Legacy in a sweetwater sea

 Fathom Five National Marine Park, Canada

Limestone Rock Pillar of Flower Pot Island, Fathom Five Marine National Park, Canada

Description and reasons for creation of marine conservation area

National marine conservation areas divide the country’s oceans and Great Lakes into 29 regions, each one combining distinct physical and biological characteristics. Parks Canada provides for the creation of marine conservation areas to represent all these ecosystems and manages them for visitors to understand, appreciate and enjoy in a sustainable manner.

View images of the park

An agreement to establish Fathom Five National Marine Park was signed in 1987, at the same time as the adjacent Bruce Peninsula National Park. Although yet to be brought under federal legislation, it has the pride of place as being the first marine protected area under the stewardship of Park Canada. Bruce Peninsula and Fathom Five form a unique tree top to lakebed protected area network.

Fathom Five National Marine Park protects a representative example of two natural regions. The terrestrial component represents the St. Lawrence Lowlands Natural Region, while the marine component represents the Georgian Bay Marine Region.

The Georgian Bay Marine Region is part of the Laurentian Great Lakes, the largest area of surface freshwater in the world. The region is characterized by its westerly sloping basin. To the east is the area characterized by its islands, the highest number in the Great Lakes, and to the west by the cliffs of the Niagara Escarpment plunging as deep as 160 m into the Bay. Shoals and reefs form a complex bottom relief. The strong currents located in the main channel, along with the frequent storms that occur in the area, have been the cause of several shipwrecks. The waters of Georgian Bay are among the clearest in the Great Lakes and visibility easily reaches 25-30 m. This visibility contributes to the community of Tobermory’s self-proclamation as the “dive capital of Canada”.

The park itself preserves a rich cultural legacy that includes 27 shipwrecks and several historic lightstations. Fathom Five’s freshwater ecosystem contains some of the most pristine waters of the Great Lakes. The rugged islands of the park are a reminder of the impressive lakebed topography found beneath the waves.

The protected waters of island bays form habitat for fishes such as Smallmouth Bass (Micropterus dolomieu), Bluntnose Minnow (Pimephales notatus) and Yellow Perch (Perca flavescens). The deep cold waters are habitat for fishes such as Lake Whitefish (Coreogonus clupeaformis), Bloater (Coreogonus hoyi) and Lake Trout (Salvelinus namaycush). At one time, Fathom Five was home to six species of deepwater ciscoes, of which only two now remain.

The islands and peninsula are widely known for their rich diversity of plants, including Great Lake endemics and over 40 species of orchids. Flowerpot Island in Fathom Five is an excellent place to view the delicate calypso orchid (Calypso bulbosa), during the blooming season of mid-May to early June. Island biogeography studies have shown the effect of island area and colonization potential on species diversity. Each island has a unique assemblage of mammals, birds, reptiles, amphibians, plants and insects.

In 1990, the park was designated by UNESCO as a core protected area within the Niagara Escarpment World Biosphere Reserve.

Year established 1987

Area: 112 km2

Fathom Five National Marine Park is an archipelago located in the south-western portion of the Canadian province of Ontario, off the Bruce Peninsula in Lake Huron. It is approximately 300 km northwest of the city of Toronto.

Habitat type: Deep waters reefs and shoals with forested islands  

Park management
Fathom Five National Park is managed by Parks Canada, the Canadian federal government agency responsible for protecting and presenting nationally significant examples of Canada’s natural and cultural heritage and fostering public understanding, appreciation and enjoyment in ways that ensure the ecological and commemorative integrity of these places for present and future generations. Founded in 1911, Parks Canada is the world’s first national parks service and is a global leader in conservation.

Threats, management challenges and measures taken in response
Fathom Five National Marine Park contains at least 40 non-native species. Some species, such as Sea Lamprey (Petromyzon marinus) and Alewife (Alosa pseudoharengus), have significantly altered the ecosystem. Sea Lamprey and Alewife, in association with over-fishing, essentially caused the collapse of Lake Trout populations (Salvelinus namaycush) by 1950 and Deepwater Ciscoes (Coregonus johannae) populations within the park by the 1990’s. In the late 1990’s, quagga mussels (Dreissena rostriformis bugensis) and round goby (Neogobius melanostomus) have invaded, further destabilizing this vulnerable ecosystem. The invasion of these species has had a large impact on the ecosystem itself, transforming the lake from a pelagic-dominated state to a benthic state due to a shunt in nutrient and energy distribution to the lakebed by the mussels.

Building resilience within park ecosystems to invasive species and climate change is a key priority for Fathom Five. Monitoring and identification of new invasive species is also a priority of Parks Canada.

Currently, Parks Canada is not directly involved in fisheries management. Since the ecosystem is in great flux and sustainability is uncertain, Fathom Five will need to engage with partners to manage these resources.

Species at risk
The Eastern Massasauga Rattlesnake (Sistrurus catenatus) is a species at risk that occurs on one island and the mainland of Fathom Five. Habitat destruction, intentional killings by humans and fragmentation are contributing factors to the decreasing numbers of the Massasauga.

Other species include six fish, one butterfly, two birds, two reptiles and one plant.

Visitor experience
Parks Canada is committed to make every national marine conservation area a treasured place and a living legacy for all Canadians, connecting hearts and minds to a stronger, deeper understanding of the very essence of Canada. Visitors can experience the wonders of Fathom Five National Marine Park through a variety of activities.

Some of the best freshwater diving opportunities in the world are in Fathom Five. Glass bottom tour boats provide those who may not wish to get wet a chance to see shipwrecks as well. Tourboats also chart their way to Flowerpot Island where there is great hiking and a chance to see one of Canada’s most recognized “Flowerpot” rock formations. The Parks Canada Visitor Centre is also a must see, with its theatre and exhibits designed to connect visitors to the depths of Fathom Five.

Prepared by Benjamin Ojoleck October 29, 2010

Work area: 
Protected Areas
North America
Go to top