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Algonquin Park Brook Trout Populations Threatened

A summary of a presentation delivered to the Muskoka Field Naturalists (MFN) by Bob and Marj Wilton, in Gravenhurst on February 5th, 2015.   Written by John Challis, editor of “Wakerobin”, MFN newsletter.

As Mike Wilton tried to connect the dots to explain why forest management in Algonquin Park is threatening brook trout, one might confess to losing the thread.

There is a kaleidoscope of different sciences connecting cause and effect. But Mike and his wife Marj have been sleuthing through various disciplines for decades, and the evidence is stacking up. The interdisciplinary nature of their research reflects the fact that Algonquin’s ecology is an intertwining web of dependencies. Soil chemistry and rainfall chemistry, prevailing winds, hydrogeology, geology, logging techniques, road construction, invasive species, dendrology and silviculture, even glaciation: they all play a part—positively or negatively—in the breeding success of brook trout in the park.

Brook trout is a sensitive, coldwater species, he said. The health of trout populations is indicative of the overall health of the park. And he feels the forest management practices that have been evolving in the park since its creation in 1893 are falling short of the goals they aim to achieve. (Forestry has been allowed in the park since it was created, but the original objective was to allow ‘forestry experimentation.’) It’s the motivation behind the work he’s been doing with Algonquin Eco Watch since 1996.

To begin with the fish: brook trout spawn on gravel beds in the uppermost lakes or ponds in the headwaters of nine watershed systems within the park. There are more than 250 self-sustaining (lacustrine) brook trout lakes in the park, making it one of the highest concentrations of brook trout breeding grounds in the world. Isolation of the trout populations makes for potentially unique genetic diversity.

Young trout hatch in the clean gravel and then make their way to other creeks that feed these upper lakes. These wetland and groundwater-fed streams, sometimes little more than 30 cm across and with above-ground flow rates as little as a litre per minute, act as nurseries for the trout fry for their first year, after which they begin to venture out to deeper waters.

Prohibition of  logging operations within these upland water system catchment areas would provide better protection for the trout, but Mike says the current 30 metres isn’t sufficient. It’s more than just the cutting of trees: it’s all the other activities that support the logging.

One such secondary threat is the creation of logging roads. The roads need gravel, in ample supply in the drumlins and eskers left behind by the glaciers. When they are adjacent to headwater lakes, these hills of sand and gravel are critical to spawning beds. Under the hills, a hydroscopic oddity takes place: the ground water swells upward, following the contour of the land, rising above the water table at lake level. This phenomenon generates the underwater springs that feed the headwater lake, flushing cold water over beds of gravel that are the chosen egg-laying grounds of brook trout.

Any time gravel is removed from a hill for road surfacing, it changes the groundwater flow underneath, compromising the flow of springs that might be supporting spawning beds. There is little science being done to determine the critical limits beyond which the springs stop, destroying the spawning bed.

Logging also affects the little feeder streams where young trout fry spend their first year. Skidders and other machinery activities, even when they’re well back from the streams, compact the ground around them, changing groundwater flow patterns. The muck stirred up by the machinery creates sedimentation that can clog up the little streams. Diesel fuel, oil, hydraulic fluids, and coolants all leak or are spilled around staging areas. Given the slow rates of flow at the headwaters, it could take a thousand years for those chemicals to flush out of the system.

Algonquin Eco Watch is also studying calcium load in the forests. It too has an impact on the brook trout. In the granitic soils of the Algonquin Dome where these watersheds begin, calcium is in low supply to begin with. Acid rain, which originated in part from Sudbury’s mining operations but also from the steel and coal industries in the middle U.S., leached calcium out of the ground and in spite of measures that have been in place since the late 1980s, rain may still be acidic enough to cause problems.

Recent research from Trent and York Universities shows, for example, that as much as 6 percent of the calcium in trees is stored in the bark. If logging practices take away the bark, that calcium is removed from the growth cycle. Mike said there is evidence that vegetation might be approaching a zero growth rate in the west end of the park, due to calcium deficiencies. Daphnia are already disappearing from the lakes because the water doesn’t have enough calcium for them to develop exoskeletons. They’re being replaced by a gelatinous invasive plankton, Holopedium, that’s unpalatable to fish.

Mike feels we’ve passed the point of natural recovery. “We have to stop taking calcium out of the system and start putting it back,” he said.

Logging can continue in the park, Mike declares, but there have to be new measures in place to protect sensitive habitat such as those in the headwaters of the Algonquin Dome.

Algonquin Eco Watch’s efforts to create change in forestry practice haven’t had much impact. Billboards in the park declaring “Logging is Unsustainable” drew a lot of attention, but more ire than positive response. Letter campaigns have created limp responses from govermnent. The Algonquin Forestry Authority’s 2010 forest management plan may decrease sustainability.

But there are glimmers of hope. Ontario’s Environmental Commissioner recently recommended a stop to logging in Algonquin.

Now living on Manitoulin Island, Mike and Marj will be stepping away from Algonquin Eco-Watch at the end of this year; after nearly 20 years, it’s time for a rest he says. As Mike and his wife begin winding down their activities with the organization, he is uncertain about its future. Since 1996, when then-premier Mike Harris “allowed me to retire” from the MNR, he has been leading its efforts to create more protection for the park. The fruit of his labours has not yet manifested itself—but in spite of the frustration, a note of optimism remains.

“Maybe in another 20 to 25 years, we can talk about the results,” he said.

Recommended Conditions to Meet True Sustainability:

1- Until such time that no-cut reserves totally encircle the entire groundwater sub-catchment basin of all headwater lakes and streams, logging in Algonquin Park cannot be considered to be truly sustainable. The present 30m set-back, an imposed “one-size-fits-all” restriction is simply not biologically adequate.

2- Until such time that a sufficient number of mutually agreed-upon permanent upland old growth stands* is established, logging in Algonquin Park cannot be considered to be truly sustainable.

*Algonquin Eco Watch considers the following definition of permanent old growth stands to be satisfactorily applicable in Algonquin Park:

“An old-growth forest is a forest that has attained great age without significant disturbance and thereby exhibits unique ecological features and might be classified as a climax community. Old-growth features include diverse tree-related structures that provide diverse wildlife habitat that increases the biodiversity of the forested ecosystem. The concept of diverse tree structure includes multi-layered canopies and canopy gaps, greatly varying tree heights and diameters, together with diverse tree, shrub and herbaceous species and classes and sizes of woody debris.

Old-growth forests are natural forests that have developed over a long period of time, generally at least 120 years without experiencing severe, stand-replacing disturbance, such as fire, windstorm, or logging. Old-growth forests may be dominated by species such as eastern hemlock, sugar maple, white spruce, or white cedar that are capable of reproducing under a shaded canopy. These old-growth forests can persist indefinitely. Old-growth forest may also be dominated by species such as red pine, white pine, or red oak that do not reproduce as well under shade and that require disturbance to open the canopy. These old-growth forests will eventually be replaced by the more shade-tolerant tree species in the absence of disturbance.

Timber harvesting in old growth stands removes future down woody debris and critical nutrients such as calcium, especially in poorly buffered granitic soils such as those in Algonquin Park.  In addition, the movement of heavy equipment in these stands causes soil compaction, which negatively affects groundwater flow patterns and the natural regeneration of shrub and herbaceous species.”


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