Conservation, restoration Conservation, restoration and effects of climate and effects of climate change on wetlandschange on wetlands

Dr Debbie ChapmanDr Debbie Chapman

School of Biological, Earth and Environmental SciencesSchool of Biological, Earth and Environmental Sciences

University College Cork, IrelandUniversity College Cork, Ireland

curriculum in natural environmental science, vol. 2, 2010

Value of wetlandsValue of wetlands

Essential habitat for rare or endangered speciesEssential habitat for rare or endangered species Commercial fisheriesCommercial fisheries Recreational fisheriesRecreational fisheries Natural improvements to waterNatural improvements to water

qualityquality Overwintering habitat for waterfowlOverwintering habitat for waterfowl Reducing erosion and buffering storm impacts Reducing erosion and buffering storm impacts

(coastal wetlands)(coastal wetlands) Mitigating impacts of sea level rise (coastal Mitigating impacts of sea level rise (coastal

wetlands)wetlands)

Wetland loss: examplesWetland loss: examples

UK East Anglian FennlandUK East Anglian Fennland 1717thth Century: 3,380 km Century: 3,380 km22

Present time: about 10 kmPresent time: about 10 km22

USAUSA 1616thth Century: 900,000 km Century: 900,000 km22

Present time: 400,000 kmPresent time: 400,000 km22 (California and Ohio lost 91% and (California and Ohio lost 91% and 90% respectively)90% respectively)

Reasons for lossReasons for loss

Natural succession (usually matched by creation Natural succession (usually matched by creation of new wetlands)of new wetlands)

Drainage and reclamation to create agricultural Drainage and reclamation to create agricultural landland

Lowering of water Lowering of water table through ground-table through ground-water abstractionwater abstraction

Interference with Interference with hydrological regimes hydrological regimes (e.g. impoundment of (e.g. impoundment of rivers, coastal rivers, coastal development)development)

Tree stumps in the reservoir created by impoundment of a river for a hydrolectiricty scheme in Southern Ireland

Degradation of coastal marshesDegradation of coastal marshes

Sea level rise and land subsidence need to be Sea level rise and land subsidence need to be matched by sediment and organic matter matched by sediment and organic matter accumulationaccumulation

Human activities are leading toHuman activities are leading toan imbalance by decreasingan imbalance by decreasingsediment accretionsediment accretion

Creation of barriers toCreation of barriers tolandward marsh growth,landward marsh growth,e.g. roads, sea wallse.g. roads, sea walls

Harvesting of treesHarvesting of trees Disturbance of hydrologicalDisturbance of hydrological

regimesregimes

A causeway has separated this wetland from the coast and created an artificial lagoon of less value to waterfowl

Climate change projectionsClimate change projections

Global mean temperature change from 1990: Global mean temperature change from 1990: 1.41.4––5.8 5.8 °°CC

Sea level rise: 10Sea level rise: 10––90 cm by year 210090 cm by year 2100 Change in frequency and intensity of extreme Change in frequency and intensity of extreme

climate events, e.g. increase in number of hot climate events, e.g. increase in number of hot days, fewer cold days, more frequent intense days, fewer cold days, more frequent intense downpours, increased frequency and intensity of downpours, increased frequency and intensity of floods and droughtsfloods and droughts

The greatest changes in temperature and The greatest changes in temperature and precipitation likely to occur in the northern precipitation likely to occur in the northern hemispherehemisphere

Possible impacts from projected Possible impacts from projected extreme climate eventsextreme climate events

Climate eventClimate event Projected impactProjected impact

Higher max temps, heat Higher max temps, heat waveswaves

Heat stress in wildlifeHeat stress in wildlife

Higher min temps, fewer cold Higher min temps, fewer cold daysdays

Extended range of pests and disease Extended range of pests and disease vectorsvectors

More intense precipitation More intense precipitation eventsevents

Increased flooding, increased soil Increased flooding, increased soil erosion, landslide damageerosion, landslide damage

Summer droughtsSummer droughts Reduced water quantity and quality, Reduced water quantity and quality, risk of firesrisk of fires

Intensified tropical cyclones Intensified tropical cyclones (wind and rain)(wind and rain)

Coastal erosion, damage to coastal Coastal erosion, damage to coastal infrastructure, physical damage to infrastructure, physical damage to coastal ecosystems such as coastal ecosystems such as mangrove swampsmangrove swamps

Climate impacts on wetlandsClimate impacts on wetlands

It is likely that climate change impacts on It is likely that climate change impacts on water resources over the next 20 years will water resources over the next 20 years will be small relative to the impacts of other be small relative to the impacts of other changeschanges

Most likely impact on wetlands will be Most likely impact on wetlands will be through alteration of hydrological regimes through alteration of hydrological regimes and occurrence of extreme weather events and occurrence of extreme weather events

Climate change: Inland wetlandsClimate change: Inland wetlands

Change of plant communitiesChange of plant communities Invasion or expansion of alien speciesInvasion or expansion of alien species Tropical wetland floodplainsTropical wetland floodplains

replaced with salt waterreplaced with salt waterhabitats and salthabitats and salttolerant speciestolerant species

Loss of feeding/breedingLoss of feeding/breedinggrounds for birds and fishgrounds for birds and fish

Interrupted migrationInterrupted migrationroutes for birdsroutes for birds Regular tidal inundation

leaves insufficient feeding area exposed for the birds

Climate change: Coastal wetlandsClimate change: Coastal wetlands

When combined with other human-induced losses, When combined with other human-induced losses, coastal wetland loss could be as high as 70%coastal wetland loss could be as high as 70%

Vulnerable wetlands are low-lying deltas and coastal Vulnerable wetlands are low-lying deltas and coastal plains – estuaries, lagoons, salt-marshes, mangrovesplains – estuaries, lagoons, salt-marshes, mangroves

Climate change will lead to:Climate change will lead to: Landward intrusion of seawaterLandward intrusion of seawater Coastal inundation and stormCoastal inundation and storm

surge floodingsurge flooding Inland and upstream salinityInland and upstream salinity

intrusionintrusion Changes in ecosystem structureChanges in ecosystem structure

caused by changes in temperaturecaused by changes in temperatureand rainfall patternsand rainfall patterns

Attempts to restrict coastal erosion have been abandoned at this beach in Western Ireland

Projected impacts of climate change in Projected impacts of climate change in Europe: inland wetlandsEurope: inland wetlands

Increased winter rainfall and river flows, leading to Increased winter rainfall and river flows, leading to floodingflooding

Decreased summer flows and higher temperatures Decreased summer flows and higher temperatures leading to low dissolved Oleading to low dissolved O22 and poor water quality and poor water quality

Increased fish productivityIncreased fish productivityand a shift towards cyprinidand a shift towards cyprinidand percid fishand percid fish

Peatlands will expand north-Peatlands will expand north-wards, possibly replacingwards, possibly replacingtundratundra

Loss of isolated depressionalLoss of isolated depressionalwetlands may affect migratorywetlands may affect migratoryand breeding bird populationsand breeding bird populations

Evidence of a breeding population of carp in a shallow lake in Ireland

Projected impacts of climate change in Projected impacts of climate change in Europe: coastal wetlandsEurope: coastal wetlands

Mediterranean and Baltic deltas, estuaries and salt Mediterranean and Baltic deltas, estuaries and salt marshes particularly at risk from sea level rise marshes particularly at risk from sea level rise (extent of development on coasts restricts (extent of development on coasts restricts options for conservation/restoration)options for conservation/restoration)

Possible loss of salt marshes andPossible loss of salt marshes andintertidal estuarine zones will intertidal estuarine zones will reduce habitats for wildlife,reduce habitats for wildlife,fish and migratory birdsfish and migratory birds

Distributions of some shorebirdsDistributions of some shorebirdsalready occurring due toalready occurring due tochanges in regional temperaturechanges in regional temperaturepatternspatterns

RhRhôône, Po and Elbe deltasne, Po and Elbe deltassusceptible due to existing reducedsusceptible due to existing reducedsediment loadssediment loads

Erosion of rare estuarine peat saltmarsh in the West of Ireland

Conservation and restorationConservation and restoration

Conservation - long-term preservation and Conservation - long-term preservation and protection of the functions and values of protection of the functions and values of wetlandswetlands

Restoration – returning a degraded Restoration – returning a degraded wetland (rehabilitation) or former wetland wetland (rehabilitation) or former wetland (re-establishment) to a pre-existing (re-establishment) to a pre-existing condition or as close to that condition as condition or as close to that condition as possiblepossible

Conservation of coastal wetlands for Conservation of coastal wetlands for impacts of climate changeimpacts of climate change

Manage landward reinstatement of coastal Manage landward reinstatement of coastal wetland habitats through removal of sea defense wetland habitats through removal of sea defense structuresstructures

Design multiple-use reserves and protected Design multiple-use reserves and protected areas which incorporate corridors that would areas which incorporate corridors that would allow for migration of organisms as a response allow for migration of organisms as a response to climate changeto climate change

Expand aquaculture that could relieve stress on Expand aquaculture that could relieve stress on natural fisheriesnatural fisheries

Integrated resource managementIntegrated resource management

Restoration: PassiveRestoration: Passive

Removal of cause of degradation and Removal of cause of degradation and allow natural regeneration (e.g. removal of allow natural regeneration (e.g. removal of grazing livestock)grazing livestock)

Not always practicable (close access to Not always practicable (close access to water and wetland species essential)water and wetland species essential)

Low costLow cost Likely that the resultant wetland will Likely that the resultant wetland will

resemble the surrounding environmentresemble the surrounding environment

Restoration: Active Restoration: Active

Appropriate when wetland Appropriate when wetland is severely degradedis severely degraded

Examples: weirs and Examples: weirs and culverts, intensive culverts, intensive planting, invasive species planting, invasive species control, substrate creationcontrol, substrate creation

Considerable design workConsiderable design workneededneeded

Construction costs may Construction costs may be highbe high

The London Wetland Centre: Wetland restoration in the suburbs on London to create a bird reserve

http://www.wwt.org.uk/visit-us/london

Restoration: traditional versus soft Restoration: traditional versus soft engineering solutionsengineering solutions

Traditional “hard” Traditional “hard” engineering solutions engineering solutions replace natural replace natural ecosystem functions ecosystem functions with human-designed with human-designed structures, e.g. concrete structures, e.g. concrete embankments to embankments to prevent erosionprevent erosion

““Soft” solutions include Soft” solutions include planting native species planting native species such as willows, log such as willows, log banks and geotextile banks and geotextile materialsmaterials

Concrete embankments

Restoration of banks along RiverThames with native vegetation

Restoration: important factors to Restoration: important factors to considerconsider

HydrologyHydrology Topography and geologyTopography and geology Soil typeSoil type Vegetation and animal lifeVegetation and animal life Land ownershipLand ownership Stakeholder involvementStakeholder involvement

Examples of wetland problems and possible Examples of wetland problems and possible remediation methodsremediation methods

ProblemProblem CauseCause Restoration actionRestoration action

Poor water qualityPoor water quality Nutrient/sediment run-off, Nutrient/sediment run-off, sediment erosion sediment erosion

Change land-use practices, Change land-use practices, install vegetation install vegetation buffers/sediment trapsbuffers/sediment traps

Altered hydrology due to Altered hydrology due to drainagedrainage

Presence of ditches and Presence of ditches and drains, embankment drains, embankment cutting off wetland from cutting off wetland from water sourcewater source

Fill ditches, remove Fill ditches, remove embankment, install gates/weirsembankment, install gates/weirs

Raised elevationRaised elevation Dumping or in-fillDumping or in-fill Remove surplus materialRemove surplus material

SubsidenceSubsidence Removal of soil, depletion Removal of soil, depletion of groundwaterof groundwater

Allow natural sedimentation, Allow natural sedimentation, add sedimentadd sediment

Loss of biodiversityLoss of biodiversity Change in habitatChange in habitat Planting of native species, allow Planting of native species, allow species to recolonise, species to recolonise,

Loss of native plantsLoss of native plants Change in hydrology, Change in hydrology, change in land use, change in land use, invasive speciesinvasive species

Restore hydrological regime, Restore hydrological regime, remove invasive species and remove invasive species and alter conditions that favour themalter conditions that favour them

Restoration: usefulness and feasibilityRestoration: usefulness and feasibility

Will there be environmental benefits (e.g. improved Will there be environmental benefits (e.g. improved water quantity, reduced eutrophication, biodiversity water quantity, reduced eutrophication, biodiversity conservation, flood control)?conservation, flood control)?

What is the cost effectiveness of the proposed What is the cost effectiveness of the proposed rehabilitation? rehabilitation?

What options, advantages or disadvantages will the What options, advantages or disadvantages will the restored area provide for local people and the region? restored area provide for local people and the region?

What is the present and possible future ecological status What is the present and possible future ecological status of the project? of the project?

What is the status of the area in terms of present land What is the status of the area in terms of present land use?use?

What are the main socio-economic constraints? What are the main socio-economic constraints? What are the main technical constraints?What are the main technical constraints?

http://www.ramsar.org/key_guide_restoration_e.htm

Sources of informationSources of information Ramsar Convention Secretariat, 2007 Ramsar Convention Secretariat, 2007 Inventory, assessment, and Inventory, assessment, and

monitoring: An Integrated Framework for wetland inventory, monitoring: An Integrated Framework for wetland inventory, assessment, and monitoring. assessment, and monitoring. Ramsar handbooks for the wise use of Ramsar handbooks for the wise use of wetlands, 3rd edition, vol. 11. Ramsar Convention Secretariat, wetlands, 3rd edition, vol. 11. Ramsar Convention Secretariat, Gland, Switzerland.Gland, Switzerland.

Ramsar Convention 2002 Climate change and wetlands: impacts, Ramsar Convention 2002 Climate change and wetlands: impacts, adaptation and mitigation. Ramsar COP8 Doc 11: Climate Change adaptation and mitigation. Ramsar COP8 Doc 11: Climate Change and Wetlands.and Wetlands.

Interagency Workgroup on Wetland Restoration (IWWR) 2003 Interagency Workgroup on Wetland Restoration (IWWR) 2003 An An Introduction and User’s Guide to Wetland Restoration, Creation and Introduction and User’s Guide to Wetland Restoration, Creation and EnhancementEnhancement. US Environmental Protection Agency, Office of . US Environmental Protection Agency, Office of Water, 95 pp. Water, 95 pp. http://www.epa.gov/owow/wetlands/pdf/restdocfinal.pdf

USEPA, 2000USEPA, 2000 Principles for the Ecological Restoration of Aquatic Principles for the Ecological Restoration of Aquatic Resources. Resources. EPA841-F-00-003. Office of Water (4501F), United EPA841-F-00-003. Office of Water (4501F), United States Environmental Protection Agency, Washington, DC. 4 pp. States Environmental Protection Agency, Washington, DC. 4 pp.