@article{clerk_quantitative_2000,
	title = {Quantitative inferences of past hypolimnetic anoxia and nutrient levels from a {Canadan} {Precambrian} {Shield} lake},
	volume = {23},
	issn = {0921-2728, 1573-0417},
	url = {https://link.springer.com/article/10.1023/A:1008147127606},
	doi = {10.1023/A:1008147127606},
	abstract = {Paleolimnological analyses were used to infer limnological changes during the past {\textasciitilde} 300 yrs in the west basin of Peninsula Lake, a small (853 ha) Precambrian Shield lake in Ontario, Canada, that has been subjected to moderate cultural disturbances (forest clearance, cottage and resort development). This study represents a pioneering attempt to use sedimentary chironomid assemblages and weighted-averaging models to quantify past hypolimnetic anoxia (expressed as the anoxic factor, AF). Impacts of forest clearance and human land-use on deepwater oxygen availability and surface water quality were assessed by comparing chironomid-inferred AF and diatom-inferred total phosphorus concentration ([TP]) to changes in terrestrial pollen and historical data. This study also discusses the ability of chironomids to quantitatively infer changes in AF.Pre-disturbance chironomid assemblages were stable and dominated by taxa indicative of oxygen-rich hypolimnetic conditions (e.g., Protanypus, Heterotrissocladius, Micropsectra type), while diatoms indicated oligotrophic lake status (diatom inferred [TP] = 5-7 μg·l-1). Chironomids characteristic of lower oxygen availability (e.g., Chironomus, Procladius) increased following land-clearance, road construction, establishment of a grist mill and lakeshore development beginning ca. 1870. Increased abundances of Tanytarsus s. lat., a multigeneric group of mainly littoral chironomids, since 1900, indicated that littoral chironomids may have comprised a greater proportion of fossil assemblages during periods of eutrophication and prolonged anoxia. Abundances of meso-eutrophic diatom taxa (e.g., Fragilaria crotonensis, Asterionella formosa, Aulacoseira ambigua, A. subarctica) increased concurrent with European settlement (ca. 1870) and diatom-inferred [TP] doubled ({\textasciitilde} 6-12 μg·l-1), further indicating that naturally-oligotrophic Precambrian Shield lakes were extremely sensitive to initial land-clearance activities.Recent increases in oligotrophic diatom taxa (e.g., Cyclotella stelligera) indicate a shift to more oligotrophic conditions since ca. mid-1960s, with greatest changes since ca. 1980. The chironomids Heterotrissocladius and Micropsectra type also increased at this time suggesting greater deepwater oxygen availability. These recent water-quality improvements, possibly in response to enhanced nutrient removal from detergents and sewage, climate-related reductions in external phosphorus loads, and catchment (but not lake) acidification and reforestation, suggest that habitat for commercially-valuable cold-water fishes has improved in recent decades despite greater recreational lake-use.Paleolimnological assessment of trophic status changes in Peninsula Lake using fossil diatom and chironomid assemblages were in good agreement. Diatom inferences of [TP] and chironomid inferences of AF both suggest that Peninsula Lake was historically oligotrophic, became oligo-mesotrophic after European settlement, and returned to oligotrophy in recent yrs. Chironomid inferences of [TP] consistently underestimated the trophic status of Peninsula Lake, possibly due to its relatively large hypolimnion. These results suggest that AF represents a useful tool for quantitatively reconstructing the past trophic status of deeper, stratified lakes.},
	language = {en},
	number = {3},
	urldate = {2018-06-11},
	journal = {Journal of Paleolimnology},
	author = {Clerk, Saloni and Hall, Roland and Quinlan, Roberto and Smol, John P.},
	month = mar,
	year = {2000},
	note = {00097},
	keywords = {\#nosource},
	pages = {319--336},
}

{"_id":"3SFWzfgQeQXZMRDRi","bibbaseid":"clerk-hall-quinlan-smol-quantitativeinferencesofpasthypolimneticanoxiaandnutrientlevelsfromacanadanprecambrianshieldlake-2000","author_short":["Clerk, S.","Hall, R.","Quinlan, R.","Smol, J. P."],"bibdata":{"bibtype":"article","type":"article","title":"Quantitative inferences of past hypolimnetic anoxia and nutrient levels from a Canadan Precambrian Shield lake","volume":"23","issn":"0921-2728, 1573-0417","url":"https://link.springer.com/article/10.1023/A:1008147127606","doi":"10.1023/A:1008147127606","abstract":"Paleolimnological analyses were used to infer limnological changes during the past ~ 300 yrs in the west basin of Peninsula Lake, a small (853 ha) Precambrian Shield lake in Ontario, Canada, that has been subjected to moderate cultural disturbances (forest clearance, cottage and resort development). This study represents a pioneering attempt to use sedimentary chironomid assemblages and weighted-averaging models to quantify past hypolimnetic anoxia (expressed as the anoxic factor, AF). Impacts of forest clearance and human land-use on deepwater oxygen availability and surface water quality were assessed by comparing chironomid-inferred AF and diatom-inferred total phosphorus concentration ([TP]) to changes in terrestrial pollen and historical data. This study also discusses the ability of chironomids to quantitatively infer changes in AF.Pre-disturbance chironomid assemblages were stable and dominated by taxa indicative of oxygen-rich hypolimnetic conditions (e.g., Protanypus, Heterotrissocladius, Micropsectra type), while diatoms indicated oligotrophic lake status (diatom inferred [TP] = 5-7 μg·l-1). Chironomids characteristic of lower oxygen availability (e.g., Chironomus, Procladius) increased following land-clearance, road construction, establishment of a grist mill and lakeshore development beginning ca. 1870. Increased abundances of Tanytarsus s. lat., a multigeneric group of mainly littoral chironomids, since 1900, indicated that littoral chironomids may have comprised a greater proportion of fossil assemblages during periods of eutrophication and prolonged anoxia. Abundances of meso-eutrophic diatom taxa (e.g., Fragilaria crotonensis, Asterionella formosa, Aulacoseira ambigua, A. subarctica) increased concurrent with European settlement (ca. 1870) and diatom-inferred [TP] doubled (~ 6-12 μg·l-1), further indicating that naturally-oligotrophic Precambrian Shield lakes were extremely sensitive to initial land-clearance activities.Recent increases in oligotrophic diatom taxa (e.g., Cyclotella stelligera) indicate a shift to more oligotrophic conditions since ca. mid-1960s, with greatest changes since ca. 1980. The chironomids Heterotrissocladius and Micropsectra type also increased at this time suggesting greater deepwater oxygen availability. These recent water-quality improvements, possibly in response to enhanced nutrient removal from detergents and sewage, climate-related reductions in external phosphorus loads, and catchment (but not lake) acidification and reforestation, suggest that habitat for commercially-valuable cold-water fishes has improved in recent decades despite greater recreational lake-use.Paleolimnological assessment of trophic status changes in Peninsula Lake using fossil diatom and chironomid assemblages were in good agreement. Diatom inferences of [TP] and chironomid inferences of AF both suggest that Peninsula Lake was historically oligotrophic, became oligo-mesotrophic after European settlement, and returned to oligotrophy in recent yrs. Chironomid inferences of [TP] consistently underestimated the trophic status of Peninsula Lake, possibly due to its relatively large hypolimnion. These results suggest that AF represents a useful tool for quantitatively reconstructing the past trophic status of deeper, stratified lakes.","language":"en","number":"3","urldate":"2018-06-11","journal":"Journal of Paleolimnology","author":[{"propositions":[],"lastnames":["Clerk"],"firstnames":["Saloni"],"suffixes":[]},{"propositions":[],"lastnames":["Hall"],"firstnames":["Roland"],"suffixes":[]},{"propositions":[],"lastnames":["Quinlan"],"firstnames":["Roberto"],"suffixes":[]},{"propositions":[],"lastnames":["Smol"],"firstnames":["John","P."],"suffixes":[]}],"month":"March","year":"2000","note":"00097","keywords":"#nosource","pages":"319–336","bibtex":"@article{clerk_quantitative_2000,\n\ttitle = {Quantitative inferences of past hypolimnetic anoxia and nutrient levels from a {Canadan} {Precambrian} {Shield} lake},\n\tvolume = {23},\n\tissn = {0921-2728, 1573-0417},\n\turl = {https://link.springer.com/article/10.1023/A:1008147127606},\n\tdoi = {10.1023/A:1008147127606},\n\tabstract = {Paleolimnological analyses were used to infer limnological changes during the past {\\textasciitilde} 300 yrs in the west basin of Peninsula Lake, a small (853 ha) Precambrian Shield lake in Ontario, Canada, that has been subjected to moderate cultural disturbances (forest clearance, cottage and resort development). This study represents a pioneering attempt to use sedimentary chironomid assemblages and weighted-averaging models to quantify past hypolimnetic anoxia (expressed as the anoxic factor, AF). Impacts of forest clearance and human land-use on deepwater oxygen availability and surface water quality were assessed by comparing chironomid-inferred AF and diatom-inferred total phosphorus concentration ([TP]) to changes in terrestrial pollen and historical data. This study also discusses the ability of chironomids to quantitatively infer changes in AF.Pre-disturbance chironomid assemblages were stable and dominated by taxa indicative of oxygen-rich hypolimnetic conditions (e.g., Protanypus, Heterotrissocladius, Micropsectra type), while diatoms indicated oligotrophic lake status (diatom inferred [TP] = 5-7 μg·l-1). Chironomids characteristic of lower oxygen availability (e.g., Chironomus, Procladius) increased following land-clearance, road construction, establishment of a grist mill and lakeshore development beginning ca. 1870. Increased abundances of Tanytarsus s. lat., a multigeneric group of mainly littoral chironomids, since 1900, indicated that littoral chironomids may have comprised a greater proportion of fossil assemblages during periods of eutrophication and prolonged anoxia. Abundances of meso-eutrophic diatom taxa (e.g., Fragilaria crotonensis, Asterionella formosa, Aulacoseira ambigua, A. subarctica) increased concurrent with European settlement (ca. 1870) and diatom-inferred [TP] doubled ({\\textasciitilde} 6-12 μg·l-1), further indicating that naturally-oligotrophic Precambrian Shield lakes were extremely sensitive to initial land-clearance activities.Recent increases in oligotrophic diatom taxa (e.g., Cyclotella stelligera) indicate a shift to more oligotrophic conditions since ca. mid-1960s, with greatest changes since ca. 1980. The chironomids Heterotrissocladius and Micropsectra type also increased at this time suggesting greater deepwater oxygen availability. These recent water-quality improvements, possibly in response to enhanced nutrient removal from detergents and sewage, climate-related reductions in external phosphorus loads, and catchment (but not lake) acidification and reforestation, suggest that habitat for commercially-valuable cold-water fishes has improved in recent decades despite greater recreational lake-use.Paleolimnological assessment of trophic status changes in Peninsula Lake using fossil diatom and chironomid assemblages were in good agreement. Diatom inferences of [TP] and chironomid inferences of AF both suggest that Peninsula Lake was historically oligotrophic, became oligo-mesotrophic after European settlement, and returned to oligotrophy in recent yrs. Chironomid inferences of [TP] consistently underestimated the trophic status of Peninsula Lake, possibly due to its relatively large hypolimnion. These results suggest that AF represents a useful tool for quantitatively reconstructing the past trophic status of deeper, stratified lakes.},\n\tlanguage = {en},\n\tnumber = {3},\n\turldate = {2018-06-11},\n\tjournal = {Journal of Paleolimnology},\n\tauthor = {Clerk, Saloni and Hall, Roland and Quinlan, Roberto and Smol, John P.},\n\tmonth = mar,\n\tyear = {2000},\n\tnote = {00097},\n\tkeywords = {\\#nosource},\n\tpages = {319--336},\n}\n\n\n\n","author_short":["Clerk, S.","Hall, R.","Quinlan, R.","Smol, J. P."],"key":"clerk_quantitative_2000","id":"clerk_quantitative_2000","bibbaseid":"clerk-hall-quinlan-smol-quantitativeinferencesofpasthypolimneticanoxiaandnutrientlevelsfromacanadanprecambrianshieldlake-2000","role":"author","urls":{"Paper":"https://link.springer.com/article/10.1023/A:1008147127606"},"keyword":["#nosource"],"metadata":{"authorlinks":{}},"html":""},"bibtype":"article","biburl":"https://bibbase.org/zotero/circ-publications","dataSources":["Mdrhvw5KhxFbTbWoS","nbqZWNnSmJwdJFEEB"],"keywords":["#nosource"],"search_terms":["quantitative","inferences","past","hypolimnetic","anoxia","nutrient","levels","canadan","precambrian","shield","lake","clerk","hall","quinlan","smol"],"title":"Quantitative inferences of past hypolimnetic anoxia and nutrient levels from a Canadan Precambrian Shield lake","year":2000}