Paleolimnological assessment of nutrients and algae in the LOW: Paleolimnological assessment of nutrients and algae in the LOW: Review of initiatives and update on research
Paleolimnological assessment of nutrients and algae in the LOW: Paleolimnological assessment of nutrients and algae in the LOW: Review of initiatives Review of initiatives • Explore possibility of link between recent algal blooms & Explore possibility of link between recent algal blooms & TP TP • Have TP concentrations increased in the last few decades?
Paleolimnological assessment of nutrients and algae in the LOW: Paleolimnological assessment of nutrients and algae in the LOW: Review of initiatives Review of initiatives • Explore possibility of link between recent algal blooms & TP • Have TP concentrations increased in the last few decades? • Survey of modern sedimentary diatom assemblages in LOW (ON) • Survey of modern sedimentary diatom assemblages in LOW (ON) • Training set of LOW sites along TP gradient • Training set of LOW sites along TP gradient • Identify areas of elevated and low nutrient concentrations • Identify areas of elevated and low nutrient concentrations • Do diatoms track within • Do diatoms track within- -lake differences in lake differences in env env. conditions & water quality? . conditions & water quality? • Development of diatom • Development of diatom- -based TP model based TP model
Paleolimnological assessment of nutrients and algae in the LOW: Paleolimnological assessment of nutrients and algae in the LOW: Review of initiatives Review of initiatives • Explore possibility of link between recent algal blooms & Explore possibility of link between recent algal blooms & TP TP • Have TP concentrations increased in the last few decades? • Survey of modern sedimentary diatom assemblages in LOW (ON) • Survey of modern sedimentary diatom assemblages in LOW (ON) • Training set of LOW sites along TP gradient • Training set of LOW sites along TP gradient • Identify areas of elevated and low nutrient concentrations • Identify areas of elevated and low nutrient concentrations • Do diatoms track within • Do diatoms track within- -lake differences in lake differences in env env. conditions & water quality? . conditions & water quality? • Development of diatom • Development of diatom- -based TP model based TP model • Full core analyses • Full core analyses – – historical changes in lake water quality historical changes in lake water quality
Paleolimnological assessment of nutrients and algae in the LOW: Paleolimnological assessment of nutrients and algae in the LOW: Review of initiatives Review of initiatives • Explore possibility of link between recent algal blooms & Explore possibility of link between recent algal blooms & TP TP • Have TP concentrations increased in the last few decades? • Survey of modern sedimentary diatom assemblages in LOW (ON) • Survey of modern sedimentary diatom assemblages in LOW (ON) • Training set of LOW sites along TP gradient • Training set of LOW sites along TP gradient • Identify areas of elevated and low nutrient concentrations • Identify areas of elevated and low nutrient concentrations • Do diatoms track within • Do diatoms track within- -lake differences in lake differences in env env. conditions & water quality? . conditions & water quality? • Development of diatom • Development of diatom- -based TP model based TP model • Full core analyses • Full core analyses – – historical changes in lake water quality historical changes in lake water quality • Comparisons between reference & impact sites • reference = lower nutrients & no algal blooms • impact = elevated nutrients & algal blooms occur
Paleolimnological assessment of nutrients and algae in the LOW: Paleolimnological assessment of nutrients and algae in the LOW: Review of initiatives Review of initiatives • Explore possibility of link between recent algal blooms & Explore possibility of link between recent algal blooms & TP TP • Have TP concentrations increased in the last few decades? • Survey of modern sedimentary diatom assemblages in LOW (ON) • Survey of modern sedimentary diatom assemblages in LOW (ON) • Training set of LOW sites along TP gradient • Training set of LOW sites along TP gradient • Identify areas of elevated and low nutrient concentrations • Identify areas of elevated and low nutrient concentrations • Do diatoms track within • Do diatoms track within- -lake differences in lake differences in env env. conditions & water quality? . conditions & water quality? • Development of diatom • Development of diatom- -based TP model based TP model • Full core analyses • Full core analyses – – historical changes in lake water quality historical changes in lake water quality • Comparisons between reference & impact sites • reference = lower nutrients & no algal blooms • impact = elevated nutrients & algal blooms occur • Have nutrient levels changed over the past ca. 200 years? • Explore alternative mechanisms for recent changes
Update on research Update on research Total Phosphorus Gradient Total Phosphorus Gradient 30 Total phosphorus ( μ g·L -1 ) 25 20 Bigstone Bay 15 PP-1 10 Whitefish Bay 5 2 3 4 6 5 5 4 7 3 2 8 1 9 1 8 0 7 9 0 6 1 1 1 - 1 - - - - - - - - 1 1 1 1 1 2 1 P P P P P P P P P - - - - - - - - - - - P P P P P P P P P P P P P P P P P P P P P P P P P P P P P P P Site Summer measurements Lake of the Woods training set Results of this initiative published in J. Great Lakes Res . Pla et al. 2005 31 :253-266
Update on research Update on research DI-TP model development for LOW DI-TP model development for LOW 16 sites in LOW 16 sites in LOW 55 Minnesota lakes 55 Minnesota lakes + Northern Lakes and Forests (NLF) sites Lake of the Woods training set From J Paleolimnol Ramstack et al. 2003 29 : 79-94 From J Great Lakes Res Pla et al. 2005 31 : 253-266
Update on research Update on research Location of sampling sites for sediment cores Location of sampling sites for sediment cores -96º -95º -94º -93º Ontario 50º 50º Manitoba Kenora PP- -1 1 PP Bigstone Bay Impact Site Whitefish Bay Reference Site 49º 49º Minnesota km 0 10 -96º -95º -94º -93º
Update on research Update on research Please visit our poster! Please visit our poster! Diatom analysis complete ~ 1980 REFERENCE SITE Whitefish Bay ~ 1970 IMPACT SITE PP-1 ~ 1970 IMPACT SITE Bigstone Bay Rühland et al.: in preparation.
Update on research Update on research Trajectories of diatom change over time Trajectories of diatom change over time 3 ca. 1884 2 ~1982 Whitefish Bay 1 0 Reference -1 -2 ca. 2002 -3 -1.5 -1.0 -0.5 0.0 0.5 1.0 1.5 2.0 3 ca. 2006 PCA axis 2 2 ~1965 1 PP-1 0 Impact -1 ca. 1800 -2 0.5 0.0 -0.5 -1.0 -1.5 -2.0 3 ~1905 2 1 Bigstone Bay 0 -1 Impact ca. 1800 -2 ca. 2005 -3 -2.0 -1.5 -1.0 -0.5 0.0 0.5 1.0 1.5 2.0 PCA axis 1 Rühland et al.: in preparation.
Update on research Update on research Kenora Kenora Temperature vs. Diatom trends emperature vs. Diatom trends Manitoba -6 6 y = 0.0112x + 1.8032 Kenora Kenora y = 0.0216x - 16.136 Winter Temperature (ºC) Annual Temperature (ºC) 50º 1.19 ºC since 1899 -8 2.29 ºC since 1899 5 O -10 n 4 t -12 a 3 r i -14 o 2 -16 1 49º -18 0 -20 Minnesota 5-yr running mean 5-yr running mean -1 -22 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 2 2 1 1 1 1 1 2 2 9 9 9 9 9 9 9 9 9 9 0 0 9 9 9 9 9 9 9 9 9 9 0 0 -96º -95º -93º - 94º 0 1 2 3 4 5 6 7 8 9 0 1 0 1 2 3 4 5 6 7 8 9 0 1 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 Year AD Year AD Rühland et al.: in preparation.
Update on research Update on research Kenora Kenora Temperature vs. Diatom trends emperature vs. Diatom trends Manitoba -6 6 y = 0.0112x + 1.8032 Kenora Kenora y = 0.0216x - 16.136 Winter Temperature (ºC) Annual Temperature (ºC) 50º 1.19 ºC since 1899 -8 2.29 ºC since 1899 5 O -10 n 4 t -12 a 3 r i -14 o 2 -16 1 49º -18 0 -20 Minnesota 5-yr running mean 5-yr running mean -1 -22 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 2 2 1 1 1 1 1 2 2 9 9 9 9 9 9 9 9 9 9 0 0 9 9 9 9 9 9 9 9 9 9 0 0 -96º -95º -93º - 94º 0 1 2 3 4 5 6 7 8 9 0 1 0 1 2 3 4 5 6 7 8 9 0 1 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 Year AD Year AD PCA sample scores Annual Temperature 4.5 2.0 a 1.5 4.0 Whitefish Bay R=0.67 1.0 3.5 Reference 0.5 3.0 0.0 2.5 Annual Temperature (ºC) -0.5 PCA scores (SD units) 2.0 -1.0 1.5 b 2.0 4.0 1.5 3.5 R=0.84 1.0 PP-1 3.0 0.5 Impact 2.5 0.0 2.0 -0.5 1.5 -1.0 c 4.0 2 R=-0.73 3.5 Bigstone Bay 1 3.0 Impact 0 2.5 2.0 -1 1.5 -2 1 1 1 1 1 1 1 1 1 1 2 2 9 9 9 9 9 9 9 9 9 9 0 0 0 1 2 3 4 5 6 7 8 9 0 1 0 0 0 0 0 0 0 0 0 0 0 0 Year AD Rühland et al.: in preparation.
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