Restoring nature, without mosquitoes?

Elizabeth Willott, Dept. of Entomology, University of Arizona, Tucson Arizona 85721-0036


This is a preprint of an Article accepted for publication in Restoration Ecology © 2003, Society for Ecological Research International. Expected publication June 2004.

Abstract

The benefits of wetlands are now widely appreciated. Less widely known is that historically many wetlands were drained to help control malaria and other deadly diseases. This essay's general theme is that there are pros and cons to restoration or creation of wetlands. The specific theme is that mosquitoes pose practical and theoretical problems. In particular, abundant mosquitoes should not be regarded as an after-the-fact surprising side effect but rather, abundant mosquitoes should be viewed as a primary and foreseeable effect of providing habitat suitable for them. Yet our funding mechanisms and educational institutions often fail properly to address the reality that restoring or creating wetlands has a downside.

Introduction

Attempts to restore, rehabilitate, or create riparian and wetland habitats are funded and otherwise supported by private citizens, corporations, non-profit groups and all levels of government. The resulting wetland and restored riparian areas aid in flood control, purify water, provide habitat for many species, and are often aesthetic delights. However, they are also great mosquito habitat. Do we want increased populations of pathogen-transmitting mosquitoes when we build or restore wetlands and riparian habitats?

Wetlands and mosquitoes have always tended to go together; so have mosquitoes and devastating diseases (For an introduction to mosquitoes, see Gillett 1972; Spielman & D'Antonio 2001). The association between disease and wetlands was known long ago (Celli 1933 pp. 4, 12, 33; Warshaw 1949 p.39; Russell 1955 p.126-128; Jones 1977, p.4, 85; Carlson 1984 p.23-24; Adler & Wills 2003). Draining swamps and marshes to control malaria has a long history, dating back at least to the early Romans (Celli 1933, p.23, p.33; Russell 1955, p.128). More recently, but still years before scientific proof that mosquitoes transmitted the malaria parasite, Freetown, Sierra Leone, in 1812, legislated drainage of water which bred mosquitoes and fever (Carlson 1984, p.33).

The U.S. also has a history of malaria and measures to control it. The southern states, being mild, humid, and swampy, were colonized not only by humans, but also by newly introduced mosquitoes and pathogens. Malaria and other arthropod-vectored diseases were horrendous problems from the 1680s through 1940s (Adler & Wills 2003). The swampy area south of Toledo, Ohio was considered almost uninhabitable due to disease, presumably malaria, until most of the swamp was drained between 1870 and 1920 (American Society of Mechanical Engineers 1988; Kinney 1999). The last major malaria epidemic struck central Illinois in 1872, causing one physician to note that almost everyone within his area had experienced a malaria attack (Johnson 1926, p.131; cited in Ackerknecht 1945, p.29). Diaries from people in the Missouri and Arkansas valleys hold similar stories (Ackerknecht 1945). The desert Southwest was not exempt: several U.S. Army camps, including Fort Wallen and Camp Goodwin, both in what is now southern Arizona, were closed due to malaria (Barnes 1960, p.127; Fink 1998).

In the United States in 1860, the average life expectancy was 40 years; in 2002 it was 77 years (Population Resource Center 2003). The increase is due to many factors, but dramatic decreases in infant, child, and early adult mortality are attributable to decreases in malaria, cholera, typhoid, and diphtheria (Doull 1952; Smillie 1952). In 1850, malaria killed more than any other diseases except tuberculosis, cholera, and dysentery/diarrhea (Smillie 1952, p.70). Smillie attributes the decline in malaria in the U.S. during the late 1800s not to quinine or knowledge that mosquitoes transmitted the malaria parasite, but to removal of mosquito habitat (by drainage of potential crop land and swamps, and removal of mill ponds), better rural housing, rapid transportation, and other components of modern civilization (Smillie 1952, p.71).

In the early to mid 1900s, U.S. malaria-control literature consistently advocated draining wetter areas for mosquito control (for examples, see Herms 1913, especially p.53; Tennessee Valley Authority 1941). Mortality from malaria was 32.2 per 100,000 people for North Carolina in 1910 (earliest figure given); by 1932, 1.6 per 100,000 (Hoffman 1933, p.30). Hoffman concludes that widespread draining enabled that reduction, not simply by removing mosquitoes, but also by exposing rich agricultural land that permitted people to increase their standard of living, resulting in better built houses, better diets, and isolation of the sick. The U.S. western expansion perhaps is due largely to mosquitoes, making Louisiana too difficult for France to defend (Gillett 1972, p.249). In 1802, Napoleon sent 33,000 men to conquer Haiti and the Mississippi; 29,000 died of yellow fever. Unable to sustain that kind of loss, France sold Louisiana to the U.S. in 1803.

Now, we create and restore swamps and wetlands. I am not claiming that malaria or yellow fever will ever return to historic levels. Houses are better built, most Americans can afford window screens, and people sick with malaria or yellow fever would have access to appropriate treatment. However, reviewing history should remind us that nature contains threats.



What we face

Western and Eastern equine encephalitis, St. Louis encephalitis, and LaCrosse encephalitis viruses are present in many parts of the U.S. West Nile virus, introduced into the U.S. in New York in the late 1990s, is spreading westward. The virus causes either a mild illness or much more serious meningitis or encephalitis. Between 6-10% of people diagnosed with the encephalitis or meningitis die. In 2002, 284 people died; in 2003, 230 deaths were reported according to the Centers for Disease Control, http://www.cdc.gov/ncidod/dvbid/westnile/ (Feb 18, 2004). Mosquito-transmitted viruses elsewhere could cause problems if introduced to the U.S. (Russell 1999 discusses viruses currently a concern for Australians). The introduction of either an exotic species of mosquito or an exotic pathogen could have serious consequences: an endemic pathogen in an exotic mosquito host or an exotic pathogen in an endemic host might result in greater disease transmission.

When we restore or create riparian and wetland habitat, we typically create excellent mosquito habitat, including habitat for mosquitoes that transmit pathogens responsible for diseases. Surely this is important. Sometimes the increase in mosquitoes is dramatic. Studies of mosquito dispersal from one wetland site in California suggested that, for 23 km2, it would be the primary source for mosquitoes capable of vectoring western encephalitis virus (Walton 2002). In California, between 1974 and 1988, at least five of nine pilot water treatment plants using aquatic macrophytes closed because of mosquito problems (Martin & Eldridge 1989, p.396; see Eldridge & Martin 1987 for more detail). At Sweetwater Wetlands in Tucson Arizona, a surface-flow, waste-water treatment constructed wetland, mosquitoes increased 100-fold after starting operation (Karpiscak et al. 2004). Weekly monitoring and several abatement methods, including removal of vegetation, weekly applications of larvicide, and judicious use of adulticides when necessary, allowed significant control of mosquitoes; now Sweetwater is an instructive example for others building wetlands. These references--and others (see also Dill 1989, cited in Kadlec and Knight, 1996)--suggest that mosquitoes can be a significant problem unless continuously managed.

Mosquitoes (and the pathogens they vector) are highly mobile; many are relatively new introductions. Culex quinquefasciatus and Aedes aegypti probably arrived in colonial times (Spielman & D'Antonio 2001, p.79). Aedes albopictus arrived in the mid-1980s, most likely in used tires shipped to Texas from southeast Asia (Craven et al. 1988). As desiccation-resistant eggs in used tires, A. albopictus rapidly spread throughout the eastern U.S. although in Florida transport of graveyard floral arrangements fostered their spread (O'Meara et al. 1992). As people receive shipments of living bamboo and banana plants bought on-line or from stores stocked via trucks moving across the country, they provide excellent opportunities for A. albopictus to spread. Ochlerotatus japonicus arrived recently (Peyton et al. 1999; Andreadis et al. 2001). These and other mosquito species may vector already established or newly introduced pathogens. Or, they may allow exotic pathogens to establish in North America. Preliminary work indicates O. japonicus can transmit Japanese encephalitis virus (Takashima & Rosen 1989; cited in Peyton et al. 1999); so the risk of Japanese encephalitis virus becoming established is possibly greater now that O. japonicus has become established.

Some people distinguish between human-inhabited space (culture) and wild space (nature). However, for mobile species this is sometimes merely a conceptual boundary, not an ecological one. For example, in southern Arizona, the mosquito C. quinquefasciatus (a possible vector for West Nile virus in the southwest, see Goddard et al. 2002), breeds readily in either wetland areas or human-made containers such as empty watering jugs or discarded cups.

What we want from restoration

Humans can--and do--care about biodiversity and habitat loss, even when there is no readily apparent human benefit. Our values are not narrowly human-centered; we can act on values beyond the narrowly anthropocentric. Some writers refer to these beyond-anthropocentric interests as "aesthetic" interests; others refer to the "intrinsic worth" of nature. In different ways, the writers are discussing interests that are not solely human-centered. (For a longer discussion, see chapter 14 of the commonly used Conservation Biology text Meffe & Carroll 1994 p.409-438. For accessing more literature addressing this point and others, Restoration Ecology and Environmental Ethics are good journal sources. Recent anthologies on environmental ethics include Throop 2000; Schmidtz & Willott 2002; Light & Rolston 2003.)

When we say we desire to experience nature (including restored environments), what most of us mean is that we desire to experience selected aspects of nature. We prefer not to experience serious illness or traumatic death. We prefer to have safe drinking water come from our taps and not be concerned about water-borne dangers (see Rolston 1992, for an interesting discussion of values and disvalues we have pertaining to nature). More generally, while recognizing the importance of predators in an ecosystem, we prefer that our families are not the prey.

Our preferences do not lead us to zero-risk tolerance (see Callicott & Mumford 1997 for a discussion of what constraints we may need to consider as appropriate for different habitats). This is consistent with our preferences in other areas: we find some risk, even deadly risk, tolerable. For example, we prefer that our children not be killed in traffic, but that preference does not lead us to refuse to have roads near schools. Instead, it leads us to restricted speed limits, and we accept that some children will die in traffic. Something similar operates with our preference for avoiding hazards in nature. We can accept that some people will die from mosquito-vectored encephalitis, but as with children dying in traffic we want the number to be small.

We distinguish between risks we find acceptable at home and those acceptable when we journey to experience "nature." It can be enjoyable to see a bear outside your cabin (if your family is safe inside), but a bear family near your child's kindergarten is more likely to evoke fear. The idea of "untouched nature" (or minimally touched) is important to many people. Wilderness sometimes is better preserved when abundant mosquitoes and black flies serve as deterrents to keep most humans away, and thereby allow the ecosystem to flourish with minimal human influence. (This "keeping out the riff-raff effect" was succinctly pointed out to me by Philip Cafaro, personal email on file with author.) We also make distinctions regarding endangered species: we may be comfortable with thousands of crows dying from West Nile, yet want to intervene--if we can--to protect condors.

We do not seek to protect ourselves from mosquitoes regardless of the costs. The benefit has to be worth the risk. Many of us would say the risks we should take into account include not only risks to humans, but also risks to wildlife or even nature as a whole.

Where do we and mosquitoes fit?

In tribute to H. T. Odum, Marsha Gilliland writes that Odum could ask "the key question, at the key moment, and at the key scale that most of us don't think about" (Gilliland 1994). During work in Cedar Key marshes, someone commented that the mosquitoes were "really, really bad" and Odum answered "the real issue is to ask and understand what the mosquitoes are doing for the system." In her letter, Gilliland concluded by asking the question: "What are we doing for the system?" Good questions.

Historically here and currently in some parts of the world, mosquitoes--by transmitting disease--limit human populations. However, as Holmes Rolston relayed to me (personal communication regarding an earlier draft of this manuscript, Sept 16, 2003, on file with author): "In a medically skilled culture, suffering from malaria is pointless." There are better ways to control human population than for people to die young from mosquito-vectored diseases. Our improved health and wellbeing now can allow us to improve our ecosystems' health and wellbeing. More of us now can want wetlands for our children if the associated risks are not too great.

What we can reasonably expect from restoring wetlands?

"Restoration" to most lay persons suggests returning something to a prior state. However, it is not desirable to return to conditions in which humans had short lives and suffered as they did. Nor could we restore conditions to exactly as they were because the conditions were then changing and we lack adequate information about the ecosystems of 150, 1500, or 15,000 years ago (for more on the need to set realistic goals, see Ehrenfeld 2000). Nor is it possible to remove and exclude all the introduced species that have invaded. What is realistic?

The Society for Restoration Ecology's Primer (SER 2002) opens with an extended definition of "ecological restoration" which includes the idea that we aim to restore underlying capacities that permit elements of the ecosystem to interact in ways promoting flourishing of species suitable (more on that later) for that region (see also Jackson et al. 1995; Hobbs & Norton 1996). The idea is to restore function, not to make the ecosystem resemble that of some earlier time. The concept of restoration as "making capable again" grounds many restoration projects and underlies much of conservation biology as both a theoretical and practical subject. This interest in function constrains what can or cannot be considered suitable species: a "suitable" species at least does not interfere with the ecosystem functioning as a thriving, biodiverse, ecosystem. The interest in restoring function is often to restore a kind and level of function suitable not only for wildlife but also for humans who form part of the ecosystem as they use, maintain, and otherwise co-exist with that ecosystem.

If our aim is to restore a kind and level of function suitable for wildlife and humans, then we need to deal, theoretically and practically, with the ongoing presence of the threats posed by mosquito-vectored pathogens. We need to be aware of what has happened in this country, and what threats due to mosquitoes currently or potentially face us. We want to be able to address those threats and we also want supplies of pure water, decreased risk of deleterious flooding, and biodiversity. We need to admit mosquitoes pose problems and explore what we can do to limit those problems. Perhaps we need the equivalent of "school zones" where mosquitoes are more aggressively monitored and managed at wetlands near significant human populations.

How our educational literature currently addresses mosquitoes

Given that mosquitoes and water go together so well, that virtually everyone has experienced at least the irritation caused by mosquitoes, and hence has some personal experience with nature's disvalue, and given the role of mosquitoes in human and U.S. history, one might expect mosquito and water issues to be addressed in general biology and ecology texts and in books and papers on wetland construction or ecology. Yet, at present, mosquito issues are rarely or only cursorily addressed in books on conservation biology, in restoration proposals, or in research papers in journals for water management personnel. This does not mean no one works in the area. People work on mosquito-related issues. However, the primary texts in conservation biology and the majority of research papers addressing restoration and wetland construction generally do not acknowledge that mosquitoes create practical implementation problems and also problems for the theoretical case for restoration as it is currently presented in much of the literature.

To find out which texts currently are in use, I searched the web for syllabi for Conservation Biology courses. The most common textbooks were Meffe and Carroll, 1994, 1997 and Primack, 2000. These texts either do not, or barely, mention mosquitoes or the negative consequences to humans--or wildlife--of restoring or developing wetlands. In talking of the restoration of wetlands, Meffe and Carroll write:

(W)etlands throughout the world have declined extensively in the last few centuries. In the coterminous United States, some 53% of the estimated original extent of wetlands has been lost in the last two centuries. Swamps, floodplains, bogs, sloughs, marshes, springs, and other wetlands that serve vital ecosystemic functions and are centers of biological diversity have been drained, pumped, and diked. The obvious restoration action in such cases is to reinstate former hydrological conditions by reestablishing historical water flows. Ditches may be closed, pumping stopped, dikes removed, and so forth. (Meffe & Carroll 1994, p.433, emphasis added)

To those who know the history of vector-borne disease in this country, there is nothing "obvious" about this. The truly obvious result--increase in mosquitoes, and hence in potential spread of vector-borne disease--is not discussed. If students are not taught the history--that many swamps were drained at least in part for health reasons--they are being misled.

Elsewhere, Meffe and Carroll write that introducing the fish Gambusia affinis and G. holbrooki can cause reductions, even local extinctions, of some fish species, including some endangered fish (Meffe & Carroll 1994, see p.223-224). They never mention that Gambusia, often called mosquitofish, frequently function in constructed wetlands and water rehabilitation projects to control mosquitoes.

Another key conservation biology text, Primack's A Primer of Conservation Biology, has no entry for either "mosquito" or "insects" in its index. Primack writes, "Wetlands are often filled in or damaged, because their importance in flood control, maintenance of water quality, and preservation of biological communities is either not known or not appreciated." (Primack 2000, p.232), Although this may explain why wetlands are currently being filled in or damaged, and certainly in the early settling of this country people would have been unaware of some of the ecological functions, a more complete explanation for filling in wetlands should acknowledge that at least some of those who filled or drained wetlands knew and appreciated something that Primack perhaps does not, namely the importance--at least historically--of wetlands in spreading disease.

According to several colleagues active in the field, the key reference on wetland construction is Kadlec and Knight's book, Treatment Wetlands. "Mosquitoes" is not in the index but with searching one can discover that mosquitoes are discussed on two of the 893 pages (Kadlec & Knight 1996). The authors' conclusion: Mosquitoes are not usually much of a problem because mosquito population levels are often no higher than in surrounding wetland areas unless organic loadings are excessive, or bulrush or cattail concentrations get too high, or there is debris (like floating dead cattails) on the surface. At the end of the two pages, they recommend: "Mosquito larvae and mosquitofish populations in wetland treatment systems should be monitored regularly to determine the need for restocking or other operational controls" (Kadlec & Knight 1996, p. 710). Despite this overt caution, the chapter's Summary of Treatment Wetland Operational Guidelines fails even to mention routine monitoring for mosquitoes and concludes with: "Through conservative design and preventive maintenance, natural wetland systems can operate almost care free for many years." (p.713)

In practice, if the wetland is close to residential or recreational areas with significant human contact, it may need to be monitored for mosquitoes at least every two weeks during mosquito season and aggressive intervention is likely necessary several times throughout the year. Vegetation grows, debris accumulates, mosquitofish die.

I also searched three key journals addressing wetlands. For the Journal of the American Water Resources Association, "mosquito" is not a searchable word. "Insects" yielded two articles, neither of which addressed mosquitoes. Nor were mosquitoes mentioned in the seven articles (published since 1995) retrieved by searching "constructed wetland." For six of the articles this makes sense since they specifically addressed other aspects of wetlands, but one (Sauter & Leonard 1997) discussed wetland design methods for residential water treatment. In the introduction, the authors list several advantages, but no disadvantages, of using wetlands for treating wastewater. The authors are aware that mosquitoes may be a problem, since in the discussion they write: "Because constructed wetlands are an above-ground treatment method, their aesthetic impact, both positive and negative, cannot be overlooked. For example, education of the community, or bordering neighbors, may be appropriate and advisable to help address concerns over odor or perceived vector problems prior to ground-breaking." (Sauter & Leonard 1997, p.162, emphasis added). We may wish mosquitoes were only a "perceived" problem, curable by "education." Sometimes, though, educating neighbors will not be enough, for sometimes the problems they perceive are real.



In Wetlands, of about 254 research articles since 2000, 15 contained the term "mosquito." In eight, mosquitoes or mosquitofish are mentioned in one or two sentences but are not the subject of the sentence or paragraph. Three articles briefly mention people's perceptions of wetlands and mosquitoes. Three papers describe the use of hemi-marsh design (Nelson et al. 2000; Smith et al. 2000; Andersen et al. 2003). Although not primarily addressing mosquitoes (each mentions mosquitoes only one or twice) they are relevant because they do connect mosquitoes to site design and, by their citations, allow a reader access to relevant papers. Of the three relevant papers they cite, only one is in the primary refereed literature and that is not in a wetlands journal but rather is in the Journal of the American Mosquito Control Association. The remaining paper, the only one emphasizing mosquitoes, addresses the mid-1800 history of wetlands in Willamette Valley, Oregon, noting that several lines of evidence support the belief that wetlands were extensive due to Indian land-management practices, mosquitoes were abundant, and that malaria killed many of the Indians soon after Europeans arrived (Taft & Haig 2003).



A search of Ecological Engineering of the approximately 560 papers since 1993 revealed that 22 supposedly contained "mosquito" (or its variations). Three papers primarily address mosquitoes and wetlands; only one is about U.S. wetlands. One studied mosquitoes in a macrophyte-based wastewater treatment system in Cameroon. The system was good breeding ground for some species of mosquitoes, although some treatment ponds were less attractive than others (Kengne et al. 2003). Another paper, often-cited, gives an Australian perspective on constructed wetlands and mosquitoes, pointing out health risks pertinent to Australia (Russell 1999). This includes several important citations for wetland design incorporating mosquito management. The third paper looked at how vegetation management strategies affected mosquito production and water quality at the Sacramento Constructed Wetlands Demonstration Project in California (Thullen et al. 2002). This paper concluded that a combination of open water and vegetation (i.e., the hemi-marsh design) gave better water purification and lower mosquito production than the alternatives tested. It, too, gives important citations.

In sum: three key journals, over one thousand research papers, and one paper devoted to managing mosquitoes in the U.S.

Similarly, in a recent special issue of Restoration Ecology (2002 Vol. 10, No. 3), the ecological benefits of breaching dikes to return water to drained wetlands are discussed, but the impacts on mosquitoes are not mentioned.

Managing mosquitoes

Controlling mosquitoes is not simply a narrow, anthropocentric concern. On the contrary, mosquito-transmitted viruses also threaten non-human species. West Nile virus primarily affects birds. Humans and horses are sometimes called "dead-end hosts:" they can acquire the virus from a mosquito but they do not transmit it. (For more information see the Centers for Disease Control webpages, http://www.cdc.gov/ncidod/dvbid/westnile/). In North America, birds of over 100 species can be killed by West Nile. For some species the death toll is substantial. In certain situations, to protect particular bird species, it may be beneficial for us to manage mosquito populations. We may find ourselves in the following dilemma:

Mosquitoes transmitting virus may threaten bird populations that are desirable inhabitants of that ecosystem.

Adding fish such as Gambusia that eat mosquito larvae may help control mosquitoes and hence reduce risk to birds, but Gambusia may threaten other fish species or other aquatic organisms.

What do we do? That biodiversity and ecological stability are important is not enough to tell us whether a proposed intervention will be beneficial. Sometimes intervening may be good, sometimes not--local context is important. We need to know how we can control mosquito populations when diseases spread by mosquitoes unduly threaten us or desired local species. People differ in what they define as "unduly" but we can make better decisions if we know as much as reasonably possible about our options and the consequences of our actions.

Interdisciplinary conferences and workshops that have included mosquito concerns have resulted in relevant publications (see, for example, Stowell et al. 1985; Dill 1989; Martin & Eldridge 1989; Tennessen 1993; Pries 2002), although some proceedings' papers and books are hard to acquire. The Journal of the American Mosquito Control Association publishes articles on managing wetlands. We have resources available now that were not available before. Our choices are not limited to only two: have no wetlands, or, have wetlands with all their hazards, known and unknown, acknowledged and unacknowledged.

Sometimes, if we communicate interests, rather than digging in to opposing positions, better solutions emerge. We want to preserve native species and we want to reduce the risk of spread of vector-borne diseases that threaten humans (and, arguably, sometimes non-human animals). One attractive possibility is to use endangered native species of fish to control mosquitoes in wetlands and private ponds. However, some wetland managers hesitate to introduce endangered fish because then the wetland project faces significantly more regulation. In Arizona, private citizens have been unable to acquire some native species of fish because it has been illegal for pet stores to sell them. These obstacles are being addressed by various government agencies. If the sale of these fish is legalized and introducing them to one's property does not add excessive legal liability, then perhaps more Gila topminnow and desert pupfish may get opportunities to eat mosquitoes in Arizona (Tobin 2003; Weedman 2003).

Conclusion

Several obstacles block people from frankly discussing mosquito problems. Financing for restoration projects is often short-term. Grants lasting three years are considered long-term in some circles; it can be three years before vegetation grows, debris accumulates, and mosquito problems get serious. People reason: "Why mention mosquitoes as a problem in the initial grant application since funding isn't going to last that long. No agency will fund modification of a restoration project that is only three years old. We need to focus on success we can achieve in the period of funding."

Even if the funding duration might be adequate, some people believe that talking about negative aspects of a project increases the likelihood the project will not receive funding since it gives the funding agency reason to reject the proposal. Perhaps in some cases this is true. However, when I speak with representatives of funding agencies, virtually all say that discussing obvious negatives and addressing the concerns reasonably well is a strong approach for a proposal. Measures can be taken to minimize mosquito problems. These can be incorporated into proposals, thereby strengthening those proposals.

Restoring mosquito habitat has both advantages and disadvantages: we want wetlands, but we do not want to increase current or potential health risks. As a society, we do a reasonable, if imperfect, job managing risks posed by things like cars traveling near schools. We can manage, also imperfectly, risks associated with wetlands.

One of the prices of restoring wetlands will be continuous monitoring. By integrating mosquito awareness and control into an entire project, it seems reasonable that some people will volunteer to monitor mosquito species and numbers. People can be supportive. After mosquitoes were under control at Rumney Marsh, Park Avenue Restorations Project in Massachusetts, support for the project increased (Montgomery 1998).

I want to close by moving from ecological to social considerations. When we create or restore wetlands, we not only restore or create wildlife habitat for humans to enjoy; we create human social environments. What type of human social environments do we promote if we write, fund, encourage, or implement proposals or books that ignore or minimize known problems?

Acknowledgments

I thank the University of Arizona based Institute for the Study of Planet Earth and the Udall Center for Study of Public Policy for a fellowship in fall 2002 that permitted me to start this paper, for the chance to present a much earlier version at a fellow's luncheon, and for continued support. Thanks to David Soren for helpful suggestions for accessing the historical literature. Many people at the 2002 Ecological Society of America/Society for Restoration Ecology meeting in Tucson, at various granting agency forums, at the Udall Center, in graduate ecology seminars at the University of North Carolina-Chapel Hill and at Ohio University shared their personal experiences and ideas. Phil Cafaro, Ken Kingsley, Cynthia Lindquist, Bruce Prior, Frank Ramberg, Robert Varady, Margaret Zinser, three reviewers for Restoration Ecology, and especially David Schmidtz offered encouragement, criticism, and suggestions for which I am grateful. The paper is much improved by their contributions; errors remaining are mine.

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Posted March 1, 2004. E. Willott.