environment aotearoa 2019 · message to our readers we are proud to present environment aotearoa...

New Zealand’s Environmental Reporting Series

EnvironmentAotearoa 2019

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CitationMinistry for the Environment & Stats NZ (2019). New Zealand’s Environmental Reporting Series: Environment Aotearoa 2019. Available from www.mfe.govt.nz and www.stats.govt.nz.

Published in April 2019 by Ministry for the Environment and Stats NZPublication number: ME 1416

ISSN: 2382-0179 (online) ISSN: 2463-3038 (print) ISBN: 978-1-98-857913-9 (online) ISBN: 978-1-98-857914-6 (print)

Cover photo: Whangaruru Harbour, Northland. Credit: photonewzealand

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Contents Message to our readers 04

Part 1 About Environment Aotearoa 2019 05Aotearoa New Zealand 06Background to this report 07A whole system approach 08A focus on what matters 10

Part 2 Themes and issues 11Theme 1 Our ecosystems and biodiversity 12 Issue1 Ournativeplants,animals,andecosystemsareunderthreat 14Theme 2 How we use our land 28 Issue2 Changestothevegetationonourlandaredegradingthesoilandwater 30 Issue3 Urbangrowthisreducingversatilelandandnativebiodiversity 40Theme 3 Pollution from our activities 44 Issue4 Ourwaterwaysarepollutedinfarmingareas 46 Issue5 Ourenvironmentispollutedinurbanareas 63Theme 4 How we use our freshwater and marine resources 72 Issue6 Takingwaterchangesflowswhichaffectsourfreshwaterecosystems 74 Issue7 Thewaywefishisaffectingthehealthofouroceanenvironment 83Theme 5 Our changing climate 90 Issue8 NewZealandhashighgreenhousegasemissionsperperson 92 Issue9 ClimatechangeisalreadyaffectingAotearoaNewZealand 98

Part 3 Towards a better understanding of our environment 105Understanding our environment 106Features of the environment 106Making informed decisions 107The knowledge system and environmental reporting 108Strengthening our knowledge and reporting systems 109

Glossary, Domain reports, Environmental indicators, and Acknowledgements 111Glossary 112Domain reports 112Environmental indicators 112Acknowledgements 113References 114

03

Message to our readers

We are proud to present Environment Aotearoa 2019, our three-yearly report on the state of the environment in New Zealand.

Ourministriesworktogethertoproduceenvironmentalreportseverysixmonths,focussedonadomainsuchasair,marine,orland.Thisreport,bycontrast,takesabroaderviewoftheenvironmentasawholebyreportingonninepriorityissuesforusin2019.Theissuestypicallyinvolvemorethanonedomain.

Toidentifythenineissues,ourscientistsanddataanalystsreviewedthemostrecentdomainreportsandworkedwithanindependent,expertsciencepanel.

Thedataandsciencepresentedinthereportisupto date,fullyexplained,andrigorouslycheckedtothehigheststandards.Theinformationisfactualandtrustworthy,andlinkstotheanalysisanddatasourcesareprovidedthroughoutthereport.

Takentogether,theissuesclearlyshowthatthechoiceswehavemadeaboutthewayweliveandmakealivingarehavingasignificantimpactonourenvironmentandthereforeonthethingswevalue.Theyhighlightareaswhereweneedtopaycloseattention.

Choosingandmakingappropriateresponsestotheissuesisnotstraightforward:theNewZealandeconomyhasbeenbuiltonourenvironment,ourpopulationcontinuestogrow,andclimatechangeisamplifyingmanycurrentpressures.Thesearecomplexchallengesthatrequireseriousconsideration.

Webelievenowisthetimetoengageinconversationsas acountryaboutwhatwevalue,whatconsequenceswearepreparedtoaccept,andthekindofcountrywewantourchildrenandmokopunatoinherit.Environment Aotearoa 2019willaddvaluetothoseconversations.

Thereportalsopointsouthowmuchwedon’tknowaboutmanyaspectsofourenvironment.Whilewehaveconsiderableknowledgeinmanyareas,understandingourenvironmentasawhole–anditsmanyinteractions–isamuchbiggerchallenge.Environment Aotearoa 2019suggestssomestepsthatcouldbetakentoimproveourknowledgeandreportingsystemsowearebetterequippedtounderstandtheeffectsofouractions,andwhatweneedtodoaboutit.

Whateveryourinterestorconnectiontotheenvironment,wetrustthatreadingthisreportoritssummarywillsupportyoutoaskquestionsandbeempoweredinconversationsabouthowtoenjoy,protect,andprosperinourAotearoaNewZealand.

Vicky RobertsonSecretaryfortheEnvironment

Liz MacPhersonGovernment Statistician

04 Environment Aotearoa 2019 NewZealand’sEnvironmentalReportingSeries

About Environment Aotearoa 2019This part of the report sets the scene and explains the approach – including how the nine priority issues were chosen. Scope, context, and governing legislation are also presented here.

PA R T 1

Photo credit: photonewzealand

05

Aotearoa New ZealandOurlandandseaareuniqueandveryspecial,havingevolvedsodistinctlyandseparatelyfromtherestoftheworld.Fromthetimeourancestorsfirststeppedontoitsshores,thelandofthelongwhitecloudhasprovidednourishment,protection,andresourcestoitsinhabitants.Peoplehavebecomepartoftheenvironmentandshapedit,modifyingthelandtogrowfood,buildinghouses,andestablishingsettlements,roads,andinfrastructure.

Therelationshipandconnectionwehavewiththeenvironmentgoeswellbeyondthegoodsandserviceswereceivefromit,likefood,fuel,andcleanwater.Ourenvironmentiswherewestand,ourtūrangawaewae–wherewelive,learn,workandearnaliving,play,andsocialise.Itisourhomeandouridentity,andthefoundationofournationalcultureandtradition.

Astangatawhenua–peopleoftheland–Māorihaveadistinctandspecialconnectiontotheland.Māoriidentity,well-being,knowledge,andlanguagesystems,andthewaysthecultureisnourished,areindivisiblefromthehealthofPapatūānuku,theEarthMother.

ThewhakapapaMāorihavewiththeenvironmentembedshumansintheenvironment.Itensurestheuniqueconnectionoftangatawhenuaisrespectedandbringsawayofthinkingthathelpsusallseeourselvesasapartof,notapartfrom,theenvironment.

TeaoMāori,theMāoriworldview,hasanimportantplaceinenvironmentalreportinginNewZealandandisintendedtobeasignificantvoiceinthisreport.Whereverpossible,ithasbeengivenspacetospeakaboutthestateoftheenvironment.Werecognisethatthereisnoonevoice ofMāori,norarethevoicespresentedinEnvironment Aotearoa 2019asstrongastheycouldbe.

TherelationshipNewZealandershavewiththeenvironmentisdynamic,butthewayswearemodifyingnaturalecosystemstomeetourneedsin2019arehavingprofoundeffects.Somepartsofourenvironmentareingoodshape,otherslessso.

Howwegoforwardfromhereisuptoallofus.

The green of a kākāpō feather, scarlet pōhutukawa, summer cicada song, and a dolphin’s silver flash – these are the colours and sounds of our Aotearoa New Zealand.


Background to this reportThisreportisdifferenttotheMinistryfortheEnvironmentandStatsNZ’sregularsix-monthlyreportsthatcycleair,freshwater,marine,atmosphereandclimate,andlanddomains.Itisasynthesisreport–bringingtogetherallthedomainreportstohelpusstepinsideandviewourenvironmentasawhole,inallitscomplexity.

TheEnvironmentalReportingActof2015(theAct)requirestheSecretaryfortheEnvironmentandtheGovernmentStatisticiantoproducesuchasynthesisstateoftheenvironmentreporteverythreeyears.Itspurposeistopresent‘adiagnosisofthehealthofourenvironment’toenableusasanation,asiwi,aswhānau,ascommunities,sectors,andindividualstounderstandthethingsthataffect,orpotentiallyaffectthehealthofourenvironment.ThelastfullreportwasEnvironment Aotearoa 2015(beforetheAct),andbeforethatversionsin2007and1997.

Sowhilenotsuggestingresponses(whichareoutofscopeunderthelegislation),Environment Aotearoa 2019providesevidencetoenableanopenandhonestconversationaboutwhatwehave,whatweareatriskoflosing,andwherewecanmakechanges.

ThedatausedinEnvironment Aotearoa 2019isdrawn fromthemostrecentdomainreports(Our marine environment 2016, Our fresh water 2017, Our atmosphere and climate 2017, Our land 2018, and Our air 2018).Theevidencebaseforthisreportisdrawnfromasetofenvironmentalindicatorwebpagesthatareavailableon theStatsNZwebsite.Oftheenvironmentalindicatorsusedinthisreport,18areneworhavebeenupdatedsincethey werelastusedinadomainreport,asnewdatahasbecomeavailable.(SeetheEnvironmental indicators section forlinkstoallnewandexistingindicatorsreferredtoin thisreport.)

Toprovidethebestpictureinthisreport,includingofemergingconcerns,thereportalsodrawsonabodyofevidence,suchasgovernmentreportsandpeer-reviewedsciencepapers.Whilethereporttellsanationalstory,itacknowledgesimportantregionalvariationswherepossible.

AspertheAct,state,pressure,andimpactareusedtoreportontheenvironment.Thelogicoftheframeworkisthat pressurescausechangestothestate oftheenvironment,andthesechangeshave impacts.Impactstoecologicalintegrity,publichealth,economy,teaoMāori,culture,andrecreationaredescribed,asrecommendedundertheAct.

Thetimeframesusedthroughoutthereportarelargelydictatedbythedatathatisavailable.Wherepossible,dataisusedtohighlightsignificantperiodsofchange.Thetimebeforehumansarrivedissometimesusedasabenchmarkwhentheconceptof‘departurefromnaturalconditions’isdiscussed,tohelpcharacterisethesignificanceofchange.

Inthisreportwehaveusedtheterm‘farming’torefer topastoralfarming(includingdairy,beef,sheep,and otherlivestock),horticulture,andarablecropping. Whenquotingfromthebodyofevidence,wehave usedtheterm‘agriculture’todescribethesameactivities,whereitisadirectquotefromthesourcedocument.

Althoughthereportdoesnotspecificallyaddressuncertaintyinmeasurementsorconclusionsinmostinstances,itacknowledgesthatitispresentinalldata andanalysis.Wherethereisenoughuncertaintytosignificantlyimpacttheunderstandingofanissueitishighlightedasaknowledgegap.

Thisreporthasthreemainparts: ‘AboutEnvironmentAotearoa2019’helpstoorient usandexplainourenvironment.

Thesecondpart‘Themesandissues’usesfivethemestopresentninepriorityenvironmentalissues.

Thelastpart‘Towardsabetterunderstandingofourenvironment’setsoutthechallengeswemustovercomesofuturedecisionsabouttheenvironmentareaseffectiveastheycanbe.

07

A whole system approachOurenvironmentholdspeople,plants,animals,soil,freshwater,seas,andsky.Inthedomainreports,weexplorejustoneelementoftheenvironmentbyconsideringitsstate,howitischanging,andtheimpactsthesechangeswillhave.Inthissynthesisreport,however,fivebroadthemesareusedtolookbeyondsingledomainstothewholeinterconnectedsystem.

Theme 1: Our ecosystems and biodiversity

Anecosystemdescribesacommunityofpeople, plants,andanimalsandhowitinteractswithaphysicalenvironment,likesoil,water,andair.Ecosystemsprovidemanybenefitsthatareintegraltoourwell-being.Theseincludegoodsandserviceslikefood,recreation,pollination,anderosioncontrol.Biodiversityisoneofthemainhealthindicatorsforecosystems.

Theme 2: How we use our land

Thewayweuseourlandandwhathappenswhenwechangefromonelandusetoanothercanhavesignificanteffectsonthehealthofourecosystems,andthebenefitswegetfromthem.Effectscanbeonthelanditselfbutalsoextendtoconnectedstreams,estuaries,andseas.

Theme 3: Pollution from our activities

Ourenvironmentispollutedwhensubstances(waste,nutrients,contaminants)andenergy(heat,sound,radioactivity)areaddedfasterthantheycanbedispersed,recycled,decomposed,orstored.Sincemanyecosystemprocessesoperateascycles(nutrients,water)pollutantscanhavelong-lastingeffectsonecosystemsandourwell-being.

Theme 4: How we use our freshwater and marine resources

Ourrivers,lakes,estuaries,andoceansarevaluedfortheirecosystemsandtheservicesandresourcestheyprovide.Thewayweinteractwiththeseresources(takingwaterforirrigation,fishingforexample)cancompromisethehealthoftheecosystemsandtheirabilitytoprovidetheculturalandsocio-economicbenefitswedependon.

Theme 5: Our changing climate

Climate,andchangesinclimate,areaffectingeveryecosystemandsomeofthethingswevalue.Here,ourroleasbothinfluencersandrecipientsofclimateisexplored.Placingclimatechangeasthefinalthemeisalsoachance toshowhowthisunprecedentedglobaldisruptionwillaffecteveryotherissue.


8. New Zealand has high greenhouse gas emissions per person.

9. Climate change is already affecting Aotearoa New Zealand.

7. The way we fish is affecting the health of our ocean environment.

4. Our waterways are polluted in farming areas.

3. Urban growth is reducing versatile land and native biodiversity.

5. Our environment is polluted in urban areas.

2. Changes to the vegetation on our land are degrading the soil and water.

1. Our native plants, animals, and ecosystems are under threat.

HOW WE LIVE AND MAKE A LIVING THINGS WE VALUE

The way we interact with our

environment affects the things

we value.

Climate change intensifies the effects of all other issues.

Forestry Fishing Farming Transport

Building & constructionWaste disposalEnergy

5. Our changing climate

3. Pollution from our activities

1. Our ecosystems and biodiversity

2. How we use our land

4. How we use our freshwater and marine resources

All issues affect ecosystem health.

6. Taking water changes flows which affects our freshwater ecosystems.

Nature Culture Recreation Stability

EconomyHealth Identity

Environment Aotearoa 2019 themes and issuesThe themes and issues in this report show how the way we live and make a living affects our environment and the things we value.

09

A focus on what mattersWhenreviewingEnvironment Aotearoa 2015,theParliamentaryCommissionerfortheEnvironment(PCE)suggestedstructuringfuturesynthesisreportsaroundissues,whereanissueisdefinedas:

…a change in the state of the environment that is (partly) caused by human activities (pressures) and has consequences (impacts).

Afocusonissueswasadoptedforthisreport.Ithasenableddifferentenvironmentalconcernstobeprioritisedindividuallybutitalsodemonstrateshowasingleissuecancrossmanydomains.

Therearemanyenvironmentalissuesinourcountry. Tonarrowdowntheissuestothoseincludedhere,findingsfromeachofthefivemostrecentdomainreportswerereviewed,ranked,andprioritised.Fourcriteriawereestablishedtohelpdescribethesenseofsignificance andurgencyoftheissue:

Spatial extent and scale –howmuchofNewZealandisaffectedbytheissue?

Magnitude of change –istheissueincreasinginscaleand/ordistribution, oraccelerating?

Irreversibility and lasting effects of change –howhardisittofix?

Scale of effect on culture, recreation, health, and economy–howmuchdoesitaffectthethingswevalue?

ThesecriteriawereinformedbythesuggestionsofthePCEinThe state of New Zealand’s environment: Commentary by the Parliamentary Commissioner for the Environment on Environment Aotearoa 2015andareconsistentwiththeselectioncriteriausedtohighlightthetopfindingsinthedomainreports.

Thefourcriteriaplusanindicationofrelatedknowledgegapsareusedtosummarisewhyeachissuematters.

Anindependentpanelofscientistsverifiedtheselectionprocesstoensurecriteriawereappropriatelyappliedagainsttheissues.TherelevanceofthenineissuestomātaurangaMāori,kaitiakitanga,andotherculturalvalueswasalsoconsideredbyMāoriresearchersandpractitioners.

Thepriorityissuesarenotanexhaustivelistofallthepressuresourenvironmentfaces.Somehaveanimpactontheenvironmentbutarenotfeaturedinthisreportastheydonotrankashighlyagainstthecriteriaasotherissues.Miningforexample,isnotincludedbecauseofitslocalisednature.

Asanissueisdefinedasachangeinthestateoftheenvironment,causedbyhumanactivities(pressures) andhavingconsequences(impacts),someenvironmentalproblemsarenotincluded.Anexampleisplasticwaste,whichisconsideredasapressurebutnotanissue,despiterecentlybeingrankedasthenumberoneenvironmentalconcernbythepublic(ColmarBrunton,2019).

Eachissueaddressessixquestions: Whydoesthisissuematter? Whatisthecurrentstateofthisissue? Whathaschanged? Whathascontributedtothisissue? Whataretheconsequencesofthisissue? Whatarethegapsinourknowledgeaboutthisissue?

Building a scientifically credible reportThisreportandalltheassociatedindicatorpages,graphics,andsummaryhavebeencompiledbyateamofscientistsanddataanalystsfromtheMinistryfortheEnvironmentandStatsNZ.

Earlyintheprojectanindependentsciencepanel,composedoffourofNewZealand’stopscientists,wasestablishedthroughacompetitiveprocess. Thepanel,chairedbytheDepartmentalChiefScienceAdvisor,advisedandprovidedindependentreviewofthestructure,allcontent,andfindings.

Wherelimitednationaldatawasavailable,moreinformationhasbeenprovidedusinga‘bodyofevidence’approach.Thisapproachlooksacrossthesciencesystemanddrawsonthescientificliteratureandthecombinedresultsofmultiplescientificstudiestosupportfindings.

Tokeeppacewithdevelopmentssincepreviousreports,somenewdataisincludedanddifferentmethodsforcollectingandinterpretingdataispresented(egmeasuringtrendsforwaterquality).

Alldataused,aswellasthebodyofevidencereferenceshavebeencorroboratedandcheckedforconsistency.

Asteeringgroup,representingbothMinistry fortheEnvironmentandStatsNZ,providedoversighttoensureEnvironment Aotearoa 2019 wasproducedinawaythatistransparentandrobust,andcanthereforebeavaluableandtrustedsourceofinformation.


PA R T 2

Themes and issuesUsing five broad themes, this part of the report presents nine priority environmental issues for us as a nation in 2019. Each issue includes information about why it matters, what has changed, and the consequences.

Photo credit: Ministry for the Environment

11

Our ecosystems and biodiversity

TH E M E 1

Our ecosystems and biodiversity


Photo credit: iStock

The biodiversity of Aotearoa New Zealand is essential to our culture, identity, and well-being. Our biodiversity – the whole variety of native plants, animals, microorganisms, the genes they contain, and the ecosystems they create – is unique to New Zealand and irreplaceable.

Becauseofitsevolutionasagroupofveryisolatedislands,NewZealandhasahighproportionofnativespeciesthatarefoundnowhereelseintheworld.Manylackdefencesorstrategiesfordealingwithmammalianpredators(likestoatsorpossums)andherbivores(suchasdeer),sincetheyevolvedalmostcompletelywithoutthem.Ournativespeciesandecosystemsarethereforeparticularlyvulnerabletointroducedspeciesanddiseases,humanactivities,andchangestotheirhabitatfromclimate,landscapechanges,andpollution.

Inthistheme,thestateofourbiodiversityisreported,consideringthelossandrisktospeciesandecosystemsacrossland,freshwater,andmarineenvironments.Themainhumanactivitiesthatimpactonecosystemsandspeciesarealsodiscussed,includingwhatchangesinbiodiversitymeanforourwell-being.

Ournativeplantsandanimals,andthecommunitiestheyform,areaffectedbyalltheissuesidentifiedinthisreport.Whenthepressurefromtheseissuesiscombinedwiththeeffectsofintroducedspecies(asignificantcurrentpressureforterrestrial,freshwater,andmarineenvironments)thecompoundingpressuresintensifytheimpactsonanimal andplantcommunities.

Forotherissuesthatimpactbiodiversitysee: Issue 2: Changestothevegetationonourlandaredegradingthesoilandwater

Issue 3: Urbangrowthisreducingversatilelandandnativebiodiversity

Issue 4: Ourwaterwaysarepollutedinfarmingareas Issue 5:Ourenvironmentispollutedinurbanareas Issue 6: Takingwaterchangesflowswhichaffects ourfreshwaterecosystems

Issue 7:Thewaywefishisaffectingthehealthof ouroceanenvironment

Issue 9:ClimatechangeisalreadyaffectingAotearoaNewZealand.

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ur ecosystems and biodiversity

SPATIAL EXTENT

AllofNewZealand’sland,freshwater,andmarine

environmentsareaffected.

DEPARTURE FROM NATURAL CONDITIONS

Therearemajordifferencesfromwhatthingswerelikebeforehumansarrived.

IMPACTS ON WHAT WE VALUE

Itcanpotentiallyhavesignificantimpactsonourwell-being,identity,

andculturalvalues.

KNOWLEDGE GAPS

Largegapsinknowledgeonthestateofourbiodiversityandtheconditionofmanyecosystemsmaylimitourabilitytounderstandandreduce

futuredeclines.

IRREVERSIBILITY

Manyaspectsareirreversible–speciesextinctionisforever. Manydeclinesmaybereversed

withsubstantialeffort.

I S S U E 1

Our native plants, animals, and ecosystems are under threatOur unique native biodiversity is under significant pressure from introduced species, pollution, physical changes to our landscapes and coast, harvesting of wild species, and other factors. Almost 4,000 of our native species are currently threatened with or at risk of extinction.

Why does this issue matter?


What is the current state of this issue?ThebiodiversityofAotearoaNewZealandisunique andvulnerabletochangeswemaketotheenvironment.Ahighproportionofthespeciesfoundherearefoundnowhereelseintheworld.Someoftheseirreplaceablespeciesinclude:

kākāpō,theworld’sonlynocturnalflightlessparrot lancewood/horoeka,atreethathasdramaticallydifferentyoungandmatureforms

giantwētā/wētāpunga,insectsthatcanweigh morethanamouse

Māuidolphin,theworld’ssmallestdolphin.

Biodiversityinallourland,freshwater,andmarineenvironmentshasdeclinedsignificantlysincethearrivalofhumans.Thisdownwardslideincludestheextinctionofnumerousnativespecies,anincreasedriskofextinctionformanysurvivingspecies,andareducedrangeofecosystems,bothbytypeandarea.Thesechangesrepresentamajordeparturefromwhatthingswereoncelike.

Thechangeshavesometimesbeendramatic,withspeciesbecomingextinctandthedegradationofentireecosystems.Otherchanges,thoughlessdramatic,areveryserious,likenon-nativespeciesbecomingestablishedhereoradeclineinthehealthofecosystems.

Whilemostmeasuresshowalossorincreasedrisktoourbiodiversity,someintensiveconservationeffortsprovide afewbrighterpoints.

Measuring ecosystem healthAnecosystemdescribestheinterrelationshipsbetweenlivingorganismsandthenon-livingenvironment.Ahealthyecosystemcontains avarietyofnativespecies,aswouldbefoundinthatsetting(egriver,forest,wetland,dunes)whenitisinapristinecondition,unaffected byhumandisturbance.

Severalcomponentsareassessedtodescribeecosystemhealth.Theseincludetheabundanceanddiversityofspeciespresent(biodiversity),theavailabilityandqualityofhabitats,andhowcompletelytheimportantecologicalprocessesaresustained(egdecomposition,nutrient cycling,andconnectionsbetweenlevelsof thefoodchain).

Measuringthesecomponentsiscomplicatedandvariesfordifferenttypesofecosystems.Infreshwaterecosystems,forexample,fivecomponentsarerecognisedasimportantforassessinghealth(Clapcottetal,2018):1. Aquatic life:Theabundanceanddiversity

ofbiotaincludingmicrobes,invertebrates,plants,fish,andbirds,andanyinvasivespeciespresent.

2. Habitat: Thephysicalform,structure,andextentofthewaterbody,itsbed,banksandmargins,riparianvegetation,andconnectionstothefloodplain.

3. Water quality:Thephysicalandchemicalmeasuresofthewater,includingthepresenceofpollutants(egexcessivenutrients).

4. Water quantity: Theextentandvariabilityinthelevelorflowofwater,includingconnectionsbetweendifferentwaterbodies.

5. Ecological processes:Theinteractions amongbiotaandtheirphysicaland chemicalenvironment.

Atpresent,sufficienthigh-qualitydataisgenerallynotavailabletodescribealltheaspectsofahealthyecosystem.Thismeansitisonlypossibletoassesssomeaspectsofecosystemhealth,andnotitsentirety.

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REGULATING SERVICESSUPPORTING SERVICES

CULTURAL SERVICES

Water Wood and fibre

Food Medicines

ECOSYSTEM HEALTHMeasuring the overall condition of our ecosystems is more than counting the number of different species. Ecosystems are complex and made of many interacting biological and physical components that can all be affected by environmental changes.

CULTURAL VALUEA healthy ecosystem enables tangata whenua to connect with the environment and each other. It provides sustenance and materials for cultural practices and expressions like waiata, karakia, and wairua.

PROVISIONING SERVICES

Water purification

The transitional habitats between landand water have many important functions.

Disease control

Climate stabilisation

Organic matter

Soil

Biomass Decomposition releases nutrients that are taken up again by plants.

Nutrient cycling

Soil formation

Flood mitigation

Erosion control

Photosynthesis

Air purification

Plant pollination

Cultural identity and expression

Species conservation and education

Mental and physical health

Recreation and tourism

BIODIVERSITYDiverse plant and animal

communities stabilise ecosystems and make them

more resilient.

Food web

Riparian zone

EcosystemsA healthy ecosystem provides many benefits (services) that are essential for native plants and animals as well as our own well-being.


REGULATING SERVICESSUPPORTING SERVICES

CULTURAL SERVICES

Water Wood and fibre

Food Medicines

ECOSYSTEM HEALTHMeasuring the overall condition of our ecosystems is more than counting the number of different species. Ecosystems are complex and made of many interacting biological and physical components that can all be affected by environmental changes.

CULTURAL VALUEA healthy ecosystem enables tangata whenua to connect with the environment and each other. It provides sustenance and materials for cultural practices and expressions like waiata, karakia, and wairua.

PROVISIONING SERVICES

Water purification

The transitional habitats between landand water have many important functions.

Disease control

Climate stabilisation

Organic matter

Soil

Biomass Decomposition releases nutrients that are taken up again by plants.

Nutrient cycling

Soil formation

Flood mitigation

Erosion control

Photosynthesis

Air purification

Plant pollination

Cultural identity and expression

Species conservation and education

Mental and physical health

Recreation and tourism

BIODIVERSITYDiverse plant and animal

communities stabilise ecosystems and make them

more resilient.

Food web

Riparian zone

NATIVE SPECIES AND THEIR HABITATS HAVE BEEN LOST

Atleast75animalandplantspecieshavebecome extinctsincehumansarrivedinNewZealand.Thisincludes59birdspecies(Robertsonetal,2017),3frogs(Newmanetal,2013),2reptiles(Hitchmoughetal,2016),4insects(Leschenetal,2012),and7plants(deLangeetal,2018). Allmoaspeciesarenowextinct–aneventrecognisedasthemostrapidextinctionofalargeanimalspeciescausedbyhumans(Allentoftetal,2014)

TheNewZealandThreatClassificationSystem(NZTCS)isusedtoassesstheriskofextinctionofNewZealandspecies(inthiscontext,speciesisusedtoreferto plantandanimalspecies,subspecies,andvarieties). Theconservationstatusofabout10,667nativespecies isknown,whichisonlyafractionofthetotalnumber ofspeciesthoughttoexistinourland,freshwater,

andmarineenvironments.TheNZTCSshowedthat 3,747ofNewZealand’snativespeciesareeitheratrisk orthreatenedwithextinction(asreportedbetween 2010and2018).(Seeindicators:Conservation status of indigenous freshwater species,Conservation status of indigenous land speciesandConservation status of indigenous marine species.)

Forourmarinespecies,90percentofseabirds,80percentofshorebirds,and26percentofnativemarinemammalsareeitherthreatenedwithoratriskofextinction.Thelatestestimates(Bakeretal,2016)suggestthatonly63individualsoftheendemic(foundnowhereelseintheworld)Māuidolphinremain.Inaddition,9percentofsharks,rays,andchimaeras(ghostsharks)werealsoclassifiedasthreatenedwithoratriskofextinctionextinction(seefigure1).(Seeindicator:Conservation status of indigenous marine species.)

Figure 1: Conservation status of native species by species group

5

51

632

4

1,803

412

31

835

106

96

107

15

105

3,721

2,744Vascular plants (2017)

Terrestrial invertebrates (2010–18)

Terrestrial birds (2016)

Shorebirds (2016)

Sharks, rays, and chimaeras (2016)

Seabirds (2016)

Reptiles (2015)

Mosses, hornworts, and liverworts (2014)

Marine mammals (2013)

Marine invertebrates (2013)

Lichens (2010)

Frogs (2017)

Freshwater invertebrates (2013)

Freshwater fish (2017)

Bats (2017)

0 25 50 75 100Percent of species

Threatened At risk Data deficient Not threatened

Figure X: Conservation status of native species by species group

Data source: Department of Conservation

Note: Only known, native, resident, living species are included. Total species are listed to the right of bars.

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https://www.stats.govt.nz/indicators/conservation-status-of-indigenous-freshwater-specieshttps://www.stats.govt.nz/indicators/conservation-status-of-indigenous-freshwater-specieshttps://www.stats.govt.nz/indicators/conservation-status-of-indigenous-land-specieshttps://www.stats.govt.nz/indicators/conservation-status-of-indigenous-land-specieshttps://www.stats.govt.nz/indicators/conservation-status-of-indigenous-marine-specieshttps://www.stats.govt.nz/indicators/conservation-status-of-indigenous-marine-specieshttps://www.stats.govt.nz/indicators/conservation-status-of-indigenous-marine-specieshttps://www.stats.govt.nz/indicators/conservation-status-of-indigenous-marine-species

Freshwaterspeciesalsofacerisks.In2017,76percent ofournativefreshwaterfishwereeitherthreatenedwithoratriskofextinction.Morethan25percentofnativefreshwaterinvertebrateshadathreatenedoratriskconservationstatusin2013(seefigure1).Almost 33percentoftheplantspeciesthatdependonfresh waterareclassifiedasthreatenedoratrisk(Gerbeauxetal,2016).Ofthese,almost20percentwereinthehighestriskcategory,ienationallycritical(Gerbeauxetal,2016).

Manyofourlandspeciesfaceextinctiontoo.Eightypercentofbats,84percentofreptiles,74percent ofterrestrialbirds,and75percentoffrogsarecurrentlythreatenedwithoratriskofextinction.Thisriskextends tolandplants:46percentofvascularplants,23percent ofmosses,hornworts,andliverworts,and10percent oflichensarethreatenedwithoratriskofextinction (seefigure1).

Manyofthehabitats–land,freshwater,andmarine–thatournativespeciesrelyonhavebeenreducedordamaged(seeWhat has changed? andIssue 2: Changes to the vegetation on our land are degrading the soil and water).Suchlarge-scalechangescanmakesomespeciesparticularlyvulnerabletoextinctionandleadtothedegradationofentireecosystems.

RARE ECOSYSTEMS ARE THREATENED OR DEGRADED

Forasmallcountry,wehaveaverydiverserangeofuniqueecosystems.Somearenaturallyrare(therewereonlyafewevenbeforepeoplearrived),whileothersareuncommoninternationally.ThebraidedriversinCanterburyandOtagoareoneexample(Groveetal,2015;O’Donnelletal,2016;Williamsetal,2007).Notonlyaretheseecosystemsrare,buttheyalsocontainuniqueplantsandanimals,manyofwhicharethreatened(egO’Donnell&Hoare,2011;O’Donnell&Moore,1983).

Almosttwo-thirdsofourrareecosystemsarethreatenedwithcollapse.Therateishigherforrarecoastalecosystems(likecoastalturfsandshinglebeaches),wheremorethanthree-quartersarethreatened.(Seeindicator:Rare ecosystems.)

THE HEALTH OF OUR FRESHWATER COMMUNITIES IS MIXED

Assessingthehealthofanecosystemiscomplicated andrequiresmanydifferentcomponentstobeevaluated. Inmostcases,theinformationthatwouldallowanassessmentoftheoverallhealthofallourecosystemsislacking.However,someinformationthatisusefulforunderstandingthehealthofriversandlakes,andthecommunitiesofplantsandanimalsthatlivethere,isavailable.Theecologicalhealthofriversispartlyinformedbythemacroinvertebratecommunityindex(MCI),which isbasedonthepresenceorabsenceofdifferentorganisms(likemayfliesandstoneflies)inawaterway.

Morethanthree-quartersofNewZealand’stotalriverlengthhadexcellentorgoodMCIscoresfor2013–17 (seefigure2).TheMCIresultsshowarelationshipbetweenthehealthofmacroinvertebratecommunitiesandthelanduseofthearea.Comparedwithareaswithnativelandcover,medianMCIscoresare31percentlowerinurbanareasand15percentlowerinpastoralfarmingareas.(Seeindicator:River water quality: macroinvertebrate community index.)(SeeIssue 4: Our waterways are polluted in farming areasandIssue 5: Our environment is polluted in urban areasforfurtherinformationthatinfluencestheecologicalhealthofourrivers.)

Thesubmergedplantindex(SPI)isonemeasureofalake’secologicalhealthandreportsthediversityandextentofnativeandinvasiveplants.SPIdataisonlyavailablefor210lakes–asmallpercentageofthetotalnumberinNewZealand(thereare3,820lakesgreaterthan1hectare insizeinNewZealand(Schallenbergetal,2013).

Between2007and2016,33percentofmonitoredlakeswereinexcellentorhighecologicalcondition,31percentwereinmoderatecondition,and36percentwereinpoorecologicalconditionorwereentirelywithoutsubmergedplants.Nearlyall(90percent)ofthemonitoredlakeswithvegetationhadsomenon-nativeplantspeciespresent. (Seeindicator:Lake submerged plant index.)

Macroinvertebrate community index (MCI)Macroinvertebrates(animalswithoutabackbonethatarevisiblewiththenakedeye,likeinsectsorsnails)spendmuchoftheirlifecycleinarelativelysmallportionofastream.Theyresponddifferentlytochangesinconditions(likepollutants,waterflows,andhabitat),sothepresenceorabsence ofparticularspeciescanprovideanindicationofthehealthofthelivingspeciesinawaterway.

Differentspeciesareassignedspecificscoresthatrelatetotheirleveloftolerancetochangesintheenvironment.AfinalMCIscoreforasiteisbasedontheaveragescoreofthevariousmacroinvertebratesfoundthere.


http://archive.stats.govt.nz/browse_for_stats/environment/environmental-reporting-series/environmental-indicators/Home/Biodiversity/rare-ecosystems.aspxhttp://archive.stats.govt.nz/browse_for_stats/environment/environmental-reporting-series/environmental-indicators/Home/Biodiversity/rare-ecosystems.aspxhttps://www.stats.govt.nz/indicators/river-water-quality-macroinvertebrate-community-indexhttps://www.stats.govt.nz/indicators/river-water-quality-macroinvertebrate-community-indexhttp://archive.stats.govt.nz/browse_for_stats/environment/environmental-reporting-series/environmental-indicators/Home/Fresh%20water/lake-submerged-plant-index.aspx

Braided rivers: Gravel, water, birds, and farming

} Lower reaches of the Waimakariri River. Photo credit: Lloyd Homer, GNS Science

LikeribbonsdrapedacrosstheCanterburyPlains,braidedriverscarrywatereastwardsfromtheSouthernAlpstothesea.Traversingalpine,forest,farm,andcoastallandscapes,theserareecosystemsareforeverchanging,withfloodsliftinggravelfromtemporaryislandsanddepositingitfurtherdownstream.Acompletelydifferentpatternofwaterchannelsandislandscanbecreatedbyalargeflood.

Braidedriversarerareinternationallyand60percentofNewZealand’sbraidedriversarefoundinCanterbury (Grayetal,2018;Gray&Harding,2007).Morethan80birdspeciesfeedandbreedinbraidedrivers, includingmorethan20wetlandbirds(O’Donnell& Hoare,2011;O’Donnell&Moore,1983).Someneston thegravelislands–justafewspeckledeggsprotected onlybytheircamouflageandwatchfulparents.

Withalmostnovegetation,braidedriverislandsallownestingbirdstokeepwatchforpredatorybirdslikesouthernblack-backedgullsandswampharriers. Beingsurroundedbywater,islandsalsooffersome defencefrompredatorslikeratsandstoats,andasupply offoodincludingmayflies,stoneflies,andsmallfish.

Anumberofthesebirdspeciesarerareandalsothreatened:blackstilt,wrybill,black-billedgull,and black-frontedternallhavenationallycritical,vulnerable, orendangeredthreatclassifications.Manyofthefish,insects,spiders,andplantsadaptedtolivinginbraidedriversarealsorareandthreatened(O’Donnelletal,2016).

Relativelyfewbraidedriversareinanaturalconditiontoday.Takingwaterfromariverforotheruses,includingirrigation,alterstheflowandcausessignificantchanges totheriverhabitat.Damsalsohaveaneffectbymaking theflowmoreuniformandreducingfloods.

Lowerriverflowsstabilisethegravelislandsandmakeiteasierforinvasiveplantslikebroomandgorsetotakehold.Theseplantsencroachonbirdfeedingandbreedinghabitatsandgivepredatorsaplacetohide.A2011studyfoundthatriverswherethenumberofblack-frontedternshaddeclinedhadrelativelylowflows,andfurtherreductionsinflowwerepredictedtoacceleratethepopulationdecline(O’Donnell&Hoare,2011).

Rivermarginsareimportantfornativespecieslikegeckosandskinksbutthishabitatislostwhenlandbesidebraidedriversisusedforotherpurposes.From1990–2012morethan11,000hectaresofthistypeoflandinCanterburywasconvertedtointensiveagriculture(Groveetal,2015).

Becauseoftheirimportance,braidedriversaretheonlytypeofecosystemtohavetheirownsetoftargetsintheCanterbury water management strategy(EnvironmentCanterbury,2009).Thesetargetsareto:

maintaintheuppercatchmentsofalpinebraided riversaslargelynaturalecosystemsandlandscapes

notbuildnewdamsonthemainstemofmajoralpinebraidedrivers

maintainactivefloodplains,flowvariability,andsedimentmovement–includingduringriver protectionworks,land-usechange,ordeliberatevegetationstabilisation

supportthedynamicsofrivermouthand coastalprocesses

implementactionstocorrectthedeclineinuseablebraidedriverbirdhabitat.

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https://ecan.govt.nz/your-region/plans-strategies-and-bylaws/canterbury-water-management-strategy/

Chlorophyll-a,ameasureofphytoplanktonbiomass,isanothermeasureoflakehealth.Between2013and2017,35percentof63monitoredlakeshadworsescoresforchlorophyll-athantheNationalObjectivesFramework(NOF)bottomlineforecosystemhealth.(Formore aboutNOFpollutioninourwaterways,seeIssue 4: Our waterways are polluted in farming areas.)

Theecologicalhealthoflakesisalsoassessedusingthelaketrophiclevelindex(TLI),whichisbasedonthetotalconcentrationsofnitrogen,phosphorus,andchlorophyll-a.LakeswithgoodorverygoodTLIratingshaveclearwater(unlesstheyhavenaturalcolourorcloudiness)andlowconcentrationsofnutrientsandalgae(egLakePukakiinCanterbury).LakeswithpoororverypoorTLItendtobemurkyandhavehighconcentrationsofnutrientsandfrequentalgalblooms.Theselakeshavehabitatsthatarenotsuitableforsomenativefreshwaterspeciesandmaynotbeuseableforrecreation(egLakeHorowhenuainManawatu-Wanganui).

Only58lakemonitoringsiteshadenoughdatatoassesstheTLIfor2013–17.ThemedianTLIratingwasverygoodorgoodat16percent,averageat28percent,andpoororverypoorat57percentofthesesites.Thesmallnumber

ofsites,therestrictiontoonlyafewregions,andthebiastowardsmonitoringlakeswithknownwaterqualityissuesmeanthedataavailabledonotrepresentNewZealandlakesingeneral.(Seeindicator:Lake water quality.)

Theculturalhealthindex(CHI)usesfactorsofculturalimportancetoMāoritoassessthehealthoffreshwaterecosystems.CHIscoresconsistofthreecomponents: sitestatus,mahingakai(foodgatheringarea)status,and theculturalstreamhealth.Of41sitesassessedbetween2005and2016,11siteshadgoodorverygoodCHIratings,21hadmoderatescores,and9hadpoororverypoorratings.(Seeindicator:Cultural health index for freshwater bodiesandIssue 4: Our waterways are polluted in farming areas.)

ThereisnotenoughdatatodirectlyassesstheecologicalhealthofallNewZealand’sterrestrialandmarineecosystems,particularlyatanationalscale(seeWhere are the gaps in our knowledge about this issue?).Ourecosystemsare,however,beingaffectedbymanyoftheissuesdiscussedinthisreport(egpollutioninourrivers,expandingurbanareas,changestotheland).

Poor

Fair

Good

Excellent

Modelled median values, 2013–17

Very likely improving

Likely improving

Indeterminate

Likely worsening

Very likely worsening

Measured trends, 2008–17

Data source: NIWA

Figure 2: River macroinvertebrate community index scores


https://www.stats.govt.nz/indicators/lake-water-qualityhttp://archive.stats.govt.nz/browse_for_stats/environment/environmental-reporting-series/environmental-indicators/Home/Fresh%20water/cultural-health-index.aspxhttp://archive.stats.govt.nz/browse_for_stats/environment/environmental-reporting-series/environmental-indicators/Home/Fresh%20water/cultural-health-index.aspx

What has changed? PAST ACTIVITIES HAVE AFFECTED OUR NATIVE ECOSYSTEMS

BeforehumansarrivedinNewZealand,forestscoveredabout80percentoftheland(Nicholls,1980),butithasbeentransformedinonly800years(Wilmshurstetal,2008).ThefirstwaveofsettlersfromPolynesiaclearedmanyforestareaswithfire,reducingtheoriginalforestbyhalf.Next,Europeancoloniserscutdownandburnedforesttomakewayforfarmingandsettlements(McGlone,1989).

Today,aboutone-thirdoftheoriginalnativeforest remains,mainlyinmountainousandhillyareas.In2012,nativeforestcovered26percentoftheland,nativetussockgrasslands9percent,andnativescrub7percent(Our land 2018).(Seeindicators:Predicted pre-human vegetation andLand cover.)

Wetlandareashavebeenreducedtoonly10percent oftheirestimatedpre-humanareaandarecontinuing todeclineinmanyregions.(Seeindicator:Wetland extent.)Activesanddunes,whichwereoncewidespread inNewZealand,declinedby80percentbetweenthe 1950sand2008.(Seeindicator:Active sand dune extent.)

ChangesinbiodiversitycanbereportedusingMāoriindicatorsofbiodiversityandbiophysicalchange(egmauri–lifeforceoressence).Thereareanumberofexampleswhereiwihavecompilednarrativesandinterviewswithkaumātuatoinformthedevelopmentofplansandstrategiesalongsidecouncilsandotherorganisations. OneexampleincludesestimatesofchangeinthesizeofkererūflocksbyTūhoeTuawhenuakaumātuainthepast100years(Lyveretal,2009).

No sooner had I finished my prayers I heard this thundering coming up the valley like a jet and I thought, “Oh! I’m in trouble here.” Then I heard this sound, ‘Whoooooosh!!!’ By crikey, the trees are moving and they [kererū] were quite a distance away when they turned around and it was white everywhere. There was a constant cooing all over the place. I was in awe and shivering with fear. I was so afraid I could feel my hairs standing. Some time went by and my excitement finally settled.

Poai Nelson, 2011, translated from Māori, Ruatāhuna (Timoti et al, 2017)

SPECIES AND ECOSYSTEMS CONTINUE TO DECLINE

RecentassessmentsintheNewZealandThreatClassificationSystemacrossallnative,resident,andlivingspeciesfromland,freshwater,andmarineenvironmentsshowedthattheextinctionriskworsenedfor86speciesinthepast15years.Thisincluded61plants,10landinvertebrates,5landbirds,2seabirds,3reptiles,1marineinvertebrate,3freshwaterinvertebrates,and1freshwaterfish(seefigure3).(Note:Changeinconservationstatusismeasuredattheconservationstatussubcategory.Forexample,ifataxa(species)movedfromthreatened–nationallycriticaltothreatened–nationallyendangered,thisisanimprovementinconservationstatus.)

Theconservationstatusof26speciesimprovedwithin thepast10years.Thisincluded2plants,1bat,1freshwaterfish,2shorebirds,7seabirds,12landbirds,and1whale.Theimprovementwasconservation-dependentformorethanhalf(57.7percent)ofthespecies–meaningthatif themanagementstopped,thespecieswouldbeexpectedtodeclinetoaworseconservationstatusoverthreeoftheirgenerations.(Seeindicators:Conservation status of indigenous freshwater species,Conservation status of indigenous land speciesandConservation status of indigenous marine species.)

Between1996and2012,thetotalareaofnativeforestwasreducedby16,108hectares.Nativescrubandshrublanddeclinedby24,187hectares,andnativetussockgrasslandsreducedby30,928hectares.(Seeindicator:Land cover.)

Wetlandareasalsocontinuedtoshrink,withatleast 1,247hectareslostbetween2001and2016.(Seeindicator:Wetland extent.)Therateofdeclineinthesepreciousecosystemscanbesubstantial–157hectaresofwetlandwerelostper yearinSouthlandbetween1990and2012(Robertsonetal,2018).

Thevolumeofwaterinmanyofourriversandlakeshasbeenreducedbyusingwaterforactivitiessuchasirrigationandhydropower–includingbraidedriversystems.Thiscanchangethenumberofchannelsinariverandincreasethespreadofinvasiveplants(Carusoetal,2013;O’Donnelletal,2016).Changesinlakewaterlevelsalsoleadtothelossofnativefreshwaterhabitatneartheshore(Thompson&Ryder,2008).(SeeIssue 6: Taking water changes flows which affects our freshwater ecosystems.)

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http://archive.stats.govt.nz/browse_for_stats/environment/environmental-reporting-series/environmental-indicators/Home/Land/pre-human-vegetation.aspxhttp://archive.stats.govt.nz/browse_for_stats/environment/environmental-reporting-series/environmental-indicators/Home/Land/land-cover.aspxhttp://archive.stats.govt.nz/browse_for_stats/environment/environmental-reporting-series/environmental-indicators/Home/Fresh%20water/wetland-extent.aspxhttp://archive.stats.govt.nz/browse_for_stats/environment/environmental-reporting-series/environmental-indicators/Home/Fresh%20water/wetland-extent.aspxhttp://archive.stats.govt.nz/browse_for_stats/environment/environmental-reporting-series/environmental-indicators/Home/Land/sand-dune-extent.aspxhttps://www.stats.govt.nz/indicators/conservation-status-of-indigenous-freshwater-specieshttps://www.stats.govt.nz/indicators/conservation-status-of-indigenous-freshwater-specieshttps://www.stats.govt.nz/indicators/conservation-status-of-indigenous-land-specieshttps://www.stats.govt.nz/indicators/conservation-status-of-indigenous-land-specieshttps://www.stats.govt.nz/indicators/conservation-status-of-indigenous-marine-specieshttps://www.stats.govt.nz/indicators/conservation-status-of-indigenous-marine-specieshttp://archive.stats.govt.nz/browse_for_stats/environment/environmental-reporting-series/environmental-indicators/Home/Land/land-cover.aspxhttp://archive.stats.govt.nz/browse_for_stats/environment/environmental-reporting-series/environmental-indicators/Home/Fresh%20water/wetland-extent.aspx

MorerivermonitoringsiteshaddecliningMCIscores thanimprovingscoresfrom2008to2017–59percent hadworseningtrendsand41percenthadimproving trends(seefigure2).Forallthesesites,trendswere ratedaslikely(67–89percentcertaintyinthetrend) orverylikely(90–100percentcertaintyinthetrend). Thismethodoftrendassessmentdiffersfromthatused inpreviousenvironmentalreports.Thenumberofmonitoringsiteshasalsoincreased.Thesetrendresultsarethereforenotdirectlycomparabletothoseinpreviousreports.(SeeIssue 4: Our waterways are polluted in farming areas.)

Nationwide,62lakesorfewerhadsufficientdatafortrendtesting.Ofthosethathadsufficientdata,moresiteshadimprovingthanworseningtrendsforTLI,chlorophyll-a,ammoniacalnitrogen,andtotalphosphorusovertheperiod2008–17.Roughlythesameproportionoflakemonitoringsiteshadimprovingandworseningtrendsfortotalnitrogenandforwaterclarityinthesameperiod.

Vascular plants (2012–17)

Terrestrial invertebrates (2005–18)

Terrestrial birds (2012–16)

Shorebirds (2012–16)

Seabirds (2012–16)

Reptiles (2012–15)

Marine mammals (2009–13)

Marine invertebrates (2009–13)

Freshwater invertebrates (2005–13)

Freshwater fish (2013–17)

Bats (2012–17)

0 10 20 30 40 50 60 70Count of species

Actual improvement Actual decline

Figure X: Change in conservation status subcategory of native species by species group

Data source: Department of Conservation

Note: Only known, native, resident, living species are included.

Figure 3: Change in conservation status subcategory of native species by species group


What has contributed to this issue?PEOPLE HAVE CHANGED THE LANDSCAPE

Farmingandurbanexpansionhavedriventheclearingofforestandthedrainingofwetlands,withassociatedlossesofhabitatanddeclineinspecies.(SeeIssue 2: Changes to the vegetation on our land are degrading the soil and water.)Māorihaveseenlargeareasoftheirlanddegradedbysuchchanges,whichhasgreatlyimpactedspeciesandhabitatsofparticularsignificancetoMāoricustomaryvaluesandresources.

Compoundingthisissueisthatlandclearancewasaccompaniedbyachangeinownershipandmanagementarrangements,whichledtoradicalchangesinthenatureoftherelationshipMāorihadwiththeirwhenua.In1840,Māorihadexclusiverightsandownershipover27millionhectaresofland,butthereareonlyabout1.4millionhectaresofMāorifreeholdlandtoday(plussmallamountsoflandreturnedthroughTreatyofWaitangiclaimsandagreementssince1975).(Asher&Naulls,1987;Durie,1998;Kingi,2008;MinistryforCultureandHeritage,2017;MinistryofJustice,2017;Orange,2004.)

Onaverage,nativevegetationmakesuplessthan2percentofurbanlandandabout10percentontheurban-ruralboundary(Clarksonetal,2007).Ecologicalstudiesshowthatdroppingbelow10percentnativevegetationcovercantriggeradeclineinmanyspecies(Drinnan,2005;McIntyre&Hobbs,1999),sourbanexpansionandthefurtherlossofnativevegetationcouldcausedisproportionatelylargechangesinthebiodiversitythatremainsoncityfringes.(SeeIssue 3: Urban growth is reducing versatile land and native biodiversity.)

Oncoastaledges,reclaimingland(byinfillingswamps/wetlandsandharbours)andbuildingmarinasandseawallshaveresultedinthelossanddegradationofcoastalhabitats,particularlyinshelteredharbours(MacDiarmidetal,2009).Manyoftheseareaswerecriticallyimportantareasforiwiandhapūassourcesofsustenanceandmana.Seagrassmeadows,forexample,havedeclinedsignificantlysincethelate19thcentury.Thesemeadowsareimportantnurseryareasforfishandoftenhotspotsofcoastalbiodiversity(Morrisonetal,2014).(SeeIssue 3: Urban growth is reducing versatile land and native biodiversity.)

POLLUTION AFFECTS OUR BIODIVERSITY

Thegrowthofurbancentrescanalsoincreasepollution.Heavymetalsenteringwaterwaysareofparticular concernastheycanbetoxictofishandinvertebrates inbothfreshwaterandcoastal-marineenvironments. (SeeIssue 3: Urban growth is reducing versatile land and native biodiversity.)

Farmingincreasescontaminantsinourfreshwaterandcoastalareas,posingthreatstobiodiversitybecauseoftheirtoxicityandassociatedhabitatdegradation.Soilwashedfrompasturesandfromforestsafterfellingmovesalongwaterwaysandsettlesassedimentonstreambeds. Itfillsinthespacesusedbyfishandinvertebratesforhidingandbreeding,andmakestheirfoodhardertofindortoeat.(SeeIssue 4: Our waterways are polluted in farming areas.)

INTRODUCED SPECIES THREATEN OUR NATIVE SPECIES

Theanimalsandorganismsthathumanshavebrought toNewZealandislands(intentionallyandunintentionally)posesignificantthreatstonativebiodiversityinland,freshwater,andmarineenvironments.Thethreatsare fromcompetition,predation,anddiseases.

NewZealandisconsideredoneofthemostinvadedcountriesintheworld(Kelly&Sullivan,2010).Non- nativeplantspeciesoutnumbernatives(Wilton&Breitwieser,2000).

Stoats,possums,andratswerepresentonmorethan 94percentofNewZealandlandin2014.(Seeindicator:Land pests.)Alongwiththeimpactthatpossumshave onournativetrees,thesespeciesposesignificantthreatstoournativebirds,lizards,andinvertebrates.Thisisalsoanissueinpopulatedareasduetopredationbyhouseholdpets(catsanddogs)andnon-nativeanimalsthatexploiturbanenvironments(egratsandmice).Exoticplants fromgardenscanbeproblematic,includingthefast-growingpestplantstradescantia(wanderingwillie)andclimbingasparagus.

NewZealandhasmanyintroducedfreshwaterfish,with21speciesnowpresentinourfreshwaterecosystems(Collier&Grainger,2015).Nineofthese(egthebullheadcatfish,goldfish,andkoicarp),alongwith11introducedinvertebratespeciesand41non-nativealgaeandplantspecies,wereidentifiedasbeingpestsofgreatestconcerninourfreshwaterenvironments.(Seeindicator:Freshwater pests.)Thesepestscompetewithnativespeciesforfoodandspace,anddamageexistinghabitats.TheriveralgalspeciesDidymo (Didymosphenia geminata)forexample,isnowinmorethan200waterwaysintheSouthIsland,whereitcanformthick,densematsoveranentirestreambed(Jellyman&Harding,2016).

Morethanhalfofthe351non-nativespecies(plants,algaeandanimals)foundinourcoastalwatershaveestablishedbreedingpopulations.Thenumberofknownnon-nativespeciesalsoincreasedby10percentbetween2010and2015.(Seeindicator:Marine non-indigenous species.)

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http://archive.stats.govt.nz/browse_for_stats/environment/environmental-reporting-series/environmental-indicators/Home/Land/land-pests.aspxhttp://archive.stats.govt.nz/browse_for_stats/environment/environmental-reporting-series/environmental-indicators/Home/Fresh%20water/fresh-water-pests.aspxhttp://archive.stats.govt.nz/browse_for_stats/environment/environmental-reporting-series/environmental-indicators/Home/Fresh%20water/fresh-water-pests.aspxhttp://archive.stats.govt.nz/browse_for_stats/environment/environmental-reporting-series/environmental-indicators/Home/Marine/marine-pests.aspx

InTuawhenuaforestsinTeUrewera,introducedspecieshavecontributedtothechangeinthelanguageoftheforestofTeUrewera(Lyveretal,2017a,b).Tuawhenuakaumātuahaveobserveddecliningpopulationsofblowflies(Calliporidae),andinsectsthatpollinateawiderangeofNewZealandplants(Heath,1982;Heine,1937;Howlett,2012).BlowfliesareattackedandeatenbyintroducedEuropeanwasps(Vespula germanica) (Doherty&Tumarae-Teka,2015;Fordham,1961).

OUR USE OF NATURAL RESOURCES IMPACTS OUR BIODIVERSITY

Inthepast,harvestingforfoodorcommercialpurposescontributedtotheextinctionofsomespecies(suchasmoaandhuia).Otherharvestscauseddrasticpopulationchanges,leavingspeciesclosetoextinction.(SeeIssue 7: The way we fish is affecting the health of our ocean environmentforinformationabouttheimpactofharvestingonwhales,seals,andsealions.)

Contemporaryharvestingisalsoimpactingourbiodiversity.Commercialseafishingimpactsourmarineecology.Theinformationwehavedoesnotshowthewholepicturebutwedohavedataabouttheeffectsoffishingonprotectedmarinespecies(fromaccidentalcatch)andonseabedhabitatsfromtrawling.(SeeIssue 7: The way we fish is affecting the health of our ocean environment.)

Mining,industrialprocessing,andmanufacturinghave hadmajoreffectsonlocalecology.Insomeplaces,activitiesfrommanydecadesagohaveanenduring effectonthesoilandwater(Our land 2018).

Takingwaterforirrigation,industry,andhousehold usecanreduceriverflowsandimpactstreamhabitats andfreshwaterbiodiversity(egCarusoetal,2013;O’Donnelletal,2016).Itcanalsodamageourunique andrareecosystemsincludingbraidedrivers.(See Issue 6: Taking water changes flows which affects our freshwater ecosystems.)

DISEASES THREATEN SOME OF OUR NATIVE SPECIES

Virulentpathogens(disease-causingorganisms)thatarenewtothecountryoftenposeseriousthreatstoourbiodiversity.Becauseourunderstandingofnewdiseasesandpathogensisoftenlimited,itmaybedifficulttoputeffectivecontrolmeasuresinplace.

MyrtlerustisathreattoplantsintheMyrtaceaefamilyincludingmānuka,pōhutukawa,andrātā.Itisanaeriallybornefungaldiseasethatcankillplantsanditsmicroscopicsporesaredispersedbythewind,makingitverydifficulttocontrol.MyrtlerustwasfirstdetectedinMay2017andisnowpresentthroughoutlargepartsoftheNorthIslandandinthenorthoftheSouthIsland.Thisdistributionisrelatedtoclimaticconditionsandthepresenceofsuitablehostspecies(Beresfordetal,2018).

Ouruniquekauriforestsarealsoseriouslythreatenedbykauridieback(Phytophthora agathidicida)–adiseaseforwhichtherearetreatments,butnocures.

CLIMATE CHANGE IS BEGINNING TO AFFECT SOME SPECIES

Evidencesuggeststhatclimatechangeisalreadystartingtoimpactournativespecies.Increasingtemperatureshaveshiftedthedistributionofsomespeciesandincreased thenumbersofinvasivepestsinsomeareas.(SeeIssue 9: Climate change is already affecting Aotearoa New Zealand.)Moreresearchisneededtofullyunderstandthepotentialimpactsofclimatechangeonourbiodiversity(seeWhat are the gaps in our knowledge about this issue?).


What are the consequences of this issue?Ouruniquenativespeciesandtheenvironmentstheyinhabitareirreplaceable.Theyhaveimmenseintrinsic valueandwide-rangingvaluestopeople.Damageto ourbiodiversityaffectsusnowandallfuturegenerations ofNewZealanders.

Alossofbiodiversitycanbefeltinculturalconnections (likeasenseofidentityandbelonging),intheresourcesavailabletous(likewildfoodsources),andinfunctions(suchaspollinationofplantsorfilteringofairpollution).Underneaththesebenefitsarebackgroundsupportingprocesses,includingsoilformationandnutrientcycling bysoilorganisms.Thedegradationorlossofbiodiversitycanaffecttheseservices,manyofwhichareessentialforourwell-being(Dymond,2013).

OUR WAY OF LIFE AND CONNECTION TO THE LAND COULD CHANGE

Thetiesbetweenusandourbiodiversityrundeep– wecallourselves‘Kiwis’andproudlyusethesilverfern(ponga)forournationalidentity.Accesstonatureisanimportantcomponentofthelifestyleweenjoy.InteaoMāori,people’swell-beingdependsonthehealthoftheenvironment.Thereverseisjustastrue–thehealthof theenvironmentisdependentonpeople’swell-being.

Ouridentityasapeoplesufferswhenweexperiencedamagedorlostnativespeciesandecosystems,andrecreationalopportunitiesandtheconnectionswe havetonaturearealsodegraded.Birdsongisrecognisedbytangatawhenuaassignificantinthelanguageoftheforest.AroundRuatāhuna40–50yearsago,itwasdifficulttohearsomeonespeakmetresawayfromyoubecauseofthevolumeofnoisefromthebirdchorus(Lyveretal,2017a,2017b).

It isn’t like the old days when the beautiful thunderous sounds of the birds were consistently heard. It may well be that I have lost the skills of listening to the sounds of our forest? Nevertheless, I have noticed the great declines in our birds from the times when we grew up. There was always a consistent uproar of birds singing in our forests. When we journeyed into the forest with our father he would dismount to give his horse a rest and, he would tell us stories pertaining to the different species of birds and trees in our environment. I remember one particular time he says “Listen! Listen to what is going on in the forest. Can you hear the birds?” He would add, “You aren’t listening to the language of the trees and the birds.” I couldn’t make any sense of it at the time and I would think to myself, now how would I know what the trees are saying? The language of the trees can be heard if you listen carefully. In those days I thought it was only the rustling of the leaves while the wind blew. But I do believe that the forest isn’t as healthy as it used to be.

Menu Ripia, 2014, translated from Māori, Ruatāhuna

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Nativebiodiversityprovidesmahingakaiandotherculturallyimportantmaterialslikeraranga(weaving), androngoā(medicinaluses)forMāoricommunities. Inadditiontheyrepresentimportantindicatorsfor kaitiakiintheirmanagementoftheenvironment, aswellasbeingkeytothemaintenanceandtransmission ofintergenerationalknowledge.Alossofbiodiversity– andthequantityoffoodandmaterialavailable–limits theopportunitiesfortangatawhenuatoconnectwith andusetheenvironment.

Customarypracticesthatsurroundtheuseofbiodiversityandnaturalmaterialscanbevitalinmaintainingandreinforcingvalueslikemana(authorityandprestige),identity(ahikāroa),familytiesandlinkages(whanaungatanga),andknowledgesystems(mātauranga),aswellastheinter-generationaltransferofknowledge(whakahekekōrero)(Harmsworth&Awatere,2013;Lyveretal,2017a,2017b).

Biodiversityalsomakessignificantcontributionstoculturalexpressionslikeprayer(karakia),songs(waiata,mōteatea,pao),instrumentalmusic(taongapuoro),performances(kapahaka),products(tāmoko,whakairo),andrepresentationsoftraditionalthought(wairua) (Harmsworth&Awatere,2013;Timotietal,2017).

Theseexpressionswereoftencraftedtoexpresswhakapapa,relationshipsbetweenthenaturalandhumanrealms,andtheresponsibilitiesandreciprocitypeoplehavewiththeenvironment(Timotietal,2017;Walshetal,2013).Theuseofmaterialsandengagementwiththeenvironmentiscriticalfortangatawhenuatocompose,protect,maintain,regenerate,andapplyknowledgeandexpressionsofculture.

LEVELS OF BIODIVERSITY MAY INFLUENCE ECOSYSTEM RESILIENCE TO CLIMATE CHANGE

Highlevelsofbiodiversityincreaseecosystemresiliencetomoderatetoextremeclimateevents(Isbelletal,2015).Declinesinbiodiversity,however,canhaveanoppositeeffect(Oliveretal,2015).Specieslossandhabitatdegradationcanmakeecosystemslessresilient toenvironmentalchange(Isbelletal,2015)leading tofurtherdeclinesinbiodiversity.

Benefits from nature – ecosystem servicesPeoplehaveaspecialrelationshipwiththeenvironment.ThisrelationshipcanbedescribedinanumberofwaysincludingthroughateaoMāoriperspective.Anotherframeworktodescribeourrelationshipwiththeenvironmentisthroughthebenefitsthatecosystemsprovidetousandoursociety.Thisisreferredtoasan‘ecosystemservices’approach.Benefitsarecategorised asprovisioning(egfoodandfibre),regulating (egfloodorclimateregulation),supporting (egphotosynthesisandnutrientcycling),andcultural(egwairua/spiritual,recreational)services.

NewZealand’snativeforestsregulatetheclimatebystoringcarbon,preventerosion,providenurseryhabitats,andcreatenectarforhoneyproduction.Theyarealsothebackboneofourrecreation andtourismactivities(Dymondetal,2015).

Naturalwetlandsalsoprovideimportantecosystemservices.Wetlandsareoftencalled‘nature’skidneys’becausetheypurifywaterbyfilteringoutnutrientsandsediments.Wetlandsregulatewaterflowduringstormsandstorecarbonaspeat.InNewZealand,theyhaveaparticularsignificancetoMāoriastaongaand formahingakai(Clarksonetal,2013).

Areductioninbiodiversityandecosystemhealthreducestheabilitytoprovidebenefitsandservices(Cardinaleetal,2012).Alossofbiodiversitycanreducethecapacityofanecosystemtoproducebiomass,decomposeandrecycleessentialnutrients,andmakeitlessstableandthereforemorevulnerabletoclimatechange.


Where are the gaps in our knowledge about this issue? ASSESSING ECOSYSTEM CONDITION IS DIFFICULT AND COMPLEX

Itisdifficulttomeasuretheoverallconditionofourecosystems(Andreasenetal,2001)becausethesystemsthemselvesarecomplex,andclimateandlandscapevariationsareoverlaid.Informationisparticularlylimited forrareandnaturallyuncommonecosystems.

Despiterecenteffortstoimprovefreshwaterquality,westillhaveincompleteknowledgeabouttheconditionofourfreshwaterecosystems,habitats,andtheirfishandinvertebratecommunities.Forexample,althoughtheareaofwetlandshasdeclined,littleisknownabouttheconditionofthewetlandsthatremain.Ourknowledgeaboutlargeriversandthebiologyofgroundwaterecosystemsisalsopoor(Sirisenaetal,2013)andonlyaround150ofthenation’smorethan3,000lakesareregularlymonitored byregionalauthorities(Larnedetal,2019).

OUR KNOWLEDGE OF SOME ECOSYSTEMS AND SPECIES IS VERY LIMITED

Therearemajorgapsinourknowledgeofthemarineenvironment.Wehaveoneofthelargestexclusiveeconomiczones(EEZ)intheworldandmostofithas neverbeensurveyed.Whilescientistshaveidentified morethan17,000species,manythousandsmoreareyet tobediscoveredandidentified.

Informationisalsomissingataspecieslevel–theconservationstatusof2,805speciescannotbeassessedbecauseofalackofdata.Somegroupsofspeciesarenotwellstudiedandmanyspeciesareyettobedescribed.Thisisparticularlytrueforinvertebrates.Formarineinvertebrates,thenumberofspeciesassessedfortheirconservationstatus(412)mayonlybe5percentofthe totalnumberofspecies.

Introducedspeciesareoneofthegreatestnegativeinfluencesonourterrestrialbiodiversity.Wedonothaveaccuratedataaboutthelocationornumberofintroducedspeciesorhowtheyarechanging.

THE FULL IMPACTS OF CLIMATE CHANGE ARE NOT KNOWN

Researchandmonitoringareneededtobetterunderstandtheconsequencesofclimatechangeonournativespeciesandourbiodiversity.Itislikelytohavesignificantimpactsonourbiodiversitylikechangingwherespeciesliveandtheirreproductivebehaviouraswellasincreasingtheir riskfrominvasivespecies.Climatechangecouldalso createmismatchesintimingbetweenspeciesandtheirsourcesoffood.

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How we use our land

TH E M E 2


Photo credit: Photonewzeland

The way we use our land and the physical changes we have made to it affect our environment. Those effects continue to the waterways that drain the land, and include loss of ecosystems and habitat as well as reduction in the quality of our soil and fresh water. There are also consequences on our well-being, including the benefits (ecosystem services) we receive from nature, like flood control, water filtering, and soil retention.

Thisthemefocusesontwomajorchangesthathavebeenmadetotheland:1. What we have removed: Cuttingdownnativeforests,

drainingwetlands,andclearinglandforfarminganddevelopmenthaveacceleratedournaturallyhighratesofsoilloss.Thishasalsodegradedarangeofecosystemservicesprovidedbynativevegetation.

2. What we have built: Human-madestructuresandhardsurfacesaffectthenaturalsystemswerelyon.Thereisaparticularfocusinthisissueonthespreadofurbanareasoverversatileland(whichcanbeusedformanypurposes,includingfarming)andscarcehigh-classsoils.

Buildingstructuresandchangingthewayweuselandenableustomovearoundthecountryandgenerateelectricity,aswellassupportindustrieslikefarmingandaquaculture.Localchanges,however,canhavesignificantimpactswhentheyareconsideredasawhole.Oneexampleisthecollectiveimpactofbarriers,likeculvertsanddamsinwaterways,onournativefish(Franklinetal,2018;Gluckmanetal,2017).(SeeIssue 1: Our native plants, animals, and ecosystems are under threat.)Anotheris theeffectonourcoastsofinfillingharboursandestuariestoreclaimland(Our marine environment 2016).

Otherpartsofthisreportpresentdifferentissuesrelated tochangestoourland:

Issue 1:Ournativeplants,animals,andecosystems areunderthreat–howchangestonativehabitataffectbiodiversityandecosystemhealth.

Issue 4: Ourwaterwaysarepollutedinfarmingareas–howmore-intensiveagricultureischangingoursoils,andhowthispolluteswaterways.

Issue 5:Ourenvironmentispollutedinurbanareas–howbuildingsandinfrastructureaffectthedistributionofpollutantsfoundinourcitiesandtowns.

Issue 6: Takingwaterchangesflowswhichaffects ourfreshwaterecosystems–howourwaterwayschangewhenwateristakenoutforirrigationandhydroelectricgeneration.

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SPATIAL EXTENT

About40percentofourlandisnowexoticgrasslandandispronetoerosioninsusceptibleareas.

DEPARTURE FROM NATURAL CONDITIONS

About65percentofournativeforesthasbeenremovedand90percentofourwetlandshavebeendrained.

IMPACTS ON WHAT WE VALUE

Lossofnativeforestsandwetlands,andincreasederosionaresignificantthreatstoourecosystems,soil

productivity,andthehealthofourfreshwater,estuarine,andmarineenvironments.Thisalsoimpactsculturalpracticesandknowledge.

KNOWLEDGE GAPS

Welackmonitoringdataforerosionandinformationaboutthebenefits ofnativevegetationandhowwell anyinterventionsareworking.

IRREVERSIBILITY

Itisdifficulttoreverseasvegetationwasremovedtosupporttheway weliveandsustainoureconomy.

I S S U E 2

Changes to the vegetation on our land are degrading the soil and water Logging native forests, draining wetlands, and clearing land have degraded a range of benefits provided by native vegetation, accelerated our naturally high rates of soil loss, and affected our waterways.

Why does this issue matter?


What is the current state of this issue?MODIFIED LAND COVER HAS INCREASED

Landcoverdescribesthetypesofvegetationand featuresthatcovertheland’ssurface,likenative andnon-native(exotic)vegetation,waterbodies, builtenvironments,andbarenaturalsurfaces(eggravel androck).NationalsurveysofAotearoaNewZealand’s landcoverwerecarriedoutin1996,2002,2008,and mostrecentlyin2012.(Seeindicator:Land cover.)

Asof2012,justunderhalfofourlandarea(49percent)wascoveredbynaturalland-covertypes(seefigure4).Nativeforestcovered26percentofourlandarea,mostlyinmountainousandhillyareas.Othernativevegetation(liketussockgrassland,scrub,andshrubland),waterbodies,andnaturallybaregroundtogetheraccountedfortheother23percent.

Bycontrast,51percentofourlandareahadmodified landcover,likeurbanareasandexoticvegetation. Exoticgrassland(pasture)wasthelargestsingletypeoflandcoverinNewZealandandaccountedforabout40percentofourtotallandarea.Exotic(plantation) forestcoveredabout8percentofourlandarea,concentratedinthecentralNorthIsland.

Forestry and logging’s contribution to our economy

$1.74billion 0.6percentofgrossdomesticproduct(GDP) 6,080(0.2percent)peoplewereemployed inforestryandloggingastheirmain incomesource.

Note: All gross domestic product (GDP) figures are from the National accounts (Industry production and investment): year ended March 2017. These figures exclude manufacturing or processing of primary products. They are in current prices, ie not adjusted for the effect of changing prices over time. The people employed information is from linked employer-employee data (LEED). The measure is main earning source, by industry using New Zealand standard industry output categories.

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http://archive.stats.govt.nz/browse_for_stats/environment/environmental-reporting-series/environmental-indicators/Home/Land/land-cover.aspx

Land cover, 2012

Cropping/horticulture

Exotic forest

Exotic grassland

Exotic scrub/shrubland

Indigenous forest

Indigenous scrub/shrubland

Natural bare/lightly-vegetated surfaces

Other herbaceous vegetation

Tussock grassland

Urban area

Water bodies

Data source: Manaaki Whenua – Landcare Research

Artificial bare surfaces

Figure 4: Land cover, 2012


EROSION RISK VARIES

Erosionriskvariesfromplacetoplace,reflectingthingsweinfluence(landcover)andnaturallyvariablefactorslikesoiltypes,geology,topography(shapeoftheland),andrainfall.

Asof2012,approximately5percentofourlandareawasclassifiedashighlypronetoerosion,and60percentofhighlyerodiblelandwasintheNorthIsland.(Seeindicator:Highly erodible land.)

Sevenregions(Gisborne,Manawatu-Wanganui,Canterbury,Hawke’sBay,Southland,Northland,andOtago)hadmorethan1,000squarekilometresofhighlyerodiblelandin2012(seefigure5).

Erosioncanhappeninvariousways.Landslideerosionoccurswhenasoilslopeisdestabilisedduringstormrainfall.Gullyerosionbeginsatagullyheadandexpandsuphillsidesoverdecades.Earthflowerosionistheslowdownwardmovement(approximately1metreperyear) ofwetsoilslopestowardswaterways.Asat2012,landslideriskappliedto77percentofthehighlyerodiblelandinNewZealand.

Southland

Otago

Canterbury

West Coast

Marlborough

Nelson

Tasman

Wellington

Manawatu-Wanganui

Taranaki

Hawke's Bay

Gisborne

Bay of Plenty

Waikato

Auckland

Northland

0Highly erodible land area (km²)

High landslide risk – delivery to stream

High landslide risk – non-delivery to stream

Severe earthflow risk

Moderate earthflow risk

Gully risk

Figure X: Highly erodible land area by region and risk type, 2012


1,000 2,000 3,000

Figure 5: Highly erodible land area by region and risk type, 2012

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https://www.stats.govt.nz/indicators/highly-erodible-land

What has changed?EXTENSIVE LOSS OF NATIVE LAND COVER CONTINUES TODAY

Thevegetationonmorethanhalfourcountry haschangedsignificantlysincehumansettlement. (SeeIssue 1: Our native plants, animals, and ecosystems are under threat.)Nativeforestsoncecoveredabout 80percentofNewZealand’slandarea–allbutthe topsofmountainsandthewettestlowlands(Nicholls,1980).About65percentofouroriginalnativeforest hasbeenremoved.

Wetlandsoncecoveredabout10percentofNewZealand’slandarea,especiallyincoastalareasandlowlands.About90percentoftheseoriginalwetlandshavebeendrained.(Seeindicator:Wetland extent.)

Thenativevegetationcoverhascontinuedtodecline, eveninrecentyears–beingconvertedtolandcoverlikeexoticgrassland(pasture),plantationforestry,andurbanareas.Between1996and2012therewasa1.3percentlossoftussockgrassland(reducedby31,000hectares),a1.3percentlossofindigenousshrubland(reducedby24,000hectares),anda0.2percentlossofnativeforests(reducedby16,000hectares).(Seeindicator:Land cover.)

Wetlandlosshasalsocontinued(Bellissetal,2017).Between2001and2016,214wetlandscoveringnearly1,250hectareswerelost,withafurther746wetlandsdeclininginsize.Theregionswiththegreatestnumber ofwetlandslostordecliningwereCanterbury,West Coast,Southland,andAuckland.Mostofourlargeremainingwetlandsareinpublicownership,butthevastmajorityofsmallerwetlandsaresurroundedbyfarmland inprivateownership(Myersetal,2013).

THE MIX OF EXOTIC LAND COVER HAS CHANGED

Shiftsbetweentypesofexoticlandcoveralsooccurredbetween1996and2012.Themainchangeswerefromexoticgrasslandandshrublandtoexoticforest(some exoticforestconversiontograsslandandshrubland) anda10percentexpansioninurbanlandcover.

Theseshiftshaveoccurredatdifferentratesbetween thenationalsurveysin1996,2001,2008,and2012. Forexample,croplandexpandedbetween1996and2001,butmoresobetween2001and2008.Between1996and2001,theareacoveredbyexoticforestincreasedbymorethan10percent(expandedby194,000hectares).Inrecentyearsdeforestationandconversiontootherlanduseshaveexceedednewtreeplanting,sobetween2008and2012theareaofexoticforestdecreasedbyabout1percent(declined24,000hectares)(seefigure6).

Figure 6: Exotic forest area net change, 1996–2012

-50

0

50

100

150

200

1996–2001 2001–2008 2008–2012

Are

a (th

ousa

nds

of h

ecta

res)

Figure X: Exotic forest area net change, 1996–2012



http://archive.stats.govt.nz/browse_for_stats/environment/environmental-reporting-series/environmental-indicators/Home/Fresh%20water/wetland-extent.aspxhttp://archive.stats.govt.nz/browse_for_stats/environment/environmental-reporting-series/environmental-indicators/Home/Land/land-cover.aspx

What are the consequences of this issue?

EROSION AND SOIL LOSS INCREASED

TheNewZealandempiricalerosionmodel(NZEEM) hasbeendevelopedtoestimateNewZealand’sannualsoilerosion,takingaccountoflandcover,thelocationofhighlyerodibleland,andaverageannualrainfall(Dymondetal,2010).Intheabsenceofmeasureddata,NZEEMprovidesestimatesofsoilerosion.Themodelledrateofsoilerosionis720tonnespersquarekilometreperyear,withsimilarratesintheNorthandSouthislands.(Seeindicator:Estimated long-term soil erosion.)

ThemodelledsoilerosionisespeciallyhighintwopartsofAotearoaNewZealand,butfordifferentreasons(seefigure7).InGisborne,thelackofwoodyvegetation(shrubsandtrees),combinedwiththearea’sgeology(steepslopesandloosesoils),resultinhighsoilerosionrates.OnthewestcoastoftheSouthIsland,despitethehighproportionofnativeforestcover,theregion’snaturallyhighrainfall andmountainousterrainaccountforhighratesofsoilloss.

Expandingareasofexoticgrasslandsincehumansarrived inNewZealandhaveacceleratedournaturalhighrates oferosionandsoilloss.NZEEMestimatesthatofthe 192milliontonnesofsoillostannuallyintowaterways,44percentofthesedimentcomesfromlandcovered inpasture(Our land 2018).

EROSION AND SOIL LOSS ARE COSTLY AND CREATE SEDIMENT

Soilproductivitymaybeaffectedwhenthetopsoilis lost.Topsoillostinlandslidescanresultindegraded soilandlostpastureproductivitythatmaynotbe regainedinourlifetimes(Lambertetal,1984;Rosser &Ross,2011).Reducedsoilproductivitycanleadtoagreaterdemandfornutrients(typicallythroughfertiliser),whichbringsanaddedfinancialandenvironmentalburden.Theeconomiclossesassociatedwithsoilerosionandlandslidesareestimatedtobeatleast$250–300million ayear(Page,2015).

Increasederosionandsoillosscanalsoincreasetheconcentrationofsedimentinourrivers,lakes,andcoastalenvironments.(SeeIssue 4: Our waterways are polluted in farming areas.)Excesssedimentcaninhibitgrowthofaquaticandmarineplants,andalgae,damagethestructuresthatmarineanimalsusetorespire(likefishgills)(Loweetal,2015),smotherseabedhabitats(Clapcottetal,2011),degradeaestheticvaluesandrecreationaluse,andincreasetheriskoffloodingintownsandcities(Davies&McSaveney,2011).

What has contributed to this issue?

LAND USE HAS CHANGED TO SUPPORT THE WAY WE LIVE

Tosupportthewayweliveandgrowoureconomy,wehaveincreasedthecoverofexoticforestry.Onceplanted,theseforestshavesomesimilarcharacteristicstothenativeforeststheyreplace.Butitisduringharvestingthatthischangeinlandusecanhaveconsequences,particularly onthestateofhighlyerodibleland.

Clear-felling(themethodusedtoharvestforestsinNewZealand)exposesanddisturbssoil,including fromtheconstructionofroadsusedforvehicleaccessduringharvesting.Thissoilexposureanddisturbance canincreaseerosionandtheamountofsedimententering ourwaterways.Hillylandthatispronetoerosionisparticularlyvulnerableforuptosixyearsafterharvest, untilnewlyplantedtreeshavegrownenoughtoprovide acanopyoverthereplantedarea(Marden&Rowan,1993).

Agricultureisoneofthelargestindustriesinthetradableeconomy.Tosupportgrazing,landhasbeenconverted,wetlandareashavebeendrained,andgrassand legumesplanted.

Exoticgrasslandsaremarkedlydifferenttonativeforestsintheecosystemservicestheyprovide,aswelltheirsusceptibilitytoerosion.Streamsinfarmedareastypicallyreceivehigherrun-off(lossofwaterfromthelandthatmaytransporterodedsoil),particularlywhereriparianvegetationhasbeenremoved.Thisisbecausepastureinterceptslessrainthanforestvegetationandgrazinglivestockcancompactthesoil.Livestockcanalsocausedamagetostreambanks,channels,andriparianareas(McDowell&Wilcock,2008).

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http://archive.stats.govt.nz/browse_for_stats/environment/environmental-reporting-series/environmental-indicators/Home/Land/long-term-soil-erosion.aspx

20,000

Figure X: Modelled long-term soil erosion, 2012 (tonnes/km²)


Note: Data was not available for Stewart Island.

Figure 7: Modelled long-term soil erosion, 2012 (tonnes/km2)


Marlborough Sounds: Pāua, water, kelp, and forestry

PāuaaredeservingoftheirplaceinNewZealandcultureasaKiwiicon.Theyarevaluedasataonga(treasure)andasourceofmahingakaibyMāoriandotherfishers.LiningtheroughexterioroftheirshellistheiridescentblueandpurplematerialbelovedofjewellersandMāoricarvers.

Commercialfishersharvestthelargerblack-footpāua(Haliotis iris).PāuaisexportedtoChina,Malaysia,Singapore,andHongKong,withagrowinginterestinliveexports.Also,sinceabaloneisadelicacyinChina,touristsoftenenjoyourpāuainChineserestaurantswhentheyvisitNewZealand.

Aslargeseasnails,pāualiveonrocksneartheshoreandusearadula(tongue)toscrapealgaeofftherocksandcutpiecesofkelp(especiallythegiantkelpMacrocystis pyrifera)downtoanediblesize.Kelpbedscreatecalmerareasforlarvaeandyoungpāua,andprovidehabitatforotherspecieslikekina,rocklobster,andbluecod.Pāuathrive inclean,clearwater–themostproductivepāuafisheriesareonexposedcoastsbesidelandcoveredinnativeforest.

IntheMarlboroughSounds,largeareasofnativevegetationhavebeenreplacedwithplantationforests–morethan17,000hectaresin2017(Ulrich,2017).Whenthesetreesmatureandareharvested,thebaresoilisexposedtowindandrainforseveralyearsuntilnewtreeshavegrown.Thisincreaseserosion(particularlyonsteepslopingsites)andtheriskofsedimentbeingcarrieddownstreamsintothesea.

Onceinthewater,sedimenthasanumberofnegativeeffects–settlingonkelpandreducingitshealth,smotheringyoungpāua,hinderingthegrowthof adultpāua,andmakingitdifficultforlarvaetosettle.Sedimentationcanalsomakepāuaeasiertodislodge fromrocksandthereforemorevulnerabletopredators. Theimpactsofsedimentationalsohaveaneconomic costandarethoughttobeafactorinanestimatedlossofquotavalueofabout$20millionforthepāuafishingindustrynationwidefor2001–14(Larnedetal,2018a).

Pāuaandkelparealsoaffectedbyfishingand climatechange(warmertemperaturesandacidification).Inresponsetothesecompoundingpressures,MoanaNewZealand(NewZealand’slargestMāori-ownedfishingcompany)pilotedanecosystemservicereviewtoidentifythreatstothepāuaecosystem(AotearoaFisheriesLimited,2014).ThiswasalignedwithMoana’sstrongbeliefintheirroleaskaitiaki(guardians)oftheseaforfuturegenerations,andaworldfirstforacommercialfishery.

Thereviewidentifiedsedimentationfromhumanactivitiesasasignificantriskforpāuafisheries.Italsoraisedtheimportanceofunderstandingthecompoundingpressuresontheecosystem;managingcustomary,recreational,andcommercialpāuafishing;collaboratingoncomplexresourcemanagementchallenges;andcalculatingthemonetarylossofecosystemservices.

Awarenessoftheimpactsofloggingonmarineecosystemshassincegrown,andrecommendationsforbetterforestrypracticeswereproposedinaScionreporttoMarlboroughDistrictCouncil’sEnvironmentCommitteeinDecember2015(Ulrich,2017).Theserecommendationsincludednotloggingtothewaterline,usingdifferentharvestmethods,andretiringthesteepestandmosterosion-proneland. ThedraftMarlboroughEnvironmentalPlanproposesprohibitingharvestingwithin200metresofthecoast.

} Pāua are found on our rocky shores. Photo credit: Claire Murphy

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Increased run-off Removing vegetation, compacting soil, and paving land all increase run-off that carries sediment and pollutants into waterways.

Farming livestock leads to run-offLand compaction by livestock and removal of riparian vegetation increase run-off. Pasture is now the most extensive land cover in New Zealand.

Unprotected soil is more susceptible to erosionDuring clear-felling, soil is exposed, erosion increases as does the amount of sediment entering our waterways.

THE PROCESS OF EROSIONWater, wind, or ice can move sediment into rivers and streams.

Nutrients and soilare washed off.

Compacted soil

Soil without cover

Grass intercepts less rain than trees and bushes.

CLIMATE CHANGEExtreme rainfall is likely to become more frequent, increasing erosion risk, especially in areas with steep slopes and loose soils, and lacking woody vegetation.

Reclaiming land

Forestry

Urban expansion

Sediment entering waterways

Loss of productive soil

Draining of wetlands

Loss of ecosystem health and services

Construction

THREAT TO FRESHWATER AND MARINE HABITATSNative forests, shrubland, and wetlands regulate water flows and help with flood control and drought recovery, store carbon, and purify water. Excess sediment reduces the growth of plants, damages fish gills, and can smother riverbed and seabed ecosystems.

Increased flood risksLoss of native vegetation from a catchment increases the risk of floods in towns and cities downstream.

Degradation of land, waterways, and marine environmentsReduces aesthetic value and cultural and recreational use.

CONSEQUENCES

Farming

The changing way we use our landReplacing native vegetation with exotic forest, grasslands, or urban areas can increase erosion and degrade land, freshwater, and marine environments.


LOSS OF NATURAL BENEFITS FROM THE LAND

Nativeforests,shrubland,andwetlandsprovideuswithawiderangeofecosystemservices.Thesebenefitsincluderegulatingtheflowofwaterinriversandstreams,storingcarbon,purifyingwater,andprovidinghabitatsfornativespecies(Patterson&Cole,2013).Bothhistoricandrecentchangesinlandcoverhaveseriousimpactsonourbiodiversityandecosystemsasnativehabitatsarelost anddegraded.(SeeIssue 1: Our native plants, animals, and ecosystems are under threat.)

Wetlandsareoneexample.Ourremainingfreshwaterwetlandswereestimatedtoprovidebenefitswithanestimatedvalueofmorethan$5millionperyearin 2012(Patterson&Cole,2013).Thosewiththehighestestimatedvalueincludedfloodcontrol,droughtrecovery,aestheticandscientificvalue,andwaterpurification(Clarksonetal,2013).Acompoundingissueisthat drainingonewetlandoftenaffectstheintegrityof anyremainingneighbouringwetlands.

CULTURAL HEALTH AND IDENTITY ARE AFFECTED

TransformationofthelandcontinuestohaveasignificanteffectonMāoriculture.Māoricommunitiesseelandandallitproducesasasourceofculturalidentityandmana(Smithetal,2017)andintegraltothespiritualwell-beingofpeople(Harmsworth&Awatere,2013).

AteaoMāoriviewexpressedthroughkiutakitai(fromthemountainstothesea)highlightsthateffectsarefelt(andaccumulate)fromthemountainstoestuaries,coasts,andmarineenvironments.Whenecosystemsandbiodiversityhavebeendegraded,thereisacorrespondingeffecton theextent,quality,andaccesstocustomaryresources.

Māoriseeaneedforimprovedprovisionsfortangatawhenuatorestoreconnectionsbetweeniwiandhapū andtheirenvironments,andenableMāoriparticipation indecision-makingatalllevels(Ruruetal,2017).

Where are the gaps in our knowledge about this issue?

POOR UNDERSTANDING OF HOW OUR ACTIVITIES AFFECT EROSION

Whiletherearenationalmodelsthatestimateerosion risksandrates,thereareveryfewsiteswhereerosionisactuallymeasured.Withoutdatacollectedatasufficientlyfinescaleandovertime(suchaslong-termtrialsandfieldsites),thereislimitedunderstandingofwhatishappening,where,andtowhatextent.Theextentofhuman-inducederosionasopposedtothatresultingfromnaturalprocesses,likestrongearthquakesorintenserainfallevents,isalso notwellunderstood.

Withoutmeasureddataonerosionrates,thereisalsolimitedquantitativeunderstandingofhoweffectivelymitigationstrategies,likeriparianplantingandsoil

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