StreamEcology

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Information about StreamEcology
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Published on January 28, 2008

Author: Rainero

Source: authorstream.com

Stream Ecology:  Stream Ecology Welcome to stream ecology! On our field trip you will be meeting lots of interesting critters. Who are they? Why are we interested in them? What is their ecological niche? •An ecological niche is the role a species plays in its community. If the habitat is the species ‘address’, its niche is its ‘job’. Their job might be as producer, decomposer, predator, or prey! Ecologists use labels such as native, nonnative, indicator, keystone or foundation to describe the major ecological role–or niche-various species play in communities. (Miller, Living in the Environment 2005: p. 147) Hi There! Perhaps we will meet! What are indicator species?:  What are indicator species? Some species can alert us to harmful changes that are taking place in biological communities (Miller,,Living in the Environment: p. 147) A famous example is the canaries that coal miners took down into the mine shafts in the 1800’s and early 1900’s. We call these bioindicators. They can tell us about the overall health of an ecosystem. We will be studying species that act as bioindicators of stream quality.:  We will be studying species that act as bioindicators of stream quality. Insect larvae that develop in streams are valuable bioindicators. An example is the Dameselfly. The presence of Damselfly adults (left) and larvae (right) indicate moderately clean water. They are somewhat sensitive to pollution and so water they are found in will be of good to fair quality. Why are we concerned about the quality of stream water, anyway? www.pennridge.org/ works/cranefly.html Why are healthy streams important? They feed into watersheds!:  Why are healthy streams important? They feed into watersheds! Bon Tempe and Alpine Lakes; Marin County, CA Photo by Alex Rabidoux http://watershed.ucdavis.edu They feed into rivers!:  They feed into rivers! Streams feed into the Bay!:  www.coastal.ca.gov/ nps/Web/cca_sfbay_c1.htm Streams feed into the Bay! Communities of organisms depend on them!:  Communities of organisms depend on them! http://www.livingwilderness.com/about/1000words/heron.html What do we mean when we say ‘healthy stream’?:  What do we mean when we say ‘healthy stream’? Plenty of Oxygen 02 A healthy food web Habitat for reproduction WHY is plenty of oxygen so important? :  WHY is plenty of oxygen so important? Producers are able to make their own food via photosynthesis. They then use this food to produce energy through cellular respiration. Consumers eat producers and use this food to produce energy through cellular respiration: 6O2 + C6H1206 ----> 6C02 + 6H20 + 36 ATP (ENERGY) Dissolved Oxygen in water:  Dissolved Oxygen in water Trout need 6 mg/L of O2 for growth and activity. Most fish need between 5 - 6 ppm of O2 The insect larvae indicator species intolerant of pollution need 4 mg/L to do well. Below 3 mg/L stressful to most aquatic life Mosquito larvae live in water with a dissolved oxgen concentraion of 1 mg/L! What would this tell you about the water? Below 1 or 2 ppm will NOT support fish; will support pollution tolerant bioindicators. Where does the oxygen in water come from? Sources of 02 in water:  Sources of 02 in water There are two main sources of dissolved oxygen in stream water: the atmosphere and photosynthesis. Waves and tumbling water mix air into the water where oxygen readily dissolves until saturation occurs. Oxygen is also introduced by aquatic plants and algae as a byproduct of photosynthesis. (www.cet.edu/ete/modules/ waterq/wqdissolvedo2.html) Photosynthesis http://www.udel.edu/communication/new_zealand/Milford%20Sound.html alpha2.bigelow.org Riffles and Waves How can we determine whether or not a stream is healthy and has plenty of oxygen?:  How can we determine whether or not a stream is healthy and has plenty of oxygen? We can study populations of Macroinvertebrates as bioindicators of the health and oxygenation of a stream.:  We can study populations of Macroinvertebrates as bioindicators of the health and oxygenation of a stream. Macro means large enough to see with your eyes. Invertebrate means animals without backbones. 95% of all animals are invertebrates! Examples: insect larvae, crayfish, worms, adult aquatic insects www.bio.utexas.edu/ grad/guisinmm/Cynthia/ I can handle some pollution! Why do these macroinvertebrates make good bioindicators of stream and watershed health?:  Why do these macroinvertebrates make good bioindicators of stream and watershed health? •live in the water for all or most of their life •stay in areas suitable for their survival •are easy to collect •differ in their tolerance to amount and types of pollution •are easy to identify in a laboratory •often live for more than one year •have limited mobility Bioindicators are grouped according to their tolerance of pollution/water quality.:  Bioindicators are grouped according to their tolerance of pollution/water quality. http://www.pca.state.mn.us/artwork/kids/dragonfly2.jpgg Dragonfly larvae tolerate some pollution. 1.http://www.schoolsliaison.org.uk/woodgate/streamhabitat. Caddisfly larvae are intolerant of pollution. Leeches and blood midge larvae are very tolerant of pollution 1.http://www.schoolsliaison.org.uk/woodgate/streamhabitat & www.pbase.com/ michellemahood/image/25470143 These are Bioindicators which are Pollution Intolerant. Their presence tells you that the water quality is excellent. We will use the dichotomous key to identify some of these! images from pathfinderscience.net unless otherwise cited :  These are Bioindicators which are Pollution Intolerant. Their presence tells you that the water quality is excellent. We will use the dichotomous key to identify some of these! images from pathfinderscience.net unless otherwise cited http://www.trilobites.info/triloimposterpennymr005872_md.jpg Who am I? I am about 1/4 - 1 inch long. I have 6 large, hooked legs, feathery gills and 3 hairlike tails.:  Who am I? I am about 1/4 - 1 inch long. I have 6 large, hooked legs, feathery gills and 3 hairlike tails. I am about 1/2 - 1 1/2 inches long, have two hair-like tails and no gills on my lower body. Who am I?:  I am about 1/2 - 1 1/2 inches long, have two hair-like tails and no gills on my lower body. Who am I? I am often seen walking on rocks or the bottom of streams with my head sticking out of a case. I make my cases from pebbles, twigs or detritus. I have 6 hooked legs on my upper body and 2 hooks at my back end. Sometimes you can see my fluffy gill tufts on my underside!:  I am often seen walking on rocks or the bottom of streams with my head sticking out of a case. I make my cases from pebbles, twigs or detritus. I have 6 hooked legs on my upper body and 2 hooks at my back end. Sometimes you can see my fluffy gill tufts on my underside! http://www.epa.gov/bioindicators/html/indicator.html Now Let’s look at Macrovertebrates somewhat tolerant to pollutants. Their presences indicates water of good to fair quality.:  Now Let’s look at Macrovertebrates somewhat tolerant to pollutants. Their presences indicates water of good to fair quality. www.pskf.ca/ecology/ bugs/hints.htm Stonefly larvae Scud Damselfly nymph www.hainaultforest.co.uk/4AquaticMinibeasts.htm Dragonfly larvae www.hainaultforest.co.uk/4AquaticMinibeasts.htm I am also a bioindicator which can tolerate a bit of polluted water. If you find lots of me and my fellow somewhat tolerant species when you study the stream, you will be able to say the stream has good or fair quality water. Notice my legs! Insects have 6 legs. Am I an insect? Find me on your key! Where did you meet one of my close relatives earlier in the year?:  I am also a bioindicator which can tolerate a bit of polluted water. If you find lots of me and my fellow somewhat tolerant species when you study the stream, you will be able to say the stream has good or fair quality water. Notice my legs! Insects have 6 legs. Am I an insect? Find me on your key! Where did you meet one of my close relatives earlier in the year? You may have realized by now that our insect bioindicators have an aquatic larval form. We all are very familiar with butterfly metamorphosis. On our field trip you will be introduced to the larval form of insects you probably know only in their adult forms. An example is the dragonfly, also a bioindicator of good to fair water!:  You may have realized by now that our insect bioindicators have an aquatic larval form. We all are very familiar with butterfly metamorphosis. On our field trip you will be introduced to the larval form of insects you probably know only in their adult forms. An example is the dragonfly, also a bioindicator of good to fair water! http://www.btinternet.com/~andyharmer/dragonflylarvae.htm http://people.colgate.edu/wda/Australia/Dragonflies And now for the ‘Tolerant of Pollution’ species. They are found in water of poor quality. :  And now for the ‘Tolerant of Pollution’ species. They are found in water of poor quality. Pouch Snail http://www.pennridge.org/works/pouchedsnail.jpg Tubifex Worms http://ebiomedia.com/prod/BOanelids.html Water Mite Leech Leech I am pollution tolerant and can be found in almost any quality of water! If I and my fellow pollution tolerant species are all that you find, the water is very polluted! Find me using your key!:  I am pollution tolerant and can be found in almost any quality of water! If I and my fellow pollution tolerant species are all that you find, the water is very polluted! Find me using your key! http://entomology.tfrec.wsu.edu/pearent/images/assorted_minors/blackfly.jpg Using your key, decide if a large population of these critters would indicate a very clean, somewhat clean, or dirty stream!:  Using your key, decide if a large population of these critters would indicate a very clean, somewhat clean, or dirty stream! http://www.biol.andrews.edu Enjoy the fieldtrip!:  Enjoy the fieldtrip!

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