Scotch Bonnet Island and Mohawk Island National Wildlife Areas Management Plan: chapter 3

3 Management challenges and threats

3.1 Lakewide threats to colonial waterbirds and their habitat

There are many challenges and threats that have significant impacts on colonial waterbirds throughout the southern Great Lakes. Colonial waterbirds are fish-eating species and are dependent on the aquatic resources of the Great Lakes. Recent key threats to the health of the Great Lakes that have affected colonial waterbird nesting areas include botulism, diseases, management activities (primarily on the U.S. side of the Great Lakes but occasionally on the Canadian side), non-native invasive aquatic (fish) species, extreme weather and human disturbance from recreational activities. More traditional threats include non-point source pollution, toxics and incompatible development.

3.2 Unauthorized access and tourism

The waters surrounding both of these islands are a popular destination for sailing and power boating in the summer months. Since these protected areas were established, population growth in nearby urban centres and increased recreation and tourism have resulted in an increase in visitors to the National Wildlife Areas (NWA)s. Noise and wave action from boats, as well as the presence of humans, are known to cause nesting colonial waterbirds to flush off their nest, or in some cases abandon nests, eggs and young, leaving nests vulnerable to predation (Carney and Sydeman, 1999; Cuthbert and Wires, 1999). Prolonged visits to the islands, or boating close to the shore during the breeding season, may also disturb nesting, roosting and loafing birds (Carney and Sydeman, 1999).

Although entry to Scotch Bonnet Island NWA is prohibited and access to Mohawk Island NWA is seasonally prohibited, there has been evidence at both sites of public access and disturbance to birds during the nesting period (Moore, personal communication, 2012). Destruction of Double-crested Cormorant nests, garbage dumping, open fires, vandalism and damage to signs have also been reported, causing disturbance to nesting birds and additional pressures on staff resources.

Local tourism promotional materials reflect a general lack of understanding about the Canada Wildlife Act, Wildlife Area Regulations, and prohibited access and activities. For example, visits to Scotch Bonnet Island NWA and opportunities to view colonial nesting birds are among listed attractions in local promotional material. Public visitors are believed to be from both Canada and nearby U.S. states, making it difficult to deliver safety and compliance messaging to various audiences.

3.3 Physical setting

The physical setting of these islands presents management challenges. The exposed bedrock and jagged shoreline make authorized access difficult. Visits to the islands for site inspections and research and surveying are often hindered by strong winds and inclement weather. Because there is no full-time staff on site, compliance promotion, prevention of prohibited activities and enforcement of regulations can be difficult.

3.4 Health and safety

Maintaining safe access for authorized visitors, and securing the required resources and expertise to meet federal standards for built structures, has been an ongoing challenge. It is further exacerbated by the remoteness of both sites.

The deteriorating Victorian-era stone lighthouses also pose health and safety risks. In 2009, staff reported that large portions of the lighthouse at Scotch Bonnet Island NWA were eroded. The remaining structure and stone rubble pile are extremely hazardous and pose an immediate threat to authorized visitors to the island. It is no longer feasible to preserve or restore this structure in its entirety. In 2010, Canadian Wildlife Service biologists reported that portions of the Mohawk Island lighthouse had eroded and formerly blocked windows and entry points are no longer blocked, posing a potential safety hazard to any visitors who attempt to enter the structure. The feasibility of preserving this structure is not known. Entry to the stone lighthouse structures at both Scotch Bonnet Island NWA and Mohawk Island NWA is prohibited.

The Canadian Wildlife Service will work with its partners and the public to develop options to improve safety for authorized visitors to these islands, while considering the heritage values associated with these lighthouses.

3.5 Increased development

In recent years, there has been significant human population growth and associated development along the shore of the lower Great Lakes. As the population continues to expand, it is expected that development pressures on islands and the mainland, and use of the nearshore and recreational boating, will also increase. Development activities along the Great Lakes shoreline north of these protected areas could have adverse effects on the habitats and wildlife of the NWAs. For example, additional recreational facilities could lead to increased boat traffic, and the potential for construction of wind turbines could impact migrating and possibly foraging birds.

Increased shipping also raises the risks of oil or chemical spills that could cause the contamination of water.

3.6 Predicted climate change scenarios

Current models predict that climate change will lead to warmer air temperatures, lower lake levels and warmer water temperatures due to a decrease in winter ice cover and subsequent increased evaporation. Although the impacts of climate change on colonial waterbirds are unknown, it is expected that there will be shifts in the range, distribution and breeding behaviour of the various species that frequent these NWAs.

Table 3: Management approaches for Scotch Bonnet Island and Mohawk Island National Wildlife Areas
Management challenges and threats Goals and objectives Management approachesa (action including level of priority)b
  • Lakewide threats to colonial waterbird populations in the Great Lakes
  • Remote location and physical setting

Goal 1: Conserve and manage wildlife and habitat. 1.1 Sub-goal:Maintain habitat for colonial nesting waterbirds and a variety of migratory bird species. Objectives:

  1. Natural processes and natural succession are allowed to occur with minimal intervention, subject to monitoring, survey or research results (section 5.1).
  2. Habitat will only be managed (e.g. invasive species removal) to maintain existing habitat quantity and quality for colonial nesting waterbirds and/or seasonal migrants, as deemed necessary by monitoring, survey or research results.

Monitoring, survey and research

  • Conduct decadal Great Lakes Colonial Waterbird and lower decadal Great Lakes Migrant Waterfowl surveys. (3)
  • Continue surveillance of toxic substances and reproductive success in colonial waterbird populations. (2)
  • Conduct site visits to survey ecological integrity, assess management actions and public activities, and identify potential threats to habitat and wildlife. (1)
  • Survey the current extent and habitat conditions of the colonial waterbirds’ nesting, roosting and loafing areas. (1)
  • Survey changes in habitat over time. (2)
  • Survey seasonal habitat use (including nearshore waters and built structures) by waterbirds, waterfowl, shorebirds and landbirds. (2)

Wildlife management

  • As required, depending upon results of monitoring, survey and research.
  • Unless demonstrated otherwise, natural processes will be allowed to continue.

Habitat management

  • As required, depending upon results of monitoring, survey and research.
  • Unless demonstrated otherwise, natural processes will be allowed to continue.

Management of invasive and non-native plants

  • As required, depending upon results of monitoring, survey and research.
  • Unauthorized access during nesting
  • Boating in nearshore disturbing waterfowl and migratory birds
  • Remote location and physical setting
  • Lack of understanding and awareness about prohibited activities and the protection afforded wildlife on NWAs
  • Health and safety risks

Goal 2: Control prohibited activities 2.1 Sub-goal: Prevent occurrence of prohibited activities and promote compliance with the Canada Wildlife Act and Migratory Birds Convention Act, 1994, and encourage timely reporting of hazardous conditions and occurrences. Objectives:

  1. Authorized visitors understand the prohibitions of the Wildlife Area Regulations.


  • Undertake site visits to inspect and maintain signs, survey shoreline and island for hazards, and document changes to the site or infractions. (1)
  • Review the status of existing collaborative arrangements and permits, revise and renew as appropriate. (2)

Risk assessment and mitigation

  • Replace/install signs to include prohibited uses and contact information to report incidents or hazardous conditions. (1)
  • Document and report the number and nature of incidents where evidence exists of illegal activities within the NWA to Environment and Climate Change Canada’s Wildlife Enforcement Directorate, and take remedial action where appropriate. (1)

Public information and outreach

  • Provide information on prohibited uses, management actions, safe practices and reporting procedures to authorized visitors (e.g. other federal departments, research permit holders), the public and stakeholders. (1)
  • Communicate with local tourism operators and the Ontario Ministry of Tourism regarding the protected status of these areas and possible cumulative environmental impacts of unauthorized visitors on nesting and migratory birds. (1)
  • Remote location and physical setting: rocky shoreline makes access difficult, often impeded by weather
  • Health and safety risks

Goal 3: Promote health and safety 3.1 Sub-goal: Reduce and mitigate health and safety risks and hazards associated with authorized visits. Objectives:

  1. Risks have been assessed and measures implemented to ensure the safety of authorized visitors, including measures to deal with landing and mooring locations and risks associated with existing built structures (e.g. concrete breakwall at Scotch Bonnet Island NWA, stone lighthouse ruins).
  2. In accordance with the Heritage Lighthouse Protection Act, lighthouse structures are allowed to decay by natural processes, with active intervention undertaken for health and safety reasons only.

3.2 Sub-goal: Communicate health and safety risks to authorized visitors. Objectives:

  1. Target audiences and collaborators are aware of health and safety risks to authorized visitors (e.g. through signage, notices and outreach materials).
  2. The status of existing collaborative arrangements and permits has been reviewed and renewed as appropriate.

Risk assessment and mitigation

  • Meet with Fisheries and Ocean Canada and Parks Canada Agency, as owners and custodians of built structures, to assess the health and safety risks related to existing built structures (e.g. steel navigation tower, concrete breakwall, stone lighthouse ruins) and develop and implement plans to address immediate health and safety risks to authorized visitors. (1)
  • Renew collaborative arrangements with other federal departments (e.g. Fisheries and Oceans Canada) and implement guidelines for access in order to avoid and reduce disturbance to colonial nesting birds. (1)

Public information and outreach

  • Communicate safe practices for authorized visitors, including the general public (i.e. for Mohawk Island NWA). (1)


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