To:GeneralBiologyStudents Fr:Mrs.GeorgoDate:April27,2020Re:AssignmentsforApril27–May15(Packet#3)-Ecology

Reminders:

-First,Ihopeyouandyourfamiliesaredoingwell.-Yourassignmentsarepostedhere:Granby’swebpage/OurSchool/LearninginPlace/Science/Georgo/GeneralBiology(thispacketwaspreparedbythedistrictlikethepreviousones)-ThesesameassignmentsarealsopostedonGoogleClassroom.-Whatyou’vedonesofarsinceschoolsclosedonMarch16th:*Assignmentpacket#1(classification,bacteria&viruses,J-labs)-March17-April3*Assignmentpacket#2(evolution)-April6-24-Assignmentpacket#3(current)isonEcology.-April27-May17*Besureyoureadthepassagesbeforeyoustartworkingonthewrittenworkthatfollows.-Ifyou’reable,pleasegotoGoogleClassroomtodoyourassignments(usetheaccesscodesIgaveyou).Ifyouneedaprintedpacketfromschool,pleasewaitfortheemail/websiteannouncementofdatesandtimesofdistribution.-Pleasecontinuetocheckyourschoolemailregularly.Ihavesentseveralemails(studentsandparents)sinceMarch17th.-E-mailmeifyouhavequestions,concerns,orjokes.-Lastly,butmostimportantreminder,takecareofyourself,keepyourmindstimulated,andenjoylearning.

NorfolkPublicSchoolsScienceLearninginPlacePlan:BiologyLessons

Week7:April27–May1,2020(CarryCapacities)

Monday Tuesday Wednesday Thursday Friday

PopulationGrowthAssignments:• Readpages:1-3• CompleteReadingCheck#1-3

PopulationGrowthAssignments:• Rereadpages1-3• CompeteReadingCheck#4• CompleteActivity#1Usevocabularytermstocreateamatchingactivity.Studytermsthensolve.

HumanPopulationGrowthAssignments:• Readpg. 4• CompleteReadingCheck#5CensusOpinionQuestion

• CompleteActivity#2HumanPopulationGrowthGraphingActivity

HumanPopulationGrowthAssignments:• Re-readpgs.#1-5• CompleteActivity#3Mystery

LogoandSloganActivity

PopulationGrowthReviewAssignments:• Re-readpgs.#1-5 • Activity#4Writeasummary

Week8:May4–8,2020(Patterns&Cycles)

Monday Tuesday Wednesday Thursday Friday

NutritionandEnergyFlowAssignments:• Readpgs.#6-8• CompleteReadingcheck#6-9• CompleteActivity#5:EnergyFlowTable

OrganismsandEnvironmentAssignments:• Readpg.#9• CompleteReadingCheck#10• CompleteActivity#6:Pyramid• CompleteActivity#7:Matching

SuccessionAssignments:• Readpg.#11• CompleteReadingCheck#11• CompleteActivity#8VocabularyReview:Matching

CyclesofMatterAssignments:• Readpgs.#13-14• CompleteReadingCheck#12• CompleteActivity#9:Cycles-ImportantFacts

CyclesofMatterAssignments:• Re-readpgs.#6-14• Activity#10List10importantfacts

Week9:May11–15,2020(NaturalEvents&VirginiaEcosystems)

Monday Tuesday Wednesday Thursday Friday

HumanImpactAssignments:• Readpg.#15• CompleteReadingCheck#13

HumanImpactAssignments:• Re-readpg.#15• Readpg.#16• CompleteReadingCheck#14-15

ChesapeakeBayandHumanImpactAssignments:• Readpgs.#17-18• CompleteReadingCheck#16• CompleteActivity#11:HumanImpact

TheBayTodayAssignments:• Readpgs.#19-20• CompleteReadingCheck#17• CompleteActivity#12:PositiveorNegativeImpact

RestoringtheBayAssignments:• Readpg.#21• CompleteReadingCheck#18• CompleteActivity#13:Letter

1

PopulationGrowth

PrinciplesofPopulationGrowth

Everyorganismisamemberofapopulation.Apopulationisagroupoforganismsofthesamespeciesthatliveinaspecificarea.Whenindividualsmoveintoapopulationitiscalledimmigration.Youmayhaveapopulationofgrassinyourbackyard.Therealsomaybeapopulationofantsthere.Youmayevenhaveapopulationofbacteriaonyourbathroomdoorhandle.Populationsgrow,die,increase,anddecrease.Factorsthataffectthegrowthrateofpopulationsincludefood,space,disease,andpredators.Scientistshavediscoveredthatpopulationsoforganismstendtogrowinthesameway.Populationsstartbygrowingslowly.Inthebeginning,therearejustafeworganismsthatreproduce.Soontherateofpopulationgrowthincreasesbecausetherearemoreorganismsreproducing.

Howdopopulationsgrow?

Scientistsusegraphstoshowhowpopulationsgrow.ThegraphofagrowingpopulationlookslikeaJ-shapedcurve.TheflatpartoftheJshowsslowgrowth.ThepartoftheJthatrisesshowsrapidgrowth.TheJ-shapedcurveisapictureofexponentialgrowth.Exponentialgrowthmeansthatasapopulationgetslarger,itgrowsatafasterrate.Forexample,youmayhaveonedandelioninyourbackyard.Afewweekslateryoumayhavetwentydandelions.Afewweeksafterthatyoumayhavehundredsofdandelions.Thereasonisexponentialgrowth.Onedandelionproducesmanyseeds.Twentydandelionsproducehundredsofseeds.Canpopulationsgrowandneverstopgrowing?No,therearefactorsthatslowdownorlimitgrowth.Thesearecalledlimitingfactors.Theeffectsoflimitingfactorsalsocanbeshownonagraph.TheJ-shapedcurvebeginstolooklikeanS-shapedcurveaspopulationgrowthslowsorlevelsoff.Whenpopulationsrunoutoffoodorspace,growthstartstoslowdown.Populationgrowthalsoslowswhendiseaseorpredatorsattackpopulations.Whenindividualsmoveoutofapopulationitiscalledemigration.Later,youwillreadaboutotherreasonswhypopulationgrowthslows.

Whatisanenvironment’scarryingcapacity?

Thecarryingcapacityofanenvironmentisthenumberoforganismsofonespeciesthatcanbesupportedforanunlimitedamountoftime.Untilcarryingcapacityisreached,therearemorebirthsthandeathsinthepopulation.Ifapopulationgrowslargerthanthecarryingcapacityoftheenvironment,therewillbemoredeathsthanbirths.Thenumberoforganismsinapopulationissometimesmorethantheenvironmentcansupportandsometimeslessthantheenvironmentcansupport.

2

ReadingCheck#1

Howdoesthenumberoforganismsinanareaaffectpopulationgrowth?______________________________________

PopulationGrowth

Density,orthenumberoforganismsinagivenarea,affectspopulationgrowth.Factorsthatarerelatedtothedensityofthepopulationarecalleddensity-dependentfactors.Theyincludedisease,competition,predators,parasites,andfood.Thesefactorsbecomemoreimportantasthepopulationincreases.Forexample,whenmembersofapopulationlivefarapart,diseasespreadsslowly.Whenthemembersliveclosetogether,diseasespreadsquickly.Thisistrueforbothplantsandanimals.Itistrueforpopulationsofpeople.Somescientiststhinkthatthepresenceofcontagiousdiseasesinpopulationsisalimitingfactorinthegrowthofthosepopulations.Density-independentfactorsaffectpopulations,nomatterhowlargeorsmall.Density-independentfactorsincludevolcaniceruptions,temperature,storms,floods,drought,chemicalpesticides,andmajorhabitatdisruption.Imagineapondcontainingapopulationoffish.Ifadroughtcausedthepondtodryup,thenthatpopulationoffishwoulddie.Itwouldnotmatteriftherewere10or100fishinthepond.Droughtisadensity-independentfactor.Humanpopulationsalsocanbeaffectedbydensityindependentfactors.Riverssometimesoverflowtheirbanksafteraheavyrain.Ifatownisflooded,itdoesnotmatterhowmanypeopleliveinthetown;everyonefeelstheeffectsoftheflood.

OrganismInteractionsLimitPopulationSize

Populationsalsoarelimitedbycontactwithotherorganismsinacommunity.Therelationshipbetweenpredatorandpreyisagoodexample.Scientistsobservecyclesofpopulationincreasesanddecreases.Somearequiteregularandpredictable.AnexampleistheinteractionofthesnowshoehareandtheCanadianlynx.Thelynx,amemberofthecatfamily,eatsthesnowshoehare.Asyoucansee,predatorpopulationsaffectthesizeofpreypopulations.Usuallythelynxpopulationcatchestheyoung,old,injured,orsickmembersoftheharepopulation.Thismakesmoreresourcesavailablefortheremaininghealthymembersoftheharepopulation.

ReadingCheck#2

WhydidthebrowntreesnakepopulationonGuamincreaseunchecked?

Istherecompetitionamongmembersofthesamepopulation?

Thelynxandharearemembersofdifferentpopulations,butmembersofthesamepopulationalsointeractwitheachother.Populationscanincreasesothatmembersarecompetingforfood,water,andterritory.Competitionisadensity-dependentfactor.Whenonlyafewindividualsneedtheavailableresources,thereisnoproblem.Whenthepopulationbecomessolargethatdemandforresourcesisgreaterthanthesupplyofresources,thepopulationsizewilldecrease.Sometimespopulationsbecomecrowdedandorganismsbegintoshowsignsofstress.Individualanimalsmaybecomeaggressive.Theymaystopcaringfortheiryoungorevenlosetheirabilitytobearyoung.Stressalsomakesanimalsmoreatriskfordisease.Allofthesestresssymptomsarelimitingfactorsforgrowth.Theykeeppopulationsbelowcarryingcapacity

3

Density-Dependent

1.

2

3

Density–Independent

1

2.Population

Growth3.

PopulationGrowth

ReadingCheck#3

VocabularyCheck:

Term Definition HowamIgoingtoRemembertheMeaning

population

immigration

J-shaped curve

exponential growth

limiting factors

S-shaped curve

emigration

carrying capacity

density-dependent factors

density-independent factors

competition

ReadingCheck#4

Thewebdiagrambelowidentifiestwofactorsthataffectthegrowthofpopulations.Writethreeexamplesofeachfactorinthediagram.(Refertothereading.)

4

Activity#1MatchingforVocabularyTerms

Createamatchingactivityusingthevocabularytermsabove.Studytermsthencomplete.

HumanPopulationGrowth

Acensus,whichcountsallthepeoplewholiveinacountry,istakeneverytenyearsintheUnitedStates.Italsocollectsinformationaboutwherepeopleliveandtheireconomiccondition.TheUnitedNationskeepssimilarinformationforeachcountryintheworld.Thestudyofinformationabouthumanpopulationsiscalleddemography(deMAHgrafee).Informationaboutpopulationsincludessize,density,distribution,movement,birthrates,anddeathrates.Humanpopulationhasgrownatarapidrateinrecentyears.Scientistsestimatethatittookfromthetimeofthefirsthumansto1800fortheworldhumanpopulationtoreach1billion.In1930,therewere2billionpeople.In1999,therewere6billionpeople.Ifthisratecontinues,scientistsestimatethatin2050therewillbe9billionpeopleonEarth.

ReadingCheck#5

Whatisyouropinionon2020censusandtheimpactthecoronaviruswillhaveonoureconomicconditions?

Whatfactorsaffectthegrowthofhumanpopulations?

Rememberthatpopulationscankeepgrowingaslongastheyhaveenoughresources.Humanpopulationsaredifferentfromotherpopulationsbecausehumanscanconsciouslychangetheirenvironment.Humanscangrowtheirownresourcesbyfarmingandraisingfarmanimals.Humanscancontrollimitingfactorssuchasdisease.Manyillnessesthatkilledpeopleinthepastcannowbetreatedwithmedicine.Peoplelivelongerandtheyareabletoproducemorechildren.Thechildrengrowupandtheyproducemorechildren,causingthepopulationtogrow.

Activity#2HumanPopulationGrowthandCarryingCapacity

Step1-CreateHumanPopulationGrowthGraphDirections:Usethefollowingdatatographthehumanpopulationstartingintheyear1650.Scalethex-axisfromyears1650through2050,andthey-axisfrom0to8billionpeople.Makesurethatyou1)labelyouraxis,2)scaletheaxessothatitusesmostofthegraph,3)plotthepoints,4)drawabest-fitline;and5)provideatitleforyourgraph.

YearA.D #ofPeople(inbillions)

1650 .501750 .701850 1.01925 2.01956 2.51970 3.61980 4.01991 5.52000 6.02004 6.42008 6.72011 6.9

5

HumanPopulationGrowth

Step2-AnswerAnalysisQ’saftercreatingthegraph.Ittook1,649yearsfortheworldpopulationtodoublefrom.25billionpeopleto.50billionpeople.

1. Howlongdidittakeforthepopulationtodoubleasecondtime? 2. Accordingtothisinformation,thehumanpopulationhasincreased/decreased(circleone)ata

decelerated/acceleratedrate(circleone).3. Basedonyourgraph,inwhatyearwillthepopulationreach8billion?

Activity#3ChapterMystery

Aplagueofrabbits

WhenanAustralianfarmerreleased24wildEuropeanrabbitsonhisfarm,thingsgotoutofcontrol.

Designalogoandsloganthatwarnspeopleofdangersofintroducingnewspecies.

Activity#4:Summary(5sentences)

Writeasummaryonhumanpopulationgrowth.Includelimitingfactorsandpredictthecarrycapacityifthepopulationcontinuestogrowatitscurrentrate.LastincludeyouropinionontheimpactofCovid-19on2020Censuscountofthepopulation.

6

NutritionandEnergyFlow

HowOrganismsObtainEnergy

AutotrophsTheultimatesourceofenergyforalllifeisthesun.Plantsusethesun’senergytomakefood.Thisprocessiscalledphotosynthesis(fohtohSINthuhsuhs).Thismakesplantsautotrophs.Autotrophs(AWtuhtrohfs),orproducers,areorganismsthatuselightenergyorenergystoredinchemicalcompoundstomakeenergy-richcompounds.Grass,trees,andotherplantsarethemostfamiliarautotrophs,butsomeone-celledorganisms,suchasgreenalgae,alsomaketheirownfood.

HeterotrophsSomeorganismscannotmaketheirownfood.Theymusteatotherorganismstogettheirfoodandenergy.Theseorganismsarecalledconsumers,orheterotrophs(HEtuhruhtrohfs).Someheterotrophs,suchasrabbits,feedonlyonautotrophs.Otherheterotrophs,suchaslions,feedonlyonotherheterotrophs.Stillotherheterotrophs,suchasbearsandhumans,feedonbothautotrophsandheterotrophs.

DecomposersThereareotherorganismscalleddecomposers.Theybreakdownthecomplexcompoundsofdeadanddecayingplantsandanimals.Theychangethesecompoundsintosimplerformsthattheycanuseforfuel.Someprotozoans,manybacteria,andmostfungiaredecomposers.

ReadingCheck#6

Defineautotrophsandheterotrophsinyourownwords.

Autotrophs:

Heterotrophs:

Decomposers:

FlowofMatterandEnergyinEcosystems

Whenyoueatfood,suchasanapple,youconsumematter.Matter,intheformofcarbon,nitrogen,andotherelements,flowsthroughthelevelsofanecosystemfromproducerstoconsumers.Scientistscallthisflowofmattercycling.Theappleismorethanmatter,though.Italsocontainssomeenergyfromsunlight.Thisenergywastrappedintheappleasaresultofphotosynthesis.Asyoucyclethematterintheapplebyeatingit,sometrappedenergyistransferredfromoneleveloftheecosystemtothenext.Ateachlevel,acertainamountofenergyisalsotransferredtotheenvironmentasheat.

Whatarefoodchains?

Ecologistsstudyfeedingrelationshipsandsymbioticrelationshipstolearnhowmatterandenergyflowinecosystems.Thesescientistssometimesuseasimplemodelcalledafoodchain.Foodchainsshowhowmatterandenergymovethroughanecosystem.Inafoodchain,nutrientsandenergymovefromautotrophstoheterotrophsto,intheend,decomposers.Afoodchainisdrawnusingarrows.Thearrowsshowthedirectioninwhichenergyistransferred.Anexampleofasimplefoodchaininaforestecosystemisshownbelow.Mostfoodchainsaremadeupoftwo,three,orfourtransfers,orsteps.Eachorganisminafoodchainrepresentsafeedingstep,ortrophic(TROHfihk)level,inthetransferofenergyandmatter.Theamountofenergyinthelasttransferisonlyasmallpartofwhatwasavailableatthefirsttransfer.Ateachtransfer,someoftheenergyisgivenoffasheat.

7

NutritionandEnergyFlow

Activity#5

Usethetablebelowtohelpyoureviewwhatyouhaveread.Foreachoftheorganismsshowninthefoodchain,choosethreefactsfromthelistbelowthetablethataretrue.Thenwritethefactsinthetableunderthecorrectorganism.

Grass Rabbit Wolf

Performsphotosynthesisonsecondtrophicleveleatsautotrophs

Primaryheterotrophautotrophsonthirdtrophiclevel

Secondaryheterotropheatsotherheterotrophsonfirsttrophiclevel

Readingcheck#7Howdoesenergyflowthroughanecosystem?_____________________________________________________________________________________________

Whatisafoodweb?

Afoodchainshowsonlyonepossiblepathforthetransferofmatterandenergythroughanecosystem.Manyotherpathsmayexistbecausemanydifferentspeciescanbeoneachtrophiclevel.Theblackbear,forinstance,doesnoteatonlymice.Italsoeatsberries.Therealsoareotheranimalsintheforestthateatberriesandmice.Foodwebsaremodelsthatshowallpossiblefeedingrelationshipsateachtrophiclevelinacommunity.Afoodwebisamorerealisticmodelthanafoodchainbecausemostorganismsdependonmorethanonetypeoforganismforfood.

Readingcheck#8

Comparefoodchainstofoodwebs.

Similarities Differences

8

NutritionandEnergyFlow

TransferofEnergy

Therearethreebroadcategoriesofecosystemsbasedontheirgeneralenvironment:freshwater,marine,andterrestrial.Withinthesethreecategoriesareindividualecosystemtypesbasedontheenvironmentalhabitatandorganismspresent.Foodchainsandfoodwebsdealwithbothmatterandenergy.Whenecologistswanttofocusonlyonenergy,theyuseanothertypeofmodel—anecologicalpyramid.Anecologicalpyramidshowshowenergyflowsthroughanecosystem.Energyflowsthroughanecosysteminonedirection,fromsunorinorganiccompoundstoautotrophs(producers)andthentovariousheterotrophs(consumers).Therearedifferenttypesofecologicalpyramids.Eachpyramidhastheautotrophs,orfirsttrophiclayer,atthebottom.Highertrophiclayersarethenlayeredontopofoneanother.Thepyramidofenergyshowsthattheamountofavailableenergybecomeslessfromonetrophicleveltothenext.Thetotalenergytransferfromonetrophicleveltothenextisonlyabouttenpercentbecauseorganismsdonotuseallthefoodenergyinthetrophiclevelbelowthem.Anorganismusesenergytodoallthethingsnecessaryforlife.Organismsuseenergytomove,tointeractwiththeirenvironment,andtodigesttheirfood.Theyalsouseenergytobuildbodytissue.Someofthisenergyisgivenoffasheat.Thelawofconservationofenergystatesthatenergyisneitherlostnorgained.Eventhoughsomeoftheenergytransferredateachtrophiclevelenterstheenvironmentasheat,itisstillenergy.Itisjustinadifferentform.Apyramidofnumbersshowsthenumberoforganismseatenbythelevelaboveit.Inmostcases,thenumberoforganismsdecreasesateachhighertrophiclevel.

Biomassisthetotalweightoflivingmatterateachtrophiclevel.Apyramidofbiomassshowsthetotaldryweightoflivingmaterialateachtrophiclevel.CyclesinNatureMatter,intheformoffood,movesthrougheveryorganism.Inthisway,matterisfoundateverytrophiclevel.Matterisnevermadeordestroyed.Itjustchangesformasitcyclesthroughthedifferenttrophiclevels.ThereisthesameamountofmattertodayastherewaswhenlifeonEarthbegan.

Readingcheck#9

Whatiseachlevelonapyramidcalled?

Whatpercentofenergyistransferredfromeachlevel?

Whataresomelifeprocessesthatrequireenergy?

9

OrganismsandTheirEnvironment

Whatisecology?

Thebranchofbiologythatdevelopedfromnaturalhistoryisknownasecology.Ecologyisthestudyofrelationshipsbetweenorganismsandtheirenvironment.Ecologistsusebothqualitativeandquantitativeresearch.

Whatplacedoesaspecieshaveinitshabitat?

Thoughseveralspeciesmayshareahabitat,thefood,shelter,andotherneededitemsinthathabitatareoftenusedindifferentwaysbyeachspecies.Forexample,ifyouturnoveralog,youmayfindacommunityofmillipedes,centipedes,insects,slugs,andearthworms.Eachspecieshasitsownniche.Aniche(neesh)isallstrategiesandadaptationsaspeciesusesinitsenvironment.Itishowthespeciesmeetsitsspecificneedsforfoodandshelter.Itishowandwherethespeciessurvivesandreproduces.Aspecies’nicheincludesallitsinteractionswiththebioticandabioticpartsofitshabitat.Twospeciescannotexistforlonginthesamecommunityiftheybothhavethesameniche.Thereistoomuchcompetition.Intheend,onespecieswillgaincontrolovertheresourcesinthecommunity.Theotherspecieswilleitherdieoutinthatarea,movesomewhereelse,orchangeinsomewaytofillanotherniche.

Symbiosis

Peopleoncethoughtthatanimalsinthesameenvironmentfoughteachotherforsurvival.Inreality,mostspeciessurvivebecauseoftherelationshipstheyhavewithotherspecies.Arelationshipinwhichthereisacloseandpermanentassociationbetweenorganismsofdifferentspeciesiscalledsymbiosis(sihmbeeOHsus).Symbiosismeanslivingtogether.Therearethreemajorkindsofsymbiosis—mutualism,commensalism,andparasitism.Mutualism(MYEWchuhwuhlihzum)isarelationshipbetweentwospeciesthatlivetogetherinwhichbothspeciesbenefit.Therelationshipbetweenantsandanacacia(uhKAYshuh)treeisagoodexampleofmutualism.Theantsprotectthetreebyattackinganyanimalthattriestofeedonthetree.Thetreeprovidesnectarasafoodfortheants.Thetreealsoprovidesahomefortheants.Inanexperiment,ecologistsremovedtheantsfromsomeacaciatrees.Resultsshowedthatthetreeswithantsgrewfasterandlivedlongerthanthetreeswithnoants.Commensalism(kuhMENsuhlihzum)isarelationshipinwhichonlyonespeciesbenefitsandtheotherspeciesisnotharmedorhelped.Forexample,mossessometimesgrowonthebranchesoftrees.Thisdoesnothelporhurtthetrees,butthemossesgetagoodhabitat.Parasitism(PERuhsuhtihzum)isarelationshipinwhichamemberofonespeciesbenefitsattheexpenseofanotherspecies.Forinstance,whenaticklivesonadog,itisgoodforthetickbutbadforthedog.Thetickgetsfoodandahome,butthedogcouldgetsick.Thetickisaparasite.Aparasiteistheorganismthatbenefitsfromtherelationship.Thedogisahost.Thehostistheorganismthatisharmedbytherelationship.

ReadingCheck:#10

1. Whatisthedifferencebetweenbioticandabioticfactors?List3examplesofeach.

2. Completethetablebelow.SymbioticRelationships Description ExamplesMutualism

Commensalism

Parasitism

10

Activity#6

Usethepyramiddiagrambelowtohelpyoureviewwhatyouhaveread.Listthefourlevelsthatecologistshaveorganizedthelivingworldinto.Startwiththeleastcomplexlevelatthebottomandworkyourwayup.

Community,ecosystem,species,population

Activity#7

InColumn1aresomenewconceptsyoulearnedaboutinthissection.Column2givesoneexampleofeachconcept.Usethelinenexttoeachconcepttoputtheletteroftheexamplethatmatchesit.

NewConcept Examples

1.Abioticfactor a.anowleatingamouse

2.Habitat b.rainforest

3.Predator-preyrelationship c.rain

4.Biologicalcommunity d.atickonacat

5.Parasitism e.insects,earthworm,slugsunderalog

11

Succession

ChangesoverTimeSuccession(sukSEshun)istheprocessofgradual,naturalchangeandspeciesreplacementthattakesplaceinthecommunitiesofanecosystemovertime.Therearetwotypesofsuccession—primaryandsecondary.Theabilityoflivingthingstosurvivethechangesintheirenvironmentiscalledtolerance.Anorganismreachesitslimitsoftolerancewhenitgetstoomuchortoolittleofanenvironmentalfactor.Forexample,cornplantsneedwarm,sunnyweatherandaregularsupplyofwater.Iftheseconditionsdonotexistoveralongperiodoftime,theplantsmaysurvive,buttheywillnotproduceacrop.Thefigureaboveshowstherangeoftolerancefororganisms.

Whatisprimarysuccession?

Primarysuccessiontakesplaceonlandwheretherearenolivingorganisms.Forexample,whenlavaflowsfromavolcano,itdestroyseverythingaroundit.Whenitcools,landforms,buttherearenolivingorganismsinthenewland.Thefirstspeciestoliveinsuchanareaiscalledapioneerspecies.Decayinglichens,alongwithbitsofsedimentincracksandcrevicesofrock,makeupthefirststageofsoildevelopment.Gradually,otherlifeformstakehold.Aftersometime,primarysuccessionslowsdownandthecommunitybecomesstable.Pioneerspecieseventuallydie.Oncelittleornochangeoccurs,thecommunityiscalledaclimaxcommunity.Aclimaxcommunitycanlastforhundredsofyears.

Whatissecondarysuccession?

Secondarysuccessionisthepatternofchangesthattakesplaceafteranexistingcommunityisdestroyed.Thedestructioncanbecausedbyaforestfireorwhenafieldisplowedoverandnotreplanted.Duringsecondarysuccession,asinprimarysuccession,organismscomeintotheareaandchangegradually.But,becausesoilalreadyexists,thespeciesinvolvedinsecondarysuccessionaredifferentfromthoseinprimarysuccession.Secondarysuccessionmaytakelesstimethanprimarysuccessiontoreachthestageofaclimaxcommunity.

Whatisalimitingfactor?

Anythingthatlimitsanorganism’sabilitytoliveinaparticularenvironmentisknownasalimitingfactor.Forexample,inmostmountainareas,thereisatimberline.Treescannotgrowabovethetimberline.Itistoohigh,toocold,toowindy,andthesoilistoothin.Somethingthatlimitsonepopulationinacommunitycanhaveanindirecteffectonanotherlifeform.Alackofwatercouldcausegrasstodieinanarea.Ifananimalgrouplivinginthatareadependsongrassforfood,itspopulationcoulddecreaseasaresult.

12

Succession

Readingcheck:#11

1. Whatissuccession?

2. Howdoeslimitingfactorsaffectsuccession?

3. Whatarepioneerspecies?

4. Afteraflooddestroyseverythinggrowingontheland,whichtypeofsuccessionismostlikely?

Activity#8

Importantvocabularyreview:

a.climaxcommunity b.limitingfactors c.pioneerspecies d.secondarysuccession e.tolerance

thefirstorganismstogrowonanewpatchofcooled,hardenedlava

weedsandwildflowersbeginningtogrowinafieldafteracorncropisharvested

abilityofmosquitoestosurviveinverydifferentconditionsallovertheworld

coldtemperaturesandhighwindsthatpreventtreegrowthinmountainareas

anoldforestthathasnothadanyfiredamageinover200years

13

CyclesinNatureMatter

Intheformoffood,movesthrougheveryorganism.Inthisway,matterisfoundateverytrophiclevel.Matterisnevermadeordestroyed.Itjustchangesformasitcyclesthroughthedifferenttrophiclevels.ThereisthesameamountofmattertodayastherewaswhenlifeonEarthbegan.Unliketheonewayflowofenergy,matterisrecycledwithinandbetweenecosystems.

Whatisthewatercycle?

Wateralsocyclesthroughdifferentstages.ItisalwaysmovingbetweentheatmosphereandEarth.Forinstance,whenyouleaveaglassofwateroutforafewdays,someofitseemstodisappear.Ithasevaporatedorchangedintowatervaporintheair.Similarly,waterfromlakesandoceansevaporates.Atsomepoint,thiswatervaporcondenses,orcomestogether,andmakesclouds.Afterevenmorecondensation,dropsofwaterform.ThiswaterthenfallsbacktoEarthasrain,ice,orsnow.

Whatisthecarboncycle?

Carbonhasitsowncycle.AlllifeonEarthisbasedoncarbon,andalllivingorganismsneedcarbon.Thecarboncyclestartswithautotrophs.Inphotosynthesis,autotrophsusethesun’senergytochangecarbondioxidegasintoenergy-richformsofcarbon.Autotrophsusethiscarbonforgrowthandenergy.Heterotrophsthenfeedonautotrophsorfeedonotheranimalsthathavealreadyfedonautotrophs.Theheterotrophsthenusethecarbonforgrowthandenergy.Asautotrophsandheterotrophsusethiscarbon,theyreleasecarbondioxideintotheair.Thecarboncyclecontinuesveryslowly.Howrapidlyitcyclesdependsuponwhetherthecarbonisfoundinsoil,leaves,roots,inoilorcoal,inanimalfossils,orincalciumcarbonatereserves.

Whatisthenitrogencycle?

Nitrogenisanotherelementimportanttolivingthings.Although78percentofairisnitrogen,plantscannotusethisformwell.Therearebacteria,though,thatchangethenitrogenfromairtoaformplantscanbetteruse.Bacteriatransformnitrogengasintoammoniainaprocesscallednitrogen-fixation.Thisformisfoundinthesoil.Plantsusethisnitrogentomakeproteins.Animalseattheplantsandchangetheplantproteinsintoanimalproteins.Theseproteinsareusedinbuildingmuscleandbloodcells.Urineisananimalwastethatletsanimalsgetridofnitrogentheydonotneed.Thisurinereturnsnitrogentothesoil.Whenorganismsdieanddecay,nitrogenreturnstothesoil.Plantsthenreusethisnitrogen.Soilbacteriaalsoactonthesedeadorganismsandputnitrogenbackintotheair.Inthisway,nitrogenisalwayscyclingthroughthesystem.

14

CyclesofMatter

Whatisthephosphorouscycle?

Phosphorusalsocyclesthroughecosystems.Itisanotherelementthatallorganismsneed.Itcyclesintwoways.Intheshort-termcycle,plantsgetphosphorusfromthesoil.Animalsgetphosphorusfromeatingplants.Whentheseanimalsdie,theirdecayingbodiesreleasephosphorusbackintothesoiltobeusedagain.Inthelong-termcycle,materialscontainingphosphorusarewashedintoriversandoceans.Asmillionsofyearspass,thephosphorusbecomeslockedinrocks.Millionsofyearslater,astheenvironmentchanges,someoftherockisnolongercovered.Asthisrockwearsaway,thephosphorusisreleasedbackintotheatmosphere.

Readingcheck#12

1. Whattypeoforganismschangenitrogenintheairintoaformplantscanbetteruse?_____________________2. Whereismostofthephosphorusstoredinthebiosphere?_____________________

Activity#9

Inthechartbelowsummarizethebenefitsofeachcycleontheecosystem.

Cycles ImportantFacts

WaterCycle

CarbonCycle

NitrogenCycle

PhosphorusCycle

Activity#10:Write10Facts

1. 2. 3. 4. 5.

6.__________________________________________________________________________________7.__________________________________________________________________________________8.__________________________________________________________________________________9.__________________________________________________________________________________10.__________________________________________________________________________________

15

NaturalEvents&Virginia’secosystems

HumanImpact

Asthehumanpopulationincreases,sodoeshumanimpactontheenvironment.Humanactivities,suchasreducingtheamountofforestcover,increasingtheamountandvarietyofchemicalsreleasedintotheenvironment,andintensivefarming,havechangedEarth’sland,oceans,andatmosphere.Someofthesechangeshavedecreasedthecapacityoftheenvironmenttosupportsomelifeform.Humansdependonotherorganisms.Peoplerelyonplantsandanimalsforfood.Peoplealsorelyonplantsforwood,cotton,andmanytypesofmedicaldrugs.Thesearejustafewexamplesofhowpeopledependonanimalsandplants.Ifbiodiversitycontinues,peoplewillalwayshaveasupplyoflivingthings.Oneday,drugstocurecancerorHIVmightevenbefoundinsomeoftheselivingthings.

LossofBiodiversity

Biodiversitycanbelostwhenspeciesbecomeextinct.Extinction(ekSTINGKshun)isthedisappearanceofaspecieswhenthelastofitsmembersdies.Acertainamountofnaturalextinctiongoesonallthetime.Butnowitseemsthatmorethanusualisoccurring.Thiscouldbeduetoadifferencebetweenhumanneedsandavailableresources.Aspeciesisconsideredtobeanendangeredspecieswhenitsnumbersbecomesolowthatextinctionispossible.Whenaspeciesislikelytobecomeendangered,itiscalledathreatenedspecies.Africanelephantsareoneexampleofathreatenedspecies.

ThreatstoBiodiversity

Thecomplexinteractionsamongspeciesmakeeachecosystemunique.Withineachecosystemeveryspeciesisusuallywelladaptedtoitsspecifichabitat(theplacewhereaspecieslives).Thismeansthatchangestoaspecies’habitatcanthreatenthespecieswithextinction.Infact,habitatlossisoneofthebiggestreasonsfordeclineinbiodiversity.HabitatLossoneexampleofhabitatlossisintheAmazonianrainforest.Inthe1970sand1980s,thousandsofhectaresoflandwereclearedforfirewoodandfarming.Clearingthelanddestroyedmanyhabitats.Noneofthemcanbebuiltupagaineasily.Withoutthesehabitats,someplantsandanimalsmaybecomeextinct.

HabitatDegradation

Habitatdegradationisanotherthreattobiodiversity.Habitatdegradationisdamagetoahabitatcausedbyair,water,orlandpollution.Airpollutioncancausebreathingproblems.Itcanalsoirritatetheeyesandnose.Acidprecipitation—rain,snow,sleet,andfogwithlowpHvalues—hasdamagedsomeforests,lakes,statues,andbuildings.Acidprecipitationformswhenpollutantsintheaircombinewithwatervaporintheair.WhentheseacidicdropletshitEarth,themoisturetakesnutrientsoutofthesoil.Withoutthenutrients,manyplantsbecomesickanddie.TheSungivesoffwaves,calledultravioletwaves,whichcandamagelivingthings.Earthhasanareainitsatmosphere,between15kmand35kmaltitude,calledtheozonelayer,whichabsorbssomeoftheseultravioletwavesbeforetheyreachEarth.Pollutionhasdamagedtheozonelayer.TodaymoreultravioletwavesreachtheEarththaninthepast.OversomepartsofAntarctica,theamountofozoneoverheadisreducedbyasmuchas60percentduringtheAntarcticspring.Thisseasonalreductionofozoneiscausedbychemicalssuchaschlorofluorocarbons(CFCs),whichareproducedbyhumans.

ReadingCheck#13

1. Howdoespollutionaffecttheenvironment? 2. Whoisresponsiblefortheseasonalreductionoftheozonelayer? 3. Listsomeexamplesofwaysvarioustypesofpollutionthatisthreateningbiodiversity.

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HumanImpact

WaterPollution

Waterpollutiondegrades,ordamages,habitatsinstreams,rivers,lakes,andoceans.Manydifferentkindsofpollutantscanharmthelivingthingsinthesehabitats.Examplesincludedetergents,fertilizers,andindustrialchemicalsthatendupinstreamsandrivers.

LandPollution

Landpollutioncomesinmanyforms.Oneformischemicalsusedtokillplantpests.ManyyearsagoDDTwasoftensprayedonfoodcropstocontrolinsects.Birdsthatatetheinsects,plants,orfishexposedtoDDThadhighlevelsofDDTintheirbodies.TheDDTpassedfromthebirdstothepredatorsthatatethem.Someofthepredators,suchasthebaldeagle,laideggswithverythinshellsbecauseoftheDDTintheirbodies.Thethinshellscrackedeasilyandmanyoftheeaglechicksdied.TheuseofDDTwasbannedintheUnitedStatesin1972.

ReadingCheck#14

1. Explaininyourownwordswhybaldeagleswereonceplacedontheendangeredspecieslist?Canyouinferwhytheyarenowaprotectedspecies?

ExoticSpecies

Sometimespeoplebringnewplantsoranimalstoanecosystemwheretheseorganismshavenotlivedbefore.Inotherwords,thesespeciesarenotnativetothearea.Suchspeciesarecalledexoticspecies.Whentheybegintoliveinanewarea,theycanupsetthebiodiversityinthatecosystem.Forexample,manyyearsago,goatsweretakentoCatalinaIslandoffthecoastofCalifornia.Therehadneverbeengoatsontheisland.Asthegoatsmultiplied,theyatemoreandmoreoftheplantsontheisland.Eventually,48kindsofplantsthatusedtobeontheislandweregone.Theydisappearedbecausethegoatshadeatenallofthem.Whenexoticspeciesaretakentoanewareatheycanmultiplyquicklybecausetheydonothavenaturalpredatorsinthearea.

Readingcheck#15

1. Ifremainuncheckedwhatimpactcouldexoticspecieshaveonanecosystem?

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ChesapeakeBaywatershedandHumanactivities

TheChesapeakeBayserveshumans,animalsandplantsalike.TheestuarineecosystemoftheChesapeakeBayissorichinnutrientsthatover3,600speciesofplantsandanimalscallithome.Plantlifeflourishesinthishabitatbecauserunofffromthelandoftencarriesessential,naturalnutrientsforplantgrowth.ForestsarecriticaltothehealthoftheChesapeakeBay.Largestandsoftreesprotectcleanwaterandair,providehabitattowildlifeandsupporttheregion'seconomy.Conservingandexpandingforestcoverisacritical,cost-effectivewaytoreducepollutionandrestoretheBay.

TheChesapeakeBayisbestknownforitsseafoodproduction,especiallybluecrabs,clams,oystersandrockfish(aregionalnameforstripedbass).TheBayisalsohometomorethan350speciesoffishincludingtheAtlanticmenhadenandAmericaneel.Unfortunately,theChesapeakeBayfacesseriousproblemsduetohumanactivities,includingpollutedstormwaterrunoff,over-fertilizationandpollutionfromanimalwastes,deforestation,wetlanddestructionfromagricultural,urban,andsuburbandevelopment,andsealevelrisecausedbyglobalclimatechange.Abrownriverofsedimentflowsintoastormdrain,takingchemicals,oil,andotherpollutantsfromstreetsandyardswithit.Therearethreemajorcontributorstothepoorhealthofourstreams,rivers,andtheChesapeakeBay—nitrogen,phosphorus,andsediment.

ReadingCheck#16

1. WhatisthemostcosteffectivewaytoreducepollutiontotheChesapeakeBay?

HumanImpact

Nearly17millionpeopleliveintheChesapeakeBaywatershed,anddemographersestimatethatthewatershed'spopulationisgrowingbyabout157,000residentsperyear.Atthisrate,thepopulationwillreach20millionby2030.AgrowingpopulationcreatesissuesthatthreatentheBayecosystem.

Landusechanges

Aspeoplemovetotheareaanddevelopmentincreases,landuseinthewatershedchanges.Newhomes,businesses,androadsreplaceforestsandfields.Landsthatonceabsorbedrainfallhavebeentransformedintoimpervioussurfacessuchasparkinglotsandroadsthatincreasestormwaterrunoff—oftenfullofsediment,excessnutrients,andchemicalcontaminants—flowingintotheBayanditstributaries.Morepeoplealsomeansmorecarsontheroad,increasingtrafficcongestionaswellasairpollution.Airpollutionthreatenstheairwebreatheandthelandandwater.Airandwaterpollutionareintricatelylinked.OfparticularconcerntotheChesapeakeregionareairbornenitrogenandchemicalcontaminantssuchasmercury.Theseairbornepollutantscomefromlargepointsourceslikepowerplantsandindustrialfacilities,vehicles,andagriculturalsources.Airbornenitrogenincreasestheacidityofsurfacewatersandsoils,formsground-levelozone,andcontaminatesdrinkingwater.Chemicalcontaminantspersistintheenvironment,movingthroughthefoodwebinaprocesscalledbioaccumulation.Thisaffectsthegrowthandreproductionofbothterrestrialandaquaticspecies.

Excessivenutrients

NitrogenandchemicalcontaminantsposethreatstotheChesapeakeBaywhentheyentertheBayeitherbyfallingdirectlyintothewaterorbyfallingontothelandandbeingcarriedintothewaterbystormwaterrunoff.Excessnutrientssuchasnitrogenandphosphorus—mostofwhichcomefromagriculturalsourcessuchasfertilizerandmanure—createalgaebloomsthatpreventsunlightfromreachingsubmergedaquatic

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vegetation,limitinggrowthofvitalunderwaterBaygrasses.Theseexcessnutrientsalsodepletedissolvedoxygen,necessaryforthesurvivalofoysters,crabs,andotherbottom-dwellingspeciesintheBay.

HumanImpact

Sedimentation

ExcesssedimentsalsocontributetotheBay'spoorhealth.Morethan18.7billionpounds(8.5billionkg)ofsedimententertheBayeachyear.Sedimentscomefromtheerosionoflandandstreambanks(watershedsources)andshorelineandnearshoreareas(tidalsources).Toomuchsedimentmakesthewatercloudy,whichkeepssunlightfromreachingunderwatergrasses;smothersoystersandotherbottom-dwellingspecies;degradesstreams;clogsportsandchannels;andbindswithpollutants,whichthenspreadthroughouttheBay.

Overfishing

ThefishingindustryisessentialtotheChesapeakeBaycharacterandeconomy.TheBayprovidesrichgroundsforbothcommercialandrecreationalfisheriesoftheChesapeake'ssignaturespecies,includingbluecrabs,oysters,Americanshad,Atlanticmenhaden,andstripedbass.Overfishing,alongwithpollution,diseases,andotherstressors,hasaffectedthepopulationsofmanyfishandshellfishintheBayand,incasesliketheAmericanshad,contributedtoclosuresofcommercialfisheriesintheBay.

Invasivespecies

Plantsandanimalscurrentlylivingandreproducinginahabitatoutsidetheirhistoricnativerangeareconsidered"exotic."Exoticspeciesbecome"invasive"whentheynegativelyimpactanecosystemorspeciesbyencroachingonhabitatandfoodsources.Introducedthroughavarietyofmeans(someintentional,somenot),invasiveplants,insects,anddiseasesthreatenallthehabitatsofthewatershed.Invasiveplantsoftengrowandreproducefasterthannativespecies,loweringthequalityofavailablefoodandshelterfornativespeciesandout-competingnativeplantsforhabitatandpollinators.

Activity#11

HumanUses(Cause)Impact(Effect)

BuildingNewHomesetc.

Overfishing

Farming

InvasiveSpecies

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TheBayToday

Increasingtemperatures

TheChesapeakeregionhasbeguntofeeltheeffectsofachangingclimate,whichhasrepercussionsfortheentireecosystem.Overthelastcentury,theaverageairtemperaturealongthecoastalmarginsoftheChesapeakeBayhaswarmed1.4°F.Between1950and2000watertemperaturesroseabout2°F.Thesewarmerairandwatertemperaturescanchangetheplantandanimalspeciesinanarea,contributetoexpandingdeadzonesandalgalblooms,andencouragetheexpansionofhardyinvasivespeciessuchasnutria.

Precipitation

MuchoftheChesapeakeregionisexperiencinggreaterprecipitationextremesanda10percentincreaseinaverageprecipitation.TheincreasingprecipitationandstormintensitieswillleadtogreatervolumesofrunoffandassociatedtoxicchemicalsandnutrientpollutioninBaywaters.

Precipitationispartofthewatercycle,alsoknownasthehydrologiccycle—themovementofwateron,above,andbelowthesurfaceoftheEarth.

Sea-levelrise

WaterlevelsintheBayhavealsorisen,withnearlyafootofsea-levelriseinsomeplaces.Manycoastalmarshesandsmallislandshavealreadybeenlosttorisingwater,andmoreareatrisk.Thesemarshesprovideimportantecosystemfunctionsbyfilteringpollution,protectingshorelines,andprovidinghabitat.Sea-levelrisewillalsoaffectsalinityanddistributionoffreshwaterintheestuary—andconsequentlytheBay'sanimalsandplants.

Effectsonwaterfowl

GlobalwarmingposesatriplethreattowaterfowlintheChesapeakeBay.First,thesummerbreedinggroundsofmanyoftheBay'smigratoryduckspeciesarethreatened.ManyofthesebirdsbreedinthePrairiePotholeRegionofsouth-centralCanadaandnorth-centralUnitedStates,whichhasanabundanceofsmall,shallowwetlands.With50percentofthenation'sduckscomingfromthisarea,itisthemostimportantbreedinggroundforNorthAmerica'smigratoryducks.Astheclimatewarms,thesevitalwetlandsareexpectedtoremainwetforshorterperiodsordryupalltogether.Second,asglobaltemperaturesincrease,somemigratingwaterfowlhavebegunaphenomenonknownas"shortstopping."ManyofthebirdsthatformerlyspentthewinterintheChesapeakeBaywatershedarestoppingfarthernorthalongtheirroutesastheyfindmoreice-freeareasaswintersbecomewarmer.AthirdthreattothemigratingwaterfowlwillaffectthosewhodomakeittotheirwinteringgroundsintheChesapeake.Theywilllikelyfacealossofshallow-waterhabitatassealevelsrise.Higherwaterlevelswillinundatethecoastalmarshesandwetlandsthatprovidevitalfoodfortheseanimals.

Effectsonfishandshellfish

Researchershavelinkedthespreadofnewdiseasesandmorefrequentepidemicstoglobalwarming.IntheChesapeake,anewspeciesofmycobacteriumrecentlyinfectedrockfish,andoutbreaksaremorecommoninotherBayfishaswell.Diseaseshavedecimatednativeoysters.Poorwaterquality,pollution,andhabitatdegradationarefactorsintheseinfections,butthestressofwarmerwatermakesthespeciesmorevulnerabletodisease.

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Effectsonsubmergedaquaticvegetation

Resourcemanagersexpectsea-levelrisetohaveadirecteffectonsubmergedaquaticvegetationintheChesapeakeBay.Aswaterdepthincreases,thesunlightavailabletotheplantsdecreases,reducingtheirabilitytophotosynthesize.Higherwatertemperaturesalsoaffectunderwatergrasses.Forexample,higherwatertemperatures,inconjunctionwithturbidityandlow-lightconditions,havecontributedtothedeclineofeelgrassinthelastdecade.Warmerwater,inconjunctionwithturbidityandlow-lightconditions,killsthegrasses.Somedocumentationindicatesthatgrassescanrecoverwhenwaterconditionsimprove,butthetrendtowardsfurtherwarmingwillhavetheoppositeeffect.IncreasedprecipitationasaresultofclimatechangealterstheamountofwaterflowingintotheBay,which,inturn,candecreasesalinityasmorefreshwaterrunoffpoursintotheBay.Thischangeinsalinitycanhaveadramaticeffectonavailablehabitatforsubmergedaquaticvegetation.Additionally,specieshavedifferentabilitiestotoleratesalinity,sothespeciesthatarepresentmaychange.

Activity#11

Impact DescribetheChange NegativeorPositive?

IncreaseinTemperature

Precipitation

Sealevelrise

EffectonWaterfowl

Effectonfishandshellfish

Effectonsubmergedvegetation

ReadingCheck:#11

1. Wereanyoftheeffectspositive?

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RestoringtheBay

TodaytheChesapeakeBayisinperil.WecanseetheresultsofhumanactivitiesandnaturaleventsthataffecttheBay'shealthanddiversity.TheBay'sabilitytosustainlifehasdiminishedinvisibleandmeasurableways.Keyspecieshavedeclined,threateningthesensitiveecosystemandthelivelihoodsofcommunitiesdependentonBayharvests.Cuttingforeststomakewayfordevelopmenthasdestroyednaturalprotectionsforfragileshorelines,habitats,andwaterquality.Thecomplexnetworkofriversandstreamswithinthesurroundingwatershedcarriespollutionandheavysedimentloadsdownstream.

Fromhistoricalaccountsleftbyearlyexplorers,weknowhowabundanttheChesapeakeBayoncewas.Throughmodernscience,weknowwhatactionsareneededtorestoreittohealth.Throughconcertedrestorationeffortsinvolvingalllevelsofgovernmentandcountlessorganizationsandindividuals,wecanseeprogress.ButrestoringtheChesapeakeBayisaraceagainsttime.Populationgrowthandotherhumanactivitiesareoffsettingmuchoftherecentrestorationprogress.ThefuturehealthoftheBaydependsonacceleratingrestorationeffortsandinvolvingeverypersonwholivesinorvisitsthewatershed.

Whatyoucando?

YoumaythinkyouhavelittleimpactontheChesapeakeBay,butcollectivelythenearly18millionpeoplelivingintheChesapeakewatershedplayaverysignificantroleinthehealthoftheBayanditsmanytributaries.ItwilltaketheactionsofallofustosuccessfullyrestoretheChesapeake.SimpleeverydayactionsmakeabigdifferenceifweeachdoourparttosavetheBay.

ReadingCheck#18

1. WhatisaffectingtherestorationprogressoftheChesapeakeBay?

Activity#13

WritealettertoyourlocallegislatorsexpressingyourconcernsfortheimpacthumansarehavingontheChesapeakeBay.Listatleast3concernsandwaysyousuggestwemakechangesinyourcommunity.

Dear _