77 resultados para freshwater marsh
em Brock University, Canada
Resumo:
Thecamoebian (testate amoeba) species diversity and assemblages in reclamation wetlands and lakes in northeastern Alberta respond to chemical and physical parameters associated with oil sands extraction. Ecosystems more impacted by OSPM (oil sands process-affected material) contain sparse, low-diversity populations dominated by centropyxid taxa and Arcella vulgaris. More abundant and diverse thecamoebian populations rich in difflugiid species characterize environments with lower OSPM concentrations. These shelled protists respond quickly to environmental change, allowing year-to-year variations in OSPM impact to be recorded. Their fossil record thus provides corporations with interests in the Athabasca Oil Sands with a potential means of measuring the progression of highlyimpacted aquatic environments to more natural wetlands. Development of this metric required investigation of controls on their fossil assemblage (e.g. seasonal variability, fossilization potential) and their biogeographic distribution, not only in the constructed lakes and wetlands on the oil sands leases, but also in natural environments across Alberta.
Resumo:
Crawford Lake, Ontario, provides an ideal natural laboratory to study the response of freshwater dinoflagellates to cultural eutrophication. The anoxic bottom waters that result from meromixis in this small (2.4 ha) but deep (24 m) lake preserve varved sediments that host an exceptional fossil record. These annual layers provide dates for human activity (agriculture and land disturbance) around the lake over the last millennium by both Iroquoian village farmers (ca. A.D. 1268-1486) and Canadian farmers beginning ~A.D. 1883. The well established separate intervals of human activity around Crawford Lake, together with an abundance of available data from other fossil groups, allow us to further investigate the potential use of the cyst of freshwater dinoflagellates in studies of eutrophication. Cyst morphotypes observed have been assigned as Peridinium willei Huitfeldt-Kaas, Peridinium wisconsinense Eddy and Peridinium volzii Lemmermann and Parvodinium inconspicuum (Lemmermann) Carty. The latter two cyst-theca relationships were determined by culturing and by the exceptional preservation of thecae of P. inconspicuum in varves deposited at times of anthropogenic reductions in dissolved oxygen.
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Letter (unsigned) to R.A. Lucas suggesting that the mapping of the marsh be put off until after the next meeting. The rest of the letter deals with licenses, Nov. 29, 1882.
Resumo:
Memo about the Point Pelee Marsh in which the writer [S.D. Woodruff] states that a considerable portion of this marsh is a Government Naval Reserve which the South Essex Gun Club has leased from the Dominion Government for a period of 21 years. The club is comprised of several men who have applied for and act of incorporation by the Long Point and Turkey Point Companies, n.d.
Resumo:
Memo regarding the drainage of marsh lands (1 page, handwritten), Jan. 15, 1855.
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Memorandum respecting the marsh drainage (2 ½ pages, handwritten), July 7, 1855.
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Report by Jacob Misner on setting contracts for deepening and clearing ditches and estimates of quantities and costs of marsh drainage (3 ½ pages, handwritten). This is marked as a copy, July 14, 1855.
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Plan of levels of marsh land on the line of the proposed ditch from Lyons Creek Culvert on the Welland Canal to lot no. 32 in the 2nd concession of Wainfleet (1 page, hand drawn), n.d.
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Estimate of amount of excavation done by A. Cook on the ditch for marsh lands drainage, Aug. 29, 1855.
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Estimate of work done on marsh drainage by A. Cook, signed by S.D. Woodruff, Aug. 31, 1855.
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Estimate of work done on marsh lands drainage by Alexander Cook, signed by S.D. Woodruff, Nov. 10, 1855.
Resumo:
Estimate of work done on marsh lands drainage by A. Cook and A. Mains and an estimate of time on the marsh lands survey from September to November by Fred Holmes, Thomas Baird and Joseph Simpson. This is signed by S.D. Woodruff, Nov. 29, 1855.
Resumo:
Estimate of work done on marsh lands drainage by Alexander Cook and Andrew Mains. This is signed by S.D. Woodruff. Also on this sheet is pay roll for engineer services for the months of September, October and November, 1855. This was paid to Frederick Holmes, Thomas Baird, Joseph Simpson and Len [illegible name], Nov.30, 1855.
Resumo:
Estimates for marsh drainage sent to Dexter Deverardo from S.D. Woodruff for Alexander Cook and Andrew Mains, Nov. 30, 1855.
Resumo:
Estimate of work done on marsh drainage by Alexander Cook and Andrew Mains, Nov. 1855.