MarineConserva,onScience&PolicyCurriculum–2012,2015DeeringEstate.Allrightsreserved.1
FocusQuestionWhatarebarrier islands?Whatarethemainfeaturesofabarrier islandandwhatorganismslivethere?Whyarebarrierislandsimportantandhowcanwebetterprotectthem?
ObjectivesStudentswillexplorethebarrierislandsandsomeofthehabitats,animalsandplantsfoundontheseformations.Studentswilllearnto:
• Identifythemainfeaturesofabarrierisland.• Identifythedifferenthabitatsfoundonabarrierislandandsomeoftheorganisms
thatlivethere.• Explaintheimportanceofthebarrierislandsanddemonstrateknowledgeby
elaboratingavisualrepresentation.Studentswilldiscusshow thishabitat canbeprotected for futuregenerations.Thiswill beaproject-basedactivityinwhichstudentswillexplorethevarioushabitatsofthebarrierisland.
BackgroundBarrierislandsarelong,narrowdepositsofsedimentthatrunparalleltoshorebutare
separatedfromthemainlandbyacalm,protectedbodyofwatercalledabayorlagoon.Barrierislandsformwhensandfromtheweatheringanderosionofrockistransportedtothecoastbyrivers, and the forceof thewaves, tidesand currentswork the sediment intoan islandorachain of islands. Current islands were formed about 4,000-6,000 years ago, when meltingglaciersfromthe last iceagecausedarapidrise insea levelandtidalactionsforcedsedimentshoreward. Barrier islands dynamic landforms, as the tides, wind and waves constantly shifttheirsedimentandmovethemtowardsthemainland.
Eachbarrier islandcanbedivided intofour zones, includingtheoceanshoreline,thesanddunes,thebackbarrierandtidal inletsanddeltas.Theoceanshoreline,oftencalledthebeach, extends from the intertidal zone to the high tide line and bears the full force of theoceanwaves,tidesandcurrents.Sedimenthere canrangefromfineto coarsesand,pebbles,seashells, and sometimes even fossils. Despite the lack of fresh water, this area hosts a richvarietyofspeciesadaptedtothetidalturbulence,includingseastars,hermitcrabs,scavenginganimalsliketheghostcrabandshorebirdssuchasseagulls,sandpipersandpelicans.
Just inlandofthebeacharesanddunes, formedbythewindblowingsediment intomoundsandthefirst colonizingplantshelpingtoanchormoresediment. Thedunesprovideahostileenvironment due to high salinity, sandy soil and lack of fresh water, but they do receivemoisturefromrain,surfandoccasionalstormsurges.Organismsfoundinthesanddunezoneincludeseaoats,bitterpancum,crabsandbirds.Onwiderbarrier islands,therootsystemsofthe plants provide stability and their leaves function as awindbreak, allowing sediment andnutrients to accumulate, sometimes forming soil rich enough to support trees. Some barrierislands are large enough to support maritime forests, with live oak, slash pine, raccoons,rabbits,evendeer,whileothersmaybelittlemorethanloosesandandafewstuntedplants.
MarineConservationScience&Policy:BarrierIslands
lassGradeLevel:
4th–12th
SubjectAreaScienceBiologyDuration1.5Hrs.
BodyofKnowledgeLifeScienceNatureofSciencePhysicalScience
BigIdeaOrganizationandDevelopmentofLivingOrganisms.ThePracticeofScience
StandardsSC.4.L.17.4Recognizewaysthathumanscanimpacttheenvironment.SC.7.E.6.6IdentifytheimpactthathumanshavehadonEarth,suchasurbanization,erosionandchangingflowofwater.SC.912L.17.16Discussthelarge-scaleenvironmentalimpactsresultingfromhumanactivity.
Benchmarks:
MarineConserva,onScience&PolicyCurriculum–2012,2015DeeringEstate.Allrightsreserved.2
BackgroundBehindthesanddunesisthebackbarrier,anareatoacertainextentshelteredbythe
dunesfromthefullforceofthewindandwaves,thoughstillfloodedanddraineddailybythetide. This protected shoreline can include salt marsh, mangroves, sawgrass and mudflatcommunitiesdependingonconditions,habitats teemingwith floraand fauna thrivingon therichorganicsedimentofthebackbarrier.Thevarietyoflifesupportedinthiszonecanincludeclams,mussels,worms,snails,crabs,smallfish,invertebratesandbirds.
Finally,barrier islandsoften feature tidal inlets thatallow tidalwater to flow inandoutofthelagoon.Inletscanbedeeperandwiderdependingonthesizeofthelagoonandthevariance in the tidal range, allowing for more water to flow between the ocean and theshelteredlagoon.Thetidessupplysustainingnutrientsandcarryawaywastesfromthebarrierislandsystem,andprovidehabitatformussels,clams,andcrabs.
Barrier islands form essential marine habitat for many organisms, including birds,manatees,endangered seaturtles,commercially importantfishspeciesandmanymore.BoththeAtlanticandGulfcoastsofFloridafeatureextensivebarrierislands includingKeyBiscayne,Caladesi Island,andSand Key,whicharehome tomore thanamillion residentsandprovidebeautiful locations for tourism and recreation.Most importantly, barrier islands are the firstlineofdefenseagainst thepowerful storms that threatencoastal communities, reducing thedevastating effects of wind and waves and absorbing some of the storm’s energy. Much ofHurricane Katrina’s disastrous effects on Louisiana could have been avoided had the coastalwetlandsandbarrierislandsbeenrestoredtotheirnaturalstate.
Unfortunately, the ability of many barrier islands to deliver these important
environmentalserviceshasbeencompromisedduetoanthropogenicdamages. Manybarrierislands have been paved with roads, parking lots and buildings that inhibit the naturalmovementofsedimentandmaketheislandsmorepronetoerosion.Becausemanyriversandestuaries have been dammed, the supply of sediments that would usually replenish barrierislands has been diminished, further reducing their ability towithstand the naturally erosiveforce of the waves. Rising sea levels and stronger storms due to climate change are alsosubjectingbarrier islands tomorewaveaction,and theaccumulating effectsof these factorsareleavingthemmorevulnerableandlessabletoprotectcoastalcommunities.
Inordertorestorebarrierislandstotheirformerhealth,manycitiesandorganizationsare working together to find solutions. Some cities are investing in beach replenishment,dredgingsandfromtheoceanbottom,pumpingitontothebeachandshapingitintonewsanddunes.However,theseexpensivesolutionsareonlytemporary,whileallowingbarrierislandstobe protected as wild seashores can help restore the natural movement of the sediment.Solutions must be made on a case-by-case basis, examining the environmental and socialfactorsofeachregionandtakingappropriateactiontoprotectthiscriticalhabitat.
SupplementalResources1-“Nature’sCoastGuard.”ScienceNewforKids.https://student.societyforscience.org/article/natures-coast-guards2-“HowBarrierIslandsWork.”HowStuffWorksScience.http://science.howstuffworks.com/environmental/conservation/issues/barrier-island.htm3-“Whatwillclimatechangeandsealevelrisemeantobarrierislands?”NASA.http://www.nasa.gov/topics/earth/features/barrier-islands.html
Vocabulary:
BarrierIslands:Long,narrowdepositsofsedimentthatrunparalleltoshorebutareseparatedbyaprotectedlagoonorbay.
Erosion:Thenaturalprocessofthebreakingdownandmovementofrocksandsedimentbywindandwater.
Beach:Theoceanfrontshoreextendingfromthelowerintertidalzonetothehightideline.
SandDunes:Asandhillorridgethatliesabovethehightidelineandisformedbyaccumulatingsedimentfromwindandtide.
MaritimeForests:Acoastalwoodedhabitatfoundonhighergroundbehinddunes,shelteredfromtheharshestwindsandsaltspray.
BackBarrier:Theinnershoreofbarrierislandsshelteredfromtheharshestoceanwavesbutstilldrainedandfloodedbythedailytide.
TidalInlets:Achannelforgedbythetidalflowconnectingtheoceanandlagoon.
BeachReplenishment:Theprocessofpumpingsandfromoffshoreontoanerodingshoreline
MarineConserva,onScience&PolicyCurriculum–2012,2015DeeringEstate.Allrightsreserved.3
DrawingaBarrierIslandMaterials
• Whitepaper• Coloringutensils(i.e.crayons,markers,orcoloredpencils)• Tapetohangillustrations• FactsheetsandmapsofdifferentFloridabarrierislands
Procedure
1. DividestudentsintopairsandassigneachpairadifferentFloridabarrierisland.Explainthateachpairwillexploretheirbarrierislandusingtheirfactsheetandmap,andthencreateanillustra,onoftheirassignedisland.
2. Passeachpaironesheetofpaperandcoloringutensilsandexplainthateachbarrierislandshouldincludeandlabelthefollowingfeatures:-Beach -Sanddunes -Ocean-Backbarrier -Tidalinlets -Lagoonorbay
3. Havestudentsillustratesomeoftheanimalsandplantsthatcanbefoundinthedifferentareasofthebarrierislandhabitat.
4. Alloweachpairtopresenttheirislandandbrieflyexplainthefeatures.Conductaclassdiscussionanalyzingtheimportanceofthesecoastallandformsandwaysinwhichtheycanbeprotected.
WorksheetAnswerKey
1. Bay2. Marsh3. Backbarrier(includingmaritimeforestonElliottKey)4. SandDunes5. Beach6. Ocean7. Likemostbarrierislands,botharelongandnarrow,andarecharacterizedbyallofthe
abovelistedfeatures.8. WhileElliottKeycansupportamaritimeforestwithtrees,thebackbarrierof
Assateagueislandismorebarren,hostingjustsmallervegetation.9. Thedifferentlatitudesandclimatesofthetwoislands,asAssateagueIslandissomuch
furtherNorth,hasprobablyresultedintheirdifferentecosystems.10. Somesuggestedspecies:ElliottKeyhostsliveoaks,raccoons,opossums,mice,the
endangeredSchausswallowtailbutterfly,andevenseaturtlesusetheislandtonest.Bothislandssupportmanybirds,includingegrets,gulls,osprey,herons,sandpipers,andAssateagueislandalsosupportseagles,ducks,andgeese,aswellaswhitetailandsilkadeer,mudturtles,seastars,seascallops,seacucumbers,spidercrabs,andevenwildhorses.
11. Theseexamples,likeallbarrierislands,areconstantlyshifting,gainingandlosingsedimentandslowlybeingrolledovertowardsthemainlandbywinds,currentsandtides.
BarrierIslands:Long,narrowdepositsofsedimentthatrunparalleltoshorebutareseparatedbyaprotectedlagoonorbay.Havestudentsinterviewaparentaboutourlocalbarrierislands.Studentsshouldplanfortheinterviewbywritingquestionsaboutwhichtheyarecuriouspriortotheinterview,questionsthatmayinclude:howmanybarrierislandsshelterthebay,havetheybeendamagedbydevelopment,haveyouevervisitedone,etc.Parentsshouldbeencouragedtohelptheirchildlocatebarrierislandsonamapandreflectontheirimportancetolocalcommunities.
HavestudentscompletetheBarrierIslandworksheetafterclassandwriteabriefparagraphonwhattheylearnedduringtoday’slessonandhowitappliestotheirdailylives.
ExtensionActivity:
Assessment:
Vocabulary:
ProgramPartner:
MarineConserva,onScience&PolicyCurriculum–2012,2015DeeringEstate.Allrightsreserved.4
MSCP
BarrierIslands
7.Carefullyobservethetwobarrierislandsfeaturedabove.Whataresomeofthesimilarities?_______________________________________________________________________________________________
8. What are some differences? _________________________________________________________________________________________________________________________________________________
9.Considerthelocationsoftheseislands.Whymighttheydemonstratesomedifferences?_________________________________________________________________________________________________
10. What animals might live on these islands? _________________________________________________________________________________________________________________________________
11.Willtheseislandsalwaysbeshapedthisway?Whyorwhynot?____________________________________________________________________________________________________________________
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Referringtothetwofiguresabove,labelthemainfeaturesofabarrierisland.
BayBackBarrierBeachSandDunesMarshOcean
1.___________________________2.___________________________3.____________________________
4.___________________________5.___________________________6.____________________________
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AssateagueIsland,NorthCarolina ElliotKey,Florida
