Table of Contents i
Acknowledgements ii

1.0 INTRODUCTION
    1.1 The Objectives of this Report
     1.2 Defining an Invasive Alien Organism
     1.3 Recognizing the Genetic Uniqueness of Alien Invasives
     1.4 Some Criteria for Assessing Individual Alien Organisms

2.0 INVASIVE ALIENS AND PROTECTED AREAS: A GLOBAL PERSPECTIVE

3.0 DESCRIPTION OF THE PROBLEM ALIEN INVASIVE ORGANISMS IN CANADA AS A WHOLE
    3.1 The State-of-Knowledge on Canadian Alien Species
    3.2 Impact on Protected Areas of Non-Invasive Aliens Growing in Disturbed     Habitats
    3.3 Linkage between Alien Invasives and Geography
    3.4 North American Versus Invasives from other Continents
       3.4.1 Alien Species Introduced from other Continents
       3.4.2 Native NA Species but Introduced to and Alien in Regions because of         Human Activities and/or Actions
       3.4.3 Native Canadian Species but Deliberately Introduced into Islands off         Canada's Atlantic and Pacific Coasts

4.0 THE SPECTRUM OF MANAGEMENT ACTIONS TAKEN WORLD-WIDE TO DEAL WITH ALIEN INVASIVES
    4.1 Categorization of Actions
         4.1.1 Prevention
         4.1.2 Mechanical Methods
         4.1.3 Biological Methods
         4.1.4 Chemical Methods
         4.1.5 Indirect Methods
         4.1.6 Integrated Methods
    4.2 Appropriateness of Available Spectrum of Management Methods
         4.2.1 In the Context of the National Parks Act
         4.2.2 In the Context of Parks Canada Guiding Principles and Operational                       Policies
    4.3 The Necessity of Understanding Prime Values
    4.4 The Imperative of Defining the Moral High Ground

5.0 CLASSIFICATION OF PROBLEMATIC ALIEN SPECIES IN CANADA'S NATIONAL PARKS
    5.1 Rationale for Prioritization of Canadian Alien Species
    5.2 The Strange Case of Classifying "Alien Natives"

6.0 PROPOSED GUIDELINES
    Guideline No. 1: Monitor in Cooperation with other Agencies and Countries
    Guideline No. 2: Prevent Introduction
    Guideline No. 3: Avoid and Minimize Ecosystem (Habitat) Disturbance
    Guideline No. 4. Determine Resident Status
    Guideline No. 5. Recognize the Genetic Uniqueness of Invasive Aliens
    Guideline No. 6. Select Species for Cost-Benefit Assessment
    Guideline No. 7. Declare Amnesty for Qualified Organisms
    Guideline No. 8. Set Priorities
    Guideline No. 9. Control and Manage Established Problem Species
    Guideline No. 10. Pursue Restoration Vigorously
    Guideline No. 11. Develop National Educational Initiatives on Values/Ethics of     Ecosystem Conservation and Restoration
    Guideline No. 12. Learn the Necessity of "Living with It" - at least for Now

7.0 CONCLUSIONS

8.0 LITERATURE CITED AND CASE EXAMPLES WITH IMPLICATIONS TO MANAGEMENT GUIDELINES

TABLES:

TABLE 1. Non-North American Alien Species Invading Natural Ecosystems and/or Impacting on Native Species in Canada's Parks and in Other Protected Areas

TABLE 2. Native North American Species whose Range in Canada has been extended by Habitat Changes thought to be due to Human Activities and including Deliberate Introductions

TABLE 3. Native Canadian Species Deliberately Introduced to Islands off Canada's Atlantic and Pacific Coasts where they have been Deemed to be "Alien Invasives"

TABLE 4. Classification of Invasive Aliens in Canada's Parks

APPENDICES:

APPENDIX 1. List of Alien Species that Invade Natural Ecosystems in Different Parts of Canada

APPENDIX 2. Alien Species Working Group Final Recommendations

APPENDIX 3. Scientists' Letter to U.S. Vice-President Al Gore

ACKNOWLEDGMENTS

I wish to thank Mr. Don Rivard, National Parks Branch, Parks Canada for his cordial assistance and suggestions in helping me first to focus on the possible scope of this interesting project and later in providing a critical review. He also provided many articles and several symposia volumes whose contents materially affected the conclusions drawn in this report.

As well, I am grateful to Jean-Guy Chavarie, Chief Park Warden, Forillon National Park and to Denise Comeau and Stephan Marchand, Park Wardens, F.N.P. for their detailed critical review of the initial draft manuscript as well as their many suggestions for improvement, most of which have been gratefully incorporated into the report.

Of the 12 guidelines proposed in this report only No's. 1, 2, 9 and 10 already constitute Parks Canada policy either in part or in whole, although management action on any of these may be extremely limited or even non-existent. Eight of the guidelines are essentially new and hence do not represent the official stance of Parks Canada. Several of these may be controversial. For example, Guideline No. 7 suggests that a way should be found to officially declare amnesty to 'ecologically qualified' alien species. This, and several other guidelines will require some informed discussion and debate, considering their obvious logic and other merits, as described in this report.

Ted Mosquin

March, 1997

1.0 INTRODUCTION

Parks Canada has a need for guidelines to assist with the management of problem alien species (definition below) in national parks. Such guidelines do not now exist. The guidelines would enable both policy and operational staff to make a range of decisions about alien species management and that cannot at present be made. These decisions relate to factors such as whether preventative actions are desirable, whether a particular alien species should be of concern, where the species should be placed on a priority list for action, and what sort of control actions, if any, might be desirable, feasible and acceptable.

The main focus of this study was to carry out the background work considered necessary for the drafting of such a "first cut" set of basic management guidelines and to provide an initial formulation of the guidelines together with rationales for each. In the review of the world literature on this subject it was found that no single framework for alien species management for protected areas exists, although particular management recommendations for specific problem species are published in a wide assortment of articles in a rapidly growing body of literature on this subject.

Non-native organisms often pose special problems in nature reserves and protected areas including national parks because such organisms variously impact on or even replace native species. As well, their presence in natural, still-near-natural or recovering ecosystems may also cause significant changes to the structure and the natural or "normal" functioning of the ecosystem of the area of land or water that has been or is now being invaded. In the words of Courtney (1993): "...no natural system can accept a non-native species without adjustments." However, one should not simply assume that these adjustments are only negative. This is because geographical and ecological circumstances can exist where an invasive alien organism appears to make a positive contribution to ecosystem function and integrity, an important matter that needs to be addressed and is considered further below with several examples.

An essential element of this study was the need to define and describe a valuation framework as well as criteria upon which judgements about the "good" or the "bad" of any known alien species must be based. Fortunately, there is a body of accumulated knowledge and insight in the fields of evolutionary geology/ biology, and Ecophilosophy which provides such a valuation framework. Once some of the obvious species and ecosystem values to be gained or lost (as a result of the effect of the alien) are considered, the justification for eradication or control through management becomes more apparent, and in serious cases, imperative. Hence, this report describes the valuation framework that should logically be the basis for judgements respecting control measures.

The general context in Canada in which this report is written is that human induced disturbance regimes, including habitat or natural area fragmentation are still a net expansion in area as well as in the severity of impact, thus providing numerous new opportunities for the introduction and establishment of problem alien species.

The findings of this study should enable Parks Canada staff, or any other agency or group concerned with the management of protected areas, to better focus on management policy alternatives, define priorities and draft management directives for park planners and operational staff. Indeed, once ecological values gained or lost associated with the presence of an invasive alien are sufficiently assessed, an ecologically based case can usually be made for categorizing, prioritizing and even for justifying "severe" management actions to control or eliminate the problem species.

1.1 The Objectives of this Report

The specific objectives to this study are:

• to describe the problem alien and North American introduced species in Canada;
• to provide an overview of the global problem of alien and other introduced species with particular reference to protected areas, including national parks;
• to review management actions taken by jurisdictions world-wide to deal with exotic and other introduced species in protected areas;
• to propose criteria for the identification and prioritization of problems and management actions;
• to evaluate the appropriateness of the available spectrum of management actions in the context of the National Parks Act and the Parks Canada Guiding Principles and Operational Policies; and
• to draft a "first cut" set of guidelines for the management of alien and NA introduced species in Canada's national parks (guideline criteria to include a classification of problematic and potentially problematic species).

The literature on alien invasive organisms, including "weeds" is extensive and includes not only articles in academic journals but also the resource literature in trade publications associated with agriculture, forestry and fisheries. There are literally thousands of titles dealing not only with specific problem species but also with a full range of methods of control of these species. While not entirely irrelevant, this literature was beyond the more limited scope of this study, except for some Canadian material (e.g. Crompton et al. 1988). Rather, in this report emphasis is placed on the literature directly relevant to invasive aliens associated with variously protected areas such as national and provincial parks, nature reserves, ecological reserves, and similar areas.

1.2 Defining an Invasive Alien Organism

A science-based definition of what constitutes an invasive alien species is essential to park managers because a credible and realistic definition will have consequences to policy formation, to the consistency of management and control actions and the prioritization of problem invasive species for control programs. The review of the world literature on this topic indicates that a consensus definition of what constitutes an alien organism or species (provided below) has emerged. The broadly accepted definition as well as some exceptions are worthy of brief review if for no other reason than to gain a clear focus and understanding of the definition issue and in order to lay it to rest so that any planning to control, ignore, or encourage invasive aliens in protected areas can move forward within a globally accepted definition.

There are a number of essentially synonymous terms used to describe the kinds of species we are dealing with in this report, vis: "introduced," "aliens," "exotics," "non-natives," "immigrants," "adventives," "neophytes," or "non-indigenous." The 1992 Convention on Biological Diversity uses the term "alien" to describe these kinds of organisms and hence this is the term now predominantly favoured in the ecological and management literature. It is specifically those alien species that either invade the living space of native species in natural habitat and that can successfully invade and alter natural ecosystems that are considered to be problems for managers of protected areas and hence the adjective "invasive" is commonly used to describe these kinds of organisms. Thus, "invasive alien" is becoming widely used (Stone 1992; White et al. 1993; Environment Canada 1994; Sandlund et al. 1996) and has been has been adopted for general use in this report.

The definition of "alien organism" used herein (and that is being recommended to Parks Canada) follows that agreed to at a workshop of a group of experts who met in February 1994 in Victoria, BC (Environment Canada 1994) to develop recommendations on alien species for consideration in the drafting of the Canadian Biodiversity Strategy (Supply & Services Canada 1995). The group met in response to Article 8(h) of the UNEP Convention on Biological diversity, which Canada has ratified. The Convention Article states that: "Each Contracting Party shall, as far as possible and as appropriate: ...Prevent the introduction of, control or eradicate those alien species which threaten ecosystems, habitats or species." The experts' definition is:

"An alien species is one that enters an ecosystem beyond its historic range, including any organisms transferred from one country or province to another."

This definition (see Appendix 2), modified from the US National Park Service (see below) implies no positive or negative impact by the alien organism, and includes organisms entering through natural range extension and dispersal, and through deliberate or inadvertent introduction by humans as well as a result of habitat changes caused by human activity. Obviously, an organism that has been extirpated from a park in historic times and later re-introduced would not be considered to be an alien. Two Canadian examples would be the Southern Flying Squirrel re-introduced in the late 1980s to Point Pelee National Park and the Swift Fox re-introduced into the area of Grasslands National Park over the last several decades.

The participants of the workshop described above (Environment Canada 1994) also recognized that an alien species would not only be alien to a natural ecosystem but may also be harmful to associated wild species, natural ecosystems and to the human interest, thus:

"Alien species, however, may be injurious. An injurious species or organism is one that causes or has the potential to cause harm to native Canadian species or ecosystems through processes including but not limited to hybridization, predation, parasitism, pathology, and competition, and potentially harmful to the human interest, including but not limited to aesthetics, economics, and health."

These definitions exclude humans from recognition as alien species regardless of biological, geographical or historical facts. The workshop participants thus re-enforced the wrong-headed notion described as the "exemptionalist paradigm," which is the simple assumption that humans stand apart from the laws and workings of nature. The belief that humans are independent of the workings of natural laws has implications to the way people interpret human-generated ecological problems in national parks and other protected areas, and places strictures on the management of peoples' activities in such areas.

Of course, it is obvious that an organism does not have to be an alien to be deemed by humans as harmful to their interests and in this regard there are thousands of species out there that automatically fall into this "harmful" category, as for example - all species present in a natural or near natural area that is being considered for conversion to an agricultural field or for a location of a toxic waste dump.

The other puzzling aspect of the report of the Workshop (Appendix 2) is the failure to recognize that some alien invasive species may NOT be harmful and indeed may be beneficial to native species, natural ecosystems and to humans. Just how many Canadian examples might fall into this category would require a "case by case" review by a ecologically knowledgeable resource managers. Some examples are offered later in this report. Such a recognition of "beneficiality" has important policy and management implications and the guidelines (Section 7.0) assume that such a category is legitimate.

For the record, some other definitions of alien (exotic, introduced, etc.) species are of interest. Thus, the US National Parks Service defines alien species in park policy as: "....those that occur in a given place as a result of direct or indirect, deliberate or accidental action by humans (not including deliberate re-introductions)." This definition is vaguer and not as explicit as the one adopted above. The US Forest Service defines alien species as ones that are basically 'un-American,' vis: those species "....not originally occurring in the United States and introduced from a foreign country." (US Forest Service 1991). Indeed, the word "alien" is widely used in the USA, applying even to any foreign national legally or illegally in the country. Thus, graduate students from other countries are recognized as "alien students," even though they belong to the same species as the rest of us. Obviously, a chauvinistic use of the term. Some additional examples: Stirton (1979) defines alien plants as those that: "... invade and oust native vegetation." Westman (1990) defines an alien species as "..one that is newly established at a significant distance from its former geographical range," and Achuff et al. (1990) define an alien species as one "...that is not native to the area under consideration." However many definitions there are in the literature, it seems preferable that the definition to be accepted for operational purposes should be based on common sense, logic and science, rather than the mere opinion of an individual. In this way of thinking, we should adopt a definition that is universally applicable, widely used, and if and when possible, amenable to some sort of historical and scientific testing, which for many species (see below) is not possible.

Using the basic, non-judgmental "Alien Species Focus Group" definition described above, it is obvious that in today's world, both globally and in Canada itself, there are hundreds, indeed sometimes thousands of alien species in a particular area or region (except in boreal and polar regions - see Section 4.0). One reason these estimated numbers are so high is that one cannot exclude invertebrate animals, fungi, macro-algae, and the enormous numbers of microfauna and flora (microorganisms) where knowledge of whether or not a species is alien, is usually unavailable and impossible to obtain (Duffy 1988; Drake et al. 1989; McKnight 1993). It is difficult, and usually not possible to determine the resident status of the myriads of tiny microscopic and submicroscopic organisms in terrestrial and aquatic habitats.

While this country's national parks (and areas near to national parks) often contain many hundreds of introduced animals, plants and microorganisms (Romo & Lawrence 1990; White et al.1993; Mills et al. 1993; Mosquin et al. 1995, pp. 63-69; Haber 1996a, 1996b), only a limited number of these are considered by ecologists and managers to have caused, and/or to continue to cause, significant impacts on native species or natural ecosystems. In this report, an introduced alien is considered to require a judgement of its destructive status only when it invades natural ecosystems and/or affects native species. A "problem invasive species" in this report includes those plants and/or animals that, in the judgement of Parks Canada staff, are now having a significant negative impact upon native species or upon the ecological integrity of natural ecosystems of the parks.

The large majority of introduced species in Canada's national parks, and this applies particularly to plants, are relatively benign in that they can reproduce and survive only in disturbed sites such as highway right of ways, lawns, yards, gravel pits, and other disturbed areas created or maintained by humans. Hence, they are not of direct concern in this report.

1.3 Recognizing the Genetic Uniqueness of Alien Invasives

Any management policy or action respecting the control of invasive alien organisms needs to always recognize that each and every species in nature is genetically unique, having its own particular distribution or occurrence pattern, some distinct aspects to its life cycle and some unique role in interacting with or affecting its immediate associates and neighbours.

While there have been some academic attempts to predict which species or classes of species might become invasives and which ecosystems will be invaded the conclusions are at best tentative and preliminary (Heywood 1989; Rejmanek 1996). The reasons are straightforward: each invading species is genetically unique. As well, every invaded ecosystem is also unique in its "abiotic" (Rowe 1990b) characteristics and its assemblage of species at a particular spot or area as is repeatedly described in the ecological and evolutionary literature.

The ecological uniqueness of plant species has been long recognized by evolutionary biologists and first encapsulated in a classic paper by Gleason (1926) entitled: "The Individualistic Concept of Plant Succession." What this means in a practical sense is that a manager cannot depend upon knowledge gained in controlling one species to apply automatically to any closely related species. Thus, one cannot predict future alien invasives of any protected area except from empirical distribution data taken over time where the expanding range of a newly introduced alien is tracked over a number of years or decades much as has been done for Frog-bit, and a number of invasive plant and animal species (Section 3.0; Appendix 1). In other words, there is no sure way of predicting whether a newly introduced species from a distant area will be invasive of natural ecosystems until it arrives and begins invading. "Nothing is more difficult than to predict what will happen to an exotic," says botanist Warren Wagner of Michigan.

In the summary to the recent Norway/UN Conference on Alien Species (Chairman's Report 1996) the following useful quote on the above issue is offered:

"Prediction of the progress and consequences of a biological invasion in a quantitative way is not possible. There are possibilities of making analytical models, but adequate estimates of variables are not possible before an invader has been introduced and has actually spread. However, sufficient independent empirical data (life history, survival rate, fertility rate) are available only for a relatively few species in order to reconstruct "old" invasions."

The practical point is that there is no scientific way to identify "potentially problematic" invasive species and also that each invasive alien present in or near a protected area deserves its own special individual management consideration. Not only are invasive species unique. Ecosystems themselves are complex beyond human description and imagination and there is no scientific way of knowing in advance which part of a similar-appearing ecosystem will be favoured by an invasive alien species and which part will resist the invasion. Hence, from a management perspective (but not from an academic one) it would be counter-productive to pursue this matter or devote any resources to the issue.

1.4 Some Criteria for Assessing Individual Alien Organisms

Whether or not an organism is to be considered a serious invasive usually requires common sense field information.

The California Exotic Pest Plant Council (1986) has offered a practicable set of criteria for assessing whether an invasive alien is to be considered an important "wildland weed" in the State of California and these criteria seem to be universally applicable, at least for plants. The assessments and lists are drawn up by the members of the Council in cooperation with members of the California Native Plant Society. The Council states that:

"Plants are NOT included as important wildland weeds if they:

1) do not spread beyond cultivation;

2) are not eradicable (e.g. Mediterranean annual grasses and filarees);

3) naturalize only sparingly. and

4) are confined to roadsides and agricultural fields."

The Council provides 2 (draft) lists, each of which includes trees, shrubs and herbs, vis:

List 1. Most Important Wildland Weeds. This includes 13 species. The criteria for inclusion in this category are:

- widespread;

- well-established; and

- can dominate a plant community

List 2. Wildland Weeds of Secondary Importance. This list includes 66 species, and the criteria for inclusion here are that the plants are:

- localized;

- in an early stage of invasion;

- lack ability to dominate a community.

Criteria for the importance of alien animals would be similar to the above but more complex. While no explicit listing was found in the literature, references to these characteristics exist - buried within specific articles. The criteria for animals would need to be developed by first making a list of a wide range of alien invaders of natural communities and competitors with native species and then encapsulating the estimated degree of impact upon native species and natural ecosystems. This has not been done here (but see Appendix 1 for a basic Canadian list). Some case examples (see Appendix 1 for others) of the range of impacts would include:

- directly usurp nesting sites of native species (e.g. starlings displace bluebirds, red-headed woodpeckers, tree swallows, prothonotary warblers, etc.);

- successfully raid nests of eggs and nestlings of native oceanic birds on islands (e.g. the Norway rat on islands off Canada's east and west coasts);

- competes for food with native species (i.e. the introduced wild turkey in Canada is said to eat food that is readily taken by the native ruffed grouse);

- severely over-graze natural ecosystems, eliminating or greatly altering required habitat for flora and fauna (horses on Sable Island and domesticated herbivorous animals in any natural ecosystems).

2.0 INVASIVE ALIENS AND PROTECTED AREAS: THE GLOBAL CONTEXT

2.1 The General Context and Scale of the Problem

Some understanding of the scale and nature of the global problems posed to native species and natural ecosystems can be of benefit when considering guidelines for protected areas in Canada.

It is the sheer scale and increasing tempo of the movement of species to and from very distant parts of the world combined with both the economic impact of some of these 'successful' introductions and their observed disruptions of native species and natural ecosystems that is at the root of the rapidly increasing concern with the subject of invasive alien organisms. This involves enormous trans-boundary and intercontinental movements on an unprecedented scale.

Some measure of the importance of the topic comes from the growing world academic research and management literature on invasive aliens and the outcries of scientists and managers who know about or are faced with the consequences. The literature includes a number of books and symposia as well as large numbers of focussed individual articles (Elton 1958; Duffy 1988; Drake et al. 1989; Natural Areas Association 1992; McNight 1993; Clout 1995; Hengeveld 1996; Eighth Grazing Land Forum 1993; Sandlund et al. 1996; Chairman's Report 1996). As well, there are now at least nine List Servers on the Internet (Aliens Internet Lists Servers, 1996) dealing wholly or in part with this topic. One list server (ALIENS-L) started in October 1996 had some 500 participants by mid November. Major international conferences have addressed this growing problem (Drake et al. 1989; McNight 1993; Sandlund et al. 1996; Chairman's Report 1996).

The world-wide increase in concern is clearly linked to the mounting scale of deliberate and unintentional introductions and movement of thousands of species daily by travel, growing commerce (including free trade) and tourism/ recreational activities. The scale of the daily transfer of organisms is such that the chances of a native species from some part of the world being introduced to an environment in another part of the world where it can thrive is now higher than ever. Given enough time, virtually every species that can survive somewhere in the world will eventually find its way there either by deliberate introduction or inadvertently. In cases where the species can invade wildlands and natural ecosystems (including suitable marine environments), it will have its effects upon native species and cause deviations from norms of ecological integrity of these places. This global phenomenon provides an good working example of Murphy's Law: 'If something can happen, it will.'

The scale of the global spread of invasives into distant marine, terrestrial and freshwater ecosystems has prompted the emergence of phrases such as the "biological homogenization of the world" (Culotta 1991). Another sign of the times is the recognition of this problem by the Convention on Biological Diversity, the holding of an associated UN Conference on alien species (Sandlund, et al. 1996; Chairman's Report 1996). In Canada some attention has been directed to this issue by Environment Canada (1994) and in the text of the Canadian Biodiversity Strategy (Environment Canada 1995) but in a practical sense, budgets and actions are at zero. The continuing "export" of organisms from very distant (but climatically similar) parts of the world to Canada is an issue that is already serious for some of our national parks and protected areas and that promises to become more serious as the tempo of global transport accelerates.

For many countries, the organized data on invasive aliens in natural ecosystems is non existent or very sketchy. However, for several areas of the world a great deal of documentation exists as well as a practicable body of direct experience with management and even eradication techniques. These data taken together provide a basis for an understanding of the Canadian situation and for preparing this report. The better known geographical areas are the mainland United States, Canada, New Zealand, Australia, Hawaii, South Africa and Europe as a whole. Where summary reports were found, these have been examined during the course of this study; otherwise the material in this report derives from reviewing a wide assortment of articles by both academic and management journals.

In the United States two recent documents summarize the nature, extent and many of the specific impacts of the entire range of invasive aliens in the country and these underline the pervasive nature and scale of this problem in the USA. All ecosystems, except possibly the boreal and alpine regions have received lesser to major changes as a direct result of many of these introductions. Thus, the Office of Technology Assessment released a report in (OTA 1993) which documents some 4,500 non-indigenous plant and 2300 animal species of foreign origin that have established free-living populations in the United States (this figure apparently includes Alaska and Hawaii). At least 15 percent of the species identified trigger severe harm, and just 79 invasive aliens caused documented losses of US $97 billion in control costs and losses of marketable goods (Eighth Grazing Land Forum, 1993; Nature Conservancy 1996). The US Department of the Interior (LaRoe et al. 1995) produced what is essentially a "state of the environment report" and which summarized the numerous negative impacts of alien species on natural ecosystems and on some native species in different parts of the country and in principal sectoral ecosystems. The Nature Conservancy (1996) has produced a fresh review and evaluation of the situation in the US. The conservancy notes that alien invasive species have been implicated in the decline of 42 percent of those species listed as threatened or endangered by the U.S. Fish & Wildlife Service, and that of the 40 North American freshwater fishes that have become extinct over the past century, the American Fisheries Society has documented that introduced species were a contributing factor in 68 percent of these extinctions. The Conservancy notes that as a group the most endangered organisms in the U.S.A. are freshwater aquatic animals. And finally: "60% of the land stewards for The Nature Conservancy's more than 1,500 preserves reported in a recent survey that exotic plants are among their top management dilemmas with 12 percent indicated that they are their single most severe problem." Species introduced into the USA and that can live somewhere north of the international border usually spread to Canada, and if a national park happens to be suitable habitat, we can be assured of an arrival sooner or later, usually sooner.

Hence, it makes sense that governments begin taking action through new legislation, policy development, management directives, guidelines to enable the problem to be addressed where possible. Particularly, such a range of fresh initiatives would be necessary with respect to alien invasives in protected areas. Actions need to be coordinated, and international in scope, considering the scale of this problem and carried out within a basic understanding the global context and the ways in which invasives elsewhere affect Canada's interests. Clearly some effective formal mechanisms are required if nations are to work together at a level above and beyond national or regional initiatives. In the United States the "National Invasive Species Act was passed by Congress in 1996 (mainly to address alien species in ship ballast) and a new book summarizing the economic and ecological scale of the problem in the United States has been published by the Nature Conservancy in October (and the text is also available on the Internet). Recent symposia cited above and particularly the most recent (Sandlund et al. 1996) demonstrate the slow movement in this direction. In February and March 1997 hundreds of concerned scientists in the United States and from around the world signed a letter to the Vice-President of the United States requesting far greater action on a new strategy to prevent and manage invasions of invasive alien species (text of letter: see Appendix 3).

These publications, conferences, new laws, and other initiatives show the monumental scale of the problem in different parts of the world and worries and concerns that exist out there regarding the consequences to other species and sometimes to entire ecosystems. Additional examples are included in the literature cited section (Section 9), but obviously, only a relatively small number of these "ecological horror stories" can be included here and an extensive literature review would bring many additional hundreds more to light.

The impact of alien invasives on tropical and subtropical oceanic islands is well known and an extensive literature on the subject exists. Major efforts are bing made to eradicate unwanted aliens from large numbers of oceanic islands, and particularly rats, rabbits, cats and goats, and these efforts are increasingly successful for ever larger islands with dramatic results to the recovery of native species and ecosystems. Some of the literature on these islands is reviewed in Section 9 of this report. However, Canadian island archipelagos along the Atlantic and Pacific coasts are fundamentally different from tropical and subtropical islands in that in Canada, all islands were glaciated and their flora and fauna, with minor exceptions, are recent in origin, and with genetics similar to their mainland species, and with very few few endemics. The various ways in which Canada's problems with invasive aliens differ from those of other regions of the world are examined in the next section.

3.0 DESCRIPTION OF THE PROBLEM ALIEN INVASIVE ORGANISMS IN CANADA AS A WHOLE

3.1 The State-of-Knowledge on Canadian Alien Species

In comparison to many other countries, a great deal has been published about the time of introduction, distribution, spread and impacts of invasive alien species in Canada, especially for vertebrates. Some of this information is summarized and discussed in Appendix 1 which includes literature references for various species. Some general taxonomic books also provide summaries of distributions, recent spreads and the like. Particularly useful are Birds of Canada (Godfrey 1986), Mammals of Canada (Banfield 1974) and Amphibians & Reptiles of Canada (Cook 1984) and a wide range of floras, as well as more specific articles. However, not surprisingly, little indeed is known about the alien-versus-native status of the overwhelming numbers of invertebrate species, particularly insects, arachnids, fungi, algae and bacteria found in Canadian waters, soils and as parasites on different species.

Some of the better studied cases where maps or other information on the gradual spread of a new introduction are available are: the House Sparrow and Starling (Cadman et al. 1987), Leafy Spurge, Euphorbia escula (Best et al. 1980; White et al. 1993), Glossy Buckthorn, Rhamnus frangula (Catling & Porebski 1994); European Frogbit, Hydrocharis morus-ranae (White et al. 1993; Catling and Porebski 1995), Purple Loosestrife (White et al 1993), and the Pacific Treefrog, Hyla regilla, in the QCI (Reimchen, 1990-good map).

There are also many articles in various publications documenting the incremental spread of invasives aliens such as the starling, gypsy moth, coyote, garlic mustard, zebra mussel and many others. Hence, assuming some agency is monitoring the spread of newly introduced alien species or expanding native species, it is often possible to anticipate the arrival of the species in a protected area. The spread of the Zebra Mussel is one recent case where such predictions are possible. However, tracing the spread of any known alien species would be a formidable task, usually impracticable considering the enormous size and complexity of land and water areas (hence, guideline No. 1 - see Section 7.0).

Management actions taken against invasive species that occur in areas contiguous with protected areas such as national parks cannot be separated from the regional and broader geographical context within which variously protected areas are nested. Thus, the management of (actual or potential) alien invasives needs to be discussed with adjacent jurisdictions and also in the context of the broader and more fundamental issue of the ecology and biology of the invasive species itself.

However, while a particular invasive can often be ignored in lands outside the Park, the requirement that national parks must retain or restore ecological integrity of their ecosystems means that legally Parks Canada is expected and required to take this matter seriously and to actively address the issues of prevention, control or eradication through policy, budget and management actions in the field. This report should be seen as a preliminary effort toward this end.

3.2 Impact on Protected Areas of Non-Invasive Aliens Growing in Disturbed Habitats

As noted in Section 1.0 this report concerns itself only with invasive alien organisms that can and do invade natural ecosystems and/or compete with, replace, parasitise or predate upon native species. However, disturbed habitats such as roadsides, lawns or lands adjacent to parks provide some special situations. One such special case exists where non-invasive 'alien weeds' (e.g. food species such as alien grasses and forbs) along highway rights-of-way and other disturbed areas in a park attract native animals and thus affect their population levels in the protected area. Native elk and big horn sheep grazing in such disturbed areas along the Trans-Canada Highway would be examples of such indirect impacts of these alien roadside weeds on native fauna.

Another example along the main highways of Banff National Park (this would apply to all Parks in southern Canada where there are disturbed roadsides, campsites, town sites, etc.) concerns the indirect impact on ecological integrity of natural areas due to the super-abundance of the common dandelion. This allegedly alien species is extremely abundant in roadsides and lawns in town sites of the park in late May and early June. When fields of dandelions come into flower, their millions of flowers offer a cornucopia of quality nectar and pollen easily accessible (on a conspicuous flat, UV-reflecting, landing platform) to any and all flower pollinators (bumblebees, leaf cutting bees, flower flies) living in the area. In these circumstances, the native pollinating bees and wasps abandon foraging on the native flora to visit only the dandelion flowers. This is thought to cause a significant reduction in seed set of native flowering plants in and close to areas where dandelions are common (Mosquin 1971). No doubt many other cases of the indirect effect on natural areas of proximal non-invasive weeds exist but studies appear to be few and far between.

Another example would be where a Honey Bee (an aggressive alien species) colony is located at the border of a park or protected area. These active bees forage for several miles at least, and are documented as competing directly with native bees thereby affecting the native bees' food supply and hence their population levels and possibly causing local extirpations of native bees (and even some extinctions) as has been found to be the case in Australia where the honey bee is widely naturalized pest (unable to re-locate two excellent references). Of interest here perhaps is that back in the summer of 1968, this author had the good fortune of spending the entire spring and summer studying pollination ecology of the flora & pollinating insect fauna in the Bow Valley (including Sunshine Meadows) where not a single specimen of the domesticated honey bee was seen among the rich native (i.e. ecologically integral) pollinating fauna.

No doubt there is an abundance of cases where the alien inhabiting a disturbed site has some subtle or indirect effect on the naturalness of the adjoining natural ecosystem and which only careful in situ field research would be able to identify and elucidate. The above examples show that sometimes distinguishing between the effects of a problem invasive species (i.e. one invading natural ecosystems) and a non-invasive species (ie. one that does not invade natural ecosystems) is not a clear-cut matter.

3.3 Linkage between Alien Invasives and Geography

Guidelines for alien species management in parks and other protected areas need to be framed within the context of Canada's geographical position and the recognized diversity and nature of ecozones of the country. This is because both the seriousness of the problem across the width and breadth of Canada as well as the potential or probability of new alien invasives arriving successfully in the future are strongly linked to our geography and our climate.

As a general and useful rule the impact of invasive aliens is greatest in subtropical and warm temperate regions of the world and particularly so on warm oceanic islands where unique faunas and floras have evolved in the security of isolation and where the effects of invasive aliens can be rapid and dramatic (Drake et al. 1989; McKnight 1993; Sandlund et al. 1996).

In Canada as in other parts of the world, certain habitats and ecosystems are far more susceptible to invasives than others. As a generality, the problem of alien invasives in natural systems is sometimes serious in parts of southern Canada but is essentially non-existent in the North. Thus, as far as is known, natural (undisturbed) tundra ecosystems of Canada contain not a single exotic species. While "weeds" from more southern regions are present, these are of no concern in this report since they occur only in places heavily disturbed by human settlement, such as roadsides, docks, villages, trails and the like. Thus, for practical purposes, there is no need for contemplating management guidelines for existing alien species in all those national parks or portions thereof where tundra ecosystems dominate except possibly a guideline to ignore the presence of alien species in any parks or portions thereof where tundra ecosystems dominate.

The linkage between climatically determined vegetation zones and the success of alien invasives is recognized in some literature. Thus, Usher (1988) who summarized the results of studies in 28 reserves around the world (Duffey, 1988) noted that: "The most important generalisation is that all nature reserves, except those in Antarctica, appear to have invasive species." However, while there is a small tundra zone in Antarctica, none of the reserves examined by Usher (1988) were located in the Tundra zone of North America nor in any of the extensive Boreal ecozones of the Northern Hemisphere.

3.4 North American Versus Invasives from other Continents

Two categories of invasive alien organisms are sometimes recognized in Canada: those that are native to North America but that have extended their ranges due to human activities, and those that originate from other parts of the world.

A number of papers indicate the importance attached to the question of the natural historical range of a species that is being considered for re-introduction into a park or removal from the park. However, it is not always easy and straightforward to determine whether an organism was present in an area in "historic times." Three examples will serve to illustrate this point. First, 500-year old fossil remains of Bison in Alaska (Peak et al. 1987) are considered to be a relevant factor in determining their status as a native or an alien in national parks in Alaska. Because of these fossils, the US National Park Service treats (the "re-introduced") bison in Alaska parks as native. This decision to accept recent fossil evidence of a valid criterion for "nativeness" is important to Parks Canada since obviously, the bison of 500 years ago in Alaska could only have travelled there through Yukon.

Another example is that of the native versus alien status of the giraffe in southern Africa. Thus, Goodman & Tomkinson (1987) examined the former distribution of the giraffe and conclude that the probability that it ever occurred in Zululand prior to their introduction is extremely small. They suggest it be classified as alien to Zululand, and note that this has implications to management.

A third example concerns mountain goats in Olympic National Park, Washington. Thus, Carlquist (1990) and Houston & Schreiner (1994) describe the historical research that has gone into attempting to determine whether mountain goats were ever native the Olympic Mountains prior to their deliberate introduction in the 1920s and concluded that the goats should properly be classed as aliens. A management plan is in place (Carlquist 1990; Houston et al. 1991). However, a management controversy as to whether to remove them is continuing in the US.

Many other similar case examples exist from around the world in a wide range of vertebrate and invertebrate groups (Drake et al. 1989; McNight 1993; Sundlund et al. 1996) and where research into the "resident status" of a species is essential to offer guidance as to what sort of management actions (if any) might be justified.

In Canada, and particularly for plants and the larger vertebrates, a wealth of historical information on resident versus alien status exists and this is reported in a number of publications (Scott & Crossman 1973; Banfield 1974; Youngman 1975; Godfrey 1986; McAllister 1990; White et al. 1993; Mosquin et al. 1995, pp.63-66). Depending on species, some of these publications include historical information outlining what is known about the timing and reasons for introductions as well as range maps showing past and present distributions and including extensive references to particular reports and studies. The information from these publications has been essential to this study and has been summarized as necessary in Appendix 1. Each of the alien species entered in the appendix meet the essential basic definition for categorization as an invasive alien organism because in the areas where they are now found they are entirely naturalized and very much a part of the invaded natural ecosystem of an area or region.

The alien organisms that can and do invade natural systems or impact directly on native species across Canada (Appendix 1) are conveniently grouped here into three categories (Tables 1, 2 and 3). Species in each category should be the subject to special and unique consideration with respect to management. The categories are:

3.4.1 Alien Species Introduced from Other Continents

Included in this group are species native to continental areas outside of North America and introduced to terrestrial, freshwater or marine parts of Canada where they now thrive and appear to significantly affect some aspect of natural ecosystems and native species. These are included in the following table (see Appendix 1 for details & references):

TABLE 1. NON-NORTH AMERICAN ALIEN SPECIES INVADING NATURAL ECOSYSTEMS AND/OR IMPACTING ON NATIVE SPECIES IN CANADA'S PARKS AND OTHER PROTECTED AREAS (list incomplete, especially for fishes and invertebrates)

3.4.2 Native North American Species but Introduced to and Alien in Regions because of Human Activities and/or Actions

These are species that are native to continental North America but have extended their range into new regions of the country either via deliberate human transport or because of habitat changes caused by human activities such as agriculture, forestry, eutrophication and urbanization. However, while the historical evidence for "extensions of range" of native species due to human actions are often very clear, it needs to be emphasized that this is a grey area for the large majority of native North American Species.

An important question is this: Should people distinguish between natural range extensions versus "human assisted" ones?: When they can, then yes. The reality is that out there in the natural landscape there are thousands of species trying to live wherever they can and are in a state of perpetual dispersion, migration or local extirpation. What happens to such organisms when humans alter the habitat in an area where these species are native? The species may or may not move to extend its range. If it does (even a few kilometres) then the individuals in the extended range would be aliens while those in the historically natural range would not.

One is reminded of the very large numbers of reports of range extensions in the Canadian Field- Naturalist or in Le Naturaliste canadien. Many of these (especially plants and other non-migratory species) records simply mean that no person has ever collected at the marginal site before. So, it is not worth the effort, in my view, to try to document whether these cases are natural or assisted since uncertainty (and hence, lack of credibility) would remain.

Complicating the picture further is the consequences to the distribution of native species as a result of global climate change. Both extensions of range and local extirpations would be expected. So, "track it if you can" would appear to be an essential element of monitoring the problem alien species, native or not. In these circumstances, to devote budget to tracking known or suspected expansions from historical range would surely be difficult (impossible) to justify.

Table 2 does not include any of these dozens (probably hundreds) of species, but rather only those native species where range extensions have obviously been caused by human actions and that have been historically documented.

And finally the logic of including some species in this group can be questioned. Thus, this report is concerned with "problem" alien species - i.e. ones that invade natural ecosystems or impact on particular native species. In the case if the Loggerhead Shrike, this prairie species has come to nest in a few spots in southern and eastern Ontario. However, it can do this only because the natural ecosystems in these areas (forest) no longer exist.

Similar species would be the coyote and brown-headed cowbird which survive and thrive in their extended ranges due to the creation by humans of open and fragmented habitat which is an abnormal habitat (e.g. in eastern and Atlantic Canada).

TABLE 2. NATIVE NORTH AMERICAN SPECIES WHOSE RANGE IN CANADA HAS BEEN EXTENDED BY HABITAT CHANGES THOUGHT TO BE DUE TO HUMAN ACTIVITIES, AND INCLUDING DELIBERATE INTRODUCTIONS. (Not including, inter alia, extensions due to winter bird feeding (e.g. mourning dove, cardinal, blue jay, house finch and others)

A fascinating historical account could be prepared on each of the above species, something outside the scope of this report although some useful annotations are provided in Appendix 1.

3.4.3 Native Canadian Species but Deliberately Introduced into Islands off Canada's Atlantic and Pacific Coasts.

Another unique group of alien species (included in Table 2 above) includes those that are native to mainland Canada but have been deliberately introduced to certain islands off Canada's Atlantic and Pacific coasts. The largest of these islands are Newfoundland, PEI, Cape Breton, Anticosti, Vancouver Island and Queen Charlotte Islands archipelago (see Appendix 1 for details on specific species) plus some other smaller islands off the both coasts. Species in this category are included in the Table 3 below.

TABLE 3. : NATIVE CANADIAN SPECIES DELIBERATELY INTRODUCED TO ISLANDS OFF CANADA'S ATLANTIC AND PACIFIC COASTS AND WHERE THEY ARE DEEMED TO BE "ALIEN INVASIVES"

For each of the above, some historical information on their introductions to these islands, together with references, is provided in Appendix 1.

4.0 THE SPECTRUM OF MANAGEMENT ACTIONS TAKEN WORLD-WIDE TO DEAL WITH ALIEN SPECIES

An eclectic spectrum of management or control actions has been developed and used world wide against invasive aliens, with adaptations to local realities and conditions. No doubt, some methods, such as "weeding" date back to the dawn of agriculture; others have been developed through sophisticated research. Most of these methods are "generic," in that they are effective for a wide range of similar or related species. Only some (e.g. use of pheromone attractants) are species-specific.

Not only can the many methods be used to control or eradicate alien invasives; they are also used with equal or more devastating effect to destroy natural ecosystems to make place for agriculture, and in crop management systems where the intent is increase agricultural production.

Inevitably, except in the most extreme kinds of actions, the nature of the action differs fundamentally depending upon taxonomic group. This is not surprising since the biological organization, behaviour, and chemistry of organisms in various kingdoms, phyla and other taxonomic levels of life right down to species is to different degrees unique and requiring different methodologies including integrated control methods which involve combinations of actions. Thus, depending on the organism, any preventative measures, eradication or management protocols can be fundamentally different. Even within each major taxonomic group such as an Order, Family or Genus, certain actions are feasible for certain species but not so for others.

Depending on the circumstances of the particular organism and/or ecosystem, some actions can be carried out quickly; others involve processes (such as succession or persistent predation) and can conceivably take years, decades and centuries to achieve the desired objective (i.e. eliminate the undesirable alien). Some are morally objectionable to certain individuals or sectors of society, others are not - a subject dealt with in Section 6.0 of this report.

4.1. Categorisation of Actions

Actions are grouped into prevention, mechanical, chemical, biological, indirect and integrated. Each is considered in turn with some examples that appear to be most relevant to alien species management for protected areas. A detailed search of the world literature would no doubt yield additional kinds of actions, particularly ones that are species-specific.

4.1.1 Prevention

Preventing the introduction and spread of alien species in protected areas is a vital element of management. Existing laws can be used. Personnel need to be in place to identify problems and enforce laws. Prevention needs to include efforts by jurisdictions outside the national parks. This matter is further considered in Guidelines No. 1 & 2.

4.1.2 Mechanical Methods

These methods include the use of machines, hand picking, soil tillage, deliberate fire, shooting, trapping,

• Hand removal of Plants: The weed control system used by generations of rural farmers, including European farmer settlers in Canada for farm fields small and large, and is still used by home gardeners, is the hand pulling of weeds, such as mustard from large acreages. Such 'search and destroy' approaches to the removal of alien plants can take place in natural areas such as parks. Although they are labour intensive, organized volunteers can usually readily be found. Such an approach was used at Point Pelee National Park in 1989 (Dunster 1990a; 1990b) when a total of 263.5 person hours was devoted to removing 12 alien herbaceous aliens and restoring some sites with native species. Randall (1993) notes that hand pulling by volunteers is effective in controlling yellow star thistle, Centaurea solstitialis, populations on a nature reserve in southwest Oregon.

This is clearly one of the most "ecologically friendly" approaches to the elimination of an alien species. As well, work by organized gangs of volunteers is available at virtually no cost. The work is "empowering" in the sense that participants can immediately see the results of their work, even though any program would need to continue until seed banks of the target species have been exhausted - a tall order but not impossible for a determined group working over a number of years.

• Fire: While burning of terrestrial ecosystems (prairie, savannah, chaparral, forest with a dry season, etc.) has been a method used by humans in deforestation and pasture development over enormous regions of the Earth, this method can be used to great advantage in reducing and sometimes eliminating the preponderance of alien species in projects whose purpose is the restoration of natural prairie ecosystems (Romo & Lawrence 1990; Morgan et al. 1995). For Parks Canada, this method would be applicable to Grasslands National, Riding Mountain, and other parks which have prairie components.
• Shooting, snaring, trapping, etc. : Whether one is intending to manage problem alien species or those native species whose populations have exploded due to human activities (Section 5.2), these well-known methods have been extensively used over hundreds of years. A few examples of the use of these methods would be:

- reducing (native) deer populations at Point Pelee, Rondeau, Long Point and other special areas;

- use of helicopter gun ships to reduce (alien) Himalayan Thar populations in the mountains of New Zealand (CCCM 1993);

- aerial shooting of entire families of (native) elephants in Kruger National park in South Africa, and possibly in other areas.

• Tillage: This is a powerful approach (but thus far little-used) method for the eradication of alien species and reduction of seed banks in former agricultural areas which are designated for restoration to its natural condition. It involves the use of plows, cultivators, harrows over several years (i.e. summer fallow). This approach has been used extensively to set the stage for the "re-prairification" of small areas (fields, roadside rights-of-way) in the western United States and Canada (references in Morgan et al. 1993). It can also be used to prepare for the natural regeneration of forest (Keever 1983; Weaver 1980/81).

4.1.3 Biological Methods

Biological control includes a number of techniques centred around the purposeful use of a living organism - predator with the aim of controlling a particular undesirable alien invasive. To achieve control or eradication with living organisms one needs a biological control agent which could be a parasite, parasitoid, pathogen, predator, herbivore insect, antagonist or a competitor (Oduor 1996). Control strategies using living organisms include:

• introduction (classical biological control) of a herbivore or parasite from the 'pest's' area of origin;
• inoculation - repeated releases (of sterile males, for example) so as to prevent pest build-up;
• inundation - where large numbers of natural enemies are cultured and released during critical periods in the life cycle of the crop or other alien species;
• conservation - where measures are taken to conserve and enhance the numbers of natural enemies already present in an area thus decreasing the mortality of the affected species; and
• augmentation - where natural enemies of a pest are at too low a level and the numbers are augmented by artificial rearing and release.

Some examples where biological control has been extremely successful are: Prickly Pear Cactus and rabbits in Australia; water hyacinth in Sudan, the cassava mealybug in Africa (cited in Oduor, l.c.); and the control of Water Lettuce, Pistia, stratiotes, (by one weevil) in South Africa. The weevil is currently in process of being introduced into the Seychelles to control Water Lettuce there. In Canada, biological control (by introductions of host-specific herbivore insects or parasites) has been attempted for Leafy Spurge, Purple Loosestrife, Gypsy Moth and some other organisms and there is a growing literature.

The bacterium, Bacillus thuringensis, which is effective against members of the Lepidoptera. It has been very via aerial applications for decades in efforts to control population explosions of the (native) spruce budworm.

However, biological control through the introduction of alien species has its risky downside. Thus, there exist dozens of examples of ecological disasters in many parts of the world which resulted from such introductions. A few are:

• the Cane Toad, introduced from Africa to Australia
• mongoose in the Carribean

4.1.4 Chemical Methods

Herbicides/Pesticides: By far, this is the most widely used method for eradicating unwanted animals and plants in agricultural areas. At Point Pelee National Park "Round-up" and similar chemicals have been used to kill stumps of the black locust (Robinia pseudo-acacia). Herbicides may be used to "spot spray" perennial patches of alien grasses in prairie ecosystems under restoration in prairies for brome.

Anti-coagulant Poisons: Single-dose anticoagulant poisons such as brodifacoum in special bait formulations, and the development of bait stations and aerial application methods for eradicating rodents from islands (Clout 1986). This has been an effective approach to eliminate all rabbits from tropical oceanic islands (Temple 1990). The particular bait station technique was developed in New Zealand and is currently being used by Mark Drever (Simon Fraser University) to eradicate rats from Langara Island (approximately 3000 ha in size and ) in the QCI.

Before the introduction of rats, Langara Island was home to the largest sea bird colonies in western North America. Rats are also found in the park islands at the tip of South Moresby (at Cape St. James,) and this method can now be effectively used to permanently eliminate them.

Immunization. An example here is the deliberate immunization of racoons and skunks in Ontario to prevent the spread of an alien invasive - the rabies virus.

Impeding Reproductive Ability: This is the use of hormones to lower reproductive potential of a species by chemically or surgically impeding the reproductive ability of individual animals. This technique has not found common usage because it is new, largely untried, and like live-trapping and removal, requires large numbers of animals to be treated. One method involves implanting a hormone releasing device which interferes with a female's ability to conceive and carry young. Any of these methods could have the positive feature of greater public acceptability but they can be prohibitively expensive.

Pheromones: Considerable research has take place on pheromone attractants for pest species. Some of this has been carried out on aliens, as for example on the gypsy moth.

4.1.5 Indirect Methods

Community Succession: Depending on the ecosystem, different variations of community succession can be used as a technique to eliminate alien species and replace them with ones that are native to the area. These variations can range from simply leaving an area alone (old field succession in forested areas), planting with native (or alien) cover crops, or planting directly with native species which, over the years will come to dominate and influence the rate and nature of succession. There is an extensive an growing literature on this, some of which is cited in this report. The use of this technique can be active or passive depending on local circumstances and the need to obtain the desired objective (elimination of alien species and replacement with what would be the natural or normal ecosystem for that site). Cost can be considerable if time lines are short.

For formerly forested areas of eastern Canada, evergreen plantations are often established on former farm lands. Within a dozen years, these may form dense closed shade canopies, effectively shading out alien grasses and forbs. Depending on the availability of seeds from adjacent natural areas, succession by in-seeding can be quite rapid or take many decades while the "full transformation" of the ecosystem may well take several hundred or more years.

4.1.6 Integrated Methods

Increasingly, the trend today is to employ "integrated pest control methods" and there is an extensive literature. This means that several of the above approaches can be knowledgeably combined to achieve the desired control or eradication of the alien organism. This is not always possible or desirable, however and each case needs to be examined to explore the potential effectiveness and public acceptance. It seems evident that specialist expertise is required to outline options, estimate costs and assess possible consequences.

4.2 Appropriateness of Available Spectrum of Management Actions

As the management of national parks is governed by legislation and policy the extent to which any of the above actions against an alien species are appropriate is examined in light of the National Parks Act and Parks Canada Guiding Principles and Operational Policies.

4.2.1 In the Context of the National Parks Act

The National Parks Act is very general in its Articles but requires that national parks be managed for the "maintenance of ecological integrity." Hence, the meaning of ecological integrity demands some understanding something within the easy reach of any person with average intelligence, fortunately. Hence, this concept is discussed briefly below with references to key literature. Deviations from ecological integrity would be considered to be undesirable and invite budget allocations for correction as well as corrective management action.

4.2.2 In the Context of Parks Canada Guiding Principles and Operational Policies

Parks Canada Guiding Principles and Operational Policies (Supply & Services, 1994) provide some general and explicit context for management of alien species in the national parks and national marine conservation areas. Relevant quotes are provided herewith:

• In the preface (p. 8) we find the following general vision: "Heritage places must be managed in a manner that sustains them and respects their intrinsic values. Heritage places contribute to .... conservation strategies by maintaining ecological integrity and biodiversity of natural areas....."
• And: "...efforts will be made to manage areas in their natural state."
• Under the national parks policy section (p. 35) we read that: All practical efforts will be made to prevent the introduction of exotic plants and animals into national parks, and to eliminate or contain them where they already exist."
• Under the national marine conservation areas policy (p. 56) we read that: "Where marine ecosystems or components thereof have been seriously degraded, Parks Canada will initiate restoration programs in cooperation with others."
• And further (page 56): "The introduction of exotic plants or animals into the wild in marine conservation areas will not be permitted."

As the above directions are quite explicit, Parks Canada management directives for alien species have not been written. However, of the five management directives covering natural resource management (pesticides; bear management; freshwater sport fishing; use of drugs to immobilize wildlife; fire management; rare, threatened & endangered species; environmental assessment) only one alludes to alien species as follows:

The Management of Pesticides by Parks Canada (Management Directive No. 2.4.1) written in 1995 states that: "The use of pesticides should be proposed only after manual, mechanical or biological control measures have been assessed and found not to be effective, and when responsibility centre managers are satisfied that...the target organism is not naturally occurring and...the insect infestation or plant disease threatens the survival of a species recognized by Parks Canada as threatened or endangered...

So, one can conclude from the above that Parks Canada staff already has some guidelines for what to do and what not to do. But there exists a wide latitude for alien species management (removal, prevention of introduction, etc.) In both the terrestrial parks and marine conservation areas. Certainly any blanket use of pesticides would kill many native, non-target species and therefore it would be violation of policy to contemplate this particular kind of action.

Otherwise, there appears to be nothing in legislation, policy or directives which would prevent almost any means available by machines or science to successfully remove problem alien species and keep them out. Only the constraint of ecological integrity coupled with budget allocation priorities prevent or limit such action. But obviously, due to public perceptions of what is appropriate in a protected area certain kinds of "nasty" actions will be inappropriate and unrealistic politically, unless of course the groundwork in public education and understanding is laid down in advance, another budget and program priority item. This matter is further considered below.

4.3 The Necessity of Understanding Prime Values

The notion that National Parks are places whose purpose is to serve as sanctuaries for nature's wild species and natural ecosystems is a strong one. The reference in the National Parks Act to managing national parks in a manner "...so as to leave them unimpaired for the enjoyment of future generations." reflects this generally held view and provides some legal back-up for this valuation perspective. At least in theory, a kind of "let it be" value system for both wild species and for their natural habitats is a recognition of their intrinsic values. These are ecocentric and biocentric values and are expected to be defended and promoted by park managers when contemplating specific management actions that will affect native species and natural ecosystems of the parks and conservation areas.

Since the areas we are focussing on in this report are special places - parks and other protected areas, the use of what to many people are morally objectionable, "nasty" (Temple 1990) or "severe" actions such as killing cuddly warm-blooded, furry animals with poisons, guns, snares, clubs, even by helicopter gun ships or automatic weapons in small planes appear to many in the public to be morally wrong and objections can be strong due to suffering and bloodshed associated with such actions. Thus, public objections to the control or removal of alien organisms, particularly if they are large, warm blooded vertebrates can cause unfortunate and ecologically damaging reversals to ecologically sound administrative and political decisions. Here are some examples of where sound ecological decisions were made regarding removal of alien invasives (or native over-abundant species) in Canada but were strongly opposed by the public, mainly on moral grounds.

• the decision to remove all horses from Sable Island in the late '50s. This was met with stiff public sympathy for the horses and caused a reversal in a federal government decision to restore the island's ecology;
• the public outcry which occurred when the total removal of alien horses living on the Sutcliffe miliary Reserve was proposed;
• in Ontario, public opposition to the reduction in deer populations (a native species) at Rondeau, Pelee and Long Point;
• in Hawai`i: where efforts using any means possible to remove feral pigs, including hunting with dogs and shooting was opposed on the grounds of "excessive cruelty to pigs." This, despite the fact that the pigs were totally transforming flora and dependent fauna in protected areas.
• the baby seal "white coat" clubbings off northern Newfoundland.

While the above examples include both alien and native species, the public reaction in each case needs to be anticipated and addressed beforehand. Of course, some humans object to killing - period, and such views would need to be set aside for the sake of saving the greater good.

4.4 The Imperative of Defining the Moral High Ground

Any program to eradicate larger warm blooded vertebrate species from a protected area using morally offensive methods requires that the agency make crystal clear to the public in advance the ecological reasons that such action is important. No agency benefits from a public uproar opposing actions which obviously may cause pain and suffering even when the action is essential to save or restore ecosystem values that are of far greater importance. To a large extent such public outcries are based upon a lack of awareness on the part of the public of fundamental/prime values that are at stake if action were not taken.

Fortunately for protected area managers, there exists an emerging, scientifically grounded (in geology, evolution, ecology) valuation system upon which management decisions about the "good" and the "bad" of almost any native or alien species can be based. The system requires that the most important (prime) ecological values be comprehended so that the "media" case can be made for controlling the species whose presence or overabundance (due to human actions) is seriously impairing these prime ecosystem values.

It is the ecocentric valuation perspective that provides the essential guiding valuation framework and which enables managers to make the case for optimizing ecological integrity of any protected area by identifying the negative variables that require corrective attention. Ecocentrism is a value system and attitude which reveals that humans are necessarily part of larger, encompassing ecological processes and systems. Ecocentrism recognizes that the planetary system and its major sectoral ecosystems and their health are elements of our world infinitely more important than humans. If and when these controlling and determining systems are retained, respected and protected, humans and their societies become elevated in importance and health; if these systems are valued only for their instrumental or utility aspects, misery and social breakdown are the logical ultimate ends, as we see even today in so many (overpopulated) countries of the world where ecological integrity is devalued and so systematically destroyed, as for example in the miserable regions of Bangladesh, India, parts of Africa and Asia and increasingly so in most countries.

To utilize ecocentrism in the management of alien species, managers must be thoroughly aware of the basic elements of ecosystem norms/standards for an area to be managed because it is deviations from these time-tested norms and standards that enable logical, purposeful, and publicly defensible decisions to be made and defended. The impact of a problem alien species on the ecosystem constitutes one such deviation but sometimes not the worst one.

So, getting back to "appropriateness," if something is very high value, then more "extreme" and "violent" management actions are justified in protecting the thing of value. For a control program to be successful, key community decision makers need to understand this primal ethical dimension so that their active support can be obtained.

The definition of ecological integrity provided by Stephen Woodley (Woodley et al. 1993) is consistent with the above geological, evolutionary and historical reality. The definition is:

"Ecological integrity is defined as a state of ecosystem development that is optimized for its geographical location, including energy input (and output) available water and nutrients and colonization history. For national parks this optimal state has been referred to by such terms as natural, naturally evolving, pristine and untouched. It implies that ecosystem structure and functions are unimpaired by human-caused stresses and that native species are present in viable population levels."

A number of recent essays/book chapters are recommended for any manager seeking to gain an essential grounding on this topic, so critical to comprehending the underlying reasons for wishing to move the planet and its systems, place by place, piece by piece toward greater, indeed optimal ecological integrity (within the circumstances or our time). These writings (with literature references) are:

• Rowe, Stan, 1990. Ethical Ecosphere. This is a chapter (pages 138-142) in a collection of essays published in the book, Home Place, by Newest Books. A variant of this essay, Environmental Ethics - Ethical Ecosphere, was also published in The Trumpeter 6(4): 123-126.
• Rowe, Stan, 1992. What 'on Earth' is Environment? Trumpeter 6(4): 123-126.
• Rowe, Stan, 1994. Ecocentrism: the Responsive Chord. Trumpeter 11(2)106-107.
• Mosquin, Ted, Peter G. Whiting and Don E. McAllister, 1995. Standards/ Norms for Biodiversity. This is Chapter 3 in the book entitled: Canada's Biodiversity; the Variety of Life, its Status, Economic Benefits, Conservation Costs and Unmet Needs. The chapter describes the components of biodiversity - genes, species, ecosystems, functions and the "abiotic" world and for which deviations from norms (deviations from ecological integrity) can be measured or estimated.

According to Eric Ribbens, Biology professor at St. John's University in

Minnesota: "Ecosystem integrity is a far better basis on which to delineate how ethical treatment should be determined." (Cited in Holdcamp 1996). As well, a number of interesting articles examine the question of how to judge "naturalness" (Bonnickson 199? ; Anderson 1991).

To conclude, it is the relatively "wild" and "uncontaminated" condition (the evolved standard/norm) of ecosystems and their organisms that would now be present in an area or region had major human influences not so swiftly modified or eliminated these evolved ecosystems in an area or region. A valuation system that is founded on what we know about how the world came to be cannot ever be credibly challenged or questioned. In the words of Berry (in Meeker-Lowry 1988) "the integral functioning of the natural world is the supreme model of managerial success."

5.0 CLASSIFICATION OF PROBLEMATIC ALIEN SPECIES IN CANADA'S NATIONAL PARKS

The categorization of individual alien species given in this section is based on the subjective judgement of the author of this report. It is based in large part upon the author's personal knowledge of each species and associated literature and on a judgement of known ecological consequences of its presence. The classification should be seen as a 'first cut' effort subject to addition, deletions, fine tuning, and the like. Considering the great diversity and number of alien species in southern Canada, and the fortuitous location of Canada's national parks, this table can be greatly expanded through systematic review of the resident status and the effect of the species on an existing park or a future park in the region. The priority sequence as well as the groupings also reflect judgements made by some other authors (e.g. White et al. 1993 for plants). The classification would benefit from input by parks field staff, ecologists and individual field botanists and naturalists across the country. The key criterion for drawing up this initial classification must be this: what is known or suspected of the degree to which an invasive alien has negative, more or less neutral, or positive effects on native species and the structure and function of the natural ecosystem that has invaded and where it would not have been present except thanks for the deliberate or inadvertent consequences of human activities? Table 4 provides a first cut (with brief rationales and/or notes) as to the reasons for each placement.

5.1. Rationale for Prioritization of Canadian Alien Species

Table 4 provides a summary of the author's subjective assessment of the kind of the practicable categories into which known invasive aliens in Canada's national parks should be grouped for management purposes. This table should be seen as a basis for discussion.

Priority 1 organisms have had the greatest, largely negative impact upon native species and natural ecosystems. In this group we have the Chestnut blight, a fungal disease. Yet, considering the immense ecological importance of this tree in the past, it is puzzling that no effort has been made by Ontario or Canada to select blight resistant seedlings, despite the known fact that there are dozens of scattered individual trees in southern Ontario and adjacent States which are partially or wholly resistant to the blight and which produce copious seed crops (for use in a breeding and selection program) periodically. As for the other species listed as Priority 1, the literature on their impacts is extensive.

Priority 2 alien species are ones whose negative impact is fairly well recognized, but the negative impact of each of these is seen as decidedly less apparent. A valuation framework needs to be clarified in order to which of these species should be moved to Priority 1 or Priority 3.

Priority 3 alien species are unusual in that they are identified for amnesty because the island areas they occupy are nothing but natural extensions of their continental ranges. Until deliberately introduced, their absence in these islands and island archipelagos off Canada's Atlantic and Pacific coasts is seen as being merely accidents of post glacial history. As well, each, as far as can be judged occupies a niche in its island home not occupied for the most part by other species. All species, whether their populations are on the mainland or the islands have some negative impact on some other species and this is considered within the normal parameters of life. For the above reasons, the presence of populations of these species on these islands is hardly worthy of further Parks Canada action or attention. Again, there is no logical reason why the notion of amnesty should not be applicable to species other than humans and their immediate domesticated animals.

Priority 4 species are targeted for a risk/benefit study before their management status is firmly settled. It should be noted, however, that species like the Mule Deer and the Racoon on QCI are known to have very significant negative consequences to local ecosystems. However, while they occur naturally on nearby mainland British Columbia, their positive input into the ecology of QCI is not known.

Priority 5 species are clearly ones that are here to stay and could not be eradicated except with enormous effort and expense except possibly some of them could be temporarily eradicated from small areas.

5.2 The Strange Case of Classifying "Alien Natives"

This seems to be the place to raise a bothersome conceptual question. There is a widespread agreement that when alien invasive organisms impact negatively on natural ecosystems the 'naturalness' of an area has been affected. However, one needs to take a closer analytical look at the word 'alien.' Sometimes human activities cause a species that is native to increase vastly in numbers (although the reverse can happen). When that species then drastically affects its fellow native species causing major population losses, or when its large numbers cause a drastic alteration of natural habitat which then becomes unsuitable for some native species which require the habitat for survival and thus causing the extirpation or even extinction of some of these natives, then surely the ecological impact on a natural area can be far greater than that of any invasive alien organism. When this situation develops, an abnormal or "alien" ecosystem can be the result.

Thus, a species does not necessarily have to be an alien in an area to be subject to severe management action for the sake of securing the ecological integrity of protected areas. Such severe control measures were recently used to reduce the total numbers of White-tailed Deer at Point Pelee National Park.

Some other native Canadian species whose populations are greatly increased by human actions are the blue jay, brown headed cowbird, evening grosbeak, ring-billed gull, and others. Individuals of these species are far more abundant than they would otherwise be had it not been for the widespread prevalence of winter bird feeding. Likewise the Ring-billed Gull is many times more abundant than it would otherwise be without the winter food it obtains from human garbage dumps. Here are some details.

• White-tailed Deer. In the almost complete absence of predators (black bears, gray wolves), this species can undergo explosive population growth when they are free from hunting as in some protected areas of southern Ontario (Hutchinson et al. 1988, and see extensive Literature Cited and Bibliography in the Hutchinson report). Thus, in Rondeau Provincial Park, Long Point National Wildlife Area, and more recently at Point Pelee National Park, deer populations have reached such high densities as to transform heavily forested habitat into a semblance of open grassland or savanna similar in appearance to over grazed cow pastures. The negative consequences are elimination of required habitat for many rare native plant species and the elimination of forest-requiring habitat for several dozen bird species, particularly neo-tropical songbirds which are in serious decline (Mosquin et al. 1995). The point not to be lost is that here we have a native species which has a far greater negative impact in creating a degraded, abnormal or "alien" ecosystem than do many invasive aliens.
• Blue Jay. Here is another example of a native Canadian species whose superabundance in parts of Southern Canada seems clearly linked to the popularity of winter bird feeding in both urban and rural areas. It is the opinion of the author of this report that the pleasuresome and disarmingly benign human activity of winter bird feeding has vastly increased the resident populations of blue jays across the country from Alberta to Newfoundland. The birds are aggressive in securing food at any artificial feeder, and will repeatedly raid and empty any feeder in short order, carrying food off to distant trees where it is wedged into bark and wood cracks for eating at a later date. Hence, population numbers of these predatory birds may be many times higher than would be the "normal" population in the absence of artificial food. The consequences to the host of neo-tropical bird eggs and fledgelings can only be imagined and numerous photos exists of their nest robbing proclivities. In Lanark County, where it is not unusual to see a dozen blue jays at a glance, entire flocks take to cruising the tree and shrub canopies when neo-tropicals such as warblers, vireos, tanagers, pewees, flycatchers and veeries are nesting. Thus, a seemingly benign human activity (winter feeding) creates major ecological sinks for many species of increasingly rare and threatened neotropical birds.
• Cattails: In areas of low or normal eutrophication cattail stands are not particularly dense. However, where eutrophication is taking place, cattails will become so dense as to eliminate other native species. This "alien" abundance not the norm for marsh ecosystems of southern Canada (Keddy pers. comm.)
• Brown-headed Cowbird: This parasitic species has greatly expanded its range from the Great Plains across eastern North America and Eastern Canada where it has become abundant due to agricultural activities and fragmentation of the landscape. In these regions female cowbirds parasitize large numbers of nests. Each female cowbird lays some 45 eggs per season in nests of a wide range of small songbirds, many of which continue to decline for this and other reasons.
• Ring-billed Gull: Abnormally large populations of this predatory bird now prey on and reduce populations of a variety of birds in many settled areas of Canada where these gulls have become super-abundant in the summer months.

Some other species could be added to this list, as for example the Mule Deer and the Racoon both deliberately introduced to the Queen Charlotte Islands and both of which drastically alter the forested ecosystem and the composition of animals in tidal flats throughout the islands.

7.0 PROPOSED GUIDELINES

Management guidelines for an invasive alien organism need to reflect what is known about its geographical, ecological, behavioural and physiological attributes so that these can be taken into account insofar as possible during conservation planning, when drafting management directives, or when carrying out possible field actions aimed at controlling or eliminating the alien invader. Canada's unique geographical position (covering temperate and cold regions of the northern half of North America with island archipelagos off our Arctic, Pacific and Atlantic coasts) will mean that guidelines for this country will differ in some important ways from those of warm temperate and subtropical areas of the world, and certainly very different from those that would apply to isolated tropical and subtropical islands around the world.

Another helpful rule would be to recognize and be aware that management thinking and actions will necessarily be very different indeed for invasive aliens in each of the five Kingdoms of life [Procaryotae (bacteria), Protoctista (algae and protozoa), Eumycota (fungi), Plantae (plants), and Animalia (animals).

By their nature "guidelines" are always voluntary and this means that they may or may not be implemented. This is just as well because the scale of the problem of invasive aliens is such that it is entirely unrealistic that budgets would be available to meet the total costs needed to be incurred to control or eradicate even the really destructive alien species in Canada's protected areas.

Certain prescriptions may control or eliminate several alien species at one time (e.g. bring about full canopy development in former naturally forested ecosystems, or, using cultural methods to eliminate numerous exotic aliens in a former prairie ecosystem as a restoration methodology). However, on the whole, management agencies will often focus their efforts on one species at a time. For reasons explained earlier, the Guidelines described and defined here are intended to apply not only to Canadian protected areas, and particularly National Parks, but to adjacent land and water areas as well.

Guideline No. 1. Monitor in Cooperation with other Agencies and Countries

An essential element in an alien species management program would be to have the capability to detect as soon as possible the location of newly introduced alien species that may invade a park or protected area in the future. This is no easy matter, considering the size of Canada and adjacent parts of the United States and also the range of terrestrial, freshwater and marine ecosystems into which alien species are first introduced and from which they later spread to protected areas (e.g. gypsy moth, garlic mustard). Not only the two countries but also the provinces and states within each are often very much concerned with the ecological and economic damage done by alien species (see Appendix 3, for example). Hence, if the rate of introductions of alien species is to be arrested or at least slowed down, then it is logical that a continent-wide monitoring system be established and maintained involving many jurisdictions.

Once the introduction of a potentially problematical species is reported by a jurisdiction, it may be possible to eradicate the alien before it has spread beyond the feasibility of control.

Not only is there a need to monitor for new introductions, but as well, the monitoring should logically include keeping track of the continuing spread of already well-established problem alien species, regardless of whether management action is contemplated, feasible or undertaken. This would be a formidable task but with modern database and communications technology, the feasibility of such an (inter-institutional) arrangement.

Early detection by monitoring, and depending on the ecological and biological characteristics of a newly discovered alien species in a protected area, it may be possible to eradicate the founding population. This is the case when the population is easily identified, small and local. For example, if the first plants of the Garlic Mustard had been discovered at Point Pelee National Park, the great buildup of a seed bank and the spread of the species could likely have been contained using a cadre of organized volunteers over a number of years. In other cases, particularly if nearby invasive populations are highly mobile and difficult to locate or find, the colonization of all suitable natural habitats in the protected area will be inevitable, as for example in the case of the Zebra Mussel, the Carp or in the case of the coyote spreading into Fundy National Park and other protected areas in the Atlantic provinces. So, again, whether or not early detection is effective depends on the nature of the invading species.

At the level of individual parks and protected areas, the practicable approach would simply be to have a keen and knowledgeable naturalist be on the lookout for such invasives on a more or less continuous basis.. When an organism is discovered it may be possible to eliminate it before it spreads, although this is sometimes not possible, depending on species (see 6..

The case for early detection is obvious, but does imply that a knowledgeable and perceptive naturalist needs to be on the constant lookout for new, potentially destructive invasives.

Whether or not time and dollars should be spent monitoring a particular invasive alien should obviously be linked to the calculated chances that the data obtained will actually achieve some desirable end. Possibly, monitoring for its own sake can be justified in academic research or when using volunteer effort. Official decisions to spend time monitoring is clearly something that depends on local circumstances and the seriousness of a possible threat from an invasive species. However, in cases where a decision has been made to eradicate an invasive, whether long established or recently arrived, monitoring at sensible intervals would be a logical requirement. Monitoring is particularly necessary when attempting to eradicate destructive aliens from islands as in the case of rat poisoning programs on bird islands along Canada's east and west coasts.

Guideline No. 2: Prevent Introduction

This guideline is closely linked to No. 1 above. It is a specific application of the adage: "A stitch in time saves nine." Obviously, down-the-road costs of eradication, monitoring and containment (and of economic and ecological impacts) can be avoided by preventing introduction in the first place.

The context for this guideline is global (Section 2.0) and this is widely recognized (Drake et al. 1989; Sandlund et al. 1996; Chairman's Report 1996; Nature Conservancy 1996). The Convention on Biological Diversity itself provides evidence of an awareness of the international scale of this problem among nations. Thus, the primary rationale behind the "National Invasive Species Act" passed in the USA in 1996 is that of preventing the introduction of additional invasive alien species via ship ballast. But the USA is only one country. Obviously, similar legislation in other countries - targeting specific areas of human activity (e.g. tourism, trade) rather than specific species would be a logical approach to reducing the risks of successful invasions of new species. However, while means of spread of invasives around the world are known, the scale of human movement and goods these days is so great that the difficulty of enforcing any legislation or regulations would restrict the effectiveness of this approach.

Since the prevention of introduction of new alien invasives is something that concerns a broad segment of society, then obviously, any input from Parks Canada should be part of a larger organized initiative involving the provinces and private sector groups. Monitoring around vulnerable points of entry has been suggested (Clout & Lowe 1996), but this would not be effective along the long Canada-US border where forests and farmland are essentially contiguous.

This guideline implies some considerable knowledge of flora and fauna both in the park and elsewhere in the country and the world and of potential invaders lurking there - a big order. Considering the monumental scale of movement of alien species (3000 species on the move at any one time) it follows that prevention is most critical at an international level. One example of an emerging strategy for possible in