There is considerable variation in the strategies used to manage large lakes. Management targets and resources for monitoring, assessment, planning and enforcement (e.g. personnel, equipment, policy, legislation) can differ considerably among countries and lakes. With a growing interest and body of research regarding Marine Protected Areas, assessments of similar freshwater areas are timely, especially considering current concerns over the global loss of biodiversity and increased interest in ecosystem-based management and the Precautionary Principle. This paper examines the use of various types of Aquatic Protected Areas in the management of large lakes (e.g. Marine Protected Area equivalents, fish sanctuaries, parks). Potential and actual benefits and drawbacks, relative uses in current management strategies, purposes for which different types of areas have been created, and related trends are discussed. Very few true equivalents of Marine Protected Areas, that permanently protect both species and their habitats from exploitation and development, have been created in freshwater systems. Most protected areas within lakes exist as fish sanctuaries, which limit or prevent harvest of one or more species, and aquatic or terrestrial (shoreline) parks, which protect aquatic and riparian habitats by preventing development or resource extraction (e.g. logging or mining). Because many Aquatic Protected Areas are established in legislation the retirement of established areas is relatively difficult and the number of Aquatic Protected Areas is increasing. Although Aquatic Protected Areas have considerable potential for improving large lake management, it is essential that management goals are compatible with the function of Aquatic Protected Areas and that factors affecting their success are determined to facilitate efficient use of resources and political will.
Various strategies are employed to manage large lakes, with the specific methods largely dependent on anthropogenic ecosystem uses, values and targets, and on the resources available for planning, monitoring and enforcement. Management can occur in several contexts. Lakes can be managed to sustain biological (e.g. fishery) resources, biodiversity, or water quality for consumption or recreation. Management strategies can incorporate biological information, ecosystem dynamics, habitat protection, pollution and nutrient loadings, water levels, and water extraction.
The use of Aquatic Protected Areas (APAs) is steadily increasing in the management of large lakes because of a shift in emphasis towards ecosystem-based strategies (Minns, 2001; Suski and Cooke, 2007). This shift is partly because of a need to address the current declines in biodiversity (Pimm et al., 1995; Ricciardi and Rasmussen, 1999). Although debate regarding the criteria that constitute an APA persist (Agardy et al., 2003), APAs are frequently defined using the International Union for Conservation of Nature (IUCN) Protected Areas Management Categories (IUCN, 1994), which provide clear gradations between absolute conservation and areas protected to support natural resource use. While the categories are defined by permitted activities, they are commonly, “dedicated to the protection and maintenance of biological diversity, and of natural and associated cultural resources, and managed through legal or other effective means” (IUCN, 1994). There has been little discussion of freshwater APAs in the literature or integration of results among studies; numerous terms have been used to describe APAs (see Suski and Cooke, 2007 for a comprehensive list), potentially leading researchers to overlook comparable studies. We consider APAs to be any location and management strategy where the allowed uses fall into IUCN Protected Areas Management Categories I-VI, whether the location is granted legal permanency or is used in a more dynamic management scheme.
Our objective is to review the current methods used to manage large lakes around the world and to determine the current uses of APAs within those management schemes. We focus on the use of Marine Protected Area (MPA) equivalents, APA locations that are permanently established to protect the entire local ecosystem, both species and habitats, preventing exploitation and development within at least one subsection of the APA. Our a priori expectation was that such locations would be rare in freshwater systems. Fortunately, variation is more informative than uniformity, and by examining the effectiveness of management strategies from multiple locations with different levels of protection, we can obtain more meaningful information within a larger context (Campbell and Fiske, 1959; Hall et al., 1994), and assess the relative effectiveness of different levels of protection and limitations on human activities for attaining management goals. Therefore, the current study incorporates a wide variety of types and levels of protection within the scope of APAs, including locations that prevent seasonal or year-round species harvest, habitat disturbance, or both.
We searched the literature for papers addressing the use and effectiveness of APAs in managing and conserving freshwater fishes in large lakes (i.e. surface area larger than 4000 km2). Literature searches were conducted using Biological Abstracts, Cambridge Scientific Abstracts, Scopus and Web of Science. Key words included aquatic protected area, freshwater protected area, fish sanctuary, shoreline park, national park, provincial park, state park, lake management, fishery management and the names of all lakes with a surface area greater than 4000 km2.
Results and Discussion
Current use of APAs
Aquatic Protected Areas, at least under a definition that includes seasonal closures and non-permanent locations, are frequently used in the management of large lakes (Cowx, 2002). Stricter definitions that limit consideration to permanently designated areas result in considerably shorter lists: 11 papers examining the use of APAs in fresh waters were identified by Abell et al. (2007). Locations that provide at least seasonal no-take zones exist within large lakes throughout the Americas, Africa, Asia and Europe (Table 1). Similarly, terrestrial parks are frequently located on the shores of large lakes (Table 1), protecting riparian and possibly near-shore habitats, although the protection of aquatic habitats or species is rarely intentional. There are a growing number of aquatic parks that protect aquatic habitat from development (Table 2); however, these locations have frequently been established to protect cultural heritage, not for the management of biological resources.
Sites that provide permanent protection of both species and habitats are rare in large lakes (Saunders et al., 2002; Suski and Cooke, 2007), although many lakes include areas that protect both separately (Table 1). While prohibitions on hunting within terrestrial parks are common and generally well accepted (at least in North America), considerable controversy is raised when fishing is at risk of increased restrictions or outright banning (Guenette and Alder, 2007), reducing political interest in creating no-take zones in freshwater systems. Seasonal and year-round fish sanctuaries created under frequently reviewed fishery regulations are quite common (Table 1). Conflict seems to primarily arise when permanent or extensive fishing closures are proposed. Public involvement in the development and implementation of APAs is purported to increase compliance with local restrictions (Beger et al., 2004, Mallory et al., 2006), but public consultation also protracts APA development and can restrict the limitations granted to such APAs (Helvey, 2004).
Several benefits are expected from APAs, although not all potential benefits have been verified. The primary benefits are a reduced risk of population or community collapse through the preservation of source populations, improved ecosystem function, reduced risk of biotic invasion and the maintenance of evolutionary processes.
Adhering to the Precautionary Principle, APAs act as a buffer against over-exploitation, providing a source population or community whose emigrants can recolonize or bolster populations in exploited areas (Roberts et al., 2001). This refuge effect can aid in the recovery of over-exploited populations and buffer against extirpation. However, refuges will not necessarily prevent the collapse of a harvested population. Protection from collapse will depend on the ratio between protected and exploited areas, and the productivity of the protected area. There is a general consensus that APAs alone cannot provide adequate protection for an entire fishery, although they provide an excellent complement to other traditional fishery management strategies (Jones, 2007), including bag and size limits. On their own, APAs have considerable potential for ecological conservation; however, fishery benefits (e.g. increases in the size of harvestable populations or individuals) should be considered an added benefit instead of a planned benefit (Halpern et al., 2004). By reducing the risk of complete loss of a biological resource and aiding the recovery of reduced populations, APAs can also provide greater population and economic stability while increasing eco-tourism when non-exploitative activities are allowed within the APA.
Ecosystems provide additional benefits to human societies besides supplying resources for extraction and eco-tourism opportunities. For example, healthy wetlands help maintain water quality, controlling or buffering terrestrial nutrient loadings (Mayer et al., 2007), and immobilizing heavy metals (Brazner and Devita, 1998). Wetlands also provide spawning and nursery habitats for many aquatic species (Jude and Pappas, 1992), making these locations prime candidates for protection. Thus, APAs can be utilized to protect ecosystem functions as well as individual species or communities and habitats, reducing the magnitude of impact from an individual disturbance and reducing associated rehabilitation or remediation costs.
The loss of a species can have cascading effects within an ecosystem, affecting predators, competitors and parasites, and making resources available for invading species. Healthy populations may be less affected by a perturbation, allowing natural recovery to take place without trophic disruption (Elton, 1958, Fargione et al., 2003). Aquatic protected areas may reduce the risk of invasion by non-native species by maintaining ‘healthier’ communities. Aquatic invasions are a current concern in many parts of the world, especially within the Laurentian Great Lakes, which currently have more than 180 non-native species (Ricciardi, 2006). Intact native communities are generally resilient to invasion (Elton, 1958); invasive species are less likely to become established in areas lacking under-utilized resources (Fargione et al., 2003), potentially requiring a higher number of propagules for establishment to occur (Kolar and Lodge, 2001; Lockwood et al., 2005). By reducing the risk of invasion, APAs could further stabilize aquatic populations and communities, and help maintain intact food webs, thereby, assisting in resource management. Invasions may occur in habitats and communities outside an APA leading to increased propagule pressure and eventual invasions; therefore, APAs need to be scaled and located appropriately, and would be most effective in conjunction with other remedial or protective efforts.
The benefits from protected, healthy ecosystems seem fairly intuitive, but APAs can and have been used to facilitate rehabilitation of imperiled populations and degraded habitats. Although there have been few assessments conducted on the effectiveness of APAs in lakes, several have focused on Lake Trout (Salvelinus namaycush) refuges within the Laurentian Great Lakes (Edsall et al., 1995; Madenjian and Desorcie, 1999; Reid et al., 2001; Madenjian et al., 2004). The Lake Trout sanctuaries encompass traditional spawning reefs; they have provided no-take zones within which Lake Trout cannot be harvested and have prevented habitat disturbances through resource extraction, although such limitations are not typically defined within the sanctuary documentation. Additionally, the sanctuaries are not established in legislation and are, therefore, not permanently designated. These refuges have been integral to Lake Trout recovery strategies following population collapses, especially in lakes Huron and Michigan where the collapses were attributed to a combination of fishing pressure and Sea Lamprey (Petromyzon marinus) predation (Coble et al., 1990; Eshenroder et al., 1992). It is generally accepted that MPAs work well for sedentary species while their effectiveness for migratory and highly mobile marine species remains debatable (Shipp, 2003, Shipp, 2004). Given the successful use of APAs in the recovery and conservation of Lake Trout, a large-bodied and potentially highly mobile freshwater top predator, APAs may prove effective in protecting other freshwater species, both sedentary species and mobile species that show site fidelity during critical times in their life cycle.
Freshwater monitoring strategies frequently incorporate indicators, such as indicator species and Indices of Biotic Integrity (IBIs), which are often dependent on sessile invertebrates (Uzarski et al., 2004), small fishes (Minns et al., 1994; Uzarski et al., 2005; Seilheimer and Chow-Fraser, 2006); amphibians (Hager, 1998) and plants (Croft and Chow-Fraser, 2007). These taxonomic groups typically involve smaller-bodied species that show good site fidelity and local recruitment. Given the general agreement that MPAs are effective for protecting sessile, locally recruiting species (Shipp, 2003; Shipp, 2004), APAs have excellent potential for protecting these freshwater species; therefore, APAs may enhance our ability to monitor the potential condition of large lakes. APAs could serve as control sites within monitoring programs and assist in tracking the progress of recovery strategies.
Concerns regarding fishery-induced evolution have recently increased, with the implications including reduced adult body size, longevity and individual fecundity (Kuparinen and Merila, 2007). Aquatic Protected Areas provide a means of combating fishery-induced evolution by allowing populations to escape the strong size-selective pressure (Baskett et al., 2005). Since some populations, or portions of populations, will still be subject to fishery-induced predation and selection, APAs may not completely halt this anthropogenic-induced evolution, but they may slow the rate of change or maintain genetic variability within a population.
Several potential drawbacks have been identified in the Marine Protected Area literature. The major MPA conflicts revolve around the usefulness of MPAs for, and even potential negative impacts on, the management of exploited biological resources. Many of the issues involve financial implications; at worst, questioning biological or ecological rationales that will impact economics, and rarely identifying biological or ecological concerns related to creating a protected area. Despite these concerns over the use of APAs for resource management, APAs have been identified as a suitable approach for conservation efforts (Halpern, 2003).
By closing a location to species harvest, resource extraction or development, traditional uses of the location may be shunted to other, potentially nearby, locations. While small-scale APAs will likely have a limited local effect, large-scale APAs may create economic and social problems by displacing historic activities with related economic impacts, potentially requiring people and businesses to relocate if the distance to an exploitable location is too great. Such situations may lead to local intransigence, reduced compliance, increased enforcement costs and legal proceedings (Guenette and Alder, 2007).
Creating an APA can be expensive. Appropriate placement, design and management require baseline data. Once an area has been created and management or conservation goals and strategies established, monitoring must also be undertaken to verify that the APA is functioning as intended and to allow appropriate modifications. The establishment process will differ among countries, ecosystems and APA types (strict nature reserves to managed resource protected areas), as will the time required for the political process or public consultation and any related financial costs.
Accompanying the costs associated with displaced economic effort and reduced total harvestable area, APAs also require funds for enforcement. There is, undoubtedly, a positive relationship between public animosity and non-compliance, which will affect enforcement costs (Beger et al., 2004; Davis et al., 2004). A balance is needed between reaching the APA goals and the resources available for enforcement. Such a balance cannot always be achieved, and this problem has occasionally been identified from public consultations during APA planning (Guenette and Alder, 2007). Failure to recognize or address this conflict can result in wasted resources, failure to achieve or even approach the APA goals, and increased public distrust and animosity, which will hinder the creation of future APAs.
Arguments against APAs have also been raised on ecological grounds (see arguments summarized in Jones (2007)). A frequent assumption, which has been verified in some situations, is that APAs will have beneficial effects on nearby populations by providing a source of emigrants (Murawski et al., 2004, Roberts et al., 2005) and allowing protected individuals to grow to large sizes (Mosquera et al., 2000). This is not always the case as density-dependent factors can reduce individual growth rates and fecundity (Grimes and Ralston, 2003; Shipp, 2003; Gardmark et al., 2006), reducing the annual productivity of a given location for some species. The dynamics of predator-prey or competitive interactions can also impact APA effectiveness for conservation; no-take zones may actually reduce the abundance of some species by protecting their predators (Salomon et al., 2002), providing little or no protection to small-bodied species. The design of an APA must, therefore, be tailored to specific conservation or management goals, potentially allowing the exploitation of predators to protect a target species.
One of the main criticisms of using APAs in the management of freshwater systems is that while APAs can protect species from harvest and their habitats from direct disruption, they provide little or no protection from non-point source pollution (Allison et al., 1998) as it enters aquatic systems through runoff, ground water and atmospheric deposition. Although similar criticisms can be made regarding MPAs, marine sites are less likely to be affected by pollution sources than freshwater sites, especially large lakes which often have concentrated human settlement and development on their shores. It must be remembered though that APAs have not been suggested as a means for dealing with impacts from pollution. Pollution sources should certainly be considered during APA establishment and within management strategies since they can undermine efforts that would otherwise prove effective. Any pollution based argument against APAs should therefore be site based, criticizing the location of a specific APA rather than the approach in general. The pollution argument simply illustrates that APAs are not a panacea for aquatic management and conservation; they are one tool which should be used in conjunction with other efforts.
Are APAs worth the effort?
Considering the literature regarding MPAs, appropriately placed and designed APAs have the potential to provide tremendous conservation benefits for many species, although migratory or highly mobile species may require extremely large APAs or APA networks to achieve conservation goals. However, there are concerns over the usefulness and effectiveness of APAs for managing or enhancing fisheries (Jones, 2007). The debate over the relative use of MPAs in the management of marine fisheries and ecosystems remains heated, although the number of MPAs is slowly increasing.
It is difficult to determine the effectiveness of various types of freshwater APAs that have already been created to protect key commercial and game species because of a general lack of data to undertake before-and-after comparisons. The possible exception may be fish sanctuaries, which typically do not meet the IUCN protected area definition. Although the purposes and limitations of fish sanctuaries easily fall within IUCN Category VI (Managed Resource Protected Area: protected area managed mainly for the sustainable use of natural ecosystems), they are typically not permanently established, and are generally excluded from APA lists. The success of APAs in protecting highly mobile freshwater species, such as Lake Trout (Edsall et al., 1995; Madenjian and Desorcie, 1999; Reid et al., 2001; Madenjian et al., 2004), when MPAs have frequently failed to protect mobile species (Shipp, 2003), and the demonstrated effectiveness of MPAs for sedentary marine species, suggests APAs could be effective for managing species with a broad range of life history characteristics. The design of a specific APA must be tailored to the target species or community keeping in mind the nature of community dynamics, specifically predator-prey interactions. Conclusions regarding factors affecting the effectiveness of APAs remain largely unidentified, particularly in freshwater systems. While meta-analyses regarding APAs are likely to prove more frustrating than enlightening given the paucity of published research (Abell et al., 2007), the diversity of protection strategies currently employed within and among freshwater ecosystems provides considerable contrast with which to examine and compare APA designs and implementations. In cases where sufficient historical data exist, it may be possible to conduct preliminary comparisons of effectiveness between different types of APAs; such analyses will assist in focusing research and management efforts.
Funding for this research was provided by the Great Lakes Fishery Commission and a Natural Science and Engineering Research Council Visiting Fellowship to Kevin J. Hedges.