wetlands - chapter 6

Wetlands

Introduction

Wetlands are the link betweenland and water (Figure 6-1) . Wet-lands generally include swamps,marshes, bogs, fens, prairie pot-holes, seeps, vernal pools, pocosins,and similar areas. Most people caneasily identify some kinds of wet-lands, such as marshes, as beingwetlands. However, other kinds ofwetlands are not as easily identifiedbecause they may not be floodedand are often dry during part of theyear .

All wetlands, however, areflooded or have water just belowthe ground surface long enoughduring the growing season todevelop oxygen-poor soils . This isimportant because almost all ani-mals and plants use oxygen toconvert sugar, protein, and otherorganic molecules into the energynecessary to grow and survive .Normally, when bacteria andmicrobes in the soil decomposedead plants and animals, the oxy-gen that they use is replaced fromthe air. However, oxygen movesthrough the water about ten thou-sand times slower than the air.When a wetland or "hydric" soil issaturated or flooded, the oxygenused by the bacteria and microbesis not replaced fast enough . As aresult, most plants cannot growthere because they do not haveenough oxygen for their roots .Wetland plants, such as cattails andwater lilies, have special adaptationsto temporarily survive without

oxygen in their roots or to transferoxygen from the leaves or stem tothe roots .

A wide variety of wetlandsexist across the country becauseof regional and local differences inhydrology, vegetation, water chem-istry, soils, topography, climate,and other factors . Wetland typeis determined primarily by localhydrology, the unique pattern ofwater flow through an area . Ingeneral, there are two broad cate-gories of wetlands: coastal andinland .

With the exception of thecoastal wetlands of the Great Lakes,coastal wetlands are closely linked

Figure 6-1

Depiction of Wetlands Adjacent to Waterbody

111111111

Ilf

Hydrologic Regime Dry 7

Low WaterFluctuatingWater Level

- Permanently Flooded

Generally Low

Wetlands are often found at the interface between dry terrestrial eco-systems, such as upland forests and grasslands, and permanently wetaquatic ecosystems, such as lakes, rivers, bays, estuaries, and oceans .Reprinted with modifications, by permission, from Mitsch/Gosselink : Wetlands 1986, fig . 1-4,p . 10 . +1986, Van Nostrand Reinhold .

1 38 Chapter Six Wetlands

to estuaries . In these estuarinesystems, sea water mixes with freshwater to form an environment ofvarying salinity and temperature .Tides and wind also cause thewater levels to fluctuate . Coastalmarshes dominated by grasses,sedges, rushes, and halophytic (salt-loving) plants are generally locatedalong the Atlantic and Gulf coastsdue to the gradual slope of theland . Mangrove swamps, which aredominated by halophytic shrubsand trees, are common in Hawaii,Puerto Rico, Louisiana, and south-ern Florida .

Inland wetlands are most com-mon on floodplains along riversand streams, in isolated depressionssurrounded by dry land, and alongthe margins of lakes and ponds .Inland wetlands include marshesand wet meadows dominated bygrasses, sedges, rushes, and herbs ;shrub swamps; and woodedswamps dominated by trees, suchas hardwood forests along flood-plains . Some regional wetlandtypes include the pocosins of NorthCarolina, bogs and fens of thenortheastern and north centralstates and Alaska, inland saline andalkaline marshes and riparian wet-lands of the arid and semiarid West,vernal pools of California, playalakes of the Southwest, cypressgum swamps of the South, wettundra of Alaska, the South FloridaEverglades, and prairie potholes ofMinnesota, Iowa, and the Dakotas .

Functions and Valuesof Wetlands

In their natural condition, wet-lands provide essential ecologicalprocesses called functions, which

are beneficial not only to wetlandsbut also to their surroundingecosystems and people . Wetlandfunctions can be grouped intoseveral broad categories :

•

Storage of water

•

Storage of sediment andnutrients

•

Growth and reproduction ofplants and animals

•

Diversity of plants and animals .

The location of a wetland in awatershed and the size of a wetlandhelp determine what functions itwill perform. Not all wetlandsperform all functions nor do theyperform all functions at equivalentlevels . For example, some wetlandsnaturally have greater capacity tostore water because of their land-scape position . Many other factorscan influence how well a wetlandwill perform these functions, includ-ing weather conditions, quantityand quality of water entering awetland, and human alteration of awetland or surrounding landscape .

Storage and Filteringof Water

The historic loss of wetlands inthe Midwest was a significant factorcontributing to the severe floodingin the Upper Mississippi and Mis-souri River Basins in the summer of1993 . Wetlands help prevent floodsby storing and slowing the flow ofwater through a watershed . Manywetlands act like natural basinsand hold water from rain storms,overland flow, and from floodingrivers . As water passes through awetland, it is also slowed by the

566

340

226

19

wetland's plants (Figure 6-2) .Through the combined effectsof retaining and slowing water,wetlands allow water to percolatethrough the soil into the groundwater and slowly move through thewatershed (Figure 6-3) . In water-sheds that have lost most of theirwetlands, the rainfall flows quicklyinto streams and rivers and over-loads their capacity to transportwater through the watershed . Thegraph in Figure 6-4 shows the flowof water in two streams in Massa-chusetts. One stream does not havemany wetlands left in the water-shed and has a steep hydrograph .The other stream has a lot ofwetlands left in the watershed andhas a more stable hydrograph .Increasing the amount of pavementin a watershed can cause similarproblems . The result is that streamsand rivers flood and damage

Figure 6-4

Streamflow Through Wetlands

homes, farms, and businesses .In addition, streams and rivers areseverely damaged as their bankserode and their channels becomeflatter and deeper. Downstreamlakes and estuaries are also dam-aged by the large influx of silt inmud that makes the water cloudy,buries plants and animals, andprevents underwater plants fromgetting the light they need .

Floods continue to seriouslydamage the property and threatenthe livelihood of thousands ofAmericans despite expenditures ofbillions of local, state, and federaldollars over the years to reduceflooding . Loss or degradation ofwetlands indirectly intensifies flood-ing by eliminating their capacity toabsorb peak flows and graduallyrelease flood waters . Following areseveral examples of the monetarycost of wetland loss .

20 21 22

August 1955

23 24 25

Chapter Six Wetlands 139

Figure 6-2

Flood ProtectionFunctions in Wetlands

Source: Washington State Departmentof Ecology.

Figure 6-3

Ground Water RechargeFunctions in Wetlands

Source : Washington State Departmentof Ecology.

479 m 3/s

Blackstone River at Northbridge, MA

IL atCharles

Charles RiverRiverVillage, MA

91 m3/s

__


Figure 6-5

Streamflow MaintenanceFunctions in Wetlands


Figure 6-6

Water Quality Improvement Functions in Wetlands

NutrientRemoval

ChemicalDetoxification

Source: Washington State Department of Ecology .

∎ In Massachusetts, the U .S. ArmyCorps of Engineers estimated thatover $17 million of annual flooddamage would result from thedestruction of 8,422 acres of wet-lands in the Charles River Basin. Forthis reason, the Corps decided topreserve wetlands rather than con-struct extensive flood control facili-ties along a stretch of the CharlesRiver near Boston . Annual benefitsof the preservation project average$2 .1 million and annual costs aver-age $617,000 .

∎ The Minnesota Department ofNatural Resources estimated that itcosts the public $300 to replacethe water storage capacity lost bydevelopment of 1 acre of wetlandsthat holds 12 inches of water. The

cost of replacing 5,000 acres ofwetlands would be $1 .5 million,which exceeds the state's annualappropriation for flood control .

∎ In 1988, DuPage County, Illinois,found that 80% of all flood damagereports came from homebuilderswhose homes were built on con-verted wetlands . The county spent$0.5 million to $1 .0 million annual-ly to correct the problem.

Restoring wetlands in a water-shed can help prevent the amountand severity of flooding . Restoringwetlands can also improve the flowof water during dry seasons byallowing water to percolate into theground water and gradually enter astream rather than having rapidrunoff (Figure 6-5) . Water enteringwetlands during wet periods isreleased slowly through groundwater, thereby moderating streamflow volumes necessary for thesurvival of fish, wildlife, and plantsthat rely on the stream .

Storage of Sedimentand Nutrients

Wetlands act like filters thatpurify water in a watershed . Oftenthe water leaving a wetland ismuch cleaner than the water thatentered the wetland . When wateris slowed or stored in a wetland,much of the sediment settles outand remains in the wetland (Figure6-6) . Thus, the water leaves a wet-land less cloudy. Wetlands also trapnutrients that are attached to thesediment or dissolved in water .Nutrients are either stored in thewetland soil or are used by plantsto grow.

Wetlands on the fringes of lakesand estuaries keep the larger watersclean by trapping sediment andpreventing shoreline erosion . Marshplants help dissipate wave energyand their extensive root networksanchor the marsh (Figure 6-7) .Without the plants, the waveswould eat away at the shore andcause extensive erosion . Marshplants also slow the movement ofwater, allowing sediment and nutri-ents to settle and remain in themarsh. Wetland loss and degrada-tion reduce water quality purifica-tion functions performed by wet-lands.

The following examples showthe value of the capacity ofwetlands to store sediment andnutrients .

∎ The Congaree Bottomland Hard-wood Swamp in South Carolinaprovides valuable water qualityservices, such as removing andstabilizing sediment, nutrients, andtoxic contaminants . The total costof constructing, operating, andmaintaining a tertiary treatmentplant to perform the same func-tions would be $5 million .

∎ Forested riparian wetlands playan important role in reducing nutri-ent loads entering the ChesapeakeBay. In one study, a riparian forestin a predominantly agriculturalwatershed removed about 80% ofthe phosphorus and 89% of thenitrogen from the runoff waterbefore it entered a tributary to theBay. Destruction of such areasadversely affects the water qualityof the Bay by increasing undesirableweed growth and algae blooms .

∎ A study of two similar sites onthe Hackensack River in New Jerseyshowed the amount of erosion thatoften results from the destruction ofmarshlands. In the study, marshvegetation was cut at one site andleft undisturbed at the other site .The river bank at the cut site erod-ed nearly 2 meters (more than 6feet) in 1 year while the uncut sitehad very little bank erosion .

These examples illustrate theintegral role of wetlands in ourecosystems and how wetlanddestruction and degradation canhave expensive and permanentconsequences . Preserving wetlandsand their functions will ensure thatwetlands continue to provide manybenefits to people and the environ-ment .

Growth andReproduction ofPlants and Animals

Some wetlands, such as saltmarshes, are among the most pro-ductive natural ecosystems in theworld. Only rain forests and coralreefs come close to matching theirproductivity. They produce hugeamounts of plant leaves and stemsthat serve as the basis of the foodweb. When the plants die, theydecompose in the water and formdetritus (Figure 6-8). Detritus andthe algae that often grow on plantsare the principal foods for shrimp,crabs, clams, and small fish, which,in turn, are food for larger commer-cial and recreational fish speciessuch as bluefish and striped bass .

Wetlands produce a wealth ofnatural products, including fish andshellfish, timber, wildlife, and wild

Chapter Six Wetlands 1 41

Figure 6-7

Shoreline StabilizationFunctions in Wetlands


142 Chapter Six Wetlands

rice . Around 95% of the fish andshellfish species commerciallyharvested in the United States aredependent on wetlands duringsome stage of their life . A nationalsurvey conducted by the U .S . Fishand Wildlife Service in 1991 illus-trates the economic value of someof the wetland-dependent prod-ucts. Over 9 billion pounds of fishand shellfish landed in the UnitedStates in 1991 had a direct, dock-side value of $3 .3 billion . Thisserved as the basis of a seafoodprocessing and sales industry thatgenerated total expenditures of$26.8 billion . In addition, 35 .6 mil-lion anglers spent $24 billion onfreshwater and saltwater fishing .

Diversity of Plantsand Animals

Wetlands are critical to thesurvival of a wide variety of animalsand plants, including numerous

Figure 6-8

Coastal Wetlands Produce Detritus that SupportFish and Shellfish

Coastal Wetlands Plants

I,)

IEstuarine Waters

DetritusGrass Shrim

I

Blue Crab Clams

Zooplankton

Mullet.u ,

Menhaden

Sheepshead MinnowOyster'

Bass l1

Bluefish

rare and endangered species . Wet-lands are also primary habitats formany species, such as the woodduck, muskrat, and swamp rose .For others, wetlands provide impor-tant seasonal habitats where food,water, and cover are plentiful .

The Arizona Game and FishDepartment estimates that 75% ormore of all Arizona's native wildlifespecies depend on healthy wet-lands and riparian systems duringsome portion of their life cycle .

The abundant wildlife in wet-lands also attracts outdoor recrea-tionists. Outdoor recreationistsattracted to national wildlife refuges(NWR), which often protect exten-sive wetlands, bring millions ofdollars and many jobs to adjacentcommunities . The Fish and WildlifeService estimated that, in 1994,bird watchers and other outdoorrecreationists spent $636,000 in thecommunities around the QuivaraNWR in Kansas, $3 .1 millionaround the Salton Sea NWR inCalifornia, and over $14 millionaround the Santa Ana NWR inTexas .

When wetlands are removedfrom a landscape or are damagedby human activities, there is adecline in the biological health of awatershed. Many species of plantsand animals decline in number . Asshown by the alarming amount ofamphibian deformities in the GreatLakes and New England regions,many animals suffer from deformi-ties and reproductive failure . Some,such as the Ivory-billed Woodpeckerand Dusky Seaside Sparrow,become extinct. The Nature Con-servancy estimates that two-thirdsof freshwater mussels and crayfishesare rare or imperiled and more thanone-third of freshwater fishes and

Extent of theResource

amphibians dependent on aquaticand wetland habitats are at risk(Figure 6-9) . Forty-six percent ofthe threatened and endangeredspecies listed by the U .S. Fish andWildlife Service rely directly or indi-rectly on wetlands for their survival(Table 6-1) .

Wetland Lossin the United StatesIt is estimated that more than 200million acres of wetlands existed inthe lower 48 states at the time ofEuropean settlement . Since then,extensive wetland acreage has beenlost . Many of our original wetlandshave been drained and convertedto farmland and urban develop-ment. Today, less than half of ouroriginal wetlands remain . Whenadded together, the total amountof wetland loss is greater than thesize of California (see Figure 6-10) .According to the U .S . Fish andWildlife Service's Wetlands Losses inthe United States I 780s to 1980s,the three states that have sustainedthe greatest percentage of wetlandloss are California (91 %), Ohio(90%), and Iowa (89%) .

The average annual loss of wet-lands has decreased over the past40 years. The U .S . Fish and WildlifeService's reports on the status andtrends of wetlands estimate averageannual losses of 458,000 acres ofwetlands from the mid-1950s tothe mid-1970s and average annuallosses of 290,000 acres betweenthe mid-1970s and mid-1980s .Recent federal studies lead to anaverage annual net loss of wetlands

Figure 6-9

YN_

da

Aquatic and Wetland Species at Risk

100%

75%

50%

25%

0%

F 4C'

`a(~S 0eS

0101.0


Q~a9~ eQ-Nell~~a\S

Source: The Nature Conservancy and State Natural Heritage Data Centers, 1996 .

Table 6-1 . SummaryThat

of hr+eatened andAre "Wetland-Associated"

Endangered Species

Category

Number of U.S .Endangered and

Threatened Speciesas of May 31, 1997,that are Wetland-

Associated orDependent

Total Number ofU.S. Endangeredand ThreatenedSpecies as ofMay 31, 1997

Percentof Total

Mammals 42 63 66.7

Birds 72 89 80.9

Reptiles 21 33 63.6

Amphibians 15 15 100

Fishes 107 107 100

Snails 10 22 45 .5

Clams 62 62 100

Crustaceans 18 18 100

Insects 9 33 27.3

Arachnids 0 5 0

Plants 143 635 22.5

Totals 499 1,082 46 .1


New England BiologicalAssessment of WetlandsWork Group

The New England BiologicalAssessment of Wetlands WorkGroup (NEBAWWG, pronounced"Nee-bog") was formed in June1998 to develop and improveexisting programs for assessing thebiological health of wetlands in theNew England region . NEBAWWGincludes representatives from eachof the New England states, variousfederal agencies, universities, andnongovernment organizations .NEBAWWG has three main objec-tives :

•

Develop and institutionalize aregion-wide biomonitoring networkfor wetlands

•

Oversee state pilot projects andaddress logistical and technicalissues

•

Coordinate with and comple-ment the efforts of other biomoni-toring groups and interested parties .

Workshops andTraining Sessions

The first NEBAWWG workshop,held in October 1998, providedfield demonstrations, an overviewof national bioassessment efforts,and a discussion of planned NewEngland pilot projects . NEBAWWGwill host a series of technical train-ing sessions with field components .

Topics to be addressed include :

•

Classifying wetlands

•

Selecting reference wetlands

• Sampling methods for differentassemblages (e .g ., macroinverte-brates, plants)

•

Data analysis, including selectingmetrics and developing an indexof biological integrity (IBI)

•

Managing, storing, and commu-nicating data and information .

State Pilot ProjectsNEBAWWG has started three

state pilot projects in Maine, Massa-chusetts, and Vermont .

Maine

The Maine Department ofEnvironmental Protection (ME DEP)started its preliminary field work inthe summer of 1998 . The objectivesof the project are to developbiological sampling protocols fornontidal wetlands, measure wet-lands attributes across a gradientof human disturbance in a pilotwatershed, and identify candidatemetrics/indicators of biologicalintegrity on a watershed basis . TheCasco Bay watershed, located insouthern Maine, was selected as the

study area because it is experiencinghigh levels of development pressureand consequent impacts to wet-lands. The Casco Bay watershedcontains a broad range of wetlandtypes and conditions, ranging fromrelatively undisturbed wetlands towetlands that are severely damaged .During 1999 and 2000, ME DEPintends to develop sampling meth-ods and identify candidate metricsfor the macroinvertebrate, algae,and plant assemblages .

Massachusetts

Since July 1995, MassachusettsCoastal Zone Management (MACZM) has been engaged in aregional research and demonstra-tion project, called the Coastal Wet-land Ecosystem Protection Project .The goal of the project is to devel-op, test, and refine a transferableapproach to evaluating the condi-tion of both salt and freshwatermarshes using plants and macro-invertebrates. MA CZM is develop-ing the bioassessment methods todetermine the impacts of adjacentland uses and nonpoint sourcesof pollution on the ecologicalintegrity of these aquatic resources .A product of the Coastal WetlandEcosystem Protection Project is thepublication, Wetland EcologicalIntegrity: An Assessment Approach,

which was published in 1998 .This included development of theWetland Health Assessment Toolbox,which can be accessed on theInternet at http://www.magnet.state.ma. us/czm/what.htm. The currentpilot project will refine the existingwetland ecological assessmentapproach, protocols, and metrics.MA CZM also intends to broadenand field test the assessmentapproach in other wetland typesand conditions .

Vermont

The Vermont Department ofEnvironmental Conservation (VTDEC) and the Vermont Nongameand Natural Heritage Program (VTNNHP) will jointly develop andimplement biological assessmentprograms for vernal pools andnorthern white cedar swamps. Theprimary objectives of the first yearare to

•

Evaluate existing information

•

Identify and classify the vernalpools and northern white cedarswamps based on physical, chemi-cal, and biological characteristics

•

Identify candidate metrics ofbiological integrity

•

Develop and evaluate samplingprotocols .


HIGHLIGH ( HI '!GHT HIGHLIGHTI J


TSTATES REPORroad

that agriculture, d res~ -construetion

I aneloPment

dential an growth areand urb sources othe leadinghand loss-recent we

Figure 6-10

50 23

33 36

52

50

46

49

56

6037

54

.o

fl

around 100,000 acres per year inthe contiguous United States .

Although losses continue todecline, we still have to makeprogress toward the Clean WaterAction Plan goal of annual net gainof 100,000 acres per year by theyear 2005 and every year thereafter(see highlight on page 152) . Inaddition, we need to be mindful ofthe long-term Administration goalof increasing the quality of thenation's wetland resource base .

The decline in wetland losses isa result of the combined effect ofseveral trends :

∎ The decline in profitability inconverting wetlands for agriculturalproduction

Percentage of Wetland Acreage Lost,1780s-1980s

o VI

Twenty-two States have lost at least 50% of their original wetlands .Seven of these 22 (California, Indiana, 171inois, Iowa, Missouri, Kentucky,and Ohio) have lost more than 80% of their original wetlands .

Source: Dahl, T. E ., 1990, Wetlands Losses in the United States 1780's to 1980's,U .S . Department of the Interior, Fish and Wildlife Service .

2874

73

∎ Passage of Swampbuster in the1985 and 1990 Farm Bills

•

Presence of the CWA Section404 permit programs as well asdevelopment of state managementprograms

•

Greater public interest andsupport for wetland protection

•

Implementation of wetlandrestoration programs at the federal,state, and local level .

Limited conclusions can bedrawn about sources of recentwetlands loss because only elevenstates and tribes listed this informa-tion in their 1998 305(b) reports(Figure 6-11) . These states andtribes cited agriculture as the lead-ing source of current losses (seeAppendix D, Table D-1, for individ-ual state information) . Other losseswere due to residential growth andurban development; constructionof roads, highways, and bridges ;filling and/or draining ; construc-tion; industrial development; hydro-logic modification ; commercialdevelopment ; and channelization,

Designated UseSupport in Wetlands

The states, tribes, and otherjurisdictions are making progress inincorporating wetlands into waterquality standards and developingdesignated uses and criteria specifi-cally for wetlands. But many statesand tribes still lack wetland-specificdesignated uses, criteria, and moni-toring programs for wetlands .Without criteria and monitoringdata, most states and tribes cannotevaluate attainment of water quality

I

standards . To date, only 11 statesand tribes reported the designateduse support status for some of theirwetlands (see Appendix D, TableD-1) . Only three states used moni-toring data as a basis for attain-ment of water quality standards .

•

California reported that 11% ofthe 138,208 acres of assessed wet-lands fully support all uses and88% are impaired for one or moreuses. Causes of impairment includemetals, nutrients, salinity/total dis-solved solids/chlorides, flow alter-ations, and other habitat alter-ations. Sources impacting wetlandsinclude agriculture, urban runoffand storm sewers, and hydrologicmodifications .

•

Iowa used best professionaljudgment to determine the use

Figure 6-11

Sources of Recent Wetland Losses(11 States Reporting)

Based on data contained in Appendix D, Table D-4 .

support status of 33,221 wetlandacres during 1996 and 1997 . Thestate reported that 6% of assessedwetland acres fully support all uses,38% fully support all uses but arethreatened for at least one use, and57% are impaired for one or moreuses. Impairment is due to nutri-ents, siltation, flow alterations,noxious aquatic plants, and exoticspecies. Sources of impairmentinclude agriculture and hydrologicand habitat modifications .

∎ Kansas assessed 35,607 wetlandacres for the current reportingcycle, of which 25,069 were moni-tored and an additional 10,538were evaluated . The state reportedthat, for aquatic life use support(acute criteria only), 29% ofassessed wetland acres are fullysupporting but threatened,


Wetland Acres Assessed byStates and Tribes

Including Alaska's Wetlands

•

9,831,988 acres = 4% assessed< Total acres (including Alaska)

= 274 million s

96% Not Assessed

Excluding Alaska's Wetlands

• 9,831,988 acres = 9% assessedTotal acres (excluding Alaska)= 107 million

/

9% Assessed

aFrom Dahl, T.E . 1990 . Wetlands Losses in theUnited States 1780's to 1980's. U .S. Departmentof the Interior, Fish and Wildlife Service .

Source: 1998 Section 305(b) reportssubmitted by states, tribes,territories, and commissions .

-"/91./. Not Assessed

Sources States

Agriculture 9

Residential Development 9and Urban Growth

Road/Highway/BridgeConstruction

8

Filling and Draining 6

Construction 5

Industrial Development 5

Hydrologic Modification 4

Commercial Development 4

Channelization

1

I

I

I

I

4

0

2

4

6

8

10

Number of States Reporting


More States aremonitoring landsacted We

untodefrne baselineconditions in healthy

Wetlands.

5% are partially supporting, and66% are not supporting this use .Major causes of impairment arenutrients, flow alterations, low dis-solved oxygen, and turbidity/silta-tion. Major sources of impairmentwere agriculture, hydrologicmodifications, and natural proc-esses such as climate variations .

•

Kentucky reported that 973,168wetland acres are threatened dueto the pressure of development .This acreage includes all wetlandsin the state not in public ownershipor under some form of protection .The estimate is based on NationalWetlands Inventory maps .

•

Louisiana assessed aquatic lifeuse support in nearly 700,000 acresof its 8 .1 million total acres of wet-lands. Over 99% of these acres areimpaired because of either mercuryor organic enrichment/low dis-solved oxygen . The state reportedunknown sources and atmosphericdeposition as sources of impair-ment .

•

Michigan reported on one wet-land 10 acres in size . This wetlandwas impaired for aquatic life use inthe past, but has now been remedi-ated and fully supports this use .The improvement is due to a reduc-tion in nickel contamination by anupstream point source discharge .

•

Nevada used best professionaljudgment to assess 21,326 acres(16%) of its 136,650 total acres ofwetlands . The state reported that allof the assessed wetlands fully sup-port designated uses .

• North Carolina used aerial pho-tographs and soil information froma 1992-1993 survey to rate use

support by current land use . NorthCarolina rated wetlands on hydricsoils with natural tree cover as fullysupporting uses . Partially support-ing wetlands have modified coverand hydrology but still retain wet-land status and support most uses .For example, pine plantations stillretain value for wildlife habitat,flood control, ground waterrecharge, nutrient removal, andaquatic habitat, although the modi-fied wetlands support these usesless effectively than undisturbedwetlands. Wetlands converted toagriculture or urban land use areclassified as not supporting originalwetland uses . The state used thismethodology to assess use supportin over 7 million acres of wetlands .The state reported that 66% of theassessed wetlands fully support usesand 34% are impaired for one ormore uses .

•

Tennessee used evaluative datato assess 787,000 wetland acres .Of the assessed acres, 93% fullysupport all designated uses . Thestate reported that siltation, flowand habitat alterations, and priorityorganic chemicals impair theremaining acres . Sources of impair-ment include agriculture, hydro-modification, filling and draining,development, ground water load-ings, and construction .

•

The U .S. Virgin Islands used eval-uative data to assess 927 wetlandacres. More than 99% of theseacres fully support all designateduse. Impairment to 1 acre is dueto sediment, bacteria, and lowdissolved oxygen associated withurban runoff, municipal pointsources, and spills .

I

∎ The Coyote Valley Tribe usedevaluative data to assess 1 .6wetland acres, all of which areimpaired for one or more uses . Thisimpairment is associated with silta-tion, habitat and flow alterations,weeds, and exotic species . The tribeidentified agriculture, development,public projects, and municipalpoint sources as sources of impair-ment .

EPA can draw only limitedconclusions about water quality inwetlands because the states useddifferent methodologies to surveyonly 4% of the total wetlands inthe nation, and because 73% of theassessed wetland acreage is in onestate alone (North Carolina) . Morestates and tribes will assess use sup-port in wetlands in the future asthey develop standards for wet-lands. Many states are still in theprocess of developing wetlandwater quality standards, which pro-vide the baseline for determiningbeneficial use support (see Chapter2). Improved standards will alsoprovide a firmer foundation forassessing impairments in wetlandsin those states already reporting usesupport in wetlands .

Monitoring WetlandHealth

More than 25 years after it waspassed, the Clean Water Act stillchallenges us to answer criticalquestions about the physical, chem-ical, and biological condition of thenation's waters . While great strideshave been made to develop andimplement methods to evaluate thecondition of streams and lakes,

research on wetlands has laggedbehind . Considering that states andtribes collectively reported the quali-ty of only 4% of the nation's wet-lands, the nation needs an effectivemeans to measure wetland health .

Currently, states and tribes haveinsufficient data to evaluate thehealth of wetlands or quantify theextent of pollutants degrading wet-lands and the sources of thesepollutants . Although most statescannot quantify the wetland areaimpacted by individual causes andsources of degradation, 11 statesand tribes identified causes and10 states and tribes identifiedsources known to degrade wetlandintegrity to some extent (Figures6-12 and 6-13) . These states listedsediment as the most widespreadcause of degradation impactingwetlands, followed by draining,habitat alterations, and flow

Figure 6-12



More information on wetlandscan be obtained fromEPA's Wetlands Hotlineat 1-800-832-7828,9 a.m. to 5 p.m. EasternStandard Time.

Causes Degrading Wetland Integrity(11 States Reporting)

Causes States

Sedimentation/Siltation 9


Habitat Alterations 6

Flow Alterations 6

Nutrients 4

Low Dissolved Oxygen 3

Metals 3

I

I

I

I

I0

2

4

6

8

10Number of States Reporting


alterations . Agriculture and hydro-logic modifications topped the listof sources degrading wetlands, fol-lowed by development and draining(see Appendix D, Tables D-2 andD-3, for individual state informa-tion) .

As states and tribes incorporatewetlands into water quality stand-ards and adopt wetland-specificuses and criteria, monitoring pro-grams will become increasinglyimportant to determine if wetlandsare meeting their existing anddesignated uses. Monitoring pro-grams are also needed to prioritizewetlands for protection and restora-tion and to develop performancestandards for successful mitigationand restoration efforts . Severalstates are developing biological

Figure 6-13

Sources Degrading Wetland Integrity(10 States Reporting)


assessment methods to evaluate thehealth of wetlands, designate usesfor aquatic life, develop biologicalcriteria, and determine if they aresupporting aquatic life uses .

•

Minnesota has developed aWetland Index of Biological Integrity(WIBI) using macroinvertebrates anda Wetland Index of VegetativeIntegrity (WIVI) using plants fordepressional wetlands. Minnesotaplans to use these tools to evaluatethe biological integrity and aquaticlife use support of depressional wet-lands. They are also partnering withlocal governments to train volun-teers to use simpler versions of thesemethods to evaluate the conditionof wetlands .

•

Montana is developing biologicalassessment methods for wetlandsusing macroinvertebrates and algae .To partition natural variabilitybetween wetland types, Montanadeveloped a classification system togroup reference wetlands by ecore-gion and then by wetland type .Preliminary results indicate detectionof impairments caused by metals,nutrients, salinity, sediment, andfluctuating water levels .

•

North Dakota started its pilotproject in 1993 . They are develop-ing bioassessment methods fordepressional wetlands that are tem-porarily or seasonally flooded . Theyhave developed a preliminary indexof biological integrity for the plantcommunity.

Sources States

Agriculture 8

Hydrologic Modification 7

Development (General) 6


Road Construction 4

Construction 4

Resource Extraction 4

Urban Runoff 4

I

I

I

I

I

I0

1

2

3

4

5

6

7

8Number of States Reporting

• Ohio started a pilot project in1994 to develop biological criteriafor wetlands. Ohio is applying thesame approach to wetlands that itused to develop its stream biologicalcriteria program. Methodologies toassess vegetation, macroinverte-brates, and amphibian assemblagesare under development . Ohio hasdeveloped a Floristic QualityAssessment Index to evaluate thecondition of the plant community.

• In 1999, Maine started a pilotproject to develop bioassessmentmethods for wetlands in the CascoBay watershed . They are using themacroinvertebrate and algal com-munities to evaluate the health ofthe wetlands . They are testing sam-pling methods and intend to usemultimetric indexes of biologicalintegrity and advanced statisticaltests to evaluate the data .

•

Florida is developing an integrat-ed biological approach for evaluat-ing wetlands. The project is focusingon forested and herbaceous depres-sional wetlands . They are develop-ing sampling methods and multi-metric indexes of biological integrityfor plants, benthic macroinverte-brates, and fish .

Summary

Currently, most states are notequipped to report on the integrityof their wetlands. Only 11 statesand tribes reported attainment ofdesignated uses for wetlands in1998 . National trends cannot be

drawn from this limited information .This is expected to change, how-ever, as states adopt wetland waterquality standards and enhance theirexisting monitoring programs tomore accurately assess designateduse support in their wetlands .

River of Words 1999 Finalist, Jennifer Koo, Earth's Cry, Age 18, CA

Chapter Six Wetlands 1 5 1


Wetlands and the CleanWater Action Plan

The Clean Water Action Plan,announced by President Clintonand Vice President Gore on February19, 1998, is a comprehensiveplan that will not only protectpublic health through clean waterprograms but will also restore thehealth of the nation's waters . ThePlan sets strong water protectiongoals and provides states, commu-nities, farmers, and landowners thetools and resources to meet them .Also included in the Action Plan arecooperative strategies that encour-age local communities to developand implement actions that take awatershed approach (http://www.cleanwater.gov/) . Within the ActionPlan are action items that addresswetlands both directly and indi-rectly. These unique waterbodiesare directly addressed through thethemes discussed below and areindirectly protected by improvingwater quality programs, implement-ing unified watershed assessments,reducing polluted runoff, andimproving monitoring and assess-ment .

A Net Increaseof 100,000 Acresof Wetlands per Yearby 2005

The Clean Water Action Plansets an ambitious goal of a net

increase of 100,000 acres ofwetlands each year, beginning in2005 . To achieve this goal, the Planincludes the following action items :

• The Corps of Engineers (Corps)and EPA will work with their part-ners to avoid wetland losses, deterunpermitted losses, increase miti-gation of unavoidable losses, andimprove the reliability of wetlandrestoration .

•

The U .S. Department of Agricul-ture (USDA) will play a large rolein restoring wetlands through theWetlands Reserve Program, a volun-tary program that farmers jointo receive financial assistance forprotecting wetlands .

• By 2005, EPA will work with theWetlands and River Corridor Part-nership, a group of 30 governmentand nongovernment organizationsinvolved in habitat restoration, torestore wetlands in 500 watersheds .

•

The National Oceanic and Atmos-pheric Administration (NOAA) willincrease the acreage of coastalwetlands restored annually byencouraging wetland restorationplanning in state coastal zonemanagement programs . NOAA willalso continue state and local part-nerships under the Coastal Wet-lands, Planning, Protection, andRestoration Program .


I- IGHLIGH (H I i ' GHT HIGHLIGHT

∎ The Federal Highway Adminis-tration (FHA) will increase netwetland acreage resulting fromfederal aid highway projects by50% in 10 years .

ConsistentDeterminationof Wetland Lossesand Gains

A necessary prerequisite toachieving the wetland goal is ensur-ing that reliable data systems are inplace to record losses and gains inthe nation's wetland inventory .Currently the federal governmentsupports two major statistical inven-tories of wetlands :

∎ U.S. Fish and Wildlife Service'sNational Wetlands Inventory (NWI)

∎ USDA's Natural Resources Inven-tory (NRI) .

These two approaches need toestimate more consistently the rateof wetland loss . The differencesbetween the two approaches needto be reconciled, and a method oftracking wetland gains achievedthrough restoration needs to bedeveloped to accurately trackprogress toward the 100,000-acre-per-year goal, evaluate the impactof policy and program decisions onthe goal, and make the inventorymore sensitive to relatively smallchanges in acreage . The Plan


HT HIGHLIGHT

contains three action items toimprove national estimates ofchanges in wetland acreage :

•

The White House Wetlands Work-ing Group will finalize a plan to useexisting inventory and data collec-tion systems to develop a singlestatus and trends report for thenation's wetlands by the year 2000 .

•

The involved federal agencies(EPA, the Corps, NRCS, FWS, andNOAA) will develop technical guid-ance on restoration, creation, andenhancement of wetland functions .

•

The White House Wetlands Work-ing Group will establish an inter-agency tracking system that willaccurately account for wetland loss,restoration, creation, and enhance-ment.

Geographic-BasedPlanning to Protectand Restore Wetlands

Although many individualwetland losses are small in termsof area, together the cumulativelosses of wetlands and other aquatichabitats accumulate to significantlevels of environmental damage inmany areas of the United States .One way to better protect thesevaluable resources is to integratewetlands and similar habitatsinto geographic-based planningprograms, such as watershedapproaches. Geographic-basedplanning offers the potential todevelop a cohesive framework that

addresses both clean water andaquatic habitat, reflecting the inter-dependence between wetlands andother components of a watershed .While geographic-based planningrelies on strong local leadership andis enhanced by state or tribal back-ing, EPA and other federal agencieswill contribute by strengtheningexisting assistance programs anddeveloping new ways to providesupport. The Plan contains threeaction items to improve geographic-based planning to protect andrestore wetlands :

•

The FWS, NOAA, NRCS, and EPAwill coordinate with states and tribesto improve access to informationon programs for wetlands and otherhabitats. Such information will bemade available to geographic-basedplanners through toll-free help lines,the Internet, one-stop informationcenters, dedicated staff for outreach,and/or newsletters and other publi-cations .

•

Watershed Assistance Grants willbe established to ensure that thosewhose wetland interests may beaffected by planning have themeans to participate in the process .

•

The Corps, NOAA, FWS, NRCS,National Park Service, and EPA willprovide technical and/or financialassistance to states and tribes tointegrate habitat considerations intogeographic-based planning andwill offer incentives to programsthat appropriately balance cleanwater and habitat factors .

I Want to Be

I want to be a dogfishand catch a leaping catfish

with whiskers as long as a stream .And I want to be

the rain trinkling down on the worldtelling it it's springtime .

River of Words 1998 Grand Prize Winner (Poetry, Grades K-2)Noah Frank, Grade 2, CA

River of Words 1998 Grand' Prize Winner (Art, Grades 3-6)Holly Heuer, Untitled, Grade 5, CA


wetlands - chapter 6

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