Postsettlement Diatom Succession in the Bay of Quinte, Lake Ontario

1985 ◽  
Vol 42 (4) ◽  
pp. 754-767 ◽  
Author(s):  
E. F. Stoermer ◽  
J. A. Wolin ◽  
C. L. Schelske ◽  
D. J. Conley
Keyword(s):  
Lake Ontario ◽  
Benthic Diatoms ◽  
Mining Activities ◽  
Maximum Flux ◽  
Chrysophyte Cysts ◽  
European Settlement ◽  
Early Settlement ◽  
Rapid Transition ◽  
Eutrophic Species ◽  
Qualitative Changes

Siliceous algal microfossil assemblages deposited in the Bay of Quinte prior to European settlement consist of low numbers of benthic diatoms and chrysophyte cysts. Early settlement activities are marked by qualitative changes in the flora and small increases in microfossil flux. Events associated with the Ambrosia horizon produced a rapid transition from assemblages characteristic of oligotrophy environments to those characteristic of eutrophic waters and a large increase in microfossil flux. This was followed by a period of decreasing siliceous microfossil flux and reestablishment of less eutrophic species ca. 1853–61. Minimum siliceous algal microfossil flux and highly atypical assemblages occurred in the period ca. 1879–88, which corresponds to the period of intensive mining activities in the Bay of Quinte watershed. Maximum flux of siliceous microfossils occurred ca. 1900 and declined thereafter, although composition of assemblages deposited indicates increasing eutrophy and displacement of summer-blooming species. We interpret this as evidence of beginning of summer silica limitation. Based on microfossil evidence, the modern eutrophic flora of the bay was established by 1928.

Differences between Nearshore and Offshore Phytoplankton Communities in Lake Ontario

1987 ◽  
Vol 44 (12) ◽  
pp. 2155-2163 ◽  
Author(s):  
I. M. Gray
Keyword(s):  
Chlorophyll A ◽  
Phytoplankton Biomass ◽  
Algal Biomass ◽  
Phytoplankton Community ◽  
Seasonal Pattern ◽  
Principal Component ◽  
Lake Ontario ◽  
Dominant Group ◽  
Phytoplankton Communities ◽  
Eutrophic Species

Differences between nearshore and offshore phytoplankton biomass and composition were evident in Lake Ontario in 1982. Phytoplankton biomass was characterized by multiple peaks which ranged over three orders of magnitude. Perhaps as a consequence of the three times higher current velocities at the northshore station, phytoplankton biomass ranged from 0.09 to 9.00 g∙m−3 compared with 0.10 to 2.40 g∙m−3 for the midlake station. Bacillariophyceae was the dominant group at the northshore station until September when Cyanophyta contributed most to the biomass (83%). Although Bacillariophyceae was the principal component of the spring phytoplankton community at the midlake station, phytoflagellates (49%) and Chlorophyceae (25%) were responsible for summer biomass, with the Chlorophyceae expanding to 80% in the fall. The seasonal pattern of epilimnetic chlorophyll a correlated with temperature. While chlorophyll a concentrations were similar to values from 1970 and 1972, algal biomass had declined and a number of eutrophic species (Melosira binderana, Stephanodiscus tenuis, S. hantzschii var. pusilla, and S. alpinus) previously found were absent in 1982.

Historical Nutrient Enrichment of Lake Ontario: Paleolimnological Evidence

1991 ◽  
Vol 48 (8) ◽  
pp. 1529-1538 ◽  
Author(s):  
Claire L. Schelske
Keyword(s):  
Primary Productivity ◽  
Nutrient Enrichment ◽  
Lake Ontario ◽  
Phosphorus Loading ◽  
Moderate Increase ◽  
Sediment Record ◽  
Carbon Production ◽  
European Settlement ◽  
Exponential Increase ◽  
Major Nutrients

Recent studies of Lake Ontario show four periods of nutrient enrichment that can be identified from the sediment record in this phosphorus-limited system: pristine phosphorus loads (early 1800s before European settlement), moderate increase in phosphorus loading after settlement (beginning approximately 1850), exponential increase in phosphorus loading from urban sources (approximately 1940–70), and decreased phosphorus loading as the result of phosphorus abatement strategies (beginning in mid-1970s). Paleolimnological data are used to infer new paradigms about historical dynamics and cycling of major nutrients. The temporal pattern of organic carbon production closely parallels changes in phosphorus loading. Silica supplies which were replete for diatom production before forest clearance in the mid-1800s became limiting for diatom production in the summer epilimnion after 1865 and in the water column after 1950. Silica reserves were depleted by increased diatom production and sedimentation that resulted from increased phosphorus loading. Biologically induced precipitation of calcite began after 1940 as an indirect effect of increased urban phosphorus loading on primary productivity. Calcite began to be precipitated when historical increases in CO2 utilized for primary productivity increased epilimnetic pH and the calcium carbonate saturation product was exceeded.

Early Founders and the Founder Effect

2019 ◽  
pp. 59-72
Author(s):  
James N. Stanford
Keyword(s):  
New England ◽  
Indigenous People ◽  
Founder Effect ◽  
Settlement Patterns ◽  
Place Names ◽  
European Settlement ◽  
Early Settlement ◽  
Early English

This chapter discusses key social, geographic, and chronological patterns of early English development in New England, including the early European settlement patterns and how they have led to long-term sociolinguistic patterns in the region (the Founder Effect). These early settlement patterns affected which regions within New England came to have different dialect features, creating regional contrasts that endured for generations after the original settlers. The chapter also discusses the role of Indigenous people in the region that came to be known as New England, including their effect on New England place names and the continuing modern role of Indigenous people in the region.

Development and Application of a Water Quality Model for Use in an Environmental Assessment

1980 ◽  
Vol 15 (1) ◽  
pp. 59-72 ◽  
Author(s):  
B.E. Halbert ◽  
B.G. Ibbotson ◽  
J.M. Scharer
Keyword(s):  
Water Quality ◽  
Environmental Assessment ◽  
Lake Ontario ◽  
Quality Parameters ◽  
Mining Activities ◽  
Quality Model ◽  
Model Simulations ◽  
Assessment Study ◽  
The Subject ◽  
Water Quality Trends

Abstract A model was developed for application in an environmental assessment study to allow predictions to be made of future water quality trends with respect to alternative proposals for expanding uranium mining activities in Elliot Lake, Ontario. Four water quality parameters were determined to be of particular importance in the assessment and were the subject of detailed investigations. Results of the model simulations formed the basis for assessing alternative development strategies and identifying those strategies which were most compatible with protection of the environment.

Historical Relationships between Phosphorus Loading and Biogenic Silica Accumulation in Bay of Quinte Sediments

1985 ◽  
Vol 42 (8) ◽  
pp. 1401-1409 ◽  
Author(s):  
Claire L. Schelske ◽  
Daniel J. Conley ◽  
William F. Warwick
Keyword(s):  
Biogenic Silica ◽  
Drainage Basin ◽  
Sediment Accumulation ◽  
Lake Ontario ◽  
Domestic Sewage ◽  
Phosphorus Loading ◽  
Accumulation Rates ◽  
Urban Centers ◽  
European Settlement ◽  
Historical Relationship

Sediments from Warwick's 1972 Glenora-B core from the Bay of Quinte, Lake Ontario, were analyzed to compare the historical relationship between the accumulation of biogenic silica (BSi) and total phosphorus (TP). The similarities in patterns provide evidence that increased phosphorus (P) inputs caused increased diatom production and BSi accumulation. BSi accumulation increased soon after initial European settlement by French Sulpicians in 1669 and reached maximum levels during the early 1850s when forest clearance and erosion of the deforested drainage basin increased sediment accumulation rates 110-fold compared with rates before 1669. Maximum rates of BSi and TP accumulation increased 170-fold and 150-fold, respectively, during the same period. Ratios of BSi:TP were about sixfold greater in the sediments deposited after 1888 than in those deposited prior to 1669, indicating that the proportion of available P in TP inputs increased with increased disposal of domestic sewage into the bay as populations shifted to urban centers. Increases in BSi accumulation above the Ambrosia horizon (dated at 1852) indicate that sediments can be a significant sink for BSi. Although the onset of Si depletion cannot be confirmed with data from this core, there is clear evidence that BSi accumulation increased as the result of increased P inputs.

GEOSPATIAL TECHNOLOGY BASED GEOENVIRONMENTAL IMPACT ASSESSMENT OF SLATE MINING ACTIVITIES

2020 ◽  
Vol 40 (2) ◽  
pp. 330-349
Author(s):  
TEJPAL T ◽  
◽  
M.S. JAGLAN ◽  
B.S. CHAUDHARY ◽  
◽  
...  
Keyword(s):  
Impact Assessment ◽  
Mining Activities ◽  
Geospatial Technology
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