Applied Wetlands Science - Chapter 13 ppsx

THE RAMSAR CONVENTION The primary instrument for the protection and management of wetlands on aglobal scale is the Ramsar Convention on Wetlands of International ImportanceRamsar Convent

Kent, Donald M “Managing Global Wetlands”

Applied Wetlands Science and Technology

Editor Donald M Kent

Boca Raton: CRC Press LLC,2001

CHAPTER 13 MANAGING GLOBAL WETLANDS

Annette M Paulin and Donald M Kent

Florida Everglades

Functions and ValuesThreats and ImpactsConservation EffortThe Mekong Delta

Functions and ValuesThreats and ImpactsConservation EffortsThe Pantanal

Functions and ValuesThreats and ImpactsConservation EffortsThe Wadden Sea

Functions and ValuesThreats and ValuesConservation EffortsReferences

Historically, a significant amount of wetland management effort has been focused

on individual wetlands Commonly, individual wetlands are encompassed and ulated by a single authoritative unit, such as a town or city With the advent ofwatershed management, the focus has broadened to include simultaneous consider-ation of multiple wetlands Watershed management typically requires cooperationand coordination among several authoritative units, such as municipalities, counties,and states Managing wetlands that cross international boundaries or wetlands within

reg-a single country, but threg-at reg-are of internreg-ationreg-al importreg-ance, poses reg-additionreg-al chreg-allenges.Managing wetlands that cross international boundaries requires cooperation andcoordination among countries This may be accomplished informally by communi-cation between respective government environmental agencies, or formally by estab-lishment of joint proclamations or management plans Understanding that an indi-vidual country’s best interests are served by ensuring protection of shared wetlandresources is fundamental to effective management

In some instances, wetland function and value, even those contained with a singlecountry, may be of global importance For example, a wetland may function as floodstorage for downstream, transboundary communities Continued wetland functionwould ensure that downstream communities have adequate irrigation for agricultureand are protected from catastrophic floods Alternatively, a wetland may be a criticalbreeding or wintering area for migratory fish and wildlife

Managing wetlands at the global level could be self-regulating That is, resourceusers, whether governments or private entities, would recognize the value of wetlandsand protect their investment The World Trade Organization might be a model or avehicle for this type of management Success would require sustainable use ofresources, an accurate valuation of all wetland values, and a mediation process.Lending institutions might also effect management Funding of significant develop-ment projects would require conduct of a cost–benefit based environmental impactassessment The perspectives of both the applicant country and the internationalcommunity would need to be considered Some international lending institutionsrequire an impact assessment, but the process does not appear to adequately valuewetland resources

Presently, the United Nations through the Ramsar Convention on Wetlandseffects management of global wetlands Participation in the Ramsar Convention isvoluntary, and there is no enforcement authority Wetland protection is effectedthrough education and management assistance The first part of this chapter describesthe approach and operation of the Ramsar Convention The balance of the chapterdescribes four wetlands of international significance The wetlands illustrate a range

of challenges and the conservation efforts being enacted to protect wetland functionsand values

THE RAMSAR CONVENTION

The primary instrument for the protection and management of wetlands on aglobal scale is the Ramsar Convention on Wetlands of International Importance(Ramsar Convention, 1999) As of 1999, there were 114 contracting nations and 975

wetlands totaling 70.7 million ha The United Nations Educational, Scientific, andCultural Organization serves as the depository for information, and funds the Con-vention The Ramsar Convention recognized that wetlands have great economic,ecological, and cultural value, and that encroachment and loss of wetlands must bereduced Because water resources for wetlands often cross political boundaries, theRamsar Convention now provides a framework for intergovernmental cooperation

in the conservation and wise use of wetlands

Membership

A nation must have one listed wetland to become a participating member of theRamsar Convention A wetland can be listed if it satisfies at least one of severalcriteria Geographical and ecological criteria include being representative of a natural

or near natural wetland, common to more than one biogeographical region, sentative of a wetland that plays an important role in the natural connection of amajor river basin or coastal system (especially where located in a transborderposition), or unique as a rare or unusual type of wetland in the biogeographicalregion A wetland may also satisfy listing criteria by playing a role in plant or animalspecies integrity For example, the wetland may support rare, vulnerable, or endan-gered species by maintaining genetic and ecological diversity of the flora or fauna

repre-of a region, by providing habitat for plants or animals at a critical stage repre-of theirbiological cycle, or by containing one or more endemic plant or animal species orcommunities The final criteria for listing are related to biological value and arebased on supporting regulatory waterfowl communities of 20,000 or more individ-uals, a substantial number of a particular group of waterfowl, or 1 percent of theindividuals in a population of a species or subspecies of waterfowl

If a wetland satisfies at least one criterion, it will be listed as a wetland ofinternational importance If a wetland fails to satisfy the criteria, measures may betaken to restore or enhance its values and function in order to meet one of the criteria

If these measures fail, the site will be not be listed

Dues are paid based on a sliding scale determined by Gross National Product

of the member nation Members of the Ramsar Convention have certain obligations.These include considering wetland conservation within the framework of land-useplanning, promoting conservation of wetlands throughout their region, and estab-lishing wetland reserves Members must also provide in-country training in the fields

of wetland research and management, and exchange information and data with othermembers of the Convention Finally, members must consult with the Ramsar Con-vention regarding management implementation, especially when it involves trans-boundary wetlands, shared water resources, or shared development aid for projects

Wetland Definition and Classification

The Ramsar Convention has a definition and classification system for identifyingwetlands of international importance Wetlands are defined as “areas of marsh, fen,peatland, or water, whether natural or artificial, permanent or temporary, with waterthat is static or flowing, fresh, brackish or salt, including areas of marine water the

depth of which at low tide does not exceed six meters … and may incorporateriparian and coastal zones adjacent to the wetland, and islands or bodies of marinewater deeper than six meters at low tide lying within the wetlands” (Davis, 1994).The definition incorporates ecosystems that are an integral part of a major watersystem and is broader than many other operational wetland definitions (seeChapter 1).

The Ramsar Convention (Davis, 1994) recognizes four major types of wetlands.Marine wetlands are coastal wetlands including rocky shores and coral reefs Estu-arine wetlands are located between salt water and fresh water bodies, or dry landincluding deltas, tidal marshes, and mangrove swamps Lacustrine wetlands arewetlands associated with lakes Palustrine wetlands are isolated marshes, swamps,

or bogs Wetlands are classified when listed as wetlands of international importance

by the Ramsar Convention

Management

The Convention assists members with plans of action for management of theirwetlands by sharing information and through the activities of a Scientific and Tech-nical Review Panel The Panel is comprised of experts in the field of wetlandmanagement They provide members with expert opinions and assist with the design

of management plans

The management planning process has three steps: description of the site, ing evaluations and objectives, and designing an action plan or prescription Descrip-tion of the site includes identifying the wetland type(s) and creating an inventory ofthe flora and fauna This first step is used to establish criteria for listing the site.The evaluation provides a detailed report of the site, including information onbiological diversity, integrity, rarity, fragility, history, cultural and aesthetic value,social and economic value, education and research opportunities, and potential usesfor recreation In evaluating the site, concise objectives are formed for best man-agement practices These objectives are based strictly on the evaluation of the site,and are intended to fully protect its characteristics After the objectives are outlined,any factors that may hinder their achievement, including both natural and human-induced, are identified Considering the objectives and mitigating factors, operationalobjectives are developed Management strategies are established based on the bestpossible alternatives under the given circumstances A limit of acceptable change isestablished to meet protection obligations

form-Finally, a plan of action is outlined which may include zoning, habitat ment, species management, contextual uses, education, and research initiatives.Specific projects and work programs are designed to implement these actions Overtime, reviews of progress at the site are presented to the Ramsar Convention toensure operational success, or to facilitate changes in objectives and action plans

manage-Additional Support

The Ramsar Convention provides additional assistance to member nationsthrough three documents: the Montreux Record and Monitoring Procedure (Davis,

1994), Towards the Wise Use of Wetlands (Davis, 1993), and the Economic Valuation

of Wetlands (Barbier et al., 1997) The Montreux Record lists priority sites that areundergoing ecological changes owing to human activities The Scientific and Tech-nical Review Panel supports a procedure for monitoring site changes and imple-menting management strategies

National management strategies are encouraged to comply with guidelinesdescribed in Towards the Wise Use of Wetlands (Davis, 1993) The Ramsar Con-vention defines the wise use of wetlands as “sustainable utilization for the benefit

of mankind in a way compatible with the maintenance of the natural properties ofthe ecosystem” (Davis, 1993) Guidelines include establishing an integratedapproach to policy making using coordinated efforts of national, regional, and localinstitutions, and providing policies that promote wetland protection in land-useplanning, environmental audits, financial incentives, and permit processes

Wise Use provides examples of management strategies by describing wetlandinventories, monitoring techniques, research on identifying values, wetland use, andlandscape function The management strategies include establishment of trainingprograms and promotion of public awareness (Davis, 1993) Actions outlined byWise Use include maintaining ecological integrity, sustainable use, balancing restric-tions with cultural uses, and integrating wetland management with developmentplans The latter seeks to achieve a balance between conservation and the use ofwetland resources Wise Use also provides 17 case studies to illustrate managementissues and lessons learned from the implementation of the Wise Use guidelines.The Ramsar Convention developed a guide, Economic Valuation of Wetlands

(Barbier et al 1997), to facilitate the economic valuation of wetland resources.Developed in conjunction with the Department of Environmental Economics andEnvironmental Management at the University of York, the Institute of Hydrology,and the World Conservation Union (IUCN), the document outlines severalapproaches to valuate the economic value of wetlands and weigh the benefit ofdevelopment strategies with the degradation it may cause to wetland resources Onesomewhat unique aspect of the document is the emphasis on social, cultural, andpolitical values for decision-making This is accomplished by addressing not onlythe valuation of direct economic benefits from wetlands (e.g., timber and foodresources), but also indirect economic benefits (e.g., biological functions such asflood attenuation and future uses and benefits) and nonuse values (e.g., biodiversityand cultural heritage)

The framework provided in Economic Valuation of Wetlands includes seven steps(Table 1) In practice, the valuation requires an interdisciplinary approach and thecooperative effort of specialists, including economists, hydrologists, fishery andwetland biologists, and sociologists

The first step in the valuation is selecting the appropriate approach There arethree assessment approaches, impact analysis, partial valuation, and total valuation,available based on the type of development and degree of impact to the wetland’sintegrity An impact analysis assesses the external costs of off-site development oractivities such as discharges from industries or mining activities This analysis wouldcompare the benefit of the activity to the losses in specific wetland resources fromoff-site impacts A partial valuation is used to evaluate changes in the allocation or

the alternative uses of wetland resources An example is the diversion of floodwaterfor irrigation While not all of the wetland resources may be impacted, valuation ofthe benefits lost is compared to benefits gained from the irrigation project In addition,evaluation of the alternative uses of the floodwater would be considered Such alter-natives may be the use of floodplains for fish farming or agricultural benefits fromnutrient loading of floodwaters The third approach, total valuation, is used to evaluate

a wetland’s contribution to society as a whole This valuation may be applied inwetland preservation strategies and regional natural resource assessments

The second step in the framework is to define the wetland area, time scale, andanalytical boundaries of the assessment The defined parameters will differ based

on the assessment approach An impact assessment may only require a short timescale such as the time discharge flows from an industry and small analytical bound-aries such as the area of the water resources impacted A total valuation may requireconsideration of all wetland resources, a large analytical boundary, and an extendedtime scale

Step three identifies the corresponding functions and attributes of the wetland.This step requires review of previous research and may require additional research

to ensure thorough identification of the functions and attributes to be considered inthe valuation This critical stage will also require the collaborative teamwork ofspecialists in differing fields

Step four in the valuation defines and prioritizes the values of the identifiedwetland functions and attributes (see Chapter 3) Functions and values may be use(e.g., direct, indirect, and option or quasi-option) or nonuse Direct uses are valuesmost often used in economic valuation studies because these activities are directlymarketed Examples of direct use include agricultural resources, fuelwood, recreation,harvesting, and transportation uses In many instances, these activities are used forsubsistence purposes and appropriate evaluation techniques must be applied How-ever, either as marketed or subsistence resources direct use can be quantified based

on a marketed economic value Indirect use values are primarily ecological functionsthat protect or support direct uses These values include flood attenuation, erosioncontrol, nutrient retention, and groundwater recharge Option and quasi-option valuesare potential future uses (both direct and indirect) and future information use Valueaccrues by delaying development or exploitation Option and quasi-option valuesmay change with changes in economic, social, and scientific circumstances.Nonuse value is the wetland’s intrinsic existence value The most difficult toquantify, nonuse value includes biodiversity, cultural heritage, and preservation for

Table 1 Framework for the Economic Valuation of Wetlands

(Barbier et al., 1997)

1 Select an assessment approach

2 Define the wetland boundary and system boundary

3 Identify and rank wetland components, functions, and attributes

4 Relate components, functions, and attributes to type of use value

5 Identify information required to assess uses

6 Quantify economic values

7 Implement the appraisal method

future generations Contributions to conservation campaigns are one indicator of thevalue society places on these uses.

Step five in the valuation process is to obtain detailed information about theidentified values This information includes scientific data, statistical data on humanuses, economic inputs and outputs of activities, and survey results, and is critical tothe valuation process For example, scientific data will provide details on indirectuse values such as flood retention capacity, degree of erosion protection, populations

of harvested species, and growth rates of forests Statistical data on human uses andeconomic inputs—outputs of activities, including agricultural and fishery yields andtourism revenues—provide detail on direct marketable uses Information from sur-veys may provide valuable information on option based or intrinsic values that areotherwise difficult to quantify

Once an appropriate assessment approach is chosen, and values are identified,classified, and defined statistically, the actual valuation is conducted Most critical

in this sixth step is choosing the proper technique for valuating resources and theiruse Economic Valuation for Wetlands does not detail the methods for each technique,although it provides a list of advantages and disadvantages For example, marketprices may be applied to direct market uses, while surrogate market price may beapplied to a wetland resource that is not marketed but is closely related to a marketedgood or service Another direct use method is indirect substitute, where the cost of

an alternative source of resources is applied to the wetland resource such as waterimported from the outside vs water used from the wetland

For indirect uses, approaches such as the value in changes in productivity anddamage costs avoided can be used to determine the impact of ecological degradation

To determine option values and nonuse values, the contingent valuation method ismost widely used Because of its context in nonuse valuation, this method is con-troversial However, it does provide an assessment of an individual’s or society’swillingness to pay for the value, or how much compensation they would requireupon loss of the use Another approach to determining option and nonuse values is

to determine the sustainable yield of current activities and alternative or sating projects that could be offered If current activities are not sustainable, alter-native scenarios that offer higher social returns are offered Compensating projectsoffer mitigation for environmental degradation, while maintaining long-term sus-tainability in the overall natural system and ensuring nonuse values

compen-The final step in the valuation framework is to implement the appropriateappraisal method Again, Economic Valuation of Wetlands does not detail methodsbut lists advantages, disadvantages, and most appropriate cases for implementation.These methods include cost–benefit analysis, multiple criteria analysis, land suit-ability/classification models, environmental impact assessments, and cost-effective-ness analysis Upon implementation of appraisal methods, Economic Valuation of Wetlands stresses the importance of applying the economic valuation methods withinsocial, political, and cultural contexts In addition, this valuation should be conductedwith interdisciplinary collaboration and provide effective institutional capacity build-ing upon decision making This capacity is based on the training and informationprovided by those conducting the valuation to those involved in decision making.Thus, the valuation should be founded on thorough information and appropriate

evaluation techniques As stated by Delmar Blasco, Secretary General for the RamsarConvention Bureau, “It is important to stress that economic valuation is not a panaceafor all decisions, that it represents just one input into the decision-making process,along with important political, social, cultural and other considerations The goal ofthis text is to assist planners and decision-makers in increasing the input fromeconomic valuation in order to take the best possible road towards a sustainablefuture” (Barbier et al., 1997).

CASE STUDIES

Four case studies illustrate the types of management issues confronting countrieswith wetlands of international importance (Table 2) Both freshwater and coastalwetland systems in developed and developing countries are represented The types

of threats and impacts include excessive resource extraction, altered hydrology, andpollution Conservation efforts include restoration, international agreements, protec-tion of critical areas, education, and use restrictions

The Everglades is contained wholly within the United States The Evergladessupports many threatened and endangered species and migratory bird populations.Groundwater recharge and surface water flow are critical to the social and economicwell-being of burgeoning South Florida The other case studies illustrate issuesassociated with transboundary wetlands The Mekong Delta is a major coastalsystem The Delta has recovered from wartime impacts but is now threatened byunsustainable subsistence use and upstream hydropower projects The Pantanal is asignificant contributor to regional biodiversity In some ways, the situation in thePantanal mirrors that of the Everglades in the early 20th century—a large, relativelypristine and productive wetland is threatened by a proposal to alter regional hydrol-ogy to accommodate economic growth The Wadden Sea is a major coastal andshallow marine system in northern Europe Located in a developed region of theworld, the Wadden Sea is subjected to coastal armament and pollution

Florida Everglades

Known as the River of Grass, the Florida Everglades is one of the largestfreshwater marshes in the world, historically encompassing about 3.5 million ha(Figure 1) It extends from Lake Okeechobee in south central Florida to the southerntip of Florida where its wide mouth empties into Florida Bay and other smaller baysand estuaries The headwaters of the Everglades begin as small streams and lakes

in central Florida and flow through the Kissimmee Lakes and River system Thissystem leads to Lake Okeechobee, a 300 ha natural reservoir formed in the center

of the state when sea levels fell during the last ice age Water historically flowedover the southern edge of Lake Okeechobee and into the Everglades From here thewater flowed to the Gulf of Mexico via the Caloosahatchee River and to the AtlanticOcean via the St Lucie River (Robinson et al., 1996)

Table 2 Characteristics of Case Study Wetlands

Function and Value

Threats and

Florida Everglades United States 3,500,000 Freshwater marsh,

mangrove, swamp, slough, estuary, shallow bay

Fish and wildlife habitat, recreation, tourism,

agriculture, drinking water, cultural heritage

Agriculture, altered hydrology, pollution, exotic vegetation

Protected areas, restoration plan, stormwater treatment areas, agricultural BMPs

Mekong Delta Laos, Myanmar,

Thailand, Cambodia, Vietnam

3,900,000 Melaleuca forest,

mangrove, tidal mudflat

Fisheries, agriculture, forest resources, transportation

Deforestation, pollution, hydropower

Protected areas, education, Commission toward Sustainable Development Pantanal Brazil, Bolivia,

Paraguay

11,000,000 Swamp, forest,

savannah, lake margin scrub, gallery forest

Flood control, fish and wildlife habitat, fisheries, cattle ranching, tourism

Cattle ranching, agriculture, overfishing, hunting, Hydrovia project

Protected areas, education, Intergovernmental Committee on Hydrovia Wadden Sea Denmark,

Germany, Netherlands

1,350,500 Tidal channel, mud

flat, salt marsh, beach, dune

Primary productivity, fish and wildlife habitat, tourism, recreation

Infrastructure development, pollution, shellfish harvesting

Joint Declaration on the Protection, protected areas, prohibited shoreline armoring

©2001 CRC Press LLC

Functions and Values

Small elevation differences within the Everglades contribute to the formation ofmany distinct ecosystems including swampy cypress domes, hydric hardwood ham-mocks, pinewoods, freshwater sloughs, brackish estuaries, shallow shorelines andembayments, and deeper gulf waters (Frazier, 1996; World Conservation MonitoringCentre, 1990) These diverse ecosystems are habitat for 25 terrestrial and 2 aquaticmammals including the endangered Florida black bear (Ursus americanus), Floridapanther (Felis concolor), and West Indian manatee (Trichechus manatus) Over 300species of birds have been observed, many of which use the area as a stop on theirmigration to and from Central and South America Many of North America’s water-fowl and shore birds can be found using the Everglades as a seasonal home Some,like the wood stork (Mycteria americana), sandhill crane (Grus canadensis), glossy

Figure 1 The Florida Everglades; the shaded area represents the remnant

Everglades–Flor-ida Bay ecosystem; WCAs are water conservation areas (Modified from South Florida Water Management District, 1999.)

Florida

Lake Okeechobee

Florida Bay

ibis (Plegadis falcinellus), and roseate spoonbill (Ajaia ajaja), are threatened orendangered The threatened or endangered American crocodile (Crocodylus acutus),American alligator (Alligator mississippiensis), indigo snake (Drymarchon corais),loggerhead turtle (Caretta caretta), hawksbill turtle (Eretmochelys imbricata), andgreen sea turtle (Chelonia mydas) are among the more than 50 species of reptilesinhabiting the Everglades.

The flora of the Everglades is as varied as its ecosystems, with 10,000 species

of seed-bearing plants and 120 species of trees Plant types range from the teristic sawgrass (Cladium jamaicensis), to bromeliads and epiphytic orchids, totropical (e.g., gumbo limbo, Bursera simaruba) and temperate (oaks, Quercus spp.)trees Over 60 plant species found in the Everglades are endemic to South Florida.Periphyton is an important component of the Everglades ecosystem High in calciteand dominated by filamentous blue-green algae, the periphyton community helpsbuild marl, a soil overlying the limestone foundation of the Everglades, and supports

charac-an intricate food web

In the transition from fresh to salt water, the Everglades estuarine systems provide

a nursery for the Florida Bay’s fishing industry In 1989, harvesting of lobster(Panulirus argus), stone crab (Menippe mercenaria), and pink shrimp (Penaeus duorarum) brought in revenue of US $61 million (Redfield et al., 1999) One countyalone made over $35 million in 1992, making the Everglades and Florida Bay animportant economic resource (Robinson et al., 1996) In addition, EvergladesNational Park is an economic center for tourism with over 250 thousand visitors ayear (World Conservation Monitoring Centre, 1990)

Another economic interest operating within the Everglades historic boundary isagriculture Based mainly on sugarcane crops, this multibillion dollar industry relies

on the rich soils of drained portions of the Everglades Unfortunately, the ment of this industry has had profound direct and indirect effects on the integrity

develop-of the Everglades ecosystem

The Everglades also has important social and cultural values Demand for water resources increased markedly with the development of South Florida Theporous nature of the limestone baserock recharges an underlying aquifer A total of

fresh-90 percent of the regional population receives its potable water from this aquifer.Freshwater recharge into the southern part of the Everglades prevents saltwaterintrusion into the aquifer The Everglades also protects South Florida residents fromheavy surf associated with hurricanes and high tides Mangrove forests and barrierislands along the coastal edges serve as protective barriers

The Everglades cultural value derives from historic and continued habitation byindigenous peoples (Robinson et al., 1996) The Calusa and Tequesta arrived inFlorida 11,000 years ago and thrived until the early 1800s when they succumbed todiseases and war accompanying European settlers Remnants of the Calusa andTequesta remain in the form of shell mounds and artifacts Other Native Americans,the Seminoles, fled to Florida in the early 18th century when tribes were pressuredwest and south by colonial expansion A small, non-Christian faction of the Semi-noles, the Miccosukee, lives in the Everglades today

Threats and Impacts

Impacts to the Everglades are related to a long history of cultural and economicdevelopment The earliest records of the first ecological changes to the system arefrom the late 19th century (Robinson et al., 1996) In 1881, one of the first devel-opers, Hamilton Disston, began draining wetlands around Lake Okeechobee to createfarmland In addition, canals were built within the northern part of the watershed.While these drainage efforts had little effect on Lake Okeechobee and its overflowsinto the Everglades, it opened the door to reclaiming the Everglades for civilization(Derr, 1993) With mild year-round weather and fertile soils, the area quickly became

an agricultural center

To support development, the State of Florida encouraged drainage The glades Drainage District excavated 700 km of canals by 1927 The Hoover Dikewas built along the southern shore of Lake Okeechobee in the late 1920s in response

Ever-to flood disasters caused by several hurricanes In large part, the dike separated thelake from the Everglades During this same time period, the Tamiami Trail wasbuilt, linking Miami with the Gulf Coast This roadway, built through the middle

of the Everglades, separated the northern and southern Everglades disrupting thenatural hydroperiod

Construction of the canals, Hoover Dike, and the Tamiami Trail had a quick andobvious impact on the hydrology of the Everglades Models indicate that the firstfour canals removed 1.5 million acre-feet of water per year from the system Impacts

to wildlife, especially waterfowl, were evident In addition, a 1.2 m decrease ingroundwater levels caused soils to oxidize and subside By 1940, 1.8 to 2.1 m ofsoil was lost and the slope of the land became concave, reversing the direction offlow in the northern part of the Everglades toward Lake Okeechobee (Robinson

et al., 1996; Redfield et al., 1999)

In 1948, in response to concerns about droughts and floods in the northern part

of the Everglades, Congress authorized an expansion of the canal system (McLeanand Bush, 1999) The US $208 million Central and South Florida Project consisted

of 1250 km of flood control canals The Central and South Florida Flood ControlDistrict was established to manage the project and to allocate water resources throughthe system of canals, levees, locks, and dams Additional levees were built south ofLake Okeechobee to block sheet flow to the increasingly populated Atlantic Coast.The levees were also used to create Water Conservation Areas that would retain thewaters of the Everglades

During this same time period, the southernmost 5 percent of the historic glades was designated as a National Park However, this designation would notprotect the Everglade’s fragile and valuable ecosystem By the 1960s, degradation

Ever-of the Everglades was a sensitive issue throughout the United States Congressenacted the Water Resource Development Act in 1970, mandating a minimum waterdelivery to the Everglades In 1972, the Water Resources Act was passed, mandatingthe protection of the Everglades through improvements in water quantity and quality.The Central and South Florida Flood Control District was renamed the South FloridaWater Management District (one of five newly formed districts in the state), with anew mission of protecting water quality and preserving environmental values

(Robinson et al., 1996) The new District was required to balance the water resourceneeds of urban, agricultural, and natural areas Areas in the northern and central part

of the Everglades, between the Everglades Agricultural Areas and EvergladesNational Park, were placed under protection and designated as the Everglades Pro-tection Area During the next 20 years, studies would indicate that the Evergladescontinued to be impacted Despite new water discharge requirements, the qualityand quantity of water resources delivered to the park were inadequate to maintainecosystem health

For decades, the most obvious change to the ecosystem was alteration of thehydrologic flow Conversion of more than 50 percent of the historic Everglades toagricultural and urban areas resulted in a decrease in regional water storage Theconstruction of canals, drainage ditches, and dikes to control floodwaters dramati-cally changed natural sheet flow and hydroperiod Sudden releases from the watercontrol structures inundated areas that that had been abnormally dry for extendedperiods, disrupting foraging and nesting habits of wading birds and herpetofauna

In addition, changes in water depth altered macrophyte and algal community position, disrupting primary production processes

com-The disruption in natural sheet flow to the Everglades has impacted areas as farsouth as the Florida Bay, and possibly the coral reefs of the Florida Keys (Robinson

et al., 1996) Because freshwater flow has decreased, salinity levels have risenstressing aquatic organisms adapted to narrower salinity ranges In addition, waters

of Florida Bay have warmed, altering current exchange patterns with the AtlanticOcean Reduction in freshwater flows to the Everglades has also impacted mangroveand upland communities of the Atlantic Coast as groundwater recharge decreasedand saltwater intrusion increased

The loss in groundwater recharge has also impacted the supply of potable water

to the region (Robinson et al., 1996) Groundwater resources, the primary source ofSouth Florida’s water supply, are used at a rate exceeding recharge rates Freshwaterhas become scarcer, and potable water must be imported to large parts of the region.Research indicates that the water reaching the Everglades is of poor quality(McCormack et al., 1999) Stormwater runoff diverted by canals to the EvergladesProtection Area contains high levels of nutrients from agricultural areas Once anoligotrophic system, the Everglades now exhibits signs of eutrophication Naturalsurface water total phosphorus concentrations are between 4 to 10 ppb, while agri-cultural runoff concentrations range between 50 to 200 ppb total phosphorus Naturalsoil total phosphorus concentrations are between 200 to 500 ppb, whereas soilconcentrations downstream of agricultural areas reach 1000 ppb total phosphorus.Elevated concentrations of total phosphorus are linked to shifts in algae species betteradapted to high nutrient loading Sudden algal blooms cause low water columndissolved oxygen levels threatening invertebrate organisms In Lake Okeechobee,algal blooms cause fish kills Florida Bay has experienced low dissolved oxygenlevels with subsequent impacts to seagrass communities vital to fisheries

High nutrient loading has also contributed to a shift from diverse wetland plantspecies to a monoculture of cattails in some parts of the Everglades Under highnutrient conditions, cattails are able to out compete sawgrass and other macrophytes,especially when accompanied by hydrologic changes

Hydrologic and other disturbances have created opportunities for the ment of exotic vegetation (Ferriter et al., 1999) Brazilian pepper (Schinus terebin- thifolius), Australian pine (Casuarina litorea), and especially melaluca (Melaleuca quinquenervia), are of primary concern Melaluca is the dominant exotic in someparts of the Everglades It thrives in lower water levels and produces thousands ofseeds per plant Melaleuca was introduced to the Everglades in the belief that itshigh evapotranspiration rate would dry out wet areas (Derr, 1993; Robinson

establish-et al., 1996)

The latest threat to the Everglades is the accumulation of mercury in sediments(Fink et al., 1999) Mercury is deposited from the atmosphere and converted tohighly toxic methylmercury by sulfate bacteria Methylmercury bioaccumulates andhas the potential for affecting wildlife at all levels of the food web Top predatorsmay accumulate up to 10 million times the concentration in water Mercury alsopresents a human health risk, and fish consumption in the Everglades, eastern FloridaBay, and the Big Cypress Conservation Area is either prohibited or restricted.Although the accumulation of methylmercury has not been observed to affect repro-ductive rates in waterbirds, it may affect eating and foraging habits (Frederick et al.,1999; Bouton et al., 1999) Mercury poisoning is the suggested cause of severalFlorida panther deaths and reduced litter sizes (Florida Panther Interagency Com-mittee, 1989)

Conservation Efforts

In 1988, the United States government sued the Florida Department of mental Regulation and the South Florida Water Management District for failing tomaintain high water quality in waters flowing to the Everglades National Park andthe Loxahatchee National Wildlife Refuge In 1991, a settlement was reached andthe defendants agreed to guarantee water quality and water quantity needed topreserve and restore the unique flora and fauna of the Park and the Refuge (Robinson

Environ-et al., 1996) With a July 2002 deadline to meEnviron-et these agreements, the state of Floridapassed the Everglades Forever Act in 1994 Strategies outlined in the Act are designed

to achieve water quality standards by December 31, 2006 The Everglades ForeverAct mandated a fair share of restoration costs be borne by agricultural interests Inaddition, the Act recognized that urban development encroached upon the naturalsystem and authorized the South Florida Water Management District to impose ahomeowner’s tax of an average of US $10 a year (Robinson et al., 1996)

Initial management efforts focused on reducing nutrient loading from agriculturalarea stormwater runoff to the Everglades Protection Area (Chimney et al., 1999).The Everglades Nutrient Removal Project purchased agricultural land and converted

it to wetland stormwater treatment areas (STAs) The STAs are macrophyte-basedsystems designed to remove phosphorus from agricultural stormwater runoff Theoriginal goal of the STAs was to reduce total phosphorus in agricultural runoff to

50 ppb or less and to discharge the treated water to the Everglades Protection Area

To date, the STAs have reduced total phosphorus concentrations to an average of

22 ppb, an 82 percent load reduction (Redfield et al., 1999) A total of 63 metric