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Restoration of Aquatic Ecosystems: Science, Technology, and Public Policy Appendix A— Restoration Case Studies The following case studies were written by several members of the Committee on Restoration of Aquatic Ecosystems, a National Research Council (NRC) consultant, and NRC staff to give the reader more details of specific restoration efforts: Lake Michigan, Lake Apopka, the Atchafalaya Basin, the Upper Mississippi River, the Illinois River, the Willamette River, the Mattole River Watershed, the Merrimack River, the Blanco River, the Kissimmee Riverine-Floodplain System, the Bottomland Hardwood Wetland Restoration in the Mississippi Drainage, the Prairie Potholes, and the Hackensack River Meadowlands. The committee made site visits to the Kissimmee River Restoration Project, the Blanco River Restoration, the Prairie potholes regions in Minnesota, and the Bottomland hardwood wetlands in the Mississippi drainage. Several case studies show that citizen participation (through either private citizen groups or public interest groups) in restoration activity was instrumental in beginning and continuing the restoration effort (i.e., Merrimack River, Upper Mississippi River, Hackensack Meadowlands, and Illinois River). Other case studies feature cooperative participation by citizens, industry, and the state, local, and federal governments working together to return an aquatic ecosystem to a superior condition, such as the Merrimack River, the Kissimmee River, and the Atchafalaya River. One case study (Lake Apopka) shows the problems that can occur over many years to render a restoration activity ineffective.
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Restoration of Aquatic Ecosystems: Science, Technology, and Public Policy LAKES LAKE MICHIGAN Claire L. Schelske and Stephen R. Carpenter General Description Restoration measures have been instituted as the result of a series of environmental problems that have occurred in Lake Michigan (Figure A.1) since the drainage basin was settled by Europeans. In the late nineteenth century, drinking water for the city of Chicago was contaminated with human and other wastes. In 1900, sewage was diverted from the lake to the Mississippi River drainage via the newly constructed Chicago Sanitary and Ship Canal. The diversion controlled waterborne vectors for diseases, including typhoid and cholera. More recently, water quality problems in the lake have resulted from accelerated nutrient enrichment. The fisheries of the lake have also been affected by changes that followed European settlement. Populations of commercially important fish have been eliminated sequentially from the combined effects of environmental degradation, overfishing, and eutrophication (Christie, 1974). In addition, the fish community has been altered by introductions and invasions of exotic species. Potentially toxic chlorinated hydrocarbons, which have been manufactured in the last four or five decades, have entered the food chain and now pose serious problems for the fish community. Historical management strategies for Lake Michigan illustrate some of the consequences of attempts to restore degraded water quality and fishery resources. The main lesson is that management is imperfect and can remediate only some problems. Therefore, whenever possible, we should try to preserve natural systems and avoid having to restore them. Five examples can be cited. First, seriously contaminated water supplies were restored at great expense in 1900 by diverting sewage from Lake Michigan to a river basin (see Illinois River case study, Appendix A). (The cost of constructing the Chicago Sanitary and Ship Canal was $36 million; this was the largest channelization project prior to construction of the Panama Canal.) Second, although problems of nutrient enrichment were alleviated initially by the Chicago sewage diversion, continued nutrient loading from sewage probably would have had severe environmental impacts
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Restoration of Aquatic Ecosystems: Science, Technology, and Public Policy pacts because Chicago is located at the shallow end of the long culde-sac of Lake Michigan, where loading effects would have been magnified. Ironically, diversion would not have been needed if modern sewage treatment facilities had been available at the time. The diversion undoubtedly provided benefits for water quality long after there was a need to control waterborne diseases. Some estimate of the importance of diversion can be obtained by extrapolating the rapidly increasing loadings from human waste in the late nineteenth century. These would have continued if sewage from Chicago had not been diverted in 1900 (Figure A.2). However, these benefits of diversion caused serious water quality problems in the Illinois River (see Illinois River case study, Appendix A) and undoubtedly contributed to degraded water quality in the Mississippi River (Turner and Rabalais, 1991). FIGURE A.1 Lake Michigan, the third largest of the Laurentian Great Lakes, is the only one to lie completely within the United States. The lake is bordered by four states: Illinois, Indiana, Michigan, and Wisconsin. Its length is 491 km, and its width is 190 km. The lake is divided into two distinct basins. The southern basin is gently sloping and has a maximum depth of 175 m. The northern basin has an irregular profile and a maximum depth of 288 m.
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Restoration of Aquatic Ecosystems: Science, Technology, and Public Policy Third, problems of nutrient enrichment were controlled in the 1970s by strategies to reduce phosphorus loading, particularly from sewage treatment plants. These sources of nutrients had become especially important beginning in the 1940s. Improved water quality that resulted from better sewage treatment was obtained at a cost of $10 billion. Benefits other than reduced nutrient loading that may accrue in the future from improved sewage treatment include reduced loadings of potentially toxic materials and vectors for waterborne diseases. Fourth, although water quality has improved, two examples can be cited to show that the chemical condition of the water in Lake Michigan has not been restored to pristine conditions. One example is that silica has been depleted as a result of phosphorus enrichment and consequent increased growth of diatoms, which require silica for growth (Figure A.2). With a shortage of this essential nutrient, the natural phytoplankton assemblages of the lake and the dependent FIGURE A.2 Computer simulation of total phosphorus loads to Lake Michigan from 1800 to 1970 (adapted from Chapra, 1977). Source: Reprinted, by permission, from Schelske (1988). Copyright © by Akademie-Verlag Berlin, Leipziger Strasse Berlin, FRG.
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Restoration of Aquatic Ecosystems: Science, Technology, and Public Policy trophic interactions cannot be restored. Because of the large volume of Lake Michigan, the reduction in silica concentration, a consequence of eutrophication, amounts to a loss of 15 million tons of silica from the lake. It is not likely that silica will be added to the lake because the cost of even partial restoration is prohibitive. The other example is that fish from the lake may not be safe to eat because they have accumulated high levels of potentially toxic chlorinated hydrocarbons. These materials are dispersed throughout the system and apparently are being renewed by atmospheric inputs. Fifth, native fish stocks have been either decimated or severely depleted, and exotic species have invaded or have been introduced into the lake. Some of the ecosystem function attributed to fish has been restored by stocking and by other forms of management. The fish community (Figure A.3) is now largely dominated by exotic species, however, and this and other parts of the original biological community have been lost. The artificial fish community is susceptible to perturbations such as hatchery-transmitted diseases of exotic salmonids, the potential evolution of lampreys resistant to 3-trifluormethylnitrophenol (TFM), and invasions of exotic species. The Lake Michigan food web is a caricature of the ancestral one and lacks the stability of a self-sustaining natural community. In summary, the case history for Lake Michigan provides important lessons about the limitations of restoration and other types of remedial action. Benefits resulting from restoration efforts include improved water quality and rehabilitation of fishery resources. An unanticipated benefit of remedial action may have been improvements in water quality that resulted from the diversion of sewage from Chicago to the Mississippi River drainage. However, this diversion of sewage undoubtedly contributed to degradation of water quality in downstream receiving waters, including the Mississippi River. Several examples show that corrective measures to restore ecosystem function were obtained only at very high costs, that some attributes can be maintained only with continuous management, and that certain losses in the ecosystem were irreversible. Types of Disturbances EUTROPHICATIONS AND NUTRIENT LIMITATION Nutrient control in the Lake Michigan basin is devoted to phosphorus reduction because experimental studies of effects of nutrient limitation on phytoplankton have clearly established that Lake Michigan is a phosphorus-limited system (Schelske et al., 1986). In addition,
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Restoration of Aquatic Ecosystems: Science, Technology, and Public Policy FIGURE A.3 Major exotic and native components of the food web of Lake Michigan. Source: Reprinted, by permission, of Kitchell and Crowder (1986). Copyright (c) 1986 by Kluwer Academic Publishers. these studies also have provided evidence that silica limitation for diatom production can be induced with increased phosphorus loading (Schelske and Stoermer, 1971). The demand for silica, an essential nutrient for diatom growth, increases as diatom production is stimulated by increased phosphorus supplies. Some proportion of the increased diatom production is sedimented, leading to silica depletion in the water column. Under these conditions, phosphorus supplies that would normally be used for diatom production can be used for production of other types of phytoplankton, including blue-green and green algae. Silica depletion and a shift in species composition of phytoplankton, therefore, are expected consequences of eutrophication. Anthropogenic nutrient loadings of phosphorus have increased rapidly, whereas loadings of silica have not increased proportionately to meet the elevated silica demand for diatom production. PHOSPHORUS LOADING Profiles of historical phosphorus loading have been obtained by computer simulation for 1800 to 1970 (Chapra, 1977). Until the 1970s, these simulations provide the main source of information about phosphorus loading to the lake (see Figure A.2). Prior to the beginning of
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Restoration of Aquatic Ecosystems: Science, Technology, and Public Policy European settlement in the mid-1800s, nearly 50 percent of the phosphorus loading was from atmospheric sources. After 1850, phosphorus loading increased, first as the result of forest clearance and associated soil erosion, and later as a result of added human waste from a rapidly increasing human population along the lake shore. The contribution from human waste increased rapidly until 1900, when sewage from Chicago was diverted to the Mississippi drainage by the Chicago Sanitary and Ship Canal. Without this diversion, phosphorus loading to and phosphorus concentration in Lake Michigan probably would have increased exponentially, following the pattern observed in Lake Erie and Lake Ontario. In Lake Michigan, the rapid, exponential increase did not occur until phosphate detergents were introduced after World War II. Phosphorus loads to Lake Michigan have decreased as a result of the 1972 Water Quality Agreement between Canada and the United States. (Although Lake Michigan is entirely within the United States, its water quality is pertinent in the international agreement because outflow from the lake enters Lake Huron, where it can affect the quality of international waters.) No detectable trend in total phosphorus loading occurred from 1974 to 1980, when loads ranged from 6,000 to 7,500 metric tons per year, with the exception of a load of 4,670 metric tons in 1977. Loads were much lower from 1981 to 1985, ranging from 3,500 to 4,500 metric tons annually. The effectiveness of phosphorus control programs is evident because loads from 1981 to 1985 were well below the target load of 5,600 metric tons per year established in the 1972 Water Quality Agreement (Rockwell et al., 1989). Response to Phosphorus Loads Long-term studies of phytoplankton standing crop, which have been restricted to nearshore sites, have shown that the annual standing crop of algae (measured either as counted cells or calculated biomass) increased from 1927 to 1965 and then decreased markedly until levels in 1976 to 1978 were essentially equal to those in the late 1920s (Makarewicz and Baybutt, 1981). Data on monthly average cell counts showed a slightly different pattern. The population density was 50 percent lower in the period 1972 to 1975 than in the preceding 4 years and lower than any 4-year period since 1953 to 1956 (Danforth and Ginsburg, 1980). The change in 1972 to 1975 resulted largely from decreases in the spring and fall maxima of diatoms. Both studies showed that the recent decreases in algal abundance were accompanied by increases in blue-green algae. Although decreases in algal standing crop occured before the implementation of nutrient reduction
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Restoration of Aquatic Ecosystems: Science, Technology, and Public Policy programs in 1972, both studies suggest that the effect may be attributable at least partly to the reversal of eutrophication. The trends in the data set for 1972 to 1984 are complicated by several factors. The first of these is the inherent problem of obtaining a representative sample from a lake the size of Lake Michigan (22,400 square miles). The second is that the trend apparently is confused by climatic factors, particularly the unusually cold winter of 1976-1977. As a result of the cold winter, when ice cover was 90 percent, compared to 20 to 50 percent under normal conditions, winter and spring resuspension of sedimented materials was minimal and the total concentration of phosphorus mean decreased from 8 to 5 µg per liter from 1976 to 1977. The third is that trends may be difficult to measure because concentrations of both total phosphorus and chlorophyll are relatively low. The final difficulty is variability introduced by biological factors. Water clarity increased dramatically in 1983, when the abundance of Daphnia pulicaria increased marked ly (Scavia et al., 1986). The increase in water clarity was attributed to increased grazing pressure from this filter feeder and to the cascading trophic effect of decreased predation on Daphnia by alewife (Scavia and Fahnenstiel, 1988). Evidence for cultural eutrophication has been obtained from the study of diatoms in a sediment core from the northern basin (Stoermer et al., 1990). These results indicate that the diatom community responded relatively little to nutrient enrichment from 1885 to 1925, with an accelerating trend between 1925 and 1954 and the most rapid change between 1954 and 1965. The reversal in trends in diatom species abundance after 1965 attributed to silica limitation was also inferred previously from trends in accumulation rates of biogenic silica in sediment cores (Schelske et al., 1983). This phasing of the effects of phosphorus loading on diatom production agrees well with historical changes in silica concentration in the water mass. Rapid silica depletion from 1955 to 1970 has been attributed to increased diatom production and sedimentation (Schelske, 1988). During these 15 years, silica concentrations decreased from approximately 4.5 to 1.5 mg per liter during the annual water maximum and from approximately 2.0 to 0.1 mg per liter in epilimnetic waters during summer stratification. Whether this rapid change in silica concentration (see Figure A.2) in the open waters of Lake Michigan can be substantiated from long-term data that were collected from nearshore waters at the Chicago Water Filtration Plant has been questioned by Shapiro and Swain (1983). In the case of Lake Michigan, several independent lines of evidence were available to document an historical decrease in silica concentration (see Schelske, 1988). The important reason
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Restoration of Aquatic Ecosystems: Science, Technology, and Public Policy here is that it may be impossible to establish the accuracy of historical data and that historical data, therefore, must be evaluated carefully. It has recently been documented that silica concentrations in the Mississippi River also decreased after 1950 (Turner and Rabalais, 1991). All the responses to phosphorus loading that have been summarized above share a common temporal feature. Large responses that have been attributed to nutrient enrichment occurred after the introduction of phosphate detergents in the period from 1955 to 1970. Although these effects are correlated with increases in phosphate detergents, it should be pointed out that this source of phosphorus increased concomitantly with increased population growth and sewage. EXOTIC SPECIES FOR LAKE MICHIGAN In this century, the food web of Lake Michigan has been almost completely reconfigured by a combination of exotic species invasions and deliberate stocking of sport fishes (Christie, 1974). The ancestral offshore fish stocks were dominated by lake char and coregonines, although 114 native fish species representing 21 families were known from the lake. Waves of introductions of exotic species and collapses of native species began in the 1940s. The collapse of lake char populations between 1946 and 1952 was correlated with an expansion of sea lamprey populations and an increase in harvest rates (Christie, 1974). Populations of the exotic, parasitic sea lamprey peaked between 1950 and 1957. Between 1950 and 1955, the gillnet fisheries of the lake converted from cotton and linen to nylon nets, which achieved at least a threefold increase in fishing efficiency. Selective harvesting of the largest lake char may have forced the lampreys to feed on smaller individuals, which are more likely to die from lamprey attacks (Kitchell, 1990). The relative importance of overfishing and of sea lamprey increases in the collapse of the lake char stock continues to be debated. Since the early 1960s, the sea lamprey has been successfully controlled by the regular additions of TFM, which kills the sedentary ammocoetes in the breeding streams. The exotic rainbow smelt was first reported in Lake Michigan in 1923 and by the 1930s had attained sufficient numbers to support a fishery (Christie, 1974). Fishery yield peaked between 1953 and 1960. It is not certain when the exotic alewife entered Lake Michigan, but populations began to increase in 1949 and reached nuisance levels by 1957. The lake char was probably an important predator of both
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Restoration of Aquatic Ecosystems: Science, Technology, and Public Policy smelt and alewife, and collapse of the lake char likely contributed to the population growth of both of these forage fish. Expansion of rainbow smelt and alewife populations corresponded with the collapsing stocks of native lake herring, and the causal mechanisms of these changes in forage fish communities continue to be debated. After 1960, smelt populations declined, whereas alewife populations boomed, culminating in the infamous die-offs that littered Lake Michigan beaches in the late 1960s. Control of the sea lamprey was followed by highly successful stocking of exotic coho and chinook salmon in Lake Michigan. By the 1980s, stocked salmonids formed the basis of a sport fishery valued in excess of a billion dollars per annum (Kitchell and Crowder, 1986). By 1978, careful analyses of salmonid diets and bioenergetic requirements indicated that heavy predation was likely to trigger a collapse of the alewife stock (Stewart et al., 1981). By 1983, it was evident that a severe decline in alewife abundance was under way (Kitchell and Crowder, 1986). It is ironic that ''Save the Alewife" tee-shirts could be purchased in Milwaukee less than 20 years after massive die-offs fouled water intakes and beaches. Lake Michigan cannot be viewed as a pristine, natural system. Ecosystem dynamics are determined mainly by nonnative species and decisions made by managers. At present, the food web's keystone species are exotic fish whose population dynamics are determined by management policies and are uncoupled from typical ecological feedbacks (Figure A.3). A substantial share of the variability in lower trophic levels is determined by the predatory effects of these fish (Kitchell and Crowder, 1986). Though the species composition of the community is dramatically different from the ancestral one, the extent to which ecosystem functions and trophic structure resemble those that existed prior to disturbance remains an open question. At present, fish biomass at all trophic levels is around twice as large as it was before collapse of the native stocks (J. F. Kitchell, Center for Limnology, University of Wisconsin, personal communication, June 1990). The management of Lake Michigan's fish stocks must be judged a success by several criteria. An extremely successful sport fishery has created and sustained public interest in the resource while controlling the nuisance alewife. However, the ecosystem is an artificial one. The exotic salmonids are susceptible to outbreaks of disease, such as the current epidemic of bacterial kidney disease, exacerbated by complete dependence on hatcheries. Restoration of native species has not occured and in many cases seems unlikely. It has proved very difficult to establish reproducing populations of lake char. Ironically,
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Restoration of Aquatic Ecosystems: Science, Technology, and Public Policy the native lake char is less respected as a game fish, and has far greater concentrations of organochlorine contaminants, than the other salmonids. High contaminant levels may contribute to low egg viability of the lake char. Lake Michigan is also vulnerable to further invasions of exotic species, with consequences that are largely unpredictable. The recent invasion of the exotic zooplankter Bythotrephes cederstroemii has had a profound effect on the planktonic community structure of Lake Michigan (Lehman, 1988). Other potentially more significant invaders are already present in other Laurentian Great Lakes: zebra mussels (also in Lake Michigan), river ruff, and white perch. One prediction can be made with relative certainty: continual vigilance and management of Lake Michigan's food web will be essential to sustain the favorable conditions that currently prevail. ORGANOCHLORINE CONTAMINANTS In Lake Michigan, organochlorine contaminants have been a major environmental concern because of their potentially deleterious effects on wildlife and humans who eat fish. Because these lipophilic compounds tend to accumulate in higher concentrations at higher trophic levels, fish-eating organisms, such as ospreys, eagles, gulls, otter, mink, and humans can be exposed to chemicals at concentrations that far exceed those in the water (International Joint Commission, 1989). Dichlorodiphenyltrichloroethane (DDT) and polychlorinated biphenyls (PCBs) provide contrasting examples of efforts to reduce organochlorine contaminant levels in fish (U.S. FWS, 1989). Until it was banned in 1970, DDT was used commonly as an insecticide. After the ban, concentrations in fish declined exponentially (Figure A.4). From a human health standpoint, concentrations reached acceptable levels by the mid-1970s and have continued to decline since then. In the case of DDT, point source reduction of inputs successfully restored concentrations to acceptable levels. Polychlorinated biphenyls were used for a variety of industrial applications until a voluntary reduction was effected in 1972, followed by a ban on manufacture of the compounds in 1976. After the ban, concentrations in fish dropped significantly (Figure A.4) and have been stable since the early 1980s, although water column concentrations have continued to decline (Swackhamer and Armstrong, 1985; Anders Andren, Sea Grant Institute, University of Wisconsin, personal communication, June 1990). Concentrations in several exploited fish stocks remain above the Food and Drug Administration action level of 2 mg/kg (De Vault et al., 1985; Masnado, 1987). Why
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Restoration of Aquatic Ecosystems: Science, Technology, and Public Policy or altered to emulate presettlement hydrologic conditions. The potholes ranged in size from 0.2 to 10 acres. The tributary watersheds ranged in size from 5 acres associated with the smallest wetland to 500 acres associated with the largest. The tiles draining the potholes were blocked. Drainage ditches were blocked by small earth fills or dikes, the longest of which was 125 ft. Each dike incorporated a spillway. On the Luthens farm, the drainage structures were modified for potholes of 1.5 and 0.7 acre. As in the Christenson case, earthen dikes were used to block the surface drainage and the tiles were removed to prevent subsurface drainage. No plant materials were introduced in the farmed wetlands being restored, and only a limited number of plant species, both warm and cool season grasses (no forbs), were planted in the buffer areas around the restored potholes. The costs for the restoration work were quite modest, in each case being less than $1,000. Each property owner signed an agreement with the U.S. Fish and Wildlife Service. The service acquired the following rights: to restore and maintain the wetlands described in the agreement by plugging drainage ditches or tiles and installing water control structures; to access the land for management purposes; and to establish a vegetative cover on soils disturbed during construction. In return, the property owner acquired the wildlife benefits (hunting, fishing, and others) received from the restored potholes. The agreement could have been terminated within 30 days by a written notice from either party. If the property owner terminated the agreement within 4 years, the owner would reimburse the service for all improvements. Conclusions The overriding goal of these restoration projects was the development of waterfowl habitat. However, flood control and water quality were often mentioned as secondary goals. None of the goals had been quantified, nor had restoration criteria been established. None of the 18 restoration projects inspected by the committee appeared to have a comprehensive plan concerning location, scale, or purpose. In fact, there is no comprehensive restoration plan for the counties, region, or state. The landowner, for one reason or another,
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Restoration of Aquatic Ecosystems: Science, Technology, and Public Policy had contracted the service for help in restoring wetlands. After the landowner agreed to participate in the service's program, a specific restoration plan was developed. After restoration, no monitoring or management of the restored areas was undertaken or planned. The success of, and the degree to which, the restoration projects meet either site-specific objectives or regional objectives are unknown. The diversity of plant communities observed in the restored areas was extremely low. Even in the surrounding buffer areas the diversity of plants and, hence, wildlife habitat was extremely low. Because no monitoring has been undertaken, it will not be easy to ascertain success or failure or to improve future restoration projects. Providing a diverse habitat for animals other than waterfowl seems not to have been a consideration. Despite the lack of well-though-out restoration goals and criteria, this case study illustrates an extremely important aspect of any restoration strategy. The U.S. Fish and Wildlife Service is creating and responding to individual, local interest in and support for restoration. With only a meager staff commitment, the service is having considerable success. Potholes are being taken out of agricultural production and returned to their natural functions of water storage, nutrient cycling, and wildlife habitat. The other lesson involves the innovative financial program that weaves together a variety of funding sources. The ingenuity of the service's project officers and the creative dedication of its administration in Region 5 should serve as an excellent example to other states and other Fish and Wildlife Service regions. If better design criteria and management programs were available and used, the chances of success would be improved and a wider range of aquatic functions achieved. References Bureau of the Census. 1981. 1978 Census of Agriculture. U.S. Department of Commerce, Washington, D.C. Clean Water Act of 1977. P.L. 95-217, Dec. 27, 1977, 91 Stat. 1566. Leitch, J. A. 1989. Politicoeconomic Overview of Prairie Potholes. Northern Prairie Wetlands Iowa State University Press, Ames, Iowa. U.S. Fish and Wildlife Service, Region III, North Central Region . 1990. Stewardship 2000. Fort Snelling, Minn. van der Valk, A, 1989. Northern Prairie Wertlands. Iowa State University Press, Ames, Iowa. Weller, M. W. 1981. Wetlands of Canada. Polyscience Publications, Montreal, Quebec. Weller, M. W. 1982. Ecology and Wildlife Management. Freshwater Marshes. University of Minnesota Press, Minneapolis, Minn.
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Restoration of Aquatic Ecosystems: Science, Technology, and Public Policy THE HACKENSACK RIVER MEADOWLANDS John Berger Introduction The Hackensack Meadowlands is a 21,000-acre estuarine area of freshwater and saltwater marshes and meadows situated in the lower Hackensack River basin amidst the New York-northeastern New Jersey metropolitan area (Figure A.13). Almost 18,000 acres of the Hackensack Meadowlands was originally wetland (M. Thiesing, U.S. Environmental Protection Agency, personal communication, 1991). FIGURE A.13 Hackensack Meadowlands district. SOURCE: Reprinted, by permission, of the Hackensack Meadowlands Development Commission, 1990.
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Restoration of Aquatic Ecosystems: Science, Technology, and Public Policy but extensive development, drainage, diking, filling, garbage dumping, and sewage pumping have occured in the Meadowlands, disturbing many of the area's natural ecological processes. Thirty-two square miles of the Meadowlands have been administered since 1969 by the Hackensack Meadowlands Development Commission (HMDC). At the time the HMDC was established, the Hackensack River reportedly was ''nearly dead," and the Meadowlands' wetlands were being used as a disposal site for 30 to 40 percent of New Jersey's garbage (Scardino, 1990). Illegal waste dumping was also common, and development was proceeding in a haphazard manner (Scardino, 1990). However, commission documents report that during the commission's tenure, "[t]he district has seen drastic improvement in its environment; the Hackensack River has returned to a state of health; wildlife is returning to the district in abundance [and] water quality has greatly improved..." (HMDC, 1989a). Former New Jersey Governor Thomas H. Kean in 1989 commended the HMDC on "the restoration of the environment of this once blighted landscape" (HMDC, 1989a). Responding to similar accounts of environmental restoration, the Committee on Restoration of Aquatic Ecosystems visited the Meadowlands in 1990 to gather evidence of environmental restoration. The Hackensack Meadowlands Development Commission Established by an act of the New Jersey legislature, the HMDC was set up to provide for the reclamation, planned development, and redevelopment of the Hackensack Meadowlands within Bergen and Hudson countries, a zone including 14 municipalities (HMRDA, 1968). The commission was also charged with providing garbage disposal sites for 116 communities (HMDC, 1989b). Currently operating with a $5.5 million annual budget (A. Galli, Hackensack Meadowlands Development Commission, personal communication, 1991), the commission usually monitors 500 to 600 development projects in the district at a time (HMDC, 1989b) and by 1989 had overseen privately funded development worth more than $1 billion (HMDC, 1989a). Another $450 million in "publicly backed funds" have been spent on a 750-acre sports complex in the Meadowlands. Some of this growth has impinged on natural areas. From the commission's inception until 1984, more than 863 acres of wetlands were filled in accordance with the HMDC's master plan. Little filling has occured since then (D. Smith, Hackensack Meadowlands Development Commission, personal communication, 1991). Wetland habitat enhancement work has been performed on only 190 acres in mitigation
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Restoration of Aquatic Ecosystems: Science, Technology, and Public Policy for the wetland filling or drainage. All but a few acres of this mitigation work was paid for by developers. (Although the HMDC controls all construction in the district, permits to fill wetlands are principally the responsibility of the U.S. Army Corps of Engineers (COE) under Section 404 of the Clean Water Act of 1977, subject to concurrence by the U.S. Environmental Protection Agency.) Commission literature states that "the Meadowlands wetlands are in need of restoration, not simple protection," but that neither the state nor the federal government would pay for the restoration," so the HMDC is left on its own to solve the problem" (HMDC, 1989b). The HMDC's solution is not to use any substantial part of its operating revenue to restore the Meadowlands, but to allow certain Hackensack wetlands to be filled in exchange for developer-sponsored mitigation (HMDC, 1989b). The commission's emphasis on development was consistent with its original 1968 mandate. The Hackensack Meadowland Reclamation and Development Act (HMRDA), which established the commission, noted that, whereas extensive portions of the Meadowlands "have so far resisted development...the orderly, comprehensive development of these [Meadowlands] areas can no longer be deffered...." The commission has pursued this goal while also taking action to improve environmental conditions in the Meadowlands by exercise of its zoning powers and advisory role on discharge permit applications. In general, the commission sought the upgrading of sewage treatment plants, and the closure and cleanup of chemical manufacturing plants and toxic waste sites. It also oversaw the closure of 23 of 24 operating landfills in the Meadowlands; it blocked the use of wetlands for new garbage dumps; and it has generally served as a "watchdog" on environmental conditions for the New Jersey Department of Environmental Protection and the U.S. Environmental Protection Agency (R. Smith, Hackensack Meadowlands Development Commission, personal communication, 1991). This environmentally oriented activity was in keeping with the declaration, in the Act establishing the HMDC, that "the ecological factors constituting the environment of the meadowlands and the need to preserve the delicate balance of nature must be recognized to avoid any aritificially imposed development that would adversely affect not only this area but the entire state..." (HMRDA, 1968). Exactly what constitutes the "delicate balance of nature" in a highly disrupted area has been a matter of some controversy in the years following the establishment of the commission. The HMDC's 1972 master plan and zoning regulations, for example, were approved by the Office of Coastal Zone Management (of the National Oceanic and
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Restoration of Aquatic Ecosystems: Science, Technology, and Public Policy Atmospheric Administration) over the objections of the COE, the U.S. Fish and Wildlife Service, the Environmental Protection Agency, and the National Marine Fisheries Service (U.S. Army Corps of Engineers, 1982). (The HMDC is now engaged in preparation of a programmatic Environmental Impact Statement for a new master plan.) The 190 acres of mitigation work performed in the Meadowlands to date has been conducted mainly by the New Jersey Turnpike Authority, the Bellemead Development Corporation, the Hartz Mountain Development Corporation, and to a minor extent, the HMDC itself (on a small wetland and swale around a landfill). The most detailed mitigation information available to this committee deals with the Hartz Mountain project and its mitigation. To assess its merits as a restoration, one must compare the conditions produced by the project with the ecological conditions prior to disturbance. History The Hackensack Meadowlands rest in the ancient basin of a lake formed during the retreat of the Wisconsin glaciation, when glacial meltwater was trapped behind a terminal moraine of rock and earth (HMDC, 1984). Over long periods of time, sediments were deposited in the lake bed, and vegetation took root in the lake's shallow reaches. Eventually, thousands of years ago, the moraine was breached, the lake drained, and tidal flows mingled with fresh waters in the resulting estuary (HMDC, 1984). Much time passed, and a succession of plant communities came and went, competing with each other and struggling to adapt to environmental fluctuations, including the sea level changes that altered salinities in the estuary. Ecological studies dating back to the late nineteenth century indicate that in the last phase of its natural succession, the Hackensack Meadowlands was a boggy area dominated by Atlantic white cedar (Chamacyparis thyoides) in a region of black ash (Fraxinus nigra) and tamarack (Larix laricina)( Kraus and Smith, n.d.). The Hartz Mountain project site may have been highly brackish marsh dominated by salt hay (Spartina patens) and salt grass (Distichlis spicata) with a white Atlantic cedar bog at its upland edge, before the whole area was ditched and then diked for mosquito control between 1914 and 1950 (Kraus and Smith, n.d.; HMDC, 1984; D. Smith, Hackensack Meadowlands Development Commission, personal communication, 1991). (This issue was not independently verified by the committee.) The altered hydrology quickly led to major changes in vegetation. With tidal flow excluded and water salinity reduced, the common
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Restoration of Aquatic Ecosystems: Science, Technology, and Public Policy reed (Phragmites australis) invaded the area and became the dominant vegetation. Another major change in the area's hydrology occured in 1922 when the Oradell Dam was built across the Hackensack River upstream from the project site by the Hackensack Water Company. Reduction in freshwater flow further altered ecological conditions in the estuary by allowing greater saltwater intrusion upstream into the Hackensack basin below the dam. The original Hartz Mountain project—a mall, office complex, and condominiums—was proposed for the Cromakill Creek and Mill Creek basins of the Meadowlands in the Township of North Bergen and the Town of Secaucus. Subsequently, the condominium component was dropped or delayed, and the company received permission to fill 127 acres of wetlands to build the mall at Mill Creek and the office complex. The COE reviewed the Hartz Mountain proposal and issued a finding in 1982 that it would have "no significant adverse environmental impacts" (U.S. Army Corps of Engineers, 1982). Thus COE did not require an environmental impact statement. Based on an interagency wetland evaluation conducted by several federal agencies, the site—still dominated by common reed—was deemed to be of only average value as a wetland. Water quality was found to be poor; vegetation diversity was low; and benthic invertebrates and fish were rated "low to medium" (U.S. Army Corps of Engineers, 1982). The COE noted, however, that filling the wetland would "essentially destroy all wildlife values within the fill area" and that loss of the wetland would reduce the highly desirable isolation of other remaining wetlands, increasing noise levels and the probability of further human encroachment on the remaining wetlands (U.S. Army Corps of Engineers, 1982). The COE also observed that the land would have much greater potential wildlife value if the water quality were improved and the diversity of wetland vegetation increased. "With improved water quality, loss of wetlands would be of much greater concern" (U.S. Army Corps of Engineers, 1982). The Hartz Mountain project was allowed to proceed with the stipulation that the company would have to mitigate its impacts by construction of a 63-acre brackish marsh. The mitigation site was slightly less than half the size of the filled wetlands, but the new marsh was intended to be of much higher ecological value. The brackish marsh ecosystem is in Secaucus, N.J., approximately south of Hackensack River mile 10.5, adjacent to the eastern shore of Mill Creek, and west of the eastern branch of the New Jersey Turnpike. As noted, the site before 1985 was a degraded tidal marsh with poor water quality, dominated by tall, dense stands of common reed
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Restoration of Aquatic Ecosystems: Science, Technology, and Public Policy (Phragmites australis)( TAMS, 1990). Tidal inundation was limited by site elevations ranging from +9.6 ft National Geodectic Vertical Datum (NGVD) to 0.0 NGVD. The mitigation goals were to enhance wildlife diversity and abundance by converting the site from a common reed-dominated community to a cordgrass (Spartina alterniflora) intertidal marsh. The plan adopted was to remove the common reed in the process of lowering the site's elevation by excavation to increase tidal inundation. An effort was also made to construct a more heterogeneous habitat, including open water and raised areas of woody vegetation in order to increase vegetative diversity and wildlife use. Replacement of the common reed by cordgrass offers several ecological benefits. Cordgrass detritus regularly enters marsh waters and breaks down relatively quickly, releasing nutrients. The detritus from common reed, which grows on higher ground, is only washed into the water on an irregular basis and decomposes relatively slowly (HMDC, 1984). Very dense stands of common reeds are not considered to be of high value to waterfowl, marsh mammals, and wading shorebirds (TAMS, 1990). In addition, the reed is very persistent, invasive, and robust, contributing to drying of marsh soil, reduction of water flow, and increases in site elevations through growth and accumulation of organic matter and ensuing entrapment of sediment. However, among the common reed's ecological services are provision of habitat for large populations of aphids that in turn support large numbers of ladybugs, which provide food for praying mantises, birds (HMDC, 1984), and occasionally for fish. Methods The mitigation site was sprayed with the herbicide RODEO by helicopter and later by hand-sprayer to eliminate the common reed. The site was then shaped and graded with Priestman variable counterbalanced excavators imported from England for the marsh work, because of their low ground pressure and ability to accomplish the very fine gradations in elevations necessary to successfully establish the elevation-sensitive cordgrass. The horticultural contractor was Environmental Concern, Inc., of St. Michaels, Md., a firm well known for its pioneering work in salt marsh restoration. The high marsh was sculpted into channels and open water, lower-elevation intertidal zones, and raised areas (berms) from +5.73 to +10.33 NGVD, built up of excavated materials. The earthwork was done from March 1985 to July 1987. Cordgrass seed was planted
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Restoration of Aquatic Ecosystems: Science, Technology, and Public Policy each spring from 1986 through 1988. Detailed biological and other monitoring has been done by TAMS Consultants, Inc., on the site and at an untreated 131-acre control site, also dominated by common reed and similar to the pretreatment mitigation site. Results Initial plantings of trees, shrub root stocks, and herbaceous vegetation experienced high mortality due to high soil salt content that was allowed to leach out with rainwater during the next 2 to 3 years. Plant survival on the berms improved in 1988 as leaching continued (TAMS, 1990). The plantings are in an early stage of establishment and are fenced to discourage muskrat depredation. More than 80 percent of the site is now inundated during part of the mean tide cycle, and a vigorous growth of cordgrass has become established on more than 75 percent of the intertidal zones between +2.0 and +3.0 NGVD. Common reeds have not reappeared in the cordgrass zones. Where they reemerged on berms, they have apparently been controlled by hand-spraying with RODEO. Some native marsh species, such as fleabane, rushes, and sedges, have reappeared naturally on the site. Channels appear to be stable throughout the site (TAMS, 1990). Although it is too early for the mitigation site to have fully recovered from earth-moving operations, fish, benthic organisms, and zooplankton already appear similar to those at the ecologically impaired control site, whereas bird life has become much more abundant and diverse (TAMS, 1990). Because of the creation of more channels, greater water surface area for oxygen exchange, and greater tidal flushing, water quality on-site seems to approximate values in the adjacent Hackensack River. High levels of coliform bacteria are still found in water samples from the site, and benthic organism samples contained a large proportion of a few pollution-tolerant species, indicative of a stressed ecosystem. Almost all the fish found at the control and mitigation site were mummichogs (Fundulus heteroclitus), an import and secondary consumer in the eastern salt marsh food web, but their physical distribution was wider in the mitigation site, as was the case for zooplankton (TAMS, 1990). Bird species diversity was markedly greater on the mitigation site (46 species) versus the control (32 species), and the distribution among species was also more equitable on the mitigation site, probably in response to its greater habitat diversity and secondary productivity (TAMS, 1990).
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Restoration of Aquatic Ecosystems: Science, Technology, and Public Policy Conclusion The intertidal cordgrass marsh created out of high marsh at the mitigation site appears to have met the goals of enhancing habitat heterogeneity, vegetational diversity, and wildlife utilization, principally by birds. In this sense the project has been a success, and the engineering and biological science used appears to be of a high caliber. However, the project should be viewed as habitat enhancement and conversion rather than ecosystem restoration for the following reasons: The mitigation did not endeavor to re-create the particular estuarine ecosystem that existed on the site prior to the damming of the Hackensack River and prior to other significant environmental modifications that have occurred in the Meadowlands. By altering the hydrology of the area and the salinity of its water and soil, the Oradell Dam made restoration of vegetation adapted to less saline conditions impossible without the reintroduction of additional fresh water to the project site. Because of the limited areal scope of the mitigation work and the limited goals, the mitigation project had virtually no impact on the regionwide ecological degradation of the Meadowlands—exemplified by the damming and ditching of Meadowland marshes, the blockage of the Hackensack River, the presence of sewage and toxic substances in soil, and the extirpation of certain species. Therefore the resulting ecosystem cannot be considered "restored" because of the influence of these intractable conditions on the mitigation project site. Where once there was probably a high marsh of Spartina patens, Distichlis spicata, and other species, the contractors produced an intertidal marsh with mud flats and raised inlands of woody vegetation. There is no evidence that the ecosystem created on the mitigation site has existed there within human memory. The regulated development of the HMDC is far better than the indiscriminate dumping and haphazard development that preceded the HMDC in the 1950s and 1960s. Water quality in the Hackensack River appears to be far better than the sewer-like conditions reported 20 years ago. Evidence is undeniable that certain aquatic organisms, such as grass shrimp and mummichog, are now thriving in vast numbers and that certain species of waterfowl and fish have returned. However, as the Committee on Restoration of Aquatic Ecosystems has pointed out elsewhere, river restoration involves more than water quality improvement and increased wildlife use. Also required are a return of ecological integrity, structure, function, and ecosystem
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Restoration of Aquatic Ecosystems: Science, Technology, and Public Policy processes, beginning with natural hydrological conditions and including restoration of communities of organisms and their interactions. An increase in the presence of a wildlife species is generally a promising indication that ecological health is returning but is insufficient cause for proclaiming that restoration has occurred. The HMDC has in the past sanctioned the development of substantial wetland acreage rather than protecting all wetlands. The commission thereby set a precedent of trading wetland development for wetland enhancement, with a resulting net loss of wetland acreage in a quest for increased wetland functional values. There are alternatives to that strategy. The commission might instead gradually begin to invest some of its own not inconsiderable revenues directly in wetland restoration year by year (and solicit federal, state, local, and private funds to augment its contribution), without choosing to sacrifice additional wetland acreage to subsidize wetland improvement. In the future, too, the commission may wish to consider developing a systematic mitigation or ecological restoration program for the Meadowlands in which individual mitigations are conducted as part of a broader overall restoration strategy. References Axelrod, H. R., C. W. Emmens, D. Sculthorpe, and W. Vorderwinkler. 1962. Exotic Tropical Fishes. T. F. H. Publications, Jersey City, N.J. Clean Water Act of 1977. P.L. 95-217, Dec. 27, 1977, 99 Stat. 1566. Hackensack Meadowlands Development Commission (HMDC). 1984. Wetland Bio-Zones of the Hackensack Meadowlands: An Inventory. Lyndhurst, N.J. June. Hackensack Meadowlands Development Commission. 1989a. Annual Report. Lyndhurst, N.J. Hackensack Meadowlands Development Commission. 1989b. Fact Sheet. Lyndhurst, N.J. October. Hackensack Meadowlands District. 1990. Special Area Management Plan. Lyndhurst, N.J. Hackensack Meadowland Reclamation and Development Act (HMRDA). 1968. State of New Jersey Statutes. Chapter 17, Sections 13:7-1 to 13-17-86. Kraus, M. L., and D. J. Smith. n.d. Competition and Succession in a Perturbed Urban Estuary: The Effects of Hydrology. Monograph. Hackensack Meadowlands Development Commission, Lyndhurst, N.J. Scardino, A. 1990. Executive Director, Hackensack Meadowlands Development Commission. Briefing to Committee on Restoration of Aquatic Ecosystems. Lyndhurst, N.J. TAMS Consultants, Inc. 1990. Comprehensive Baseline Studies: IR-2 Site and Off-Site Mitigation Areas—Evaluation of Harmon Meadow Western Brackish Marsh Mitigation Area. January. New York, N.Y. U.S. Army Corps of Engineers. 1982. Statement of Findings for Application No. 81-391-J2 by the Hartz Mountain Development Corporation. New York District. Regulatory Branch. December 16.
Representative terms from entire chapter: