Use of Fish–Otolith-Length Regressions to Infer Size of Double-Crested Cormorant Prey Fish from Recovered Otoliths in Lake Ontario

2005 ◽  
Vol 12 (2) ◽  
pp. 133-140 ◽  
Author(s):  
Robert M. Ross ◽  
James H. Johnson ◽  
Connie M. Adams
Keyword(s):  
Lake Ontario ◽  
Prey Fish ◽  
Fish Otolith

Prey fish exploitation, salmonine production, and pelagic food web efficiency in Lake Ontario

1998 ◽  
Vol 55 (2) ◽  
pp. 318-327 ◽  
Author(s):  
Peter S Rand ◽  
Donald J Stewart
Keyword(s):  
Food Web ◽  
Lake Michigan ◽  
Oncorhynchus Tshawytscha ◽  
Lake Trout ◽  
Coho Salmon ◽  
Lake Ontario ◽  
Osmerus Mordax ◽  
Prey Fish ◽  
Rainbow Smelt ◽  
Time Model

Estimates of production and predation rates from bioenergetic models of chinook salmon (Oncorhynchus tshawytscha), coho salmon (Oncorhynchus kisutch), and lake trout (Salvelinus namaycush) suggest a long-term decline in their gross conversion efficiency (gross production/prey consumption) and the gross production to biomass ratio in Lake Ontario during 1978-1994. The former pattern was caused primarily by a declining trend in adult alewife (Alosa pseudoharengus) energy density during 1978-1985; the latter pattern resulted from reductions in growth rates (coho salmon) and a buildup of the older age-classes in the population (lake trout) over time. Model results suggest that over 100 and 25% of the annual production of adult alewife and rainbow smelt (Osmerus mordax), respectively, was consumed by salmonines during 1990 in Lake Ontario; hence, we claim that recent observations of reduced salmonine growth in Lake Ontario may be a result of prey limitation. Energy transfer from primary production to salmonines appeared to be more efficient in Lake Ontario than in Lake Michigan, probably due to higher stocking levels per unit area and higher densities of preferred prey fish in Lake Ontario. Through separate analyses, we arrived at conflicting conclusions concerning the sustainability of the food web configuration in Lake Ontario during 1990.

Survey of four essential nutrients and thiaminase activity in five Lake Ontario prey fish species

2012 ◽  
Vol 38 (1) ◽  
pp. 11-17 ◽  
Author(s):  
Dale C. Honeyfield ◽  
Marion E. Daniels ◽  
Lisa R. Brown ◽  
Michael T. Arts ◽  
Maureen G. Walsh ◽  
...  
Keyword(s):  
Fish Species ◽  
Lake Ontario ◽  
Prey Fish ◽  
Essential Nutrients

Effect of lake-wide planktivory by the pelagic prey fish community in Lakes Michigan and Ontario

1995 ◽  
Vol 52 (7) ◽  
pp. 1546-1563 ◽  
Author(s):  
Peter S. Rand ◽  
Donald J. Stewart ◽  
Brian F. Lantry ◽  
Lars G. Rudstam ◽  
Ora E. Johannsson ◽  
...  
Keyword(s):  
Lake Michigan ◽  
Supply And Demand ◽  
Lake Ontario ◽  
Production Model ◽  
Trophic Relationships ◽  
Prey Fish ◽  
Prey Resources ◽  
Wet Weight ◽  
Pelagic Prey ◽  
Zooplankton Production

We compared predatory demand by pelagic planktivorous prey fish with invertebrate production in Lake Michigan during 1987 and in Lake Ontario during 1990. Predation by the planktivores in Lake Ontario was nearly fourfold higher than in Lake Michigan (approx. 87 g wet weight∙m−2∙year−1). Predation rates on Mysis were comparable in Lakes Michigan and Ontario (approx. 21 g∙m−2∙year−1), while predation on Diporeia was markedly higher in Lake Michigan than in Lake Ontario (21.3 vs. 8.5 g wet weight∙m−2∙year−1). In Lake Ontario, predatory demand on zooplankton exceeded our best estimate of production by a factor of 1.7. Similarly, predation estimates on Mysis in Lake Ontario were 1.2–2.0 times the estimated rate of production, depending on the production model used. Lake Michigan planktivores consumed approximately 55% of available zooplankton production in 1987, indicating that competition for prey resources, if operating, was not as intense as that in Lake Ontario in 1990. It is unclear how to resolve the paradox that predation could markedly exceed available prey production in some cases. There could be sources of error in the estimates of both the supply and demand sides of these trophic relationships.

Lakewide Estimates of Alewife Biomass and Chinook Salmon Abundance and Consumption in Lake Ontario, 1989–2005: Implications for Prey Fish Sustainability

2010 ◽  
Vol 139 (1) ◽  
pp. 223-240 ◽  
Author(s):  
Brent A. Murry ◽  
Michael J. Connerton ◽  
Robert O'Gorman ◽  
Donald J. Stewart ◽  
Neil H. Ringler
Keyword(s):  
Chinook Salmon ◽  
Lake Ontario ◽  
Prey Fish

Chemical and Biological Changes in Nelson Lake, Ontario Following Experimental Elevation of Lake pH

1977 ◽  
Vol 12 (1) ◽  
pp. 213-232 ◽  
Author(s):  
N.D. Yan ◽  
W.A. Scheider ◽  
P.J. Dillon
Keyword(s):  
Heavy Metal ◽  
Lake Ontario ◽  
Background Concentrations ◽  
Precambrian Shield ◽  
Metal Levels ◽  
Zooplankton Communities ◽  
Shield Lakes

Abstract Intensive studies of Nelson Lake, a Sudbury area lake of intermediate pH ~5.7), were begun in 1975. The chemistry of the lake was typical of that of most PreCambrian Shield lakes except that low alkalinities and high sulphate concentrations were observed along with elevated heavy metal levels. After raising the pH of Nelson Lake to 6.4 by addition of Ca(OH)2 and CaCO3, the metals were reduced to background concentrations. Phytoplankton and Zooplankton communities, which at pH of 5.7 were typical of PreCambrian lakes, were not affected by the experimental elevation of lake pH.

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