EPA904-B-96-002
                                            January,    1996
                   BEYOND THE ESTUARY:
               The Importance of Upstream Wetlands
                      in Estuarine Processes
           U.  S.  Environmental Protection Agency
                          Region  4
                 345 Courtland Street  N.  E.
                Atlanta, Georgia  30365-2401
                          U. S. A.

              WETLANDS HOTLINE:   800   832-7828
 WETLANDS HOTLINE  e-mail: Wetlands-Hotline@epamail.epa.gov
WEB site:  http://www.epa.gov/docs/Region4Wet/wetlands  html
              (404) 347-3555 ext. 6515    voice
              (404)  347-3830            TTY/TDD
              (404) 347-3064               fax
                U.S. Environmental Protection Agency
                Region 5, Library (PL. 12J)

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               BEYOND THE ESTUARY:
THE IMPORTANCE  OF UPSTREAM  WETLANDS
            IN  ESTUARINE PROCESSES
         WHICH WETLANDS ARE IMPORTANT
         TO THE ESTUARY?

         Coastal, brackish, and freshwater wetlands
         all perform important functions affecting
         estuarine processes.  In addition to their
         aesthetic appeal, coastal wetlands have well-
         known functions including habitat  for
         wildlife, spawning and feeding grounds for
         fish and shellfish, flood protection, pollution
         removal,  shoreline erosion control,  and
         recreation.

        The relative importance of the networks of
        wetlands located above estuaries has not
        been as widely recognized. These wetlands
        include bottomland hardwoods, riparian
        forests, bogs, vernal pools, and emergent
        marshes. These networks are of ten extensive
        and can have a significant impact on the
        quality and functions  of the downstream
        estuary.

        The cumulative effects of all of these areas
        should be  considered in discussions  of
        estuarineprocesses and impacts. Thebenefits
        these inland  wetlands provide should be
        factored into estuary managementdecisions.
        In addition, restoration of previously altered
        wetlands along the network of streams and
        tributaries may provide a solution to many
        of the problems in the estuary itself.
                                 WHAT FUNCTIONS DO THESE AREAS
                                 PERFORM?

                                 Upstream  wetlands  perform  various
                                 functions within a given watershed:

                                      • greatly influence the water quality
                                        of adjacent river or stream by re-
                                        moving pollutants such as
                                        sediments, nutrients, and
                                        organics / inorganics

                                      • increase detention time of
                                        floodwaters thereby reducing flow
                                        velocity, erosion, and flood peaks
                                        in downstream areas

                                      • provide habitat for wildlife
                                        including waterfowl, mammals,
                                        and unique vegetation

                                      •  serve as spawning and nursery
                                        grounds for many estuarine and
                                        marine species of fish

                                      •  contribute to the aquatic food
                                        chain by providing detritus
                                        (decaying organic matter) to the
                                       biota of the adjoining waters

                                      •  prevent excessive water
                                       temperatures during summer
                                       months which could be lethal to
                                       invertebrates or fish

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  HOW DO THESE FUNCTIONS
  TRANSLATE TO ESTUARINE
  PROCESSES?

  Water Quality
  The estuarine system is complex and highly
  dependent  on the  balance of its many
  components. The organically rich water and
  sediments within the estuary, in their proper
  proportions, support a myriad of  aquatic
  plant and animal life.  During periods of
  minimal rainfall in the estuarine zone, the
  quality and quantity of inflowing fresh water
  from  upstream tributaries becomes  even
  more crucial. Without the pollution removal
 function of upstream wetlands, the estuary
 could be adversely affected in several ways:

    •  High levels of nitrogen and
       phosphorus (plant nutrients) could
       be transported from upstream
       areas to the estuary. This often
       results in high algal standing crops
       (algal blooms) which greatly
       reduce the level of available oxygen
       which can  cause massive fish kills

    •  Transported pollutants such as
       pathogens and toxics could impact
       the estuary unless upstream areas
       trap and absorb these substances

    •  Beneficial levels of nutrients and
       sediments would not be available
       for estuarine systems if stream
       flow is decreased or stopped
       altogether, or if stream flow is
       channelized sending nutrients to
       deeper, offshore waters.

Riparian forests,in particular, act as nitrogen
sinks and reduce the load of nutrients from
  agricultural lands (Peterjohn and Correll,
  1986).   Conversion of forested areas  to
  agriculture has resulted in decreased surf ace
  water salinity,  increased turbidity,  and
  increased phosphorus,  nitrogen,  and
  ammonia  concentrations in the adjacent
  tributary  (Kirby-Smith and Barber, 1979).
  Within the normally  saturated soils of
  riparian forests, the process of denitrification
  permanently removes excess nitrogen in
  surface runoff and shallow groundwater.
  Although  storage   of  nitrogen  and
  phosphorus by riparian vegetation is mostly
  temporary, these nutrients are transformed
 inawaythatmakesthemlesslikelyto support
 nuisance  algae  in  downstream  estuaries
 (Elder, 1985).
        How can water quality be altered?

      In discussions of water quality, it is important
      to remember that some factors have the
      potential to be both favorable and detrimental
      There are levels of certain nutrients,
      sediments, or biota that are tolerable or
      essential to the overall productivity of the
      estuary or other waterbody, yet, when these
      levels are surpassed, these same materials
      may prove toxic or detrimental. Generally,
      water quality can be affected in several ways:

      • Addition of artificial materials

      • Alteration (increase or decrease) of the
       "normal" levels of naturally occuring
       materials

      • Addition of natural materials which prove
       toxic or detrimental when combined with
       naturally occurring materials
The first 19 -  20 meters of the wetland,
immediately  below  the  source  of
contaminated nonpoint runoff, may be the
most effective filter, both in riparian systems
(Peterjohn and Correll, 1984; Correll and
Weller, in press) and in salt marshes (Hook
and Brinson, 1989). Similarly, studies of
bottomland  hardwood  wetlands have
indicated that when a significant proportion

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   of the watershed is converted to agriculture,
   stream concentrations of phosphorus tend to
   increase (Gosselink and Lee, 1987).

   Water Regime
   The ability of wetlands to temporarily store
   floodwater plays an integral role in the flow
   of freshwater to the estuary. These natural
   functions are  commonly  hindered  by
  structures, such as dams and levees, which
  are designed to do just theopposite—manage
  flow and define direction. Constructed levees
  result in the increased height of the inflow
  downstream because flood waters are not
  able to overflow the  natural banks of the
  river or stream. Such alterations may cause
  essential constituents to be deposited into
  deeper offshore waters where they will not
  be available for estuary processes. Along the
  Mississippi River, early modifications to
  upstream areas to control flooding increased
  flow velocity making it necessary to construct
  similar structures downstream closer to the
  estuary.

  The Charles River Basin, on the other hand,
 still remains a prime example of controlling
 flooding using  the   natural  process of
 watershed  wetlands.  This flood  control
 project was developed by the U.S. Army
 Corps of Engineers and involved setting aside
 upstream wetlands for floodwater detention
 along  the Charles  River in  eastern
 Massachusetts. These wetlands allowed the
 river to overflow in upstream areas, thus,
 decreasing the velocity and height of the
 floodwaters in the more highly populated
 areas downstream. This method was found
 to be not only the most effective means of
 flood control, but also the most economical.

 Habitat
The importance of freshwater wetlands in
providing habitat for numerous species of
waterfowl, fish, and invertebrates, including
  many rare and endangered species, is well
  known and well documented (Niering, 1988).

  Many species are dependent upon both
  estuarine and freshwater wetlands during
  differentstages of their lifecycles. Waterfowl,
  for example, adapt to seasonal food supplies
  duringtheirmigraaonpatternsby exploiting
  avarietyofhabitats^singfreshwater inland
  marshesduringbreedingandcoastalmarshes
  during wintering  (Bellrose and  Trudeau
  1988). Prevettet al. (1985) found thatCanada
  geese (Branta canadensis) in James Bay made
  dailytrips between thecoastal marshes where
  they fed and the adjacentmuskeg areas where
  they  nested.   Further, Fredrickson and
  Drobney (1977) found a definite  tendency
  for waterfowl  to  shift from  unstable
  freshwater areas utilized during breeding to
  morestable,permanentwetlandsandmarine
  areas  in the winter. In their review of tidal
  freshwater marshes, Odum  et al.  (1988)
  reported that in many cases a large number
  of  freshwater,  estuarine,  marine,  and
  anadromous fish and invertebrates utilized
  these  areas as nursery sites before moving
 downstream to the estuary.

 In recent years, movement among habitats
 has become  increasingly difficult due to
 various  habitat  modifications including
 reservoirs, hydroelectric dams, and stream
 alterations, as well as loss of wetland habitat
 to development and agriculture.  Habitat
 enhancementmeasures, such as fish ladders,
 are a component that increasingly needs to
 be addressed  when viewing estuarine
 processes on a watershed level.

 Sediment Load
 The role of wetlands as sediment sinks has
 been well documented (Gosselink and Lee,
 1987; Tiner, 1984). Due to their low slope'
 and position  downslope from uplands,
wetlands such  as bottomland hardwood

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 forests can remove moderate amounts of
 sediment from turbid  runoff  without
 ecological damage. As upstream areas are
 altered, sediments  are often left exposed.
 This makes them highly susceptible to the
 effects of erosion which result in increased
 loads  of sediment  to adjacent streams or
 rivers  and,  ultimately,  to  the  estuary.
 Upstream vegetated wetlands also stabilize
 soils along the banks of rivers and streams
 which helps control the volumes of sediment
 transported  downstream (Mahoney  and
 Erman, 1981).

 The  turbidity  caused  by suspended
 sediments affects estuarine waters in several
 ways.  High turbidity can interfere with the
 recreational aspects of the watershed making
 water contact sports or fishing undesirable.
 The amount of light available for aquatic
 plants is significantly reduced which is
 detrimental to many  species. As excess
 sediments settle, bottom dwelling organisms
 may be adversely affected.   Finally, high
 turbidity can adversely affect fish spawning.
 In larger quantities, loads of sediment can
 change the pattern of stream flow, fill a
 channel, or raise the level of the channel bed
 which increases the  chance of flooding.

 Furthermore,  upstream wetlands  reduce
 the amount of toxic laden sediment particles
 that might otherwise be transported to the
 estuary as well as produce organic substances
 which reduce the toxicity of heavy metals to
 estuarine life (Sugai and Burrell, 1984). Even
 though sediment transport is an important
factor in building and maintaining  some
 coastal  wetland areas, as with nutrients,
there exists a delicate balance which is ideally
regulated by the upstream wetlands.
HOW ARE UPSTREAM WETLANDS
THREATENED?

There are many threats  to these wetland
resources  due to physical, chemical, and
biological  impacts.  As  more and more
people occupy the watersheds of the nation,
these areas become more susceptible to
alterations.

   • The  practices of clearing, draining,
     and filling wetlands for agriculture
     continue. When an agricultural area
     is cultivated right to the edge of a
     river or stream, runoff of
     agricultural chemicals or pesticides
     increases. As these chemicals are
     deposited into the tributaries, the
     chances of transport to the estuary
     are greatly increased.  In addition,
     some timber harvesting practices,
     such as clear cutting, may
     significantly degrade wetlands.

 •   Development and other activities in
     urban areas continue to pose threats
     to wetlands. The most obvious
     impacts are filling or draining
     wetlands for development.
     Urbanization of these areas has
     introduced high levels of nutrients,
     toxics, and sediments into upland
     runoff. Toxic input has also been
     traced to industrial plants, domestic
     sewage, hazardous waste sites,
     illegal dumping, pesticides, oils, and
     heavy metals from urban runoff,
     petroleum hydrocarbons from oil
     exploration and production, and
     spraying of herbicides for aquatic
     weed and insect control. Even
     though wetlands have been
     identified as a potential filter for
     pollutants, the long term effects of

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     the indiscriminate introduction of
     substances to these ecosystems have
     not been determined.

 • Levees  for flood control  and water
   supply may completely eliminate some
   wetlands and may substantially change
   water flow patterns. In some instances,
   the presence  of  these structures has
   completelyeliminated freshwater inflow
   thus upsetting the delicate balance of the
   brackish  environment   which  is
   characteristicoftheestuarineecosystem.

 •  Other channel alterations such as dams,
   channel diversion structures, and linear
   canals all contribute to the  limitations
   placed on wetlands  in  the natural
   functions they perform.
/HAT CAN WE DO?
 The wave  of  awareness is growing.
 Increasingly,  estuarine  and  wetland
 environments are receiving recognition as
 delicate ecosystems deserving our protection
 and restoration.    By  promoting  this
 awareness we can coordinate our efforts in
 thecomprehensive management, protection,
 and enhancement of the upstream wetlands
 and the estuaries.

 Estuary resource advocates have  already
 begun developing a network to address the
 problems and concerns relating to these areas.
 OnerecentlyestablishedmechanismisEPA's
 National Estuary Program  (NEP)  which
 goes through a  process  of  identifying
 problems,  setting goals, selecting options,
 and  developing action plans. Through the
 expansion of this network, awareness of the
role  of  upstream wetlands to estuarine
systems can be increased.  Since many of
these areas are privately  owned, we must
also increase citizen involvement and seek
support on a watershed basis, not just at the
site specific level.

Limitations in our current understanding
obviously exist.  However, we must join
together to improve our understanding of
the  complexities  of the  systems—both
ecologicaUyandpolitically—toeffectchange.
Here are some steps to improve protection of
these vital resources:

Resource Assessment

      • Locate the wetlands along rivers
       and streams which eventually feed
       into the estuary of concern

      • Identify the wetland types

      • Map out the wetlands to allow a
       landscape understanding of how
       they work within the watershed

      • Use historical data (if available) to
       determine the extent and location
       of wetland losses and associated
       problems

     • Assess the value of remaining
       wetlands
                                        Planning
                                           1.
       Incorporate wetland protection
       into the NEP estuary planning
       conference or through other
       federal, state, regional, and
       local planning processes such
                                               as:
                                               • Special Area Management
                                               Plans (authorized under the
                                               Coastal Zone Management
                                               Program)

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    2.
• Multi-Objective River Corridor
Management Plans (supported
by the National Park Service)

• Advance Identification
(conducted by EPA and the
Corps of Engineers)

• Critical Habitat Plans
(authorized by the Endangered
Species Act)

• Statewide Comprehensive
Outdoor Recreation Plans
(state acquisition plans prepared
for Fish and Wildlife Service)

• Regional or local zoning and
land use plans

Use such planning approaches to
coordinate wetlands protection
tools on the local, state, and
federal levels within the
watershed
Regulation
        Enhance the wetland protection
        afforded by the Section 404
        Clean Water Act federal
        regulatory program

        Develop state regulatory
        programs designed explicitly to
        protect wetland areas as they
        relate to the entire watershed

        Improve the wetlands protection
        potential of states' existing
        authority under Section 401 of
        the Clean Water Act to certify
        that a federal permit or license
        will comply with state water
        quality standards
       • Incorporate wetland protection
        measures into local and regional
        zoning provisions

 Restoration and Acquisition

       • Develop restoration and
        acquisition strategies, including
        funding mechanisms, and
        incorporate these components
        into local comprehensive plans

       • Identify opportunities for
        restoration of wetland sites or
        upstream embankments as one
        solution to problems in the
        estuary downstream

       • Encourage farmers in the
        watershed to enroll their cropped
        wetlands into the Conservation
        Reserve Program.  Also
        encourage farmers to participate
        in exchanges of debt, or grant
        conservation easements, where
        allowable, to permanently
        protect wetland resources

Public Education / Awareness

      • Promote values of wetlands
        through the community including
        local schools

      • Start an "Adopt A Wetland"
       program for citizen monitoring
       of key wetland areas
                                  Additional information on these  wetland
                                  and estuary protection measures  can be
                                  obtained from the EPA regional offices or
                                  from other agencies and organizations listed
                                  in the back of this brochure.

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   Sources cited in this document:

   Bellrose,F.C.andN.M.Trudeau. 1988. Wetlands and
   their relationship to migrating and winter populations
   of waterfowl. Pp. 183-194 in D.D. Hook and others
   (eds.) The Ecology and Management of Wetlands.
   Vol. I: Ecology of Wetlands.  Timber Press, Portland,
   Oregon.

   Bryant, M.D.1984b. The role of beaver dams as coho
   salmon habitat in southeast Alaska streams.  In JJtf
  Walton and D.B. Houston (eds).  Proc. Olympic Wild
  Fish Conf., Port Angeles, WA. pp. 183-192.

  Burger, C.V. and D.B. Wangaard, R.L. Wilmot, AJST.
  Palmisano. 1983. Salmon investigations in the Kenai
  River, Alaska. U.S. Fish & Wildl. Serv., Anchorage.

  Correll, D.L. and Weller, D.E.  In press.  Factors
  limiting processes  in  freshwater  wetlands:  an
  agricultural primary stream riparian forest.

  Elder, J.F. 1985. Nitrogen and phosphorus speciation
  and flux in a large Florida river wetland system
  Water Resour. Res. 21:724:732.

  Fredrickson, L.H. and R.D. Drobney.  1977. Habitat
  utilization by postbreeding waterfowl. Pp. 119-131 ,'„
  T.A. Bookhout (ed.) Waterfowl and Wetlands - An
  Integrated Review.   Proc. of symposium at 39th
  Midwest Fish and Wildlife Conference. Madison
 Wisconsin.                                    '

 Gosselink,J.G.andLee,L.C. 1987. Cumulative impact
 assessment in bottomland hardwood forests. Center
 for Wetland Resources, Louisiana State University
 Baton Rouge.  LSU-CEI-86-09.  113pp.

 Hook, P.B. and M.M. Brinson. 1989.  Influence of
 landscape position, hydrologic forcing, and marsh
 size on ecological differentiation within an irregularly
 flooded brackish marsh.  Paper presented at the 4th
 Annual Landscape Ecology Symposium, Fort Collins,
 Colorado, March 15-18,1989.

 Jordan, T.E.,  D.L. Correll, W.T. Peterjohn and D.E.
 Weller. 1986. Nutrient flux in a landscape: the Rhode
 River Watershed and receiving waters. Pp. 57-76 in
 D.L. Correll (ed.), Watershed Research Perspectives.
 Smithsonian Institution Press, Washington, D.C.

 Kirby-Smith, W.W. and Barber, R.T. 1979. The water
 quality ramifications in estuaries of converting forest
 to intensive agriculture. Water Resources Research
Institute of North Carolina Report No. 148.
  Mahoney, D.L. and Erman, D.C 1984.  The role of
  streamside buffer strips in the ecology of aquatic
  biota.  In R.E.  Warner and  K.M. Hendrix (eds.),
  California riparian systems: ecology, conservation,
  andproductivemanagement. UniversityofCalifornia
  Press. Berkley, CA.

  Merrell, T.R. Jr. and K.V. Koski. 1979. Habitat values
  of coastal wetlands for Pacific Coast Salmonids. Pp.
  256-266m P.E.Greesonetal. (eds.) Wetland Functions
  andValues:TheStateofOurUnderstanding. AWRA,
  Minneapolis, MN.

  Niering,WA.  1988.  Endangered, threatened and
  rare wetland plants and animals of the continental
  United States. Pp. 227-238 in D.D. Hook and others
  (eds.) The Ecology and Management of Wetlands.
  Vol. 1: Ecology of Wetlands. Timber Press, Portland,
  Oregon.

  Odum, W.E., L.P. Rozas and C.C. Mclvor.  1988. A
  comparison of fish and invertebrate community
  compositionin tidal freshwater andoligohalinemarsh
  systems.  Pp. 561-569 in D.D. Hook and others (eds.)
  The Ecology and Management of Wetlands. Vol. 1:
  Ecology  of Wetlands.  Timber Press,  Portland,
  Oregon.

  Peterjohn, W.T. and Correll, D.L.  1984.  Nutrient
  dynamics in an agricultural watershed: observations
  on the role of riparian forest. Ecology 65:1466-1475.

 Peterjohn, W.T. and Correll, D.L. 1986. The effect of
 riparian  forest  on the  volume  and  chemical
 composition of baseflo win an agricultural watershed.
 In D.L. Correll (ed.), Watershed research properties.
 Smithsonian Institution Press, Washington, D.C.

 Peterson, N.P. 1982, Immigration of juvenile coho
 salmon into riverine ponds. Can. J. Fish. Aquat Sci
 39:1308-1310.

 Powell, G.VJST. 1987. Habitat use by wading birds in
 a subtropical estuary: implications of hydrology The
 Auk 104:740-749.

 Prevett, J.P., I.F. Marshall, and V.G. Thomas. 1985.
 Spring foodsof snow and Canada geese at James Bay.
 J. Wildl. Manage. 49(3): 558-563.

 Sugai, S.F. and D.C. Burrell. 1984. Transport of
 dissolved organic nutrients and trace metals from the
Wilsonand Blossom Rivers to Smeaton Bay, Southeast
Alaska, USA.  Can. J. Fish. Aquat Sci. 41:180-190.

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                 U.S. Environmental Protection Agency Regions
 For more information, ask for the Wetlands
 Coordinator or the Estuarine in any of these
 EPA regions:
 EPA Region 1
 JFK Federal Building
 Boston, MA 02203
 (617)565-4430

 EPA Region 2
 26 Federal Plaza
 New York, NY 10278
 (212)264-5170

 EPA Region 3
 841 Chestnut Street
 Philadelphia, PA 19107
 (215)597-9301

 EPA Region 4
 345 Courtland Street, N.E.
 Atlanta, GA 30365
 (404)347-3004

 EPA Region 5
 230 South Dearborn Street
 Chicago, IL 60604
 (312)353-2079
EPA Region 6
1445 Ross Avenue
Dallas, TX 75202
(214,655-2260
 EPA Region 7
 726 Minnesota Avenue
 Kansas City, KS 66101
 (913)236-2823

 EPA Region 8
 One Denver Place
 99918th Street. Suite 1300
 Denver, CO 80202
 (303)293-1575

 EPA Region 9
 215 Fremont Street
 San Francisco, CA 94105
 (415)974-2318

EPA Region 10
1200 Sixth Avenue
Seattle, WA 98101
(206)442-1412
             ion Agency
       For EPA Headquarters:

          EPA Headquarters
           401 M Street, SW
        Washington, DC 20460
     Office of Wetlands Protection
     ^-— (202) 4f
    Office of Marine and Estuarine
             Protection
           (202) 382-7166
 "\~ J7 /] 
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