Phallodrilus hallae, a new tubificid oligochaete from the St. Lawrence Great Lakes

1975 ◽  
Vol 53 (7) ◽  
pp. 934-941 ◽  
Author(s):  
David G. Cook ◽  
Jarl K. Hiltunen
Keyword(s):  
Great Lakes ◽  
Indicator Species ◽  
Lake Superior ◽  
Lake Huron ◽  
High Quality ◽  
Relict Species ◽  
Marine Transgression ◽  
Georgian Bay ◽  
Restricted Distribution

The predominantly marine tubificid genus Phallodrilus is defined, a key to its nine species constructed, and an illustrated description of Phallodrilus hallae n. sp. from the St. Lawrence Great Lakes presented. The species is distinguished from other members of the genus by its well-developed atrial musculature, extensions of which ensheath the posterior prostatic ducts.Phallodrilus hallae n. sp. is a small worm which is widely distributed in the sublittoral and profundal benthos of Lake Superior; lakewide it occurred in mean densities of 50 individuals per square metre. Available records indicate a more restricted distribution in Lake Huron and Georgian Bay. We suggest that P. hallae n. sp. is either a glaciomarine relict species, or that it entered the Great Lakes system at the time of the marine transgression of the St. Lawrence valley. The apparent restriction of P. hallae n. sp. to waters of high quality suggests that it may be a sensitive oligotrophic indicator species.

Paleohydrology of the upper Laurentian Great Lakes from the late glacial to early Holocene

2009 ◽  
Vol 71 (3) ◽  
pp. 397-408 ◽  
Author(s):  
Andy Breckenridge ◽  
Thomas C. Johnson
Keyword(s):  
Great Lakes ◽  
Lake Michigan ◽  
Lake Superior ◽  
Late Glacial ◽  
Lake Huron ◽  
Michigan Basin ◽  
Great Lakes Basin ◽  
Lake Agassiz ◽  
Sharp Drop ◽  
Freshwater Fluxes

AbstractBetween 10,500 and 9000 cal yr BP, δ18O values of benthic ostracodes within glaciolacustrine varves from Lake Superior range from − 18 to − 22‰ PDB. In contrast, coeval ostracode and bivalve records from the Lake Huron and Lake Michigan basins are characterized by extreme δ18O variations, ranging from values that reflect a source that is primarily glacial (∼ − 20‰ PDB) to much higher values characteristic of a regional meteoric source (∼ − 5‰ PDB). Re-evaluated age models for the Huron and Michigan records yield a more consistent δ18O stratigraphy. The striking feature of these records is a sharp drop in δ18O values between 9400 and 9000 cal yr BP. In the Huron basin, this low δ18O excursion was ascribed to the late Stanley lowstand, and in the Lake Michigan basin to Lake Agassiz flooding. Catastrophic flooding from Lake Agassiz is likely, but a second possibility is that the low δ18O excursion records the switching of overflow from the Lake Superior basin from an undocumented northern outlet back into the Great Lakes basin. Quantifying freshwater fluxes for this system remains difficult because the benthic ostracodes in the glaciolacustrine varves of Lake Superior and Lake Agassiz may not record the average δ18O value of surface water.

Walleye (Stizostedion vitreum vitreum) Fluctuations in the Great Lakes and Possible Causes, 1800–1975

1977 ◽  
Vol 34 (10) ◽  
pp. 1878-1889 ◽  
Author(s):  
J. C. Schneider ◽  
J. H. Leach
Keyword(s):  
Great Lakes ◽  
Lake Erie ◽  
Lake Superior ◽  
Lake Huron ◽  
Stizostedion Vitreum ◽  
Spawning Habitat ◽  
Green Bay ◽  
Western Lake ◽  
Foreign Species ◽  
Western Lake Erie

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

ELECTRONIC DESKTOP MAPPING: ENVIRONMENTAL SENSITIVITY ATLASES OF THE GREAT LAKES

1995 ◽  
Vol 1995 (1) ◽  
pp. 855A-855
Author(s):  
Philip Baker ◽  
Christine Rowe
Keyword(s):  
Information System ◽  
Geographic Information System ◽  
Great Lakes ◽  
Lake Superior ◽  
Lake Ontario ◽  
Hazardous Materials ◽  
Geographic Information ◽  
Lake Huron ◽  
Environmental Sensitivity ◽  
Common Basis

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.

scholarly journals How Many Ciscoes are Needed for Stocking in the Laurentian Great Lakes?

2021 ◽  
Author(s):  
Benjamin Rook ◽  
Michael J. Hansen ◽  
Charles R. Bronte
Keyword(s):  
Great Lakes ◽  
Lake Michigan ◽  
Lake Superior ◽  
Production Capacity ◽  
Lake Huron ◽  
Laurentian Great Lakes ◽  
Saginaw Bay ◽  
Thunder Bay ◽  
Western Lake ◽  
Coregonus Artedi

Historically, Cisco Coregonus artedi and deepwater ciscoes Coregonus spp. were the most abundant and ecologically important fish species in the Laurentian Great Lakes, but anthropogenic influences caused nearly all populations to collapse by the 1970s. Fishery managers have begun exploring the feasibility of restoring populations throughout the basin, but questions regarding hatchery propagation and stocking remain. We used historical and contemporary stock-recruit parameters previously estimated for Ciscoes in Wisconsin waters of Lake Superior, with estimates of age-1 Cisco rearing habitat (broadly defined as total ha ≤ 80 m depth) and natural mortality, to estimate how many fry (5.5 months post-hatch), fall fingerling (7.5 months post-hatch), and age-1 (at least 12 months post-hatch) hatchery-reared Ciscoes are needed for stocking in the Great Lakes to mimic recruitment rates in Lake Superior, a lake that has undergone some recovery. Estimated stocking densities suggested that basin-wide stocking would require at least 0.641-billion fry, 0.469-billion fall fingerlings, or 0.343-billion age-1 fish for a simultaneous restoration effort targeting historically important Cisco spawning and rearing areas in Lakes Huron, Michigan, Erie, Ontario, and Saint Clair. Numbers required for basin-wide stocking were considerably greater than current or planned coregonine production capacity, thus simultaneous stocking in the Great Lakes is likely not feasible. Provided current habitat conditions do not preclude Cisco restoration, managers could maximize the effectiveness of available production capacity by concentrating stocking efforts in historically important spawning and rearing areas, similar to the current stocking effort in Saginaw Bay, Lake Huron. Other historically important Cisco spawning and rearing areas within each lake (listed in no particular order) include: (1) Thunder Bay in Lake Huron, (2) Green Bay in Lake Michigan, (3) the islands near Sandusky, Ohio, in western Lake Erie, and (4) the area near Hamilton, Ontario, and Bay of Quinte in Lake Ontario. Our study focused entirely on Ciscoes but may provide a framework for describing future stocking needs for deepwater ciscoes.

Prescribed Courses for the Navigation of the Great Lakes of North America

1964 ◽  
Vol 17 (4) ◽  
pp. 376-385
Author(s):  
O. T. Burnham ◽  
C. M. Jansky
Keyword(s):  
United States ◽  
North America ◽  
Great Lakes ◽  
Lake Michigan ◽  
Lake Superior ◽  
The United States ◽  
Lake Huron ◽  
Border Line ◽  
West Lake ◽  
North Lake

The Great Lakes of North America, four of which form the border-line between the United States and the Dominion of Canada, increase in size from east to west, Lake Ontario being the smallest but still 180 statute miles in length. Lake Erie is the shallowest, with an east to west extent of 236 statute miles. Lake Huron has a maximum length of 247 statute miles from south to north. Lake Michigan is the only one of the lakes entirely within the confines of the United States, extending 321 statute miles from north to south. The largest and deepest of the group is Lake Superior, where the principal sailing course from Sault Ste. Marie to Duluth is 383 statute miles.

Role of Phosphorus in Great Lakes Eutrophication: Is There a Controversy?

1979 ◽  
Vol 36 (3) ◽  
pp. 286-288 ◽  
Author(s):  
Claire L. Schelske
Keyword(s):  
Great Lakes ◽  
Lake Michigan ◽  
Lake Superior ◽  
Conclusive Evidence ◽  
Lake Huron ◽  
Limiting Factors ◽  
Upper Great Lakes ◽  
Limiting Nutrients ◽  
Cast Doubt

Phosphorus is undoubtedly the major plant nutrient controlling phytoplankton growth in the upper Great Lakes and the nutrient responsible for accelerated eutrophication in the lower Great Lakes. No studies published before 1970 provide conclusive evidence of the specific roles of phosphorus and other nutrients as growth limiting factors for phytoplankton. Improper citation of references can inadvertently cast doubt on the key role of phosphorus, or denigrate uncited work, depending on the reader's background. Key words: phosphorus, nitrogen, eutrophication, phytoplankton, limiting nutrients, Lake Michigan, Lake Superior, Lake Huron

THE GROUNDING OF THE IMPERIAL ST. CLAIR A CASE HISTORY OF CONTENDING WITH OIL IN ICE

1979 ◽  
Vol 1979 (1) ◽  
pp. 371-375 ◽  
Author(s):  
C. J. Beckett
Keyword(s):  
Great Lakes ◽  
Diesel Fuel ◽  
Case History ◽  
Oil Products ◽  
Lake Huron ◽  
Winter Period ◽  
Georgian Bay ◽  
Remaining Oil ◽  
History Of ◽  
Ice Conditions

ABSTRACT During mid-morning on December 23, 1976, the oil products tanker Imperial St. Clair, carrying over 10,400 tons of cargo, grounded in the approaches to Parry Sound. Located on the eastern shores of Georgian Bay in Lake Huron, this port is a central depot supplying a large hinterland with petroleum. At the time of grounding, new winter ice was present in varying thicknesses and temperatures and winds varied from day to day, resulting in very difficult conditions in which to effect operations. An estimated 57,000 gallons of diesel fuel and gasoline was lost during the initial impact and later during oil transfer operations. The methods used to boom off the remaining oil through the winter period accounted for almost 40,000 gallons of the remainder. This paper deals with the chronology of events after the grounding, the problems encountered with the safety of personnel, methodology of removal under ice conditions and the logistics of the operation. The result was total success, thus safeguarding one of the most beautiful areas of the Great Lakes.

scholarly journals Toxins and Other Bioactive Metabolites in Deep Chlorophyll Layers Containing the Cyanobacteria Planktothrix cf. isothrix in Two Georgian Bay Embayments, Lake Huron

Toxins ◽  
2021 ◽  
Vol 13 (7) ◽  
pp. 445
Author(s):  
Arthur Zastepa ◽  
Todd R. Miller ◽  
L. Cynthia Watson ◽  
Hedy Kling ◽  
Susan B. Watson
Keyword(s):  
Thermal Stratification ◽  
Chemical Defence ◽  
Euphotic Zone ◽  
Lake Huron ◽  
Metabolic Inhibitors ◽  
Bioactive Metabolites ◽  
Total Biomass ◽  
Key Factors ◽  
Georgian Bay ◽  
And Function

The understanding of deep chlorophyll layers (DCLs) in the Great Lakes—largely reported as a mix of picoplankton and mixotrophic nanoflagellates—is predominantly based on studies of deep (>30 m), offshore locations. Here, we document and characterize nearshore DCLs from two meso-oligotrophic embayments, Twelve Mile Bay (TMB) and South Bay (SB), along eastern Georgian Bay, Lake Huron (Ontario, Canada) in 2014, 2015, and 2018. Both embayments showed the annual formation of DCLs, present as dense, thin, metalimnetic plates dominated by the large, potentially toxic, and bloom-forming cyanobacteria Planktothrix cf. isothrix. The contribution of P. cf. isothrix to the deep-living total biomass (TB) increased as thermal stratification progressed over the ice-free season, reaching 40% in TMB (0.6 mg/L at 9.5 m) and 65% in South Bay (3.5 mg/L at 7.5 m) in 2015. The euphotic zone in each embayment extended down past the mixed layer, into the nutrient-enriched hypoxic hypolimnia, consistent with other studies of similar systems with DCLs. The co-occurrence of the metal-oxidizing bacteria Leptothrix spp. and bactivorous flagellates within the metalimnetic DCLs suggests that the microbial loop plays an important role in recycling nutrients within these layers, particularly phosphate (PO4) and iron (Fe). Samples taken through the water column in both embayments showed measurable concentrations of the cyanobacterial toxins microcystins (max. 0.4 µg/L) and the other bioactive metabolites anabaenopeptins (max. ~7 µg/L) and cyanopeptolins (max. 1 ng/L), along with the corresponding genes (max. in 2018). These oligopeptides are known to act as metabolic inhibitors (e.g., in chemical defence against grazers, parasites) and allow a competitive advantage. In TMB, the 2018 peaks in these oligopeptides and genes coincided with the P. cf. isothrix DCLs, suggesting this species as the main source. Our data indicate that intersecting physicochemical gradients of light and nutrient-enriched hypoxic hypolimnia are key factors in supporting DCLs in TMB and SB. Microbial activity and allelopathy may also influence DCL community structure and function, and require further investigation, particularly related to the dominance of potentially toxigenic species such as P. cf. isothrix.

scholarly journals Lake-to-Lake Cloud Bands: Frequencies and Locations

2007 ◽  
Vol 135 (12) ◽  
pp. 4202-4213 ◽  
Author(s):  
Yarice Rodriguez ◽  
David A. R. Kristovich ◽  
Mark R. Hjelmfelt
Keyword(s):  
High Resolution ◽  
Great Lakes ◽  
Satellite Imagery ◽  
Lake Superior ◽  
Great Lakes Region ◽  
Lake Effect ◽  
Time Period ◽  
High Resolution Satellite Imagery

Abstract Premodification of the atmosphere by upwind lakes is known to influence lake-effect snowstorm intensity and locations over downwind lakes. This study highlights perhaps the most visible manifestation of the link between convection over two or more of the Great Lakes lake-to-lake (L2L) cloud bands. Emphasis is placed on L2L cloud bands observed in high-resolution satellite imagery on 2 December 2003. These L2L cloud bands developed over Lake Superior and were modified as they passed over Lakes Michigan and Erie and intervening land areas. This event is put into a longer-term context through documentation of the frequency with which lake-effect and, particularly, L2L cloud bands occurred over a 5-yr time period over different areas of the Great Lakes region.

Biogeography of island floras in the Great Lakes. I. Species richness and composition in relation to gull nesting activities

1989 ◽  
Vol 67 (4) ◽  
pp. 961-969 ◽  
Author(s):  
E. H. Hogg ◽  
J. K. Morton ◽  
Joan M. Venn
Keyword(s):  
Species Richness ◽  
Great Lakes ◽  
Plant Species ◽  
Vascular Plants ◽  
Soil Nutrient ◽  
Lake Huron ◽  
Great Lakes Region ◽  
Alien Plant ◽  
Species Area ◽  
The Difference

Species–area relations of vascular plants and the effect of nesting colonies of gulls on plant species composition were investigated for 77 islands in Georgian Bay and Lake Huron in the Great Lakes region of Canada. The percentage of plant species classed as alien, annual, or biennial was significantly greater on islands with gull colonies. The slope of the species–area curve was significantly steeper on islands supporting gull colonies compared with islands lacking gull colonies. The expected decline in species richness with increased island remoteness was not detected statistically using multiple regression analysis. The difference in species–area slopes does not appear to reflect a lower propagule immigration rate to islands with gull colonies, because gulls are important in the dispersal of alien plant species to these islands. Larger islands with gull colonies tended to have richer floras than islands of similar size without gull colonies. It is suggested that on these larger islands the presence of gull colonies produces a gradient of soil nutrient and disturbance regimes, thus increasing habitat heterogeneity and species richness.

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