A comparison between diatom inferred ph changes and diatom populations in brownwater and clearwater lakes

The objective of this study was to determine whether clearwater and brownwater lakes differed in their rate of acidification as inferred by subfossil diatoms analyzed in recent downcore sediments. Differences between associations of diatom populations in brownwater and clearwater environments were characterized. Sediment cores were taken from four lakes located north and east of Lake Superior, near Wawa, Ontario. Two of these lakes were humicrich, brownwater lakes ( lakes U1 and CB2). The two other lakes were clearwater lakes ( lakes Xl and CF). The regression of Nygaard log index-alpha for surficial diatom sediments on observed pH ( Inferred pH = 6.57 - 0.82 log index-alpha ), was utilized to infer lake pH in recent sediments of these lakes. Upon analyzing the downcore diatoms, it was discovered that no significant change, in downcore diatom inferred pH, could be detected in the two brownwater lakes. In contrast, the two clearwater lakes showed significant shifts in downcore diatom inferred pH. In one of these lakes, pH had dropped from 5.3 to 4.5, in the top 9.0 cm of the core, while in the second lake, pH had dropped from 5.4 to 5.0 in the top 1.5 cm of the core. These findings suggested that humic substances, found in brownwater lakes, imparted a buffering capacity to these lake waters. In the clearwater lakes, the decrease in pH was very probably a consequence of acid precipitation. The Ambrosia rise ( circa 1890 ) occurred at the same depth in both brownwater lakes ( 11.0 - 12.0 cm). In both clearwater lakes, the Ambrosia rise occurred at a depth of 14.0 - 15.0 cm. This suggested a lower sedimentation rate in the brownwater lakes. pH influenced the total percentage composition of diatom pH indicator groups. Greater numbers of alkaliphilous taxa were found in less acidic lakes ( e.g. Lake Ul ), While greater numbers of acidloving forms were found in highly acidic lakes ( e.g. Lake Xl ). There was a greater abundance of indifferent forms in the brownwater lakes, than in the clearwater lakes. A number of diatom genera and species were found to be associated with either clearwater or brownwater conditions. The centric diatom, ~elosira distans, significantly increased in abundance in the recent sediments of both clearwater lakes. This may be indicating a shift toward a more oligotrophic state within these acidic, clearwater lakes. This study suggested that a pH index based on subfossil diatoms may be a sensitive indicator of changing lake pH. This study also indicated that humic substances may playa more important role, than previously acknowledged, in controlling the pH dynamics of lake waters, and in determining diatom populations.

Richelieu & Ontario Navigation Company Official Guide 1901

Descriptive of that delightful trip down the River St. Lawrence and up the world-famed Saguenay. The finest inland water trip in the world.

Chemical composition of the soluble fraction of oxidate portions of Lakes Shebadnowan ferromanganese concretions

Shebandowan Lakes, Ontario, are the site of at least 49 shallow (2-12 m) ferromanganese concretion deposits, widely distributed throughout the 48 km of the watercourse. X-ray diffraction and Mossbauer methods have revealed the presence of goethite in some of the concretions. Chemical analyses of the acid soluble portions of 72 samples gave an average composition of 43.1% Fe and 5.65% Mn with a low content of trace elements. The Shebandowan concretions are among the richest in iron of lake concretions reported, possibly because only the acid soluble portion was analysed. Their low content of trace elements suggests rapid growth rates and a relatively young age. A positive correlation was found between Mn and K, Ca, Mg, Cu, Ni, and Co and the relationship between the last three and Mn was deemed significant. Zn was independent of association with either Mn and Fe, probably due to the presence locally of zinc sulphide deposits. Analyses of lake bottom and influent waters suggested that frequent resampling of the sites would be required throughout the year to permit meaningful interpretation of the effect of water composition of concretions. Analyses of sediment cores from 20 concretion sites indicated an upward increase in Fe and Mn and in the Mn/Fe ratio, consistent with the model of upward migration of the elements, where Mn is more mobile than Fe. This study concludes that a considerable proportion of the elements have been supplied to the Shebandowan concretions via the diagenetic process; generally a minor fraction of the elements has been abstracted directly from the superjacent water.

Diatoms as indicators of lake trophic status

Relationships between surface sediment diatom assemblages and lake trophic status were studied in 50 Canadian Precambrian Shield lakes in the Muskoka-Haliburton and southern Ontario regions. The purpose of this study was to develop mathematical regression models to infer lake trophic status from diatom assemblage data. To achieve this goal, however, additional investigations dealing with the evaluation of lake trophic status and the autecological features of key diatom species were carried out. Because a unifying index and classification for lake trophic status was not available, a new multiple index was developed in this study, by the computation of the physical, chemical and biological data from 85 south Ontario lakes. By using the new trophic parameter, the lake trophic level (TL) was determined: TL = 1.37 In[1 +(TP x Chl-a / SD)], where, TP=total phosphorus, Chl-a=chlorophyll-a and SD=Secchi depth. The boundaries between 7 lake trophic categories (Ultra-oligotrophic lakes: 0-0.24; Oligotrophic lakes: 0.241-1.8; Oligomesotrophic lakes: 1.813.0; Mesotrophic lakes: 3.01-4.20; Mesoeutrophic lakes: 4.21-5.4; Eutrophic lakes: 5.41-10 and Hyper-eutrophic lakes: above 10) were established. The new trophic parameter was more convenient for management of water quality, communication to the public and comparison with other lake trophic status indices than many of the previously published indices because the TL index attempts to Increase understanding of the characteristics of lakes and their comprehensive trophic states. It is more reasonable and clear for a unifying determination of true trophic states of lakes. Diatom specIes autecology analysis was central to this thesis. However, the autecological relationship of diatom species and lake trophic status had not previously been well documented. Based on the investigation of the diatom composition and variety of species abundance in 30 study lakes, the distribution optima of diatom species were determined. These determinations were based on a quantitative method called "weighted average" (Charles 1985). On this basis, the diatom species were classified into five trophic categories (oligotrophic, oligomesotrophic, mesotrophic, mesoeutrophic and eutrophic species groups). The resulting diatom trophic status autecological features were used in the regressIon analysis between diatom assemblages and lake trophic status. When the TL trophic level values of the 30 lakes were regressed against their fi ve corresponding diatom trophic groups, the two mathematical equations for expressing the assumed linear relationship between the diatom assemblages composition were determined by (1) uSIng a single regression technique: Trophic level of lake (TL) = 2.643 - 7.575 log (Index D) (r = 0.88 r2 = 0.77 P = 0.0001; n = 30) Where, Index D = (0% + OM% + M%)/(E% + ME% + M%); 4 (2) uSIng a' multiple regressIon technique: TL=4.285-0.076 0%- 0.055 OM% - 0.026 M% + 0.033 ME% + 0.065 E% (r=0.89, r2=0.792, P=O.OOOl, n=30) There was a significant correlation between measured and diatom inferred trophic levels both by single and multiple regressIon methods (P < 0.0001, n=20), when both models were applied to another 20 test lakes. Their correlation coefficients (r2 ) were also statistically significant (r2 >0.68, n=20). As such, the two transfer function models between diatoms and lake trophic status were validated. The two models obtained as noted above were developed using one group of lakes and then tested using an entirely different group of lakes. This study indicated that diatom assemblages are sensitive to lake trophic status. As indicators of lake trophic status, diatoms are especially useful in situations where no local trophic information is available and in studies of the paleotrophic history of lakes. Diatom autecological information was used to develop a theory assessing water quality and lake trophic status.

The utility of sedimentary diatoms as a measure of historical lake ph

As a result of increased acid precipitation, the pH of a large number of Canadian Shield lakes has been falling. Prior to this study there was no documentation available to explain the history of lake acidification for the Algoma area lakes. In order to obtain this information the diatom inferred pH technique was developed in this study. During two field seasons, July 1981 and July 1982, short sediment cores (circa 25-30 cm) were collected from 28 study lakes located north of Lake Superior, District Algoma, Ontario. The surface sediment diatoms (0-1 cm) from each of these lakes were carefully identified, enumerated, and classified in terms of their pH indicator status. The surface sediment diatom analysis indicated that lake pH is one of the most important factors affecting the species composition and relative abundance of diatom populations. Thus diatom assemblages can be sensitive indicators of lake acidification. When Nygaard's index alpha was plotted against observed lake pH, a statistically significant relationship resulted (r=-0.89; p=

Niagara to the Sea (1911)

Includes schedules and rates.

A comparative study of the change in diatom inferred ph of a staircase of lakes in the Algoma District, Northern Ontario /

Four staircase lakes occupying a single watershed located in the Algoma District, north of Lake Superior were chosen for this study. I examined the subfossil diatom assemblage in the top twenty centimeters of the surface sediments in each of these four lakes in an attempt to reconstruct their respective past pH history. From these analyses it was possible to test the hypothesis that the rate of change of diatom inferred pH was not significantly different in lakes located one below the other in a single "staircase" within a single watershed system. My results indicated that the four Z lakes had been acid for at least the last century. The water color of the three upper Z lakes (Z1, Z2 and Z3) was brown (>30 Pt Co units). The bottom lake (Z4) was the only clear water lake in the system «5 Pt Co units). This bottom staircase lake had no muskeg development around its shoreline. The alkaliphilous diatoms in the Z watershed system were important in determining the diatom inferred pH of the four Z lakes. The centric diatoms were extremely rare in the clearwater bottom lake (Z4). The ecology of the Eupodiscales is perhaps important in the interpretation of sediment in the more acid environment. Lake Z4 was the only one that had a progressive as well as a significant decrease in its downcore diatom inferred pH since the early 1960's. This lead me to speculate that the humic substances present in the upper three brown water lakes (Z1, Z2 and Z3) were perhaps Important in buffering them against a further decrease in water pH even though they were located within an area which was sensitive to acid precipitation.

Palynology of late-glacial and postglacial sediments in Georgian Bay, Ontario, Canada, as related to the Great Lakes history /

This investigation comprises three parts: (1) the source, mechanism of transport, and distribution of pollen, spores and other palynomorphs in Georgian Bay bottom sediments and a comparison of these data with the contemporary vegetation, (2) the relative significance of fluvial transportation of pollen and spores, and (3) the late- and postglacial history of vegetational and climatic changes in the Georgicin Bay region. Modem pollen and spore assemblages in Georgian Bay do reflect the surrovinding vegetation when preservation and pollen production by the different species are considered and accounted for. Relative pollen percentage and concentration isopoll patterns indicate that rivers contribute large quantities of pollen and spores to Georgian Bay. This is further substantiated by large amounts of pollen and spores which were caught in traps in the Moon, Muskoka, and Nottawasaga Rivers which flow into Georgian Bay. The majority of pollen and spores caught in these traps were washed into the rivers by surface water runoff and so reflect the vegetation of the watershed in a regional sense. In a 12.9 metre long sediment core from northeastern Georgian Bay the relative percentage and absolute pollen concentrations allow correlation of Georgian Bay Lake phases with climatic and forest history. Four distinct pollen zones are distinguished: zone GB IV which is the oldest, reflects the succession from open spruce woodland to boreal forest; zone GB III represents a period of pine-mixed hardwoods forests from about 10,000 to 7,500 years ago. A pine-maplehemlock association dominated in zone GB II, although during the culmination of postglacial warming about 4,000 to 5,000 years ago the Georgian Bay forests had a more deciduous character. Zone GB I clearly shows European man's disturbance of the forest by logging activities.

Palaeopigment accumulation and implcations for paleolimnology over the lost century for two Ontario lakes

Crawford Lake is a meromictic lake, which is 24 m deep and has an area of 2.5 ha, and has never been reported to have mixed below 16 m. Lady Evelyn Lake, which became a reservoir when a dam was built in 1916, is dimictic with a maximum depth of about 35 m. 1 My research proved that both native chlorophylls and the ratio of chlorophyll derivatives to total carotenoids were better preserved in the shallower lake (Crawford Lake) because it was meromictic. Thus the anaerobic conditions in Crawford Lake below 16 m (monimolimnion) provide excellent conditions for pigment preservation. Under such conditions, the preservation of both chlorophylls and carotenoids, including oscillaxanthin and myxoxanthophyll, are extremely good compared with those of Lady Evelyn Reservoir, in which anaerobic conditions are rarely encountered at the mud-water interface. During the period from 1500 to 1900 A. D. in Crawford Lake, the accumulation rates of oscillaxanthin and myxoxanthophyll were extremely high, but those of chlorophyll derivatives and total carotenoids were relatively low. This was correlated with the presence of a dense benthic mat of cyanobacteria near the lake's chemocline. Competition for light between the deep dwelling cyanobacteria and overlying phytoplankton in this meromictic lake would have been intensified as the lake became more and more eutrophic (1955-1991 A. D.). During the period from 1955 to 1991 A. D., the accumulation rates of chlorophyll derivatives and total carotenoids in the sediment core from Crawford Lake (0-7.5 cm, 1955-present) increased. During this same period, the accumulation rates of cyanobacterial pigments (Le. oscillaxanthin and myxoxanthophyll) declined as the lake became more eutrophic. Because the major cyanobacteria in Crawford Lake are benthic mat forming Lyngbya and Oscillatoria and not phytoplankton, eutrophication resulted in a decline of the mat forming algal pigments. This is important because in previous palaeolimnological studies the concentrations of oscillaxanthin and myxoxanthophyll have been used as correlates with lake trophic levels. The results of organic carbon a13c analysis on the Crawford Lake sediment core supported the conclusions from the pigment study as noted above. High values of a13c at the depth of 34-48 cm (1500-1760 A. D.) were related to a dense population of benthic Oscillatoria and Lyngbya living on the bottom of the lake during that period. The Oscillatoria and Lyngbya utilized the bicarbonate, which had a high a 13C value. Very low values were found at 0-7 cm in the Crawford sediment core. At this time phytoplankton was the main primary producer, which enriched 12C by photosynthetic assimilation.

Tourist travel via Grand Trunk Railway System : and connections, including Niagara Falls and Gorge, the Highlands of Ontario, comprising Georgian Bay, Muskoka Lakes ; St. Lawrence River, Montreal, Quebec, the Saguenay River, the Rangeley Lakes, White Mountains, and the Atlantic Sea-Coast /

Previous editions of this work have appeared under the title: Gateways of tourist travel.

Niagara Ship Canal : letter from the Secretary of War, transmitting report by Colonel Blunt, on the surveys for a ship canal to connect Lakes Erie and Ontario (1868)

March 3, 1868. -- Referred to the Select Committee on the Niagara Ship Canal.