Fathom Five National Marine Park – Conservation Options

Fathom Five is a 114 km2 freshwater, protected area located on Lake Huron at the top of the Saugeen Peninsula. It was established as a provincial park in 1972 to protect sunken shipwrecks. Then in 1987, along with the regional islands of Georgian Bay Islands National Park (e.g., Flowerpot Is.), Fathom Five became the first site to be managed under the stewardship of Parks Canada’s national marine conservation area program.

The 2013 Sources of Knowledge Forum on “Changing Lakes” featured Scott Parker, a climate change ecologist with Parks Canada. Dr. Parker made the case for adopting a “resilience” approach to lake conservation as opposed to a traditional management approach.

Ecological resilience is the ability of an ecosystem to cope with disturbance and retain defining structures, functions and feedbacks. Whereas a traditional management approach may focus on resisting change, maintaining historic conditions or promoting system efficiency (e.g., maximum sustainable yield, single stable state), resilience prepares for disturbance by enhancing adaptive capacity and system diversity.

Today, Lake Huron is arguably a novel ecosystem, a system that no longer resembles its historic state in terms of composition and function. It’s a challenging context for conservation, and management approaches focused solely on maintaining or restoring the abundance of native species may simply be untenable. It is here that resilience creates space for discussing conservation goals based on ecosystem structure and function, and on disturbance and adaptive capacity.

In 2013, Dr. Parker found that much of the current change in the offshore ecosystem was coincident with the invasion of quagga and zebra mussels. This most recent disturbance followed an earlier invasion of sea lamprey and alewife and period of over-fishing which contributed to the near lake-wide extirpation of lake trout and loss of four of the six deepwater cisco species (two are extinct). The subsequent decline of the sea lamprey and alewife created favourable conditions for native lake trout and cisco to recover. However, their recovery was limited because the newly established mussels had played a role in making the lake less productive. Coincidently, one of the primary lake bed crustaceans, Diporeia spp (a tiny shrimp-like organism) a major food item for whitefish and other fishes, was experience a population collapsing. Together, these impacts contributed to a break in traditional transfer of energy and nutrients back into the water column. Thus, after the recovery from the sea lamprey and alewife invasion the lake, although resilient as shown by the return of the native species, did not return to its original state. Further, the subsequent dominance of invasive quagga and zebra mussels has virtually eliminated any prospect of restoring this ecosystem to its historical composition. It appears the offshore ecosystem of Fathom Five transitioned to a resilient although less-desired state.

As to the coastal areas there was, in 2013 a widespread concern with low lake levels, which by 2012 had approached twelve years of sustained low levels as compared with a maximum period of five years during the past century. Non-native species, including round goby, common carp, and Eurasian watermilfoil were present and had the potential to impact some coastal areas. In spite of this, in 2013 Dr. Parker felt that the coastal ecosystem of Fathom Five appeared to be in a resilient and desirable state.

There are a number of impediments to adopting a resilience approach to conservation. The relatively small size of Fathom Five (114 km2) and limited connectedness with other protected areas in Lake Huron makes aspects of resilience, such as protection of representative biodiversity and facilitation of disturbance recovery, more challenging. Secondly, governance of the lake is complex involving a multitude of organizations, stake-holders and rights-holders, such as Parks Canada and other federal department’s the Province, and the Saugeen Ojibway Nation.

In 2013, Dr. Parker felt that it was an opportune time for Fathom Five to consider incorporating resilience within its planning and management processes. Now, six years later, the topic of this years’ SOKF is intended to focus on whether the expectations for Fathom Five have been met and what should be its future. Accordingly, Dr. Parker’s 2013 observations and prescriptions for the lake are relevant. At the Forum on May 3 to 5 of this year, Dr. Parker, together with Cavan Harpur, Parks Canada Ecologist will be offering an update of resilience in their presentation entitled: But Doth Suffer a Sea Change, Into Something Rich and Strange: An Update on the State of the Fathom Five Ecosystem

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