Inshore-offshore Distribution of Larval Fishes in Lake Superior off the Western Coast of the Keweenaw Peninsula, Michigan

2004 ◽  
Vol 30 ◽  
pp. 369-384 ◽  
Author(s):  
Jason K. Oyadomari ◽  
Nancy A. Auer
Keyword(s):  
Lake Superior ◽  
Western Coast ◽  
Larval Fishes ◽  
Keweenaw Peninsula

scholarly journals Changing Water Levels in Lake Superior, MI (USA) Impact Periphytic Diatom Assemblages in the Keweenaw Peninsula

Water ◽  
2021 ◽  
Vol 13 (3) ◽  
pp. 253
Author(s):  
M. Megan Woller-Skar ◽  
Alexandra Locher ◽  
Ellen Audia ◽  
Evan W. Thomas
Keyword(s):  
Water Level ◽  
Surface Area ◽  
Lake Superior ◽  
Water Levels ◽  
Ecological Processes ◽  
Periphyton Community ◽  
Water Level Changes ◽  
Community Assemblages ◽  
Keweenaw Peninsula ◽  
The Impact

Predicted climate-induced changes in the Great Lakes include increased variability in water levels, which may shift periphyton habitat. Our goal was to determine the impacts of water level changes in Lake Superior on the periphyton community assemblages in the Keweenaw Peninsula with different surface geology. At three sites, we identified periphyton assemblages as a function of depth, determined surface area of periphyton habitat using high resolution bathymetry, and estimated the impact of water level changes in Lake Superior on periphyton habitat. Our results suggest that substrate geology influences periphyton community assemblages in the Keweenaw Peninsula. Using predicted changes in water levels, we found that a decrease in levels of 0.63 m resulted in a loss of available surface area for periphyton habitat by 600 to 3000 m2 per 100 m of shoreline with slopes ranging 2 to 9°. If water levels rise, the surface area of substrate will increase by 150 to 370 m2 per 100 m of shoreline, as the slopes above the lake levels are steeper (8–20°). Since periphyton communities vary per site, changes in the surface area of the substrate will likely result in a shift in species composition, which could alter the structure of aquatic food webs and ecological processes.

Transport and growth of larval cisco (Coregonus artedi) in the Keweenaw Current region of Lake Superior

2008 ◽  
Vol 65 (7) ◽  
pp. 1447-1458 ◽  
Author(s):  
Jason K. Oyadomari ◽  
Nancy A. Auer
Keyword(s):  
Growth Rate ◽  
Surface Water ◽  
Temperature Regime ◽  
Growth Rates ◽  
Lake Superior ◽  
Temporal Variations ◽  
Western Coast ◽  
Coregonus Artedi ◽  
Current Region ◽  
Spawning Sites

Larval cisco ( Coregonus artedi ) were sampled from Lake Superior off the western coast of the Keweenaw Peninsula (Michigan, USA) to determine if the Keweenaw Current influences their distribution and growth. Bongo net tows were conducted during April–June 2000 from four transects extending from 0.1 to 17 km offshore. For most sampling dates, cisco tended to be slightly more abundant, larger, and older at inshore locations. Later-hatched larvae appeared at the western-most transects first, during which time earlier-hatched larvae disappeared from the study area. This pattern followed what would be expected if larvae were being transported eastward by the prevailing Keweenaw Current. Estimated growth rates were 84% higher for later-hatched compared with earlier-hatched larvae and 25% lower for offshore larvae from the eastern-most transects compared with elsewhere. Accordingly, surface water temperatures partly explained spatial and temporal variations in growth rate. These results indicate that cisco larvae in Lake Superior may be transported great distances from major spawning sites by longshore currents and that the temperature regime of nursery areas may largely control their growth.

Movements of Hatchery-Reared Lake Trout in Lake Superior

1965 ◽  
Vol 22 (4) ◽  
pp. 999-1024 ◽  
Author(s):  
Richard L. Pycha ◽  
William R. Dryer ◽  
George R. King
Keyword(s):  
Great Lakes ◽  
Lake Trout ◽  
Lake Superior ◽  
Salvelinus Namaycush ◽  
Surface Currents ◽  
Gill Nets ◽  
East Lake ◽  
History Of ◽  
Keweenaw Peninsula

The history of stocking of lake trout (Salvelinus namaycush) in the Great Lakes is reviewed.The study of movements is based on capture of 24,275 fin-clipped lake trout taken in experimental gill nets and trawls and commercial gill nets.Yearling lake trout planted from shore dispersed to 15-fath (27-m) depths in [Formula: see text]. Most fish remained within 2 miles (3.2 km) of the planting site 2 months, but within 4 months some fish had moved as much as 17 miles (27 km). The highest abundance of planted lake trout was in areas 2–4 miles (3.2–6.4 km) from the planting site even 3 years after release. Distance moved and size of fish were not correlated.Dispersal of lake trout begins at planting and probably continues until the fish are mature. Most movement was eastward in southern Lake Superior and followed the counterclockwise surface currents. Movement is most rapid in areas of strong currents and slowest in areas of weak currents or eddies. Movement to areas west of the Keweenaw Peninsula was insignificant from plantings in Keweenaw Bay and nil from other plantings farther east. Lake trout planted in the eastern third of the lake dispersed more randomly than those planted farther west. Few fish moved farther offshore than the 50-fath (91-m) contour. Lake trout planted in Canadian waters made insignificant contributions to populations in US waters.

Life history, distribution, and production of Diporeia near the Keweenaw Peninsula Lake Superior

2009 ◽  
Vol 35 (4) ◽  
pp. 579-590 ◽  
Author(s):  
Nancy A. Auer ◽  
Bridget A. Cannon ◽  
Martin T. Auer
Keyword(s):  
Life History ◽  
Lake Superior ◽  
Keweenaw Peninsula

An interpretation of the first-arrival data of the Lake Superior Experiment by the time-term method

1966 ◽  
Vol 56 (1) ◽  
pp. 141-171
Author(s):  
M. J. Berry ◽  
G. F. West
Keyword(s):  
Lake Superior ◽  
Igneous Rocks ◽  
Low Velocity ◽  
The West ◽  
Head Waves ◽  
First Arrival ◽  
Keweenaw Peninsula ◽  
Time Term ◽  
Similar Basis ◽  
Mohorovičić Discontinuity

abstract The first-arrival data of the Lake Superior Experiment of 1963 have been interpreted by the time-term method. The analysis has shown the method to be well suited to this type of survey, and the results appear to be consistent and meaningful. Approximately 500 first-arrivals from head waves generated at the Mohorovičić discontinuity, have been reduced to estimates of crustal time-terms at over 100 locations. A much shallower refracting surface (here called the Upper Refractor) furnished nearly 1,000 observations to yield upper crustal time-terms at the same locations. The analysis reveals the material beneath the UR and beneath the M to have velocities of 6.63 and 8.10 km/sec respectively. The surface of the Upper Refractor, on the basis of a simple interpretation of the time-terms, is revealed as undulating, coming close to the surface at the edges of the lake and reaching maximum depths of approxmately 15 km to the east and west of the Keweenaw Peninsula. On a similar basis the Mohorovičić discontinuity is revealed as an easterly dipping surface, having a depth of approximately 35 km at the west end of the lake and reaching a maximum depth of about 60 km in the region just west of the Keweenaw Peninsula. Eastwards, the time-term values fluctuate but do not increase or decrease systematically. The velocity of the material lying above the Upper Refractor is not well determined, but appears to be roughly 5.5 km/sec. A perusal of geological literature suggests that this low velocity material is mostly sedimentary, filling a well-known synclincal basin whose axis bends around the Keweenaw Peninsula. This mainly sedimentary section is known to be underlain by a great thickness of igneous rocks, which in all probability corresponds to the Upper Refractor mapped by the seismic studies.

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