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Laurentian Great Lakes phytoplankton and their water quality characteristics, including a diatom-based model for paleoreconstruction of phosphorus.

Reavie ED, Heathcote AJ, Shaw Chraïbi VL - PLoS ONE (2014)

Bottom Line: Further, TP was minimally confounded by other environmental variables, as indicated by the relatively large amount of unique variance in the diatoms explained by TP.We demonstrated the effectiveness of the transfer function by hindcasting TP concentrations using fossil diatom assemblages in a Lake Superior sediment core.The diatom-based transfer function can be used in lake management when retrospective data are needed for tracking long-term degradation, remediation and trajectories.

View Article: PubMed Central - PubMed

Affiliation: Center for Water and the Environment, Natural Resources Research Institute, University of Minnesota Duluth, Duluth, Minnesota, United States of America.

ABSTRACT
Recent shifts in water quality and food web characteristics driven by anthropogenic impacts on the Laurentian Great Lakes warranted an examination of pelagic primary producers as tracers of environmental change. The distributions of the 263 common phytoplankton taxa were related to water quality variables to determine taxon-specific responses that may be useful in indicator models. A detailed checklist of taxa and their environmental optima are provided. Multivariate analyses indicated a strong relationship between total phosphorus (TP) and patterns in the diatom assemblages across the Great Lakes. Of the 118 common diatom taxa, 90 (76%) had a directional response along the TP gradient. We further evaluated a diatom-based transfer function for TP based on the weighted-average abundance of taxa, assuming unimodal distributions along the TP gradient. The r(2) between observed and inferred TP in the training dataset was 0.79. Substantial spatial and environmental autocorrelation within the training set of samples justified the need for further model validation. A randomization procedure indicated that the actual transfer function consistently performed better than functions based on reshuffled environmental data. Further, TP was minimally confounded by other environmental variables, as indicated by the relatively large amount of unique variance in the diatoms explained by TP. We demonstrated the effectiveness of the transfer function by hindcasting TP concentrations using fossil diatom assemblages in a Lake Superior sediment core. Passive, multivariate analysis of the fossil samples against the training set indicated that phosphorus was a strong determinant of historical diatom assemblages, verifying that the transfer function was suited to reconstruct past TP in Lake Superior. Collectively, these results showed that phytoplankton coefficients for water quality can be robust indicators of Great Lakes pelagic condition. The diatom-based transfer function can be used in lake management when retrospective data are needed for tracking long-term degradation, remediation and trajectories.

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Related in: MedlinePlus

Redundancy analysis of the diatom training set constrained to significant water quality variables.Eigenvalues indicate variance explained by each axis. Passive plotting of the Lake Superior sedimentary assemblages is indicated by the black line set in a thicker gray line. The lower panel is a zoomed-in plot of the passive ordination of Lake Superior sedimentary diatom assemblages. The core top (2010) and bottom (∼1707) are indicated and the date of each interval (based on 210Pb dating) is provided for each interval.
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pone-0104705-g003: Redundancy analysis of the diatom training set constrained to significant water quality variables.Eigenvalues indicate variance explained by each axis. Passive plotting of the Lake Superior sedimentary assemblages is indicated by the black line set in a thicker gray line. The lower panel is a zoomed-in plot of the passive ordination of Lake Superior sedimentary diatom assemblages. The core top (2010) and bottom (∼1707) are indicated and the date of each interval (based on 210Pb dating) is provided for each interval.

Mentions: An RDA of the diatom assemblages constrained by the 11 significant environmental variables indicated that these variables account for a major part (16.7% on the first axis; Table 3, Figure 3) of the underlying gradients in the diatom relative density data. Axis 1 of an unconstrained PCA captured 20.6% of the variation in the diatom data, indicating that the significant environmental variables accounted for a large portion of the underlying species gradients. Environmental data accounted for a larger portion of the variance in diatom relative biovolume data (20.0%; Table 3). TP (and the related TDP) were strongly correlated to axis 1, the main gradient of species turnover. There is also a clear alkalinity/chloride gradient that diagonally represents axes 1 and 2. Axis 2 captures a smaller proportion of variance (6.4%), although it is closely correlated to the NOx gradient. These proportions of explained variance are typical and informative in multivariate analyses of biological abundance data that tend to be noisy (Gauch [45]).


Laurentian Great Lakes phytoplankton and their water quality characteristics, including a diatom-based model for paleoreconstruction of phosphorus.

Reavie ED, Heathcote AJ, Shaw Chraïbi VL - PLoS ONE (2014)

Redundancy analysis of the diatom training set constrained to significant water quality variables.Eigenvalues indicate variance explained by each axis. Passive plotting of the Lake Superior sedimentary assemblages is indicated by the black line set in a thicker gray line. The lower panel is a zoomed-in plot of the passive ordination of Lake Superior sedimentary diatom assemblages. The core top (2010) and bottom (∼1707) are indicated and the date of each interval (based on 210Pb dating) is provided for each interval.
© Copyright Policy
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4126776&req=5

pone-0104705-g003: Redundancy analysis of the diatom training set constrained to significant water quality variables.Eigenvalues indicate variance explained by each axis. Passive plotting of the Lake Superior sedimentary assemblages is indicated by the black line set in a thicker gray line. The lower panel is a zoomed-in plot of the passive ordination of Lake Superior sedimentary diatom assemblages. The core top (2010) and bottom (∼1707) are indicated and the date of each interval (based on 210Pb dating) is provided for each interval.
Mentions: An RDA of the diatom assemblages constrained by the 11 significant environmental variables indicated that these variables account for a major part (16.7% on the first axis; Table 3, Figure 3) of the underlying gradients in the diatom relative density data. Axis 1 of an unconstrained PCA captured 20.6% of the variation in the diatom data, indicating that the significant environmental variables accounted for a large portion of the underlying species gradients. Environmental data accounted for a larger portion of the variance in diatom relative biovolume data (20.0%; Table 3). TP (and the related TDP) were strongly correlated to axis 1, the main gradient of species turnover. There is also a clear alkalinity/chloride gradient that diagonally represents axes 1 and 2. Axis 2 captures a smaller proportion of variance (6.4%), although it is closely correlated to the NOx gradient. These proportions of explained variance are typical and informative in multivariate analyses of biological abundance data that tend to be noisy (Gauch [45]).

Bottom Line: Further, TP was minimally confounded by other environmental variables, as indicated by the relatively large amount of unique variance in the diatoms explained by TP.We demonstrated the effectiveness of the transfer function by hindcasting TP concentrations using fossil diatom assemblages in a Lake Superior sediment core.The diatom-based transfer function can be used in lake management when retrospective data are needed for tracking long-term degradation, remediation and trajectories.

View Article: PubMed Central - PubMed

Affiliation: Center for Water and the Environment, Natural Resources Research Institute, University of Minnesota Duluth, Duluth, Minnesota, United States of America.

ABSTRACT
Recent shifts in water quality and food web characteristics driven by anthropogenic impacts on the Laurentian Great Lakes warranted an examination of pelagic primary producers as tracers of environmental change. The distributions of the 263 common phytoplankton taxa were related to water quality variables to determine taxon-specific responses that may be useful in indicator models. A detailed checklist of taxa and their environmental optima are provided. Multivariate analyses indicated a strong relationship between total phosphorus (TP) and patterns in the diatom assemblages across the Great Lakes. Of the 118 common diatom taxa, 90 (76%) had a directional response along the TP gradient. We further evaluated a diatom-based transfer function for TP based on the weighted-average abundance of taxa, assuming unimodal distributions along the TP gradient. The r(2) between observed and inferred TP in the training dataset was 0.79. Substantial spatial and environmental autocorrelation within the training set of samples justified the need for further model validation. A randomization procedure indicated that the actual transfer function consistently performed better than functions based on reshuffled environmental data. Further, TP was minimally confounded by other environmental variables, as indicated by the relatively large amount of unique variance in the diatoms explained by TP. We demonstrated the effectiveness of the transfer function by hindcasting TP concentrations using fossil diatom assemblages in a Lake Superior sediment core. Passive, multivariate analysis of the fossil samples against the training set indicated that phosphorus was a strong determinant of historical diatom assemblages, verifying that the transfer function was suited to reconstruct past TP in Lake Superior. Collectively, these results showed that phytoplankton coefficients for water quality can be robust indicators of Great Lakes pelagic condition. The diatom-based transfer function can be used in lake management when retrospective data are needed for tracking long-term degradation, remediation and trajectories.

Show MeSH
Related in: MedlinePlus