Fin Degeneration of Young-of-the-Year Alosa pseudoharengus (Clupeidae) in Southern Lake Michigan

Copeia ◽  
1970 ◽  
Vol 1970 (4) ◽  
pp. 766 ◽  
Author(s):  
Edward H. Brown ◽  
Carroll R. Norden
1981 ◽  
Vol 38 (6) ◽  
pp. 662-668 ◽  
Author(s):  
Larry B. Crowder ◽  
John J. Magnuson ◽  
Stephen B. Brandt

The potential for ecological segregation of Lake Michigan fishes was examined by comparing diets and thermal habitat use of common species. Samples were collected by bottom trawling (N = 68) off Grand Haven, Michigan, September 7–13, 1977. Five common species exhibited complementarity in the use of food and thermal habitat resources. During the day, adult alewife (Alosa pseudoharengus), and rainbow smelt (Osmerus mordax) had similar diets but occupied somewhat different thermal habitats. Young-of-the-year (YOY) alewives segregated from adult alewife and rainbow smelt on both habitat and food. Spottail shiner (Notropis hudsonius), YOY alewives, and yellow perch (Perca flavescens) used similar thermal habitats but fed on different prey. Trout-perch (Percopsis osmiscomaycus) tended to segregate from the others based on both food and thermal habitat but may experience diffuse competition. Adults of the three native species consume entirely different prey than exotic alewife and rainbow smelt. The native species which declined during the invasion of alewife and rainbow smelt were those with apparently similar habitat and food requirements to the exotics. These data suggest that competition is important in maintaining the structure of the Lake Michigan fish community.Key words: competition, fishes, food, habitat, Lake Michigan, predation, temperature


1995 ◽  
Vol 52 (5) ◽  
pp. 925-935 ◽  
Author(s):  
Edward L. Mills ◽  
Connie Adams ◽  
Robert O'Gorman ◽  
Randall W. Owens ◽  
Edward F. Roseman

The objective of this study was to describe the diet of young-of-the-year and adult alewife (Alosa pseudoharengus) and rainbow smelt (Osmerus mordax) in nearshore waters coincident with the colonization of Lake Ontario by Dreissena. Laboratory experiments and field observations indicated that alewife and rainbow smelt consumed dreissenid veligers and that the veligers remained intact and identifiable in the digestive tract for several hours. Dreissenid larvae were found in field-caught alewife and rainbow smelt in August 1992, even though veliger densities were low (<0.1/L). Zooplankton dominated the diet of all fish and veliger larvae were <0.1% of the biomass of prey eaten by these fish. Density of veligers and the distribution of settled dreissenids declined from west to east along the south shore of Lake Ontario. Based on veliger consumption rates we measured and the abundance of veligers and planktivores, we conclude that planktivory by alewife and smelt in the nearshore waters of Lake Ontario did not substantially reduce the number of veligers during 1991–1993. However, our results indicate that if the density of veligers in Lake Ontario decreases, and if planktivores remain abundant, planktivory on veliger populations could be significant.


2015 ◽  
Vol 41 (2) ◽  
pp. 436-447 ◽  
Author(s):  
Michael J. Weber ◽  
Blake C. Ruebush ◽  
Sara M. Creque ◽  
Rebecca A. Redman ◽  
Sergiusz J. Czesny ◽  
...  

1983 ◽  
Vol 40 (6) ◽  
pp. 681-698 ◽  
Author(s):  
Donald J. Stewart ◽  
David Weininger ◽  
Donald V. Rottiers ◽  
Thomas A. Edsall

An energetics model is implemented for lake trout, Salvelinus namaycush, and applied to the Lake Michigan population. It includes an egestion function allowing any proportional mix of fish and invertebrates in the diet, a growth model accounting for both ontogenetic and seasonal changes in energy-density of predator and prey, a model for typical in situ swimming speed, and reproductive energy losses due to gametes shed. Gross conversion efficiency of energy by lake trout over their life (21.8%) is about twice the efficiency of converting biomass to growth because they store large amounts of high-energy fats. Highest conversion efficiencies are obtained by relatively fast-growing individuals, and over half the annual energy assimilated by older age-classes may be shed as gametes. Sensitivity analysis indicates a general robustness of the model, especially for estimating consumption by fitting a known growth curve. Largest sensitivities were for the intercept and weight dependence coefficients of metabolism. Population biomass and associated predatory impact of a given cohort increase steadily for about 3.5 yr then decline steadily after fishing mortality becomes important in the fourth year in the lake. This slow response time precludes manipulation of lake trout stocking densities as a means to control short-term prey fluctuations. Predation by lake trout on alewife, Alosa pseudoharengus, has been increasing steadily since 1965 to about 8 400 t∙yr−1, and is projected to rise to almost 12 000 t∙yr−1 by 1990.


2020 ◽  
Vol 77 (3) ◽  
pp. 594-601 ◽  
Author(s):  
Rita Monteiro Pierce ◽  
Karin E. Limburg ◽  
Daniella Hanacek ◽  
Ivan Valiela

Alosa pseudoharengus (alewife) has declined throughout New England. A factor that may be responsible for such stock reductions is urbanization of watersheds discharging into alewife nursery ponds. We found that young-of-the-year (YOY) alewife length, weight, condition factor, and growth rate decreased in relation to increased urban land cover on watersheds of nine Massachusetts and Maine ponds. The watersheds ranged from 3% to 60% urbanized land cover. YOY δ15N increased significantly in proportion to urbanized land cover on watersheds, suggesting a concrete link between watershed land cover and YOY alewife metrics, which is in agreement with previous knowledge that N discharges from more urbanized watersheds bear higher δ15N. The New England results confirmed results across a wide latitudinal gradient that suggested that the size of YOY alewife decreased as urban land cover on watersheds increased. The dominant influence of urban land cover in the YOY is highlighted by the fact that YOY alewife from ponds with the highest percentage of urban cover reached δ15N as high as that of adult spawners migrating from the ocean, who feed at higher trophic levels.


1993 ◽  
Vol 71 (6) ◽  
pp. 1153-1160 ◽  
Author(s):  
J. K. Leslie ◽  
C. A. Timmins

Thirty-eight taxa of young-of-the-year fishes were collected with a beach seine and plankton nets in Mitchell Bay, a shallow, densely vegetated embayment on Lake St. Clair, from April to October, 1983, 1984, and 1990. The ecosystem of the bay and adjacent land has been altered by agricultural, industrial, and recreational development for more than a century. Although taxa were numerous, most species were rare or uncommon in collections. The assemblage of larval fish consisted primarily of brook silverside (Labidesthes sicculus), pumpkinseed (Lepomis gibbosus), spottail shiner (Notropis hudsonius), emerald shiner (Notropis atherinoides), alewife (Alosa pseudoharengus), and gizzard shad (Dorosoma cepedianum). Many species were distributed in or near submerged macrophytes at the shore. The species most abundant were pumpkinseed, which reached peak density (11 931 young of the year/100 m3) in late June 1990, and brook silverside (1363 young of the year/100 m3) in late June 1984.


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