that drifts down from the top. Decomposers are also part of this community
11WetlandsEcosystems in which the roots of plants are submerged under water at least part of the year. Soils are soaked with water, and very low in dissolved oxygen.Marshes, swamps, bogsAct as filters, detoxifying chemicals that passes through themCan be used as part of a treatment system for waste waterImportant breeding, feeding, and resting grounds for waterfowl.
12Endangered Wetlands Wetlands are being destroyed by human activity. Many do not find wetlands as attractive as other natural habitatsLand (especially in coastal areas) is developed for resorts and homesSwamp Lands Act of 1849 encouraged the filling and draining of wetlands
13Florida EvergladesOnce a swampy marsh that covered 160 km from Lake Okeechobee to the tip of Florida.Region has a wet season from May to October, followed by a dry season. Natural fires occur during the dry season, burning off dried plant material.Home to a large number of organisms, that are adapted to the annual cycle of growth, drought, and fire.
14In 1983, “Save Our Everglades” campaign was launched. 100,000 acres returned to wetlandFlow of water adjusted to provide a more natural water supply
15Flowing-Water Ecosystems Rivers, streams, creeks, brooksAll water that flows over land - to a scientist they are all streamsWater that flows underground is an aquiferStream OrganismsAdapted to the rate of the water’s movementHooks to grab hold of plantsSuckers that anchor to rocks
17Important Definitions River System____________ – a stream and all its tributaries________ – a smaller stream that empties into a larger stream_________ – the land area drained by a river system______ – a high point that separates river systemsTributaryWatershedDivide
29Human Impact on Streams Flow and course of streams has been changed by human activitiesDams create reservoirs and are used for hydroelectric plantsDams and levees can be used to irrigate farmlandDams and levees affect farmland by preventing sediments from being deposited on floodplainsChange of course damages or destroys the habitats of organismsAreas that were once streambeds become the bottoms of deep lakes
30Chapter 10 ReviewTo be considered fresh water, water must contain salt in a concentrationMore than 30 parts per thousandLess than 0.5 parts per millionMore than 40 parts per millionLess than 0.5 parts per thousand
31Brackish water is common in LakesOceansCoastal marshesaquifers
32Sunlight reaches the benthic zone in PondsDeep lakesOceansVents in the ocean floor
33Organisms that live in the benthic zone of deep lakes are often ProducersPlantsScavengersplankton
34A type of standing-water habitat in which the soil is acidic and decay is slow is called a BogSwampMarshpond