Prince Edward Point National Wildlife Area Management Plan: chapter 3

3 Management challenges and threats

3.1 Loss of grassland habitats

Prior to the establishment of the Prince Edward Point National Wildlife Area (NWA), the land within and surrounding the NWA was used for mixed farms and livestock grazing. While agriculture continues to be the predominant land use in the region, many of the agricultural lands around the NWA have since been abandoned and much of the area is now characterized by regenerating shrubby fields and thickets. Native species such as Red Cedar and Prickly Ash have spread into many of these abandoned fields. Over time, the Prince Edward Point NWA is likely to return to its pre-European settlement state (i.e. forested condition).

These changing conditions benefit some wildlife species but are a detriment to others. Of particular concern is their effect on the suite of open-country bird species, which have been identified as showing the most consistent and severe population declines of any birds in North America (Bird Studies Canada 2009). Sharp-tailed Grouse (Tympanuchus phasianellus), which previously bred in the NWA, have been extirpated locally; other grassland species such as the Bobolink may soon follow. Potential effects on migrating grassland birds are not as well documented, but the loss of open grasslands over time is expected to change the mix of species using the NWA as a migratory staging area.

3.2 Lake levels and projected climate change

The main threat to wetlands is the fluctuating water levels of Lake Ontario. The levels have been regulated since 1959 resulting in a lack of extreme high and low water levels that have contributed to changes to riparian wetland vegetation. Vegetation tolerant of drier conditions has expanded, and meadow marsh communities have declined, reducing the diversity of wetland habitat. The influence of precipitation and local climate are more important factors now than changing lake levels in controlling riparian wetland vegetation.

Wetlands along the south shore of the Prince Edward Point NWA, separated from Lake Ontario by barrier beaches, are also showing changes related to the lack of periodic flooding necessary to maintain their diversity and extent. These nearshore marshes provide important spawning, nursery and food sources for fish and aquatic species that subsequently provide food for many species of birds. Several wetland species at risk, including the King Rail (Rallus elegans) and the Least Bittern (Lxobrychus exilis) no longer breed within the NWA, although some of their former habitats may be considered in future as recovery habitat for these species.

Water-level regulation and control of Lake Ontario have also influenced Long Point Harbour. The harbor is naturally infilling as a result of wave action and sediment. Possible dredging and other activities related to maintaining an open harbor to the Lake is jurisdictionally complex and outside of the mandate of Environment and Climate Change Canada.

In the face of projected climate change and continued variability, the resources required to monitor and maintain these habitats and to manage invasive and non-native plant species are expected to increase (Galloway et al. 2006). Current models predict that climate change and variability will lead to warmer air temperature due to a decrease in winter ice cover and subsequent increased evaporation. Although the impacts of climate change on the habitats and wildlife of the NWA are unknown, it is expected that there will be changes in distribution, range and breeding behaviours of migratory birds and wildlife using the NWA.

3.3 Invasive and non-native plant and wildlife

Invasive and Non-native plant species

A large number of non-native plant species occur within the NWA. However, some are well-established over decades and in essence are integrated into existing habitats. Problems arise with aggressive species that have the ability to rapidly spread and consequently displace native species and decrease biodiversity.

Within the Prince Edward Point NWA, the expansion and invasive characteristics of three species are of particular concern: Dog-Strangling Vine (Pale Swallow-wort) (Cynanchum rossicum), Purple Loosestrife (Lythrum salicaria), Garlic Mustard (Alliaria petiolata). These species out-compete native plant species and reduce the area’s native biodiversity including milkweed required for Monarchs.

Determining effective management options to reduce the impacts of these species is often hampered by limited knowledge of the species and the ability of many species to adapt to Ontario growing conditions. Early detection is key to the control and management of invasive species before species are established and adapt to local conditions. Treatment for invasive species is resource intensive.

Feral and domestic animal species

Several feral and domestic animals have been documented within the NWA. These include feral cats and dogs and unwanted wildlife (wild boar, raccoons, and skunks) that have been released illegally in the NWA. Although the number of feral cats and dogs in the NWA may be low and their presence infrequent, these animals can exert significant predatory pressure on native wildlife through nest destruction and the eating of eggs and individuals (birds and turtles), transfer disease and pathogens to wild animals, and disrupt natural habitats through soil disturbance, all of which require ongoing active management.

3.4 Increase demand for public access and services

Since the NWA was established, the population growth in nearby urban centres and increased public interest in recreation has resulted in a rise in the number of visitors to the NWA and an increased demand for services. This trend is expected to continue particularly as Prince Edward Point NWA is encouraging further visitation through the Connecting Canadians to Nature (CCtN) initiative. Prior to the initiative, the visitation level was not likely to cause direct habitat damage (e.g., through widespread trampling of vegetation), however, the anticipated rise in number of visitors may have the potential to put additional pressure on the site.

There may be an increase in the demand on infrastructure and availability of resources for maintenance of grounds and facilities (e.g. trails, parking lot, access roads, signs, and washrooms), as well as an increase in the need to develop outreach materials to promote responsible and non-detrimental practices and activities. The occurrence of prohibited activities in the Prince Edward Point NWA, such as off-road All-terrain vehicle (ATVs) and vehicle use, garbage dumping, vandalism, and collection of plants and wildlife places additional pressures on resources required to prevent and mitigate these activities and their impacts.

3.5 Legacy issues

A legacy from the purchase of lands for the NWA is the presence of 21 lots and associated leases around the Point Traverse (Long Point) Harbour area which had been leased by the previous landowners to commercial fishers. Environment and Climate Change Canada entered into 10 five-year leases in 1981. The leases were issued for the sole purpose of permitting the land-based activities normally associated with a commercial fishing enterprise, including temporary structures for storage and seasonal accommodation, docks, and water access for the purposes of commercial fishing. These arrangements were initially made so as not to impose undue hardship on the existing leaseholders. Several of the leases have been terminated; while others that were not formally renewed are considered to be in over-holding.

As well as representing a commercial use that would not normally be permitted within an NWA under the Wildlife Area Regulations of the Canada Wildlife Act, this activity requires an ongoing investment of management resources to promote compliance and has ecological ramifications such as the need to maintain roads, lawns, increases the risk of potential fuel spills, etc.. There are also ecological implications for the waters surrounding the NWA as periodic dredging of the harbor mouth (provincial jurisdiction) to allow access (sufficient draft/depth) by commercial fishing boats disrupts the natural succession and filling in of the embayment (harbor). Efforts are required to restore the harbor and associated habitats for the benefit of all Canadians to connect to nature and to balance the needs to multiple user groups.

The NWA lands and surrounding waters were also used as a practice bombing range during World War II and the Korean War, and unexploded munitions may remain in the area; however none have been found on the surface to date by the Department of National Defence (DND). The Prince Edward Point NWA has been designated as low risk based on public access to the site (DND 2013).

3.6 Multi-species conservation and recovery

Multi-species conservation and recovery is an ongoing challenge in the Prince Edward Point NWA which requires active management to maintain ecosystem functions and species diversity and abundance. For example, invasive species management and grassland maintenance are integral to sustaining habitats. Many species have complex habitat requirements that are not well understood, and small and/or widely distributed populations are often under-represented in general research studies, and their site-specific habitat requirements are unknown. A foreseeable challenge will be how to balance the varying habitat needs of multiple species, including both common species and species at risk.