Nitrogen and C/N ratios in the sediments of Lakes Superior, Huron, St. Clair, Erie, and Ontario

1977 ◽  
Vol 14 (10) ◽  
pp. 2402-2413 ◽  
Author(s):  
A. L. W. Kemp ◽  
R. L. Thomas ◽  
H. K. T. Wong ◽  
L. M. Johnston

The distribution of nitrogen (N) was determined on 1238 surface sediment samples (0–3 cm) and 24 cores from Lakes Superior, Huron, St. Clair, Erie, and Ontario. The concentration of N was greatest in the depositional basins of the lakes. The N concentrations decreased sharply from high values at the sediment–water interface to uniformly lower N values at the base of the cores. The surface enrichment was related to increased inputs of N to the lakes since settlement of the region in the order: Lake Ontario > Lake Erie [Formula: see text] Lake Superior > Lake Huron > Georgian Bay.The organic carbon: total nitrogen (C/N) ratios averaged 10.2 in the surface sediments with a range of 5.1 to 66.0. The lowest ratios were found in the depositional basins, with the exception of Lake St. Clair. The magnitude of the C/N ratios was related to the source of the organic matter. Plankton, which are the main source of Org-N in the lakes, accounted for C/N ratios between 7 and 9. Dilution of the modern sediment with organic matter from glacial deposits yielded the higher ratios and low Org-C contents in the nondepositional zones. The high C/N ratios and Org-C contents in Lake St. Clair were believed to be due to a large component of macrophytes in the inputs of organic matter to the lake sediments.

1984 ◽  
Vol 19 (1) ◽  
pp. 27-36 ◽  
Author(s):  
Alena Mudroch

Abstract Surface sediment samples obtained at the offshore and nearshore area of Lake Erie were separated into eight different size fractions ranging from <2 µm to 250 µm. The concentration of major elements (Si, Al, Ca, Mg, K, Na, Fe, Mn and P), metals (Zn, Cu, Cr, Ni, V, Co and Pb) and organic matter was determined together with the mineralogical composition and morphology of the particles in each size fraction. The distribution of the metals in the offshore sediment was bimodal with the majority of the metals divided between the 63 to 250 um size fraction which also contained the highest concentration of organic matter (about 20%) and the <4 µm fraction containing up to 60% of clay minerals. However, the metals in the nearshore sediment were associated mainly with the clay minerals.


1977 ◽  
Vol 34 (10) ◽  
pp. 1878-1889 ◽  
Author(s):  
J. C. Schneider ◽  
J. H. Leach

Changes in walleye (Stizostedion vitreum vitreum) stocks in the Great Lakes from 1800 to 1975 were linked to proliferation of foreign species of fish and culturally induced sources of stress — exploitation, nutrient loading, alteration of spawning habitat, and toxic materials. During the 1800s, three small spawning stocks (and probably many others) were damaged or destroyed because of either overfishing or elimination of spawning habitat through logging, pollution, or damming.During 1900–40, stocks in the Michigan waters of Lake Superior, southern Green Bay, the Thunder Bay River of Lake Huron, the North Channel of Lake Huron, and the New York waters of Lake Ontario declined gradually. Pollution, in general, and degradation of spawning habitat, in particular, probably caused three of the declines and overexploitation was suspected in two instances. In addition, the decline of three of these stocks occurred when rainbow smelt (Osmerus mordax) were increasing.During 1940–75, stocks in seven areas declined abruptly: Saginaw Bay (1944), northern Green Bay (1953), Muskegon River (mid-1950s), western Lake Erie (1955), Nipigon Bay (late 1950s), Bay of Quinte (1960), and Black Bay (mid-1960s). The decline of each stock was associated with a series of weak year-classes. The stocks were exposed to various sources of stress, including overexploitation, pollution, and interaction with foreign species, which, if not important in the decline, may be suppressing recovery. Only the western Lake Erie stock recovered, in part due to a reduction in exploitation and, possibly, because of the relatively low density of smelt and alewives (Alosa pseudoharengus) in the nursery areas.Relatively stable stocks persisted in five areas: Wisconsin waters of Lake Superior, Lake St. Clair — southern Lake Huron, eastern Lake Erie, northern Lake Huron, and parts of Georgian Bay. Pollution problems were relatively minor in these areas and exploitation was light during recent decades. Apparently these stocks were more capable of withstanding the additional stresses exerted by alien species. Key words: population fluctuations, Percidae, Stizostedion, Great Lakes walleye, history of fisheries, summary of stresses, harvests, management implications


1986 ◽  
Vol 43 (2) ◽  
pp. 407-415 ◽  
Author(s):  
Claire L. Schelske ◽  
Eugene F. Stoermer ◽  
Gary L. Fahnenstiel ◽  
Mark Haibach

Our hypothesis that silica (Si) depletion in Lake Michigan and the severe Si depletion that characterizes the lower Great Lakes were induced by increased phosphorus (P) inputs was supported by bioassay experiments showing increased Si uptake by diatoms with relatively small P enrichments. We propose that severe Si depletion (Si concentrations being reduced to ≤0.39 mg SiO2∙L−1 prior to thermal stratification) results when P levels are increased to the extent that increased diatom production reduces Si concentrations to limiting levels during the thermally mixed period. Large P enrichments such as those that characterized the eastern and central basis of Lake Erie and Lake Ontario in the early 1970s are necessary to produce severe Si depletion. It is clear that severe Si depletion in the lower lakes was produced by P enrichment because inflowing waters from Lake Huron have smaller P concentrations and larger Si concentrations than the outflowing waters of either Lake Erie or Lake Ontario. Severe Si depletion probably began in the 1940s or 1950s as the result of increased P loads from expanded sewering of an increasing urban population and the introduction of phosphate detergents. The model proposed for biogeochemical Si depletion is consistent with previous findings of high rates of internal recycling because, under steady-state conditions for Si inputs, any increase in diatom production will produce an increase in permanent sedimentation of biogenic Si provided some fraction of the increased biogenic Si production is not recycled or unless there is a compensating increase in dissolution of diatoms.


1995 ◽  
Vol 1995 (1) ◽  
pp. 855A-855
Author(s):  
Philip Baker ◽  
Christine Rowe

ABSTRACT Environmental sensitivity atlases of the Canadian shorelines of Lake Superior, Lake Ontario, and Lake Huron have been completed in digital (desktop geographic information system) and paper formats for use in responses to spills of oil and other hazardous materials. These atlases allow responders to work from a common basis to rapidly identify the resources at risk during a spill and their relative priorities for protection and cleanup.


2010 ◽  
Vol 77 (3) ◽  
pp. 1061-1068 ◽  
Author(s):  
George E. Hannett ◽  
Ward B. Stone ◽  
Stephen W. Davis ◽  
Danielle Wroblewski

ABSTRACTThe genetic relatedness ofClostridium botulinumtype E isolates associated with an outbreak of wildlife botulism was studied using random amplification of polymorphic DNA (RAPD). Specimens were collected from November 2000 to December 2008 during a large outbreak of botulism affecting birds and fish living in and around Lake Erie and Lake Ontario. In our present study, a total of 355 wildlife samples were tested for the presence of botulinum toxin and/or organisms. Type E botulinum toxin was detected in 110 samples from birds, 12 samples from fish, and 2 samples from mammals. Sediment samples from Lake Erie were also examined for the presence ofC. botulinum. Fifteen of 17 sediment samples were positive for the presence ofC. botulinumtype E. Eighty-oneC. botulinumisolates were obtained from plants, animals, and sediments; of these isolates, 44C. botulinumisolates produced type E toxin, as determined by mouse bioassay, while the remaining 37 isolates were not toxic for mice. All toxin-producing isolates were typed by RAPD; that analysis showed 12 different RAPD types and multiple subtypes. Our study thus demonstrates that multiple genetically distinct strains ofC. botulinumwere involved in the present outbreak of wildlife botulism. We found thatC. botulinumtype E is present in the sediments of Lake Erie and that a large range of bird and fish species is affected.


1996 ◽  
Vol 31 (2) ◽  
pp. 411-432 ◽  
Author(s):  
Michael E. Comba ◽  
Janice L. Metcalfe-Smith ◽  
Klaus L.E. Kaiser

Abstract Zebra mussels were collected from 24 sites in Lake Erie, Lake Ontario and the St. Lawrence River between 1990 and 1992. Composite samples of whole mussels (15 sites) or soft tissues (9 sites) were analyzed for residues of organochlo-rine pesticides and PCBs to evaluate zebra mussels as biomonitors for organic contaminants. Mussels from most sites contained measurable quantities of most of the analytes. Mean concentrations were (in ng/g, whole mussel dry weight basis) 154 ΣPCB, 8.4 ΣDDT, 3.5 Σchlordane, 3.4 Σaldrin, 1.4 ΣBHC, 1.0 Σendosulfan, 0.80 mirex and 0.40 Σchlorobenzene. Concentrations varied greatly between sites, i.e., from 22 to 497 ng/g for ΣPCB and from 0.08 to 11.6 ng/g for ΣBHC, an indication that mussels are sensitive to different levels of contamination. Levels of ΣPCB and Σendosulfan were highest in mussels from the St. Lawrence River, whereas mirex was highest in those from Lake Ontario. Overall, mussels from Lake Erie were the least contaminated. These observations agree well with the spatial contaminant trends shown by other biomoni-toring programs. PCB congener class profiles in zebra mussels are also typical for nearby industrial sources, e.g., mussels below an aluminum casting plant contained 55% di-, tri- and tetrachlorobiphenyls versus 31% in those upstream. We propose the use of zebra mussels as biomonitors of organic contamination in the Great Lakes.


Water ◽  
2020 ◽  
Vol 12 (12) ◽  
pp. 3511
Author(s):  
Elena Gershelis ◽  
Andrey Grinko ◽  
Irina Oberemok ◽  
Elizaveta Klevantseva ◽  
Natalina Poltavskaya ◽  
...  

Global warming in high latitudes causes destabilization of vulnerable permafrost deposits followed by massive thaw-release of organic carbon. Permafrost-derived carbon may be buried in the nearshore sediments, transported towards the deeper basins or degraded into the greenhouse gases, potentially initiating a positive feedback to climate change. In the present study, we aim to identify the sources, distribution and degradation state of organic matter (OM) stored in the surface sediments of the Laptev Sea (LS), which receives a large input of terrestrial carbon from both Lena River discharge and intense coastal erosion. We applied a suite of geochemical indicators including the Rock Eval parameters, traditionally used for the matured OM characterization, and terrestrial lipid biomarkers. In addition, we analyzed a comprehensive grain size data in order to assess hydrodynamic sedimentation regime across the LS shelf. Rock-Eval (RE) data characterize LS sedimentary OM with generally low hydrogen index (100–200 mg HC/g TOC) and oxygen index (200 and 300 CO2/g TOC) both increasing off to the continental slope. According to Tpeak values, there is a clear regional distinction between two groups (369–401 °C for the inner and mid shelf; 451–464 °C for the outer shelf). We suggest that permafrost-derived OM is traced across the shallow and mid depths with high Tpeak and slightly elevated HI values if compared to other Arctic continental margins. Molecular-based degradation indicators show a trend to more degraded terrestrial OC with increasing distance from the coast corroborating with RE results. However, we observed much less variation of the degradation markers down to the deeper sampling horizons, which supports the notion that the most active OM degradation in LS land-shelf system takes part during the cross-shelf transport, not while getting buried deeper.


1972 ◽  
Vol 50 (9) ◽  
pp. 1183-1188 ◽  
Author(s):  
M. Chen ◽  
G. Power

In samples taken monthly throughout the year the percentage of American smelt in Lake Ontario and Lake Erie containing cysts of Glugea hertwigi was 5.2% and 62.7% respectively. Sexual differences in incidence were observed, the significance of which was uncertain as results from the two lakes were contradictory.In male fish infection was almost entirely restricted to the digestive tract with few cysts in the liver, skin, and testes. In female fish the digestive tract and ovaries were similarly infected.Seasonal fluctuations in Glugea infection were obvious and seemed correlated with the gonadal cycle. In both sexes the highest parasite load corresponded with the onset of maturation.A striking difference in fecundity between the two smelt populations was attributed to the Glugea infection. In females parasite cysts replaced ovarian tissue, causing a reduction in the number of maturing eggs.


2017 ◽  
Vol 68 (9) ◽  
pp. 1704 ◽  
Author(s):  
Leandro Bergamino ◽  
Mark Schuerch ◽  
Adriana Tudurí ◽  
Silvina Carretero ◽  
Felipe García-Rodríguez

We investigated carbon isotopic ratios (δ13C) v. carbon to nitrogen (C : N) ratios for surface sediments throughout a large estuarine system (Río de la Plata, RdlP), combined with sediment cores from adjacent marshes to infer main carbon sources. We also evaluated the influence of the El Niño–Southern Oscillation (ENSO) and associated high freshwater-discharge events on the organic-matter transport within the estuary. The isotopic pattern in surface sediments of the RdlP showed the upper reaches to be influenced by riverine particulate matter (δ13C range: –24 to –26‰). Similarly, in the sediment cores from marshes of the upper reaches, δ13C values decreased from –24‰ in ancient sediments to –28‰ in recent sediments, reflecting an increased contribution of organic matter from land, including C3 plants and freshwater phytoplankton, during the past 50 years. However, the lower reaches represent a depositional environment of marine algae (δ13C range: –21 to –23‰), with no influence of detritus from adjacent marshes, indicating minor erosion of the marshes in the lower reaches operating as carbon-sink habitats. Our isotopic analysis showed that the transport and deposition of terrigenous organic matter within the RdlP and adjacent marsh habitat appear to be both temporally and spatially linked to hydrology patterns.


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