Freshwater Ecology BIOE 155
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This 20 page Class Notes was uploaded by Zane Greenholt on Monday September 7, 2015. The Class Notes belongs to BIOE 155 at University of California - Santa Cruz taught by Jonathan Moore in Fall. Since its upload, it has received 68 views. For similar materials see /class/182248/bioe-155-university-of-california-santa-cruz in Biology Ecology & Evolutionary at University of California - Santa Cruz.
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Date Created: 09/07/15
BIOE 155 Autumn 2008 PHYSICAL Types morphometry and origins of lakes and streams read pp 164 265 288 in Dodson WATER IN THE BIOSPHERE 0 There is very little accessible fresh water in the biosphere Volume Percent of Percent of available Renewal time km3 1000 Total freshwater years Oceans 1370000 9761 0 3100 Polar ice glaciers 29000 208 0 16000 Groundwater 4000 029 954 300 Freshwater lakes 125 0009 30 1100 Saline lakes 104 0008 0 101000 Soils 67 0005 16 280 days Rivers 12 000009 003 1220 days Atmosphere 14 00009 0 9 days Table modi ed from Wetzel 2001 0 Surface water O Lakes I Fresh I Saline o Reservoirs I Streams that are blocked by a dam o Streams o Wetlandsiregions of shallow and slow surface ow that have rooted and emergent aquatic plants macrophytes 0 Ground wateriwater below the surface of the earth 0 Important source of drinking water I 50 of world population I 95 of rural America 0 Easily depleted renewal time N 300 years 0 Aquifersideep reservoirs of ground water BIOE 155 Autumn 2008 MAJOR AQUATIC COMMUNITIES pp 164 in Dodson o Lenticistanding water lakes 0 Lotici owing water streams o Lakes 0 Pelagic zoneiopen water 0 Littoral zoneinear shore o Benthic communityilocated at the bottom of the lake StereOtypical Lake Stereotypical Stream Macrophytesiaquatic plants Littoral rif e Pelagic hyporheic Benthic crosssectional Views o Streams 0 Main channelimain watercourse of a stream 0 Rif esiareas of fast owing water over coarse substrate 0 Hyporheiciarea in substrate that has contact with the stream 0 Runiareas with fastmoving water that has smooth ow 0 Poolsiareas of stream that are relatively deep and low ow 0 Riparianiland area along the banks of the stream BIOE 155 Autumn 2008 WATER IN LANDSCAPES pp 265288 0 There has been increasing appreciation of the importance of the larger landscape to freshwaters For example The lake as a microcosm by Forbes 1887 describes the lake as separate from the surrounding world In reality freshwaters are controlled by the landscapes around them as proposed by The stream in its valley Hynes 1975 Morphometryithe size and shape of lakes and streams o Controlled by surrounding geology 0 Mountain vs lowland 0 Origin of streamlake Aspects of Lake Morphology 0 Shape unitless ratio DL 0 Shore length 0 Index of Shoreline Development index DL I The ratio of the observed shoreline length to circumference of circle of area equal to that of the lake I When DL l the lake is a circle L D L 2 where L observed length of the shoreline andAo the area of the lake 0 In uences I Potential for interactions between land and water 0 Surface Area m2 0 In uences I Sunlight I Evaporation I Wind effects 0 F etchithe distance over which the wind acts I Gas exchange between lake and atmosphere 0 Depth m o Zmaximaximum depth 0 meniaverage depth volume divided by surface area 0 In uences I Vertical mixing I Distribution of biotic and resultant processes 0 Volume L or m3 0 In uences I How much material water nutrients etc is in lake I Residence times of materials in lakes BIOE 155 Autumn 2008 o Quantifying lake morphology o Bathymem39c maps 0 H ypographic curveideptharea curve 0 Depthvolume curves 0 See diagrams below Diagrams of stream morphology Bathymetric maps W Cross sectional pro le Volumetric curves Hypsographic curves Area Volume B Depth Depth B A A Stream Morphometry 0 Velocity ms 0 rate of movement 0 Gradient mkm or 0 drop in elevation over a distance BIOE 155 Autumn 2008 o Crosssectional area m2 0 area of the stream perpendicular to main ow 0 Discharge m3s 0 rate of water movement 0 in uences I substrate conditions I disturbance of biota o Stream order 0 Increases in stream order occur when two streams of the next lower order are joined I Eg A second order stream is formed when two first order streams are joined LAKE ORIGINS Lakes are formed when depressions are created in the ground which lls with water Most lakes are young and temporary features of the landscape Lakes and streams are continuously evolving o Lakes gradually ll with sediments o Streams move and migrate laterally and down Major processes and types of lakes include the following o Glaciation o Glacial dams and moraines Kettle pondiholes left from blocks of melted ice Glacial scouriglaciers carve out basins Plunge basinimelting glaciers can produce deep plunge basins 000 o Riverine o Oxbow lakes 0 Sinkholes 0 Rock pools 0 Frost polygons o Tectonic activity 0 Rift lakes 0 Graben lakes multiple faults o Volcanic activity BIOE 155 Autumn 2008 PHYSICAL STRATIFICATION AND WATER MOVEMENTS read pp 39 44 50 56 in Dodson In spring the water of the pond is like blue wool endlessly tossing The heavy cold water has sunk to the black bottom of the pond and struck by this weight the bottom water stirs and rises lling the pond s basins with wild nutrition Mary Oliver 1991 as quoted by Dodson VERTICAL STRATIFICATION IN LAKES StratificationiThe study of layers Temperature Lakes often exhibit strong stratification of temperature due to density differences of water Remember that temperature and salinity are the predominant factors that cause density differences in water Thus water that is 4 degree C will sink and warmer and colder temperatures will rise Salty water will sink Key terms for lake strati cation o Epilimnioniupper layer 0 Hypolimnionilower layer 0 Metalimnionitransition zone between the epilimnion and hypolimnion o Thermoclineifound within the metalimnion this is the depth where temperature changes the most rapidly o Isothermalithe same temperature from top to bottom Three example temperature profiles Stratification Reverse stratification Isothermal Temp Temp Temp 0 1o 20 30 o 5 1o 15 20 0 10 20 0 0 o 2 2 2 4 4 4 e e 6 g 8 s s g 10 10 10 3 12 12 12 14 14 14 1e 1e 1e 1s 1s 1s 20 20 20 BIOE 155 Autumn 2008 Isopleth plots are common and useful ways to graph temperature profiles across an entire season Strati cation is in uenced by 0 Time of year 0 Lake depth 0 Fetch o Topography o Solutes Annual mixing patterns 0 Dimicticistratifying twice per year once during summer and once under the ice reverse stratification o Monomicticistratifying once per year This can be stratifying during the summer in lower latitude lakes or stratifying during summer in high latitude lakes 0 AmicticiAlways stratified and not mixing often due to permanent ice cover 0 PolymicticiFrequently mixed Often shallow lakes and tropical lakes 0 MeromicticiLakes that don t mix due to chemicals especially salt Global climate change strongly impacts these seasonal patterns in stratification and mixing Specifically scientists have observed lakes are thawing earlier and freezing later now than over the last 100 years How would expect that these seasonal changes would in uence the seasonal dynamics of lakes BIOE 155 Autumn 2008 WATER MOVEMENTS Water movements occur across multiple scales ranging from microscopic diffusion to kmscale waves or currents Two main factors cause water movements 0 Wind 0 Gravity Diffusionirandom and smallscale movement of water molecules Types of water movements 0 Laminar owiSmooth ows that move water without mixing it o Turbulent owiChaotic flows that result in mixing Whether or not ows are laminar or turbulent depends on the velocity of the water movement TWO KEY NUMBERS FOR UNDERSTANDING WATER FLOWS 1 Reynolds number This ratio of viscosity to inertia forces considers scale and velocity differences in estimating whether currents or movements will be laminar or turbulent Re V1 7 V2 distance or sizekinematic viscosity V equals velocities of the two currents or movement of an object Re lt l viscosity forces dominate Re lt 500 ow will be laminar Regt200 ows will be turbulent 2 Richardson number Ratio of turbulent wind mixing and water s resistance to mixing R is proportional to density differenceswind speed Horizontal Currents Movement of water across the lake Caused by 0 Windidrives water movements of about 2 of wind speed 0 Water inputs such as lakes or streams BIOE 155 Autumn 2008 CHEMICAL NITROGEN AND PHOSPHORUS read pp239250 in Dodson BACKGROUND Lakes are o en classi ed according to trophic status speci cally how much energy or food is available for the lake food web OligotrophiciLow rates of primary productivity These lakes usually have few nutrients and are relatively pristine These lakes are generally characterized by having low light attenuation low nutrients and orthograde oxygen curves Mesotrophicilntermediate rates of primary productivity Eutrophicihigh rates of primary productivity This is generally caused by high levels of nutrient loading Eutrophic lakes are generally characterized by having high nutrients rapid light attenuation and clinograde oxygen curves 0 Cultural eutrophicationiOne of the major human perturbations of freshwaters is eutrophication Eutrophication refers to a lake becoming more productive and exhibiting characteristics of this type of lake rapid light attenuation high rates of primary productivity Excess nutrient inputs generally P drive eutrophication PHOSPHORUS Phosphorus is usually the limiting nutrient in freshwaters Thus understanding the Phosphorus cycle has proved critical in management and conservation of freshwater systems Excess phosphorus is the leading driver of eutrophication There are several lines of evidence that demonstrated that P is the main driver of lake productivity olelake experiment by DW Schindler 1977 Surveys of many lakes that found strong relationships between TP and lake production 0 8 g g 3 MEnN ANNLAL cNmaapNyLL a rugm3 a 25 MEAN ANNUAL TOTAL PnospHoNus mqm Graph DW Schindler 1977 Science BIOE 155 Autumn 2008 Forms of Phosphorus o Soluble Reactive Phosphorus SRP7Dissolved forms of phosphorus that are available for uptake by primary producers Includes organic and inorganic forms eg Orthophosphate Generally around 10 of TP Orthophosphateilnorganic form of phosphate PO43 Orthophosphate is a key form of SRP Dissolved organic phosphorus DOP7Released by organisms livingdead includes ATP Particulate organic phosphorus POP7Phosphorus locked up in living or dead plant and animal matter Particulate inorganic phosphorus PIP7Orthophosphate that has been locked up by other molecules such as calcium iron Fe or magnesium Relatively inert inactive form of P pa eservoirs of Phosphorus o Rocks and soil lithosphereiP is common in many rocks and soils Often found as apatite calcium phosphate Most important reservoir 0 BioticiEspecially in freshwaters a lot of P is found in plants and animals Excretion is a major pathway by which accessible P becomes available 0 Freshwatersisee below A lot P in freshwaters is found in the sediments or in living and dead animal and plant material OceaniA lot of P has been locked up and deposited in sediments of oceans Thus old ocean sediments are often Prich being an important landscapelevel control of P o Atmosphere70ccurs generally as particulate matter in dust Stratificatio Over the summer available P P04 is often depleted in the epilimnion Thus there can be pronounced stratification of P in some lakes RecyclingAnimals play a huge role in cycling P in lakes Fish and zooplankton eat particulate organic phosphorus POP and then excrete soluble P DOP and P04 BIOE 155 Autumn 2008 Phosphorus cycle Inputs of various types Food web Particulate Organic P 1 Pathways 2 T l4 K 1 Excretion 3 Dissolved 4 P04 orthophosphate 2 Uptake organic P 3 Sedimentation I ecom os1tlon DOP 4 D p 39 39 l 3 Fe Ca l Benthic E articulate Organic PO a 1cu a e norganic PIP NITROGEN Nitrogen is the second most likely nutrient to limit primary production in a lake after Phosphorus Nitrogen limitation can develop in a lake when there is excess P input such as due to sewage inputs Forms 0 Nitrogen gas N2 This gas makes up 80 of the atmosphere Thus the atmosphere is a huge reservoir of Nitrogen However it is relatively inert and only some bacteria and lightning can convert NZ to more usable forms such as nitrogen oxides NOxor ammonia NH4 Nitrate N0339 and nitrite NOz39 Nitrate can be used by plants Nitrite can be toxic to life 0 Ammonia NH4 This form is created by nitrogen xation by bacteria or human industry In addition ammonium is often released as a waste product When 02 is present Ammonia oxidizes to Nitrate In water NH3 is ionized to produce NH4 Organic nitrogen Nitrogen is often found as part of organic nitrogen compounds such as amino acids RNH3 Reservoirs 0 Atmosphere This is the dominant reservoir of nitrogen where N2 gas composes 80 of the atmosphere 0 Rocks N can be found in rocks but this is not as important as the atmosphere 0 Oceans N is also found dissolved in ocean water Freshwaters N2 gas dissolves into water but is inert unless transformed during N fixation BIOE 155 Autumn 2008 0 Food webs Like P N is often found within the materials of plants and animals of aquatic food webs Processes that transform N o N xation N2 9 NH4 Nitrogen gas to Ammonia N xation is performed by bacteria alone or in symbiosis Bluegreen algae aka cyanobacteria x nitrogen with special enzymes that only work in the absence of oxygen H eterocysts are morphological adaptations of many bluegreen algae that allow this to happenithickwalled cells without oxygen N xation is energetically costly so generally only happens when nitrogen becomes limiting often due to excess P inputs 0 Nitri cation NH49 NO or N03 Ammonia to NitrateNitrite Happens due to bacteria only in the presence of Oxygen o Denitri cation N039Nz Nitrate to Nitrogen gas Happens in the absence of Oxygen o Assimilation NO39RN Nitrate to organic matter Algae and bacteria take up NH4 ammonia and N03 nitrateishown above to build matter such as amino acids 0 Excretion 9 NH4 ammonia or HNCH32 urea Organisms excrete nitrogen as a waste product of metabolism Vertical strati cation of Nitrogen There can strong seasonal stratification of Nitrogen mainly depending on strati cation of Oxygen which in turn depends on primary production Eutrophic lake Oligotrophic lake 20 o 10 20 0 A 2 A A 4 A A e A A s 2 5 A S 10 A E A 12 A BEmP i 14 A A News gt 2 N03 16 A A A A A Freshwater Ecology BI OE 1 55 FLOW REGIMES AND DAMS read Poff et al 1997 GENERAL THEORY AND BACKGROUND ABOUT DISTURBANCE Disturbanceian episodic event that removes or kills organisms eg wildfire hurricanes waves oods etc Disturbances can be characterized in terms of o Magnitude 0 Frequency 0 Duration Thus disturbances can include small events or large events We might predict that there are frequent small magnitude disturbances and that larger magnitude disturbances are more rare SuccessioniChange in the community following disturbance Impacts of disturbance on diversity Ecological theory predicts that over time competitively dominant species will outcompete the competitive inferior If this is true how can there be so many species For example in lakes Hutchinson termed this the paradox of the plankton Research has shown that one mechanism that may help prevent competitive exclusion is events that keep the community out of equilibriumilike disturbances Intermediate disturbance hypothesis Diversity is highest at an intermediate level of disturbance because this allows both early colonization species and competitive dominants to coexist Connell 1978 Diversity Disturbance frequencyintensity There is some support for this possibility in stream ecosystems Menge Sutherland hypothesis These rocky intertidal 39 39 1r quot 39 A that as J t get harsher the relative impact of topdown control will decrease This assumes that top predators are the least tolerant of environmental conditions and disturbance There is some support for this in freshwater systems from work by Mary Power Freshwater Ecology BI OE 1 55 FLOODS AND FLOW REGIMES Flow regimeithe pattern of ow including oods over time of a given system Quantifying ow regime Stream ow regimes can be characterized similar to other disturbances 0 Degree of intermittency o Perennial streamsistreams that ow yearround o Intermittent streamsistreams that periodically go dry 0 Magnitude o The discharge at a given point and time 0 Frequency 0 How often a ow above a given level occurs For example a lOOyear ood is a ood that reaches a level that on average happens only once every 100 years 0 Duration 0 How long a given magnitude ow occurs 0 Predictability o In some systems high ows are extremely predictable happening at the same time each year Alternatively some systems have unpredictable oods o Flashiness rate of change 0 How quickly ow changes from one magnitude to another magnitude You can understand a lot about a river by examining its ow regime Rivers with different ow regimes have different communities species with different adaptations and different nutrient cycling Impacts of oods on stream communities Given that different organisms have different adaptations to oods and different vulnerabilities the same ood will likely impact different species differently Severe floods often dramatically reduce the abundance of benthic invertebrates and fishes However stream communities generally recover rapidly from floods but it depends on the flood and the stream community Species that are good at colonizing will generally be the first ones to show up These species are usually short lived species that are good at dispersal Refugia from Flood Disturbance 0 Large substrates Dead zones where no shear stress Hyporheic zone Upstream habitats Adult terrestrial phases Freshwater Ecology BI OE 1 55 Impacts of oods on connectivity of streams 0 Longitudinal connectivityiconnections between upstream and downstream habitats o Floods have great power and increase longitudinal connectivity For example they move large woody debris and sediments from the headwaters to lower down in the river 0 Lateral connectivityiconnections between a stream and its oodplain 0 Through periodically inundating oodplains oods connect rivers with the landscape around them This is important for both aquatic and riparian habitats 0 Therefore oods blur the boundaries between aquatic and terrestrial habitats What is dry land one day may be under 10 feet of water the next day Through movements of materials nutrients and animals oods connect rivers to their oodplain Floods are an important selective agent and drive evolution They have stronger selection strength when they are 0 Predictable o Frequent relative to the lifespan of the organism 0 Large in magnitude Lytle and Poff 2004 Adaptations to ooding o Lifehistory o Eg Cottonwood seed release timed to oods o Behavioral o Eg Giant water bugs eeing desert streams after rainfall cues o Morphological o Eg Flattened shape of many benthic invertebrates Flow regimes and species composition 0 Not surprisingly ow regimes will define which species do well in a certain system This will in uence the community composition for both native and invasive species 0 For example Fausch et al 2001 found that ow regime predicted the invasion success of rainbow trout Systems that had ow regimes similar to rainbow trouts native habitat were more likely to be invaded successfully Freshwafer Ecology BIOE I 55 The oodepulse concept i Floods in many natural systems are predictable events Floods cause the predictable advance and retreat of Water onto the oodplain Organisms and ecosystems have evolved in response to them Because organisms are adapted to this oods 0 Increase biological productivity The ood lain 1 W s a LOWER RHINE meme 0 E 5 w E o 0 9 wen Rmn u MlsslSSlPPl momss lnlluancad by nvar 1kg haquotyrl n te mineralizes nutrient o Maintains diversity i i i 5 I I 0 1 5 I1 2 D n 2 0 Yields imm equivalent stable walEr level bodies kghn lyrll From Bayley 1995 This shows Fisheries yields are higher riom ooding rivers ALTERATIONS OF FLOW REGIMES n Y z I z 1 He J quotin quotHy alteration of flow regimes Some scary stats o 172 out of 292 large river systems are affected by dams o There are gt45000 dams over 15 m hi h Holds back N6500 km3 ofWater N15 of global river runoff o Eg Three Gorges Dam on the Yanng River in China 181 m high gt39 km o are an unknown number of smaller dams from Nilsson et al 2005 Freshwater Emlugy BIOE 1 55 History of ow allerau39ons in the US m 7 la nar smmmn mu dams replace Deana mm a mm 5 yamd vmzo rcrenlmnm Army Snip m Engmars wnh w ac mm Mrs nuwgab e mam gnuemmm beam mum ul cumm quotmam an m Mumsqu 525 c mm m En Cam crauunmmnsvnu mm mm me Hudsnn Rivnu lb mm lakes us 350 ssor Swarm ma Mu mnmng 55 nuba am mamas m 15m mmuuemw sum admvmslnlmn 1mm ulnmnage msu M Jg ves Enigmas m mm Im39s sumquot and um mg mmlunus m Inhuluesm he Mussssxwx Enemy um 42nd hm hm Omar u Fivev u 51mm Smk Inn m mvaua vwey 5 mm mus a winmus mm sum 5quot m In Mr 45 Du mu m n mm manual 1m nehmalmn Fm anl m gamma Rac amahan Sam 0 39nnmnuhzz m mm m mam wan 4mm Pawar Aclaumums umm m nunamm hydmpmr ams 1915 quot927 Mmsls nm Rmmuodx pmng em ng nua lnadequale and mum m 192 am Cumm m 1928Cu1mmu a var Canaan mum nanmmwe W s water 193 rmsm Vany Aumnmy Am vases m mm mm an lilsl Mlhpum vm ammrmnlmHMg m m ded camd by FDR my Cumswmmm emu 2mm mecKummg uDDIrMmsxsanl mo an mmcanuneum iwnu 7 mm mgmmng at mm as m m less nm muman mu Hm com m Means mm Damauauan m quotand caner pmml am Isahsnes meanquot a a M p m45 Heavy Ba gmam r u 5 9517795 Buw mg m Mom mam cam aegm an m Mussum Nva 759 mm enunnenm upmmumomm mom m wanest PmacIon am am Frevsuum m uegms Emma sw Cunssrvalmn Sam mvwemsm m epr mums m manmhn mmms quotsea 75m cum mm cumphved 1934 us an Canaan muly Cummma Rerrealy I955 cm sum mm Pmmx appmu Amss 7 mm m Seems wars m pusu m presNu ca am Mu m neevamgcmd lmn ms 7w wan mm pmwdlng mrkm uumallscn e Mdmwwervanem mn uao A sum Cnnsumers onlecmn m amends anew ansr m require FERC m we equal cansxdemucm u mar mum 9mm and En wMNe Mma un and whey asnecks m Enwwvmemal mm mm dim hcensmglehcensmg ma 7 aglslmlun mma mrreamv numhaxn and mm m 2 pnvale uhmson me am Rwer la 155mm m manage 71993 7 mamr mm on Meansxuox Rwereauses exvenswe damage Iaae r Camaued oeu a Colman Huey 31 Gram swam reslnrauun m Evecgla es new 2mm From Poffet a1 1997 BIOE 155 Autumn 2008 OVERVIEW OF CHEMISTRY SOLUBILITY pH REDOX SALINITY read 32 37 231 232 in Dodson INTRODUCTION TO CHEMISTRY 0 Water is a good solvent of various polar chemicals 0 Examples of soluble chemicals include I Acids bases salts sugars alcohols o Freshwater studies generally focus on Carbon I Oxygen I Nitrogen I Phosphorus Remember that there is a strong relationship between water temperature and solubility of gases 0 Higher temperatures 9 lower dissolved concentrations 0 Lower temperature higher dissolved concentrations Chemicals can be quanti ed as I Mass gm I Mass concentrations gmL I Molar concentrations M L I Molar equivalents Chemicals cycle between compartments within freshwaters This cycling can occur very rapidly phytoplankton nutrient uptake or very slowly rock weathering o Compartments can be I different forms of the chemical I different reservoirs Lithosphereiearthrocks lt gt Biota t I Atmosphere lt gt Water Biogeochemistryilargescale cycling of chemicals including living organisms Term developed by Hutchinson 1944 Loadingitotal amount of chemical added per unit time Human activities have globally altered chemical cycling For example increased rates of erosion generally increase loading of nutrients from the lithosphere to freshwaters BIOE 155 Autumn 2008 DISSOCIATION AND PH 0 The water molecule often dissociates into two ions H20 2 H OH39 0 Hydrogen ion H o Hydroxyl ion OH39 0 Two ions are in chemical equilibrium 0 pH 0 A quanti cation of the concentration of hydrogen ions 0 pH logH 0 Acid pH lt 7 0 Alkaline pH gt 7 7 more basic 0 Neutral pH N 7 but this is temperature dependent o Bufferingiability of water to absorb a lot of acid without changing pH 0 Acid rain or acid deposition 0 Wet and dry deposition with excess H o H generally associated with sulfate and nitrate ions 0 SOx productionithe most important source of acid for acid deposition I Sources 0 Fossil fuel burning 70 Tg per year 0 Wildfires 28 Tg per year 0 Volcanoes 78 Tg per year I Worst in NE US and also industrial Europe and China 0 NOx productioniincreasing importance as source of acid as regulation of sulfur emissions increase I Sources 0 Auto exhaust emissions increasingly regulated 0 Coal plants 0 Lightening 0 Factors controlling acidity of freshwaters 0 Hydrogen ion loading 0 Acid Neutralizing Capacity ANC7ability of water to absorb a lot of acid without pH In other words the water is wellbuffered I Calcium carbonate is the dominant source of ANC I Granitic soilsilittleno buffering capacity I Limestone lots 0 calcium carbonateihigh buffering capacity 0 Biological alkalinity generation I Alkalinity production can buffer lakes 0 Acidity of water controls which organisms can thrive o DW Schindler 1985 did a wholelake experiment demonstrating the dramatic impacts of acidity on lake communities BIOE 155 Autumn 2008 pH of Rainfall 1993 m 1 339 7397 REDOX POTENTIAL 0 Different chemical reactions can take place in oxygenated water vs anoxic water water wo oxygen 0 Redoxiquantifies the potential for reductionoxidation reactions I Oxidation reactionsiincrease positive charge loss of electrons few available free electrons o Occurs in the presence of oxygenated water e g Fe ferrous ironisoluble 9 Fe fenic ironiinsoluble I Reduction reactionsibecome more negatively charged SALINITY AND OTHER DISSOLVED CHEMICALS IN WATER I Salinityitotal concentration mgL of ions dissolved in water I Common ions salt include I Calcium Ca I Magnesium Mg I Bicarbonate HCO3 I Sodium Na
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