Ooze Lake
On Wednesday June 06, I (Bob) visited Ooze Lake in Eastern Algonquin Park. I started at the Brigham Lake parking lot and traveled by canoe down the Barron River to Brigham Lake and then portaged to Opalescent Lake and then again to Ooze Lake. I returned via High Falls Lake and descended the Barron River through The Cascades back to the parking lot. My goal was to search for orchids. I have had good recent success in finding Arethusa bulbosa outside of Algonquin Park and since they are rare within the Park, I thought it would be fun to find one. Ooze Lake struck me as a good candidate location. I was wrong; none were found.
2007 June 06
Ooze Lake is a small lake that lies on the canoe route from Achray to the Barron Canyon, between High Falls Lake and Opalescent Lake. While these neighbouring lakes are noted for their beauty, Ooze Lake is usually dismissed as an undistinguished muck hole, best to be passed through and forgotten as quickly as possible. Such a view is very short sighted. The other two lakes are more photogenic but in other ways, less interesting.

(photo by Bob: 2007-06-06 - explore)
When I arrived at Ooze lake, I noted a dark shape at the far end of the lake; my binoculars revealed it to be a moose. I decided to check out the moose and look for orchids later. The moose was feeding in the small creek that drains Ooze Lake into High Falls Lake. I paddled slowly and quietly towards it.
I broke off my approach at this point; the moose was getting nervous and I didn't want to upset it unnecessarily. I turned the canoe around and retreated up the shore a little way. The moose left the creek and started heading deliberately towards me. I was now the stalked rather than the stalker. I retreated off shore.

(photo by Bob: 2007-06-06 - explore)
It was only then that I realized that the moose was accompanied by a calf. The calf would have been only a few weeks old (calving occurs in early to mid May). They walked along the shoreline and, while keeping an eye on me, did not seem overly concerned about my presence. Off shore I was not a threat. Nobody panicked. I returned to the top of the lake to start my orchid search and they faded into the bush
I am currently trying to educate myself as to the character of wetlands of the local area. My motivation is to help me recognize the various habitats that I encounter and thus facilitate intelligent guesses as to what interesting plants might be present. Secondly — but just as importantly — the study of these environments is interesting in its own right. While I have consulted many references, the most influential of these has been A Focus on Peatlands and Peat Mosses by Howard Crum, published by The University of Michigan Press.
As I no longer have the mental energy of a young graduate student, I am shucking it to some extent; this is meant to be a hobby, not a late-life research career. I operate without instruments; I am not going to get into field measurements of water pH and mineral concentrations. I have not (yet?) invested the considerable effort required to learn to identify the various sedges and sphagnum mosses that are the best indicator-species for these environments. However, I believe that a thoughtful observation of the environment and contained plant communities can lead to a useful classification of a swamp / marsh / rich fen / poor fen / bog / etc.
The following is my interpretation of Ooze Lake.

The mouth of the creek that drains Opalescent Lake into Ooze Lake. (This is the creek that the portage crosses.) This area is very marsh like.
Opalescent Lake is interesting in that it has two drainages: this one into Ooze Lake and then to High Falls Lake, and another via Mulock Creek into Cork Lake and thence to the Barron River below the canyon. Opalescent Lake is about 2m higher than Ooze lake and 8m higher than Cork Lake. The Cork Lake drainage is controlled by a beaver dam. An interesting speculation is how the history of that beaver dam has affected the history of Ooze Lake.
In general, Ooze Lake is marshy rather than boggy. That is, it is characterized by emergent vegetation and in particular, cattails and water lilies. This indicates a nutrient and mineral rich environment and moving water. The high number of cedar trees in the general area, suggests that the water has a meaningful calcium content. As a consequence, it would be at least somewhat buffered and resistant to acidification.

The southern shoreline of Ooze Lake is characterized by a lake-mat fen.
Along the south-eastern shore of Ooze Lake is a lake-mat fen. I am unclear as to the mechanism of the formation of this grounded mat. I saw no evidence of an excessive buildup of Sphagnum and consequently, no evidence of its irreversible evolution towards becoming a bog. Indeed, it would seem to me that the flow through the lake of minerotrophic water from Opalescent Lake would preclude Ooze Lake from evolving into a bog. Instead I would expect it to trend to the fen / marsh side of the equation.

The lake-mat fen on the south-eastern shore of Ooze Lake. Significant species include leather-leaf (Chamaedaphne calyculata), cattails (Typha) and scattered small tamaracks (Larix). Sphagnum is present but not markedly. Also present are are laurel (Kalmia), bog rosemary (Andromeda glaucophylla), sweet gale (Myrica gale), cranberries (Vaccinium) and sedge (Carex). The lower photo also includes a pitcher plant (Sarracenia purpurea) almost dead center.

Pitcher plant (Sarracenia purpurea) flower. (Photographed on a previous trip to Ooze Lake on 2004 June 25.)

Pitcher plant (Sarracenia purpurea) base. This carnivorous plant digests insects that get trapped in these cups. (Photographed on a previous trip to Ooze Lake on 2004 June 25.)

A turtle sunning itself (but perhaps egg laying) on the edge of the lake-mat. I believe it was a snapping turtle (largely from its size). I did not disturb it.

A mat of Sphagnum. I have not tried to identify the species. It is my assessment, that while Sphagnum was present, it was only one of many components of the environment. (In a bog, by contrast, Sphagnum defines the environment.)

A patch of sundews growing on the exposed false bottom (rhizome mat).

Spatulate-leaved sundew (Drosera intermedia), a carnivorous plant of northern bogs and fens.

By late summer, the lake is choked with water lilies and floating mats of their muck-encased rhizomes (That's why the late season canoe trippers love this lake so much.) Given enough time, it is to be expected that these floating mats will eventually stabilize and be permanently colonized; the open water will largely disappear. Perhaps these rhizome mats are the origin of the lake-mat fen on the south-eastern shore of the lake. (The first of these two pictures was taken on 2002 September 18 while the second was taken on 2003 September 09.)
I would appreciate some insight as to how these floating rhizome mats are colonized. My (perhaps limited) observations are that these sorts of mats are underwater in the spring and only emerge later in the year. But it also appears to me that the emergence is due to a buoyancy change rather than a water level change. I assume that the mat must be out of the water all year round to be effectively colonized. My two questions are thus: How does stabilization occur and in the seasonal-emergence case, what causes the buoyancy change?
I don't fully understand the dynamics of the Ooze Lake environment. However, it seems likely that the floating fen mat is a richer environment than where I have found Arethusa bulbosa elsewhere. Therefore, its nonoccurence here is not so surprising.
I think that Ooze Lake is a very interesting lake — much more interesting than the neighbouring "pretty" lakes. Dismissing this lake as a muck hole to be avoided is missing out on many interesting aspects of the ecology of Eastern Algonquin Park. This lake needs a better PR agent!
Notes
(Note that some parts of this bushlog entry are more speculative than I am comfortable with. Any feedback on this material would be appreciated.)
Sources
Brenda Chambers, Karen Legasy, and Cathy V. Bentley (1996), Forest Plants of Central Ontario, Lone Pine Publishing and Queeen's Printer for Ontario.
Howard Crum (1988), A Focus on Peatlands and Peat Mosses, University of Michigan Press.
Timothy Dickinson, Deborah Metscer, Jenny Bull, and Richard Dickinson (2004), The ROM Field Guide to Wildflowers of Ontario, The Royal Ontario Museum and McClelland and Stewart.
John Eastman (1995), The Book of Swamp and Bog, Stackpole Books.
Steven G. Newmaster, Allan G. Harris, and Linda J.Kershaw (1997), Wetland Plants of Ontario, Lone Pine Publishing and Queeen's Printer for Ontario.
Joyce M. Reddoch and Allan H. Reddoch (1997), The Orchids in the Ottawa District: Floristics, Phytogeography, Population Studies and Historical Review, in The Canadian Field-Naturalist, vol. 111 no. 1, The Ottawa Field-Naturalist Club.