Scaled chrysophytes (Chrysophyceae and Synurophyceae) from national park lakes in southern and central Finland

A total of 34 scaled chrysophyte taxa (18 Mallomonas spp., 6 Synura spp., 2 Chrysosphaerella spp., 6 Spiniferomonas spp. and 2 Paraphysomonas spp.) were recorded by SEM techniques in 61 samples from 59 lakes locating in 8 national parks of southern and central Finland in July 1987. Most of the lakes were small forest and peat bog lakes with acid (pH 4.6–7.2) and soft-water and with variable water colour (10–350 mg Pt/l). The number of taxa per lake varied from 0 to 15 and it correlated very significantly with the water pH. The species structure was rather typical for the oligotrophic and acid lakes. Besides the eurytypic and common species like Mallomonus caudata (fr. 72.1% of lakes), M. crassisquama (65.6%), M. allorgei (62.3%) and M. akrokomos (52.5%) also M. canina (41.0%) and M. hamata (21.3%) were frequently observed. M. calceolus, M. costata, M. papillosa, M. pugio and M. paludosa were more rare but typical for acid lakes. Synuru splendida which occurred in two lakes was the most rare and a new species for Finland.     

The relationship between sedimentary chrysophyte scales (Chrysophyceae and Synurophyceae) and limnological characteristics in 25 Norwegian lakes

The relationship between 16 taxa of chrysophyte scales (Chrysophyceae and Synurophyceae) from the surface sediments of 25 soft-water Norwegian lakes and 16 limnological variables from these lakes was examined using canonical correspondence analysis (CCA). The Norwegian chrysophyte flora reported in this study is typical of assemblages described from acidic to circumneutral lakes. Lake-water pH was the environmental variable that explained the most variation in the weighted averages of the chrysophyte taxa, although total aluminium, colour, and specific conductivity were also important. Predictive models were developed to infer lake-water pH based on species composition of chrysophyte scales in the 25 lakes, using weighted averaging regression and calibration with and without tolerance down-weighting. Model performance was evaluated by a computer-intensive bootstrapping procedure to derive root mean squared errors of predictions. In our data set, tolerance corrected weighted average regression and calibration was shown to be a more reliable predictor of pH than simple weighted averaging. This study shows that the remains of chrysophyte scales in Norway can be used as palaeo-biological indicators of lake-water pH.     

CHRYSOPHYTE POPULATION AND ENCYSTMENT PATTERNS IN TWO CANADIAN LAKES1

The dynamics of chrysophyte populations and the onset of encystment in relation to several physical, chemical, and biological variables were studied in two Canadian lakes, Lake Opinicon (LO) and Upper Rock Lake (URL). LO is shallow and polymictic during the ice-free season, whereas URL is deep and dimictic. Seasonal patterns of many limnological variables, as well as species composition and seasonal dynamics of chrysophyte assemblages, were broadly similar in both lakes. Three groups of chrysophytes were recognized: 1) taxa that were more abundant during ice cover and/or early spring and occasionally in late fall (Dinobryon spp. Ehrenberg and Synura spinosa Korsh), 2) taxa that seemed to prefer moderately warm water proglena americana Calkins and Ochromonas sp. Wyssotzki) and had maximum densities in late summer and occasionally in the fall, and 3) taxa that occurred in low numbers and did not exhibit any discernible seasonality in the two lakes (Mallomonas spp. Perty). Encystment rarely occurred during ice cover in both lakes. Stomatocyst concentrations were highest shortly after ice breakup (late April or early May), declined to trace levels by June, and remained at those levels until the end of the sampling season (late November). Encystment rates (cyst concentrations) were higher in dimictic URL. Encystment in both lakes coincided with concurrent changes in physical and chemical variables and chrysophyte vegetative cell densities, but it was not possible to pinpoint the exact conditions responsible for triggering encystment. Only a small proportion of chrysophytes encysted. Cyst production within a lake may vary from year to year.     

Chrysophyte scales recorded in lake sediments from eastern Finland

Chrysophyte (mallomonadacean) scales were examined from the surface sediments of 18 lakes from eastern Finland, representing a wide range of limnological characteristics. Scales were always well preserved and 23 taxa were observed. The relative frequencies of the dominant taxa were plotted relative to the average autumn lakewater pH. The distribution of chrysophyte species in the calibration set was ordinated by means of DECORANA analysis. The occurrence of these species appeared to be closely related to pH, colour and nutrients in the ordinated lake groups. Chrysophyte scales are potentially useful environmental and paleolimnological indicators in eastern Finland.     

Chrysophyte cyst biogeographical and ecological distributions: a synthesis

The distributions of chrysophyte stomatocysts in the sediments of 221 lakes from four study areas located in British Columbia, Canada (two datasets), New York, U.S.A., and south central Siberia were examined. The combined lake set spanned a wide range of chemical and morphometric variables. Approximately 400 cyst morphotypes were identified, from which we selected sixty-three common types for further analysis. Canonical ordination (detrended canonical correspondence analysis (DCCA) and constrained DCCA) showed that four environmental variables (pH, conductivity, depth and total phosphorus (TP) ) were significant (Monte Carlo permutation test, P =0.01 for all four variables) and independent determinants of the cyst distributions. Weighted averaging (WA) inference models were developed for each variable. The best models, in terms of their r ², were developed for pH and conductivity ( r ²=0.78 and 0.73, respectively). The models for depth and TP were less robust ( r ²=0.47 and 0.46, respectively). We discuss the relative importance of conductivity and salinity, lakewater acidity and metal concentrations, lake morphometry and trophic status as determinants of chrysophyte population distributions, and possible causal mechanisms for each variable. We identify assemblages of cysts that appear to be associated with six different groups of lakes: (1) very acidic (pH <6.5) lakes; (2) acidic (pH <7.0), softwater lakes; (3) circumneutral (pH 7–8), oligo- to mesotrophic lakes; (4) alkaline, hardwater, meso- to eutrophic lakes; (5) shallow, alkaline (pH 8–8.5), meso- to eutrophic lakes; and (6) shallow, very alkaline (pH >8.5) lakes, including sub- and hyposaline lakes. Finally, we suggest further possible avenues for research that will improve the usefulness of chrysophyte stomatocysts as paleolimnological indicators.     

Long-term trends in limnological characteristics in the Aurora trout lakes, Sudbury, Canada

Paleolimnological techniques were employed to document the limnological histories of the aurora trout lakes, located in the Sudbury region of Ontario. Two of these lakes are of special interest to fisheries managers, as they represent the only known native habitats of a rare strain of brook trout: the aurora trout. These lakes were limed as part of restoration efforts. Stratigraphic changes in diatom and chrysophyte assemblages from dated lake sediment cores indicate that all the lakes have been impacted by anthropogenic acidification, although the timing and the magnitude of acidification were different amongst the lakes. For example, Whirligig Lake was likely the most naturally acidic lake in the past, but it had further acidified since about 1960. This lake was limed in 1989 and then again in 1993. In Whitepine Lake, acidification started 1940; however, in the most recent sediments (1992), some recovery in lakewater acidity has occurred. In Little Whitepine Lake (a reference lake), acidification started earlier (1920) and the lakewater pH continued to decline until about 1990. This lake was limed in 1989. The chrysophyte paleoindicators suggest a recent recovery in this lake. The successful re-introduction of aurora trout in Whirligig and Whitepine lakes is undoubtedly related to the improved water quality through liming but, based on our paleolimnological indicators, the lakes' limnological characteristics (e.g. pH and metal concentrations) are still different from those present before atmospheric deposition of strong acids from the Sudbury smelters.     

ENVIRONMENTAL FACTORS CORRELATED WITH CHRYSOPHYTE CYST ASSEMBLAGES IN LOW ARCTIC LAKES OF SOUTHWEST GREENLAND1

We analyzed the relationship between chrysophyte cyst assemblages in surface sediment samples and limnological and geographical variables for 70 lakes located along Søndre Strømfjord in southwest Greenland. Over 247 stomatocysts were identified and of these, 153 were sufficiently abundant for use in statistical analyses. Eight stomatocysts were considered to be new and are described formally. Canonical correspondence analysis indicated that conductivity was the dominant variable explaining cyst distribution, reflecting the large conductivity gradient in lake water chemistry in this area. High conductivity lakes had distinctive cyst assemblages with lower diversity than low alkalinity lakes, where assemblages were similar to alpine soft‐water lakes elsewhere. The high conductivity lakes, however, had similar cysts to other saline lakes elsewhere in the arctic. Additionally, pH, calcium, maximum depth, longitude, sulfate, total phosphorus, and altitude all explained significant amounts of variability of cyst assemblages. Longitude was the only geographical variable that explained cyst variability independently of other variables (i.e. had a unique effect), which suggests that the climatic gradient from the coast to the head of the fjord has a structuring effect on cyst assemblages. Conductivity (weighted‐averaging partial least squares, r²=0.917; root mean square error=0.142; r²_jack=0.861, root mean square error of prediction=0.191) and pH inference models (weighted averaging, r²=0.924; root mean square error=0.158; r²_jack=0.826, root mean square error of prediction=0.240) were developed. For the pH model, high conductivity lakes (>800 μ S₂₀·cm^?1) were removed. Both models are statistically robust and could be applied to lakes in west Greenland to reconstruct conductivity and/or pH. Such paleolimnological reconstructions provide the means of acquiring long‐term data for use in the evaluation of, for example, regional paleoclimatic models.     

Tracking Recovery Patterns in Acidified Lakes: A Paleolimnological Perspective

Long-term data are often lacking to effectively assess patterns of lake acidification and recovery. Fortunately, paleolimnological techniques can be used to infer past changes in lakewater acidity and related variables by means of biological indicators, such as diatom valves and chrysophyte scales, preserved in ²¹⁰Pb-dated sediment cores. We summarize paleolimnological data that we have gathered from 36 Sudbury (Ontario) and 20 Adirondack Park (New York) lakes to estimate the magnitude of lake acidification and any subsequent recovery in these lake systems. In both regions, many lakes were shown to have acidified considerably, some over two pH units, since the 1850s. Although some recovery was noted in both lake regions, Sudbury lakes generally showed larger increases in inferred lakewater pH with recent declines in sulfur emissions. Possible explanations of these differences include the greater decrease in sulfate deposition in the Sudbury area, as well as generally longer residence times of lakes in Sudbury, perhaps allowing for more in-lake alkalinity generation. In addition, Sudbury lakes generally had higher pre-industrial pH levels, suggesting that lakes with higher natural buffering capacities are more likely to recover more quickly with declines in deposition, even if they had been acidified to a great extent.     

Silica‐scaled chrysophytes from Abisko (Swedish Lapland)

The silica‐scaled chrysophyte flora of Swedish Lapland (near Abisko) was examined. Chrysophyte scales were found in 18 of the 32 investigated water bodies (lakes and pools). Altogether, 28 taxa from the classes Chrysophyceae and Synurophyceae were found. The most abundant species was Synura echinulata. Three species were observed for the first time in Sweden: Mallomonas maculata, M. rasilis and Spiniferomonas serrata.     

DIATOM COMMUNITY DYNAMICS IN STREAMS OF CHRONIC AND EPISODIC ACIDIFICATION: THE ROLES OF ENVIRONMENT AND TIME1

Community dynamics of epiphytic diatoms were studied for 3 years in a chronically and an episodically acidified tributary of Buck Creek, Adirondacks. Both streams experienced pulses of acidity during hydrologic events but these pulses were more pronounced in the episodically acidified stream, where pH decreased over two units (between 4.53 and 6.62) and the acid‐neutralizing capacity (ANC) became negative. In the chronically acidified stream, pH was below 4.9 and the ANC was negative 94% of the time. In this stream, high inorganic acidity following SO₄^2? enrichment from snowmelt or rainstorms alternated with high organic acidity derived from a headwaters wetland during base flow. The fluctuating water chemistry generated shifts in diatom community composition: from exclusive dominance of Eunotia bilunaris (Ehrenberg) Mills during periods of high inorganic acidity to proliferation of several subdominant species during periods of high organic acidity. In the episodically acidified stream, the pulses of acidity were associated with high NO₃^? concentrations and the corresponding high ratios of inorganic monomeric Al (Al_im) to organic monomeric Al (Al_om). Diatom communities there were dominated exclusively by E. exigua (Brébisson) Rabenhorst year round; however, this species peaked during periods of low acidity. Periods of high acidity and Al_im:Al_om ratios were marked by a decline in E. exigua and a concomitant increase in the subdominant species. Variance partitioning into terms of environmental and temporal variance, and their covariance, suggested that diatom communities in the chronically acidic stream were governed primarily by environmental factors while in the episodically acidic stream environmental and temporal factors had equal contributions.     

USING EPILITHIC ALGAL COMMUNITIES TO ASSESS TROPHIC STATUS IN IRISH LAKES1

Relationships between taxonomic composition of shallow epilithic algal communities and nine environmental variables in 32 lakes of different trophic states in Ireland were explored using gradient analysis. A canonical correspondence analysis using four representative environmental variables, alkalinity (correlated with pH and conductivity), maximum phytoplankton chl a (CHL_max) (correlated with total P, total N, and chl), turbidity, and water color explained 21% of the variance in taxa distributions. The first two axes were significant and accounted for 77% of the variance in the periphyton–environmental relationship. The first axis was strongly related to alkalinity and color, which reflected geology and land use in the watersheds. The second axis was most correlated with CHL_max, and separation of lakes corresponded to their Organization for Economic Cooperation and Development (OECD) trophic classification based on water chemistry. Eutrophic lakes were characterized by cyanobacteria taxa and Stigeoclonium sp. Diatoms and desmids were generally more abundant in oligotrophic and mesotrophic lakes. Values for diatom trophic indices were poor indicators of trophic state. Weighted averaging regression and calibration techniques were used to develop transfer functions between 84 taxa and total P, total N, and CHL_max. The total P inference model predicted OECD trophic classification correctly for 84% of the lakes. Values for taxa preferences resulting from such models can provide the foundation for biomonitoring schemes using extant periphyton communities. The turnover time of periphyton taxa should integrate changes in environmental conditions at a temporal scale intermediate to surface‐sediment fossil diatom assemblages and water column variables, which may be more appropriate for detecting annual changes.     

BENTHIC DIATOM AUTECOLOGY AND INFERENCE MODEL DEVELOPMENT FROM THE CANADIAN HIGH ARCTIC ARCHIPELAGO1

Diatom assemblages were analyzed from 64 lakes and ponds from Alert, Ellesmere Island and Mould Bay, Prince Patrick Island in the Canadian High Arctic Archipelago. Diverse water chemistry conditions and diatom communities were present in these sites. Small benthic taxa typically dominated diatom communities; however, assemblages were markedly different between Alert and Mould Bay sites in response to disparate water chemistry characteristics in the two regions. The most abundant taxa belonged to the genera Navicula, Cymbella, Achnanthes, Nitzschia, and Pinnularia. Canonical correspondence analysis indicated that pH, specific conductivity, dissolved organic carbon, and total phosphorus were the most important limnological variables in determining species composition. Diatom inference models were developed for pH, specific conductivity, and dissolved organic carbon using weighted averaging and weighted averaging partial least squares techniques; these had root mean square error of prediction/r²_boot values of 0.40/0.77, 0.28/0.70, and 0.24/0.55, respectively. These models are applicable to sites with large ranges of taxonomic and limnological variation and will allow the reconstruction of past changes of climate‐related limnological parameters from biostratigraphic records in future paleolimnological studies.     

Silica-scaled chrysophytes from West Greenland: Disko Island and the Søndre Strømfjord region

The flora of silica-scaled chrysophytes (Chrysophyceae and Synurophyceae) is known from two previous investigations in southern Greenland, from Narssaq (61°N) and Nuuk (64°N).
In connection with a course in Arctic Biology 25.7.-20.8 1990 chrysophyte samples were obtained from altogether 53 localities, 41 from the Godhavn region in Disko Island (69°N) and 12 from S0ndre Str0mfjord (67°N). The localities were lakes, ponds and puddles, on basalt or an acid bedrock. Fixed samples were examined by EM, and altogether twenty species were identified by their silica scales. Eight of these were new to Greenland, viz. Spiniferomonas silverensis, Mallomonas acaroides, M. alpina, M. crassisquama (previous records proved to belong to M. duerrschmidliae), M. oviformis, M. paludosa, M. tonsurata , and Synura mammillosa. The composition of the flora is discussed from ecological and biogeographic viewpoints.     

LAKE SEDIMENT CHRYSOPHYTE SCALES FROM THE NORTHEASTERN U.S.A. AND THEIR RELATIONSHIP TO ENVIRONMENTAL VARIABLES

Chrysophyte scale assemblages were analyzed in the surface sediments (0–1 cm) of 146 lakes sampled in the U.S. Environmental Protection Agency's (EPA) Environmental Monitoring and Assessment Program–Surface Waters (EMAP-SW) in the northeastern U.S.A. Chrysophyte data from the EMAP lakes were combined with a previous study of 71 Adirondack PIRLA (Paleoecological Investigation of Recent Lake Acidification) lakes and collectively analyzed to examine the indicator potential of scaled chrysophytes in the northeastern U.S.A. with respect to several environmental variables. Canonical correspondence analysis (CCA) was used to determine which environmental variables influenced the distributions of species. Forward selection and Monte Carlo permutation tests showed that 51% of the variance in the chrysophyte assemblages was related to pH. The other six significant variables (conductivity, chloride, total phosphorus [TP], elevation, lake depth, and watershed area) contributed an additional 31% of the total (82%) variance explained by the seven forward-selected variables. Similar to previous studies, many taxa showed distinct distribution patterns with respect to pH. Partial and constrained CCAs indicated that, although all seven variables explained significant proportions of variation in the species data, a reliable inference model could be developed only for lake-water pH. The strength of this model ( R ²= 0.78, RMSE_boot= 0.47 of a pH unit) is comparable to a recently constructed diatom-based model for the EMAP lakes. The use of both models in paleolimnological and biomonitoring studies would be advantageous because they would provide two independent lines of evidence of environmental change.     

ELECTROPORATION AND FUSION OF HUMAN CANCER CELLS MODIFIED BY AMINO ACIDS AND POLYPEPTIDES

The influence of adsorbed polypeptides on electrofusion of histiocytic U937 and myeloidic K562 cells was extended by the corresponding monomeric amino acids in 0.3 M mannitol solution at pH 6.6 and other pH values. In all cases the monomers showed a similar behavior to the polymers, namely, an increase in the relative fusion yield F_r, or, in the case of sulfur-containing compounds, a decrease in F_r at higher concentrations. These electrostatic effects—dominated by the isoelectric points pI and the pH of the medium—are modified by mechanical interventions (e.g., bridging), because the F_r value also depends on the molecular mass (M_m) of the polypeptides. In fact, it rises with increasing M_m. These results demonstrate the fundamental interactions among cell membranes and proteins, polypeptides, and amino acids, which are responsible for essential life processes.     

Ecological distributions of <Emphasis Type="Italic">Chaoborus</Emphasis> species in small,shallow lakes from the Canadian Boreal Shield ecozone

Small, shallow lakes and ponds are often the dominant landscape features in many regions, but are comparably less studied than larger lakes. Shallow lakes are more likely to lack fish populations; however, it is often difficult to ascertain whether these sites were naturally fishless or lost their fish populations due to anthropogenic or natural stressors. We examined the distributional abundances of four Chaoborus species by identifying and enumerating their larval mandibles in the surface sediments of 146 randomly selected lakes from northwestern Ontario, Canada, to determine the key environmental gradients influencing chaoborid distributions. Chaoborus mandibles were encountered at 110 lakes and, in 65% of those lakes, total counts were ≥10. Direct gradient analyses were then used to show that lakewater total aluminum concentrations (negatively correlated with pH), lakewater sodium concentrations, lake surface area, and maximum water depth were significant predictors of the distributional abundances of Chaoborus. Generalized linear models indicated that Chaoborus species varied in their responses to significant environmental factors. C. (Sayomyia) was not significantly associated with any environmental variable and the abundances of larger chaoborids may be an important biotic factor affecting this taxon. Chaoborus americanus, an indicator of fishless lakes, was significantly correlated with all five key variables and demonstrated a clear threshold of occurrence in relatively small lakes (i.e., <10 ha in surface area). Furthermore, based on the occurrence and abundance of C. americanus, we estimated that 20% of the lakes we surveyed are currently fishless. These lakes significantly differ in several geomorphic and water-chemistry measures compared to the other study lakes.     

Purification and characterization of a glucokinase from young tomato (Lycopersicon esculentum L. Mill.) fruit

In order to clearly establish the properties of the enzymes responsible for hexose phosphorylation we have undertaken the separation and characterization of these enzymes present in tomato fruit (Martinez-Barajas and Randall 1996). This report describes the partial purification and characterization of glucokinase (EC. 2.7.1.1) from young green tomato fruit. The procedure yielded a 360-fold enrichment of glucokinase. Tomato fruit glucokinase is a monomer with a molecular mass of 53 kDa. Glucokinase activity was optimal between pH 7.5 and 8.5, preferred ATP as the phosphate donor (K _m = 0.223 mM) and exhibited low activity with GTP or UTP. The tomato fruit glucokinase showed highest affinity for glucose (K _m = 65 μM). Activity observed with glucose was 4-fold greater than with mannose and 50-fold greater than with fructose. The tomato fruit glucokinase was sensitive to product inhibition by ADP (K _i = 36 μM). Little inhibition was observed with glucose 6-phosphate (up to 15 mM) at pH 8.0; however, at pH 7.0 glucokinase activity was inhibited 30–50% by physiological concentrations of glucose 6-phosphate. Received: 4 October 1997 / Accepted: 10 January 1998     

Growth characteristics of three Mallomonas species (silica-scaled chrysophytes) at different temperatures and pH

Three species of Mallomonas ( M. crassisquama , M. elongata and M. tonsurata ) were isolated from Kachang dam in Daegu, Korea and the individual species were grown as batch cultures in the laboratory. The growth characteristics of these species were investigated at different temperatures and pH. Mallomonas crassisquama exhibited the highest growth rates (μ_max) at 18°C, whereas the maximum growth rates of M. elongata and M. tonsurata were observed at 21°C. The maximum growth rates of M. crassisquama and M. elongata were observed at pH 6, and M. tonsurata exhibited maximum growth rate at pH 5. Mallomonas crassisquama and M. tonsurata showed high growth rate between pH 4 and 6, and M. elongata showed high growth rate below pH 7. The three species showed similar growth characteristics except that M. elongata proliferated at a narrower temperature range and at a wider pH range than other two species.     

Diatom assemblages and their relationship to environmental variables in lakes from the boreal forest-tundra ecotone near Yellowknife,Northwest Territories,Canada

The relationship between diatom (Bacillariophyceae) taxa preserved in surface lake sediments and measured limnological and environmental variables in 22 lakes near Yellowknife (N.W.T.) was explored using multivariate statistical methods. The study sites are distributed along a latitudinal gradient that includes a strong vegetational gradient of boreal forests in the south to arctic tundra conditions in the north. Canonical correspondence analysis (CCA) revealed that lakewater concentrations of dissolved inorganic carbon (DIC) and dissolved organic carbon (DOC) each accounted for independent and statistically significant proportions of variation in the distribution of diatom taxa. Weighted-averaging (WA) models were developed to infer DIC and DOC from the relative abundances of the 76 most common diatom taxa. These models can now be used to infer past DIC and DOC concentrations from diatom assemblages preserved in sediment cores of lakes in the Yellowknife area, which may provide quantitative estimates of changes in lakewater chemistry related to past vegetational shifts at treeline.     

Development of diatom-based salinity models for paleoclimatic research from lakes in British Columbia (Canada)

Diatoms were identified and enumerated from the surface sediments of 65 lakes located on the Cariboo and Chilcotin Plateaux (British Columbia, Canada). These lakes span a large gradient in lakewater ionic concentration (fresh through hypersaline) and composition, as well as other physical/chemical variables. Almost all of the study lakes had higher salinities in the late-summer than in the spring. The lakes with spring salinities >8 g l^–1 showed the largest seasonal increases in salinity. Ionic composition was similar in the spring and late-summer for most lakes. Both ionic concentration (i.e. salinity) and composition were important environmental variables that could account for the different diatom floras in the lakes. Diatom assemblages characteristic of carbonate-dominated and sulfate-dominated waters were identified. Other variables such as water depth and phosphorus concentration were also important.The majority (87%) of diatom taxa had estimated salinity optima < 3 g l^–1 Halophilic diatom taxa had broader tolerances to salinity when compared to the fresh water taxa, however taxa with narrow and broad tolerances could be identified across the salinity gradient. Species diversity was weakly but significantly correlated to lakewater salinity (r ² = 0.18 to 0.3, P < 0.05).Salinity inference models were developed based on the relationship between the diatom assemblages and the spring, late-summer and average salinity. The correlations between the measured and diatominferred salinity, based on the spring (r = 0.95), late-summer (r = 0.94) and average (r = 0.95) salinity data, are high because there was an extremely strong correlation (r = 0.98) between the log transformed spring and late-summer measured salinities. These salinity reconstruction models provide a tool that can be used to infer past climatic changes as part of paleolimnological studies from appropriate closed-basin lakes in British Columbia.