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.

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.

Mysis relicta: Assessment of Metalimnetic Feeding and Implications for Competition with Fish in Lakes Ontario and Michigan

1994 ◽  
Vol 51 (11) ◽  
pp. 2591-2602 ◽  
Author(s):  
Ora E. Johannsson ◽  
Lars G. Rudstam ◽  
David C. Lasenby
Keyword(s):  
Lake Michigan ◽  
Significant Proportion ◽  
Lake Ontario ◽  
Planktivorous Fish ◽  
Energy Requirements ◽  
Crustacean Zooplankton ◽  
Additional Energy ◽  
Mysis Relicta ◽  
Zooplankton Consumption ◽  
Zooplankton Production

Mysis relicta and planktivorous fish in Lakes Ontario and Michigan both feed on crustacean zooplankton in the metalimnion. Are these zooplankton sufficient to meet the energy requirements of mysids? Could mysids remove a significant proportion of zooplankton production? Are the energy requirements in the two lakes similar? Comparisons in Lake Ontario of zooplankton consumption based on clearance rates, with energy requirements based on bioenergetic modelling, revealed that individual mysids, particularly larger ones, required additional energy sources. The denser mysid populations beyond 100 m depth in Lake Ontario could exert high mortality rates on metalimnetic zooplankton, remove a significant proportion of daily zooplankton production, and consequently, potentially compete with planktivorous fish. At depths < 100 m, the mysid population was smaller and could remove only 6–19% of zooplankton production per day in summer when competition with planktivorous fish would be maximal. Generation time is shorter in Lake Michigan because winter growth rates remain high. Consequently, less energy is required to complete a generation in Lake Michigan than in Lake Ontario.

scholarly journals Subglacial water-sheet floods, drumlins and ice-sheet lobes

1999 ◽  
Vol 45 (150) ◽  
pp. 201-213 ◽  
Author(s):  
E.M. Shoemaker
Keyword(s):  
New York ◽  
Lake Michigan ◽  
New York State ◽  
Ice Sheet ◽  
Lake Ontario ◽  
High Water ◽  
Green Bay ◽  
Subglacial Lake ◽  
Western Lake ◽  
Subglacial Lakes

AbstractThe effect of subglacial lakes upon ice-sheet topography and the velocity patterns of subglacial water-sheet floods is investigated. A subglacial lake in the combined Michigan–Green Bay basin, Great Lakes, North America, leads to: (1) an ice-sheet lobe in the lee of Lake Michigan; (2) a change in orientations of flood velocities across the site of a supraglacial trough aligned closely with Green Bay, in agreement with drumlin orientations; (3) low water velocities in the lee of Lake Michigan where drumlins are absent; and (4) drumlinization occurring in regions of predicted high water velocities. The extraordinary divergence of drumlin orientations near Lake Ontario is explained by the presence of subglacial lakes in the Ontario and Erie basins, along with ice-sheet displacements of up to 30 km in eastern Lake Ontario. The megagrooves on the islands in western Lake Erie are likely to be the product of the late stage of a water-sheet flood when outflow from eastern Lake Ontario was dammed by displaced ice and instead flowed westward along the Erie basin. The Finger Lakes of northern New York state, northeastern U.S.A., occur in a region of likely ice-sheet grounding where water sheets became channelized. Green Bay and Grand Traverse Bay are probably the products of erosion along paths of strongly convergent water-sheet flow.

Particle-Size-Conversion Efficiency and Contaminant Concentrations in Lake Ontario Biota

1983 ◽  
Vol 40 (3) ◽  
pp. 328-336 ◽  
Author(s):  
Uwe Borgmann ◽  
D. M. Whittle
Keyword(s):  
Particle Size ◽  
Body Size ◽  
Conversion Efficiency ◽  
Food Chain ◽  
Lake Ontario ◽  
Dry Weight ◽  
Growth Efficiency ◽  
Fish Production ◽  
The Relationship ◽  
Zooplankton Production

The particle-size-conversion efficiency (log food consumption/production divided by log predator prey size ratio) is shown to be directly related to the relationship between the concentration of persistent contaminants accumulated primarily through the food chain and body size for organisms in pelagic ecosystems. The difference between particle-size-conversion efficiency for biomass and that for the contaminant gives the slope of the relationship between log contaminant concentration and log body size. This provides a useful theoretical framework for analyzing contaminant concentrations in aquatic biota without the need for specifying trophic level but still incorporating the idea of food chain accumulation. Concentrations of PCB, DDT, and mercury were examined in aquatic organisms from Lake Ontario, ranging in size from zooplankton to large salmonids (a 108 -fold range in dry weight). The slope of the double log plot of concentration versus weight varied from 0.20 to 0.22 for PCB and DDT and was approximately equal to 0.13 for mercury. This indicates that mercury is accumulated less efficiently through the food chain than PCB or DDT. After correcting for incomplete uptake and retention of the contaminant, an estimate of particle-size-conversion efficiency for biomass of about 0.26 was obtained, which agrees reasonably well with previous estimates obtained from growth efficiency experiments and analysis of particle-size spectra. These calculations indicate that potential fish production in Lake Ontario is ~ 120-fold lower than zooplankton production (for fish averaging 108-fold larger in body size as compared to zooplankton).Key words: particle-size-conversion efficiency, PCB, DDT, mercury, zooplankton production, fish production

Bioaccumulation and Trophic Magnification of Short- and Medium-Chain Chlorinated Paraffins in Food Webs from Lake Ontario and Lake Michigan

2008 ◽  
Vol 42 (10) ◽  
pp. 3893-3899 ◽  
Author(s):  
Magali Houde ◽  
Derek C. G. Muir ◽  
Gregg T. Tomy ◽  
D. Michael Whittle ◽  
Camilla Teixeira ◽  
...  
Keyword(s):  
Food Webs ◽  
Lake Michigan ◽  
Lake Ontario ◽  
Medium Chain ◽  
Chlorinated Paraffins

Phosphorus Enrichment, Silica Utilization, and Biogeochemical Silica Depletion in the Great Lakes

1986 ◽  
Vol 43 (2) ◽  
pp. 407-415 ◽  
Author(s):  
Claire L. Schelske ◽  
Eugene F. Stoermer ◽  
Gary L. Fahnenstiel ◽  
Mark Haibach
Keyword(s):  
Steady State ◽  
Great Lakes ◽  
Urban Population ◽  
Thermal Stratification ◽  
Lake Erie ◽  
Lake Michigan ◽  
Lake Ontario ◽  
Lake Huron ◽  
Phosphorus Enrichment

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.

Stratigraphy of the Sixteen Mile Creek lagoon, and its implications for Lake Ontario water levels

1988 ◽  
Vol 25 (8) ◽  
pp. 1175-1183 ◽  
Author(s):  
J. E. Flint ◽  
R. W. Dalrymple ◽  
J. J. Flint
Keyword(s):  
Water Level ◽  
Lake Michigan ◽  
Drainage Basin ◽  
Average Rate ◽  
Lake Ontario ◽  
Open Water ◽  
Water Levels ◽  
Beach Sand ◽  
Water Level Fluctuations ◽  
Lake Outlet

The sequence of units (from the base up) in the Sixteen Mile Creek lagoon (Lake Ontario) mimics the longitudinal sequence of surficial environments: pink silt—overbank (flood plain – dry marsh); bottom sand—stream channel and beach; orange silt—marsh; gyttja—wet marsh and very shallow (deltaic) lagoon; and brown and grey clay—open-water lagoon. This entire sequence accumulated over the last 4200 years under slowly deepening, transgressive conditions caused by the isostatic rise of the lake outlet. Land clearing by European settlers dramatically increased the supply of clastic sediment and terminated the deposition of the organic-rich silty clays (gyttja) that make up most of the lagoon fill.Because the gyttja and beach sand are interpreted to have accumulated in water depths of less than 0.5 m, the elevation–time plot of 14C dates from these units can be used to reconstruct a very closely constrained lake-level curve. The data indicate that water levels have risen at an average rate of 0.25 cm/a over the last 3300 years as a result of differential, isostatic rebound. Superimposed on this trend are water-level oscillations with amplitudes on the order of 1 m and periods of several hundred years. These oscillations are synchronous and in phase with water-level fluctuations in Lake Michigan, and with a variety of other climatic variations in North America and Europe. We propose, therefore, that the water-level oscillations are a result of long-term, climatically produced variations in precipitation in the Great Lakes drainage basin.

Sign in / Sign up

Export Citation Format

Share Document