The relationship between the size of some salmonid fishes and the intensity of their acanthocephalan infections

1985 ◽  
Vol 63 (4) ◽  
pp. 924-927 ◽  
Author(s):  
Omar M. Amin
Keyword(s):  
Lake Michigan ◽  
Oncorhynchus Tshawytscha ◽  
Lake Trout ◽  
Coho Salmon ◽  
Linear Regression Analysis ◽  
Partial Replacement ◽  
Steady Increase ◽  
Host Feeding ◽  
Host Age ◽  
Maximal Increase

Of the complex factors affecting the abundance of acanthocephalan infections in their definitive fish hosts, those related to fish age are considered. In Lake Michigan, the abundance of some 8000 worms, mostly Echinorhynchus salmonis (Müller, 1784), was independent of the age (weight) of coho salmon, Oncorhynchus kisutch (Walbaum), chinook salmon, Oncorhynchus tshawytscha (Walbaum), and lake trout, Salvelinus namaycush (Walbaum), using linear regression analysis. Other E. salmonis infection patterns include steady increase in abundance with host age and a maximal increase in midage. A decrease in abundance with host age was demonstrated in other acanthocephalan species. The above patterns were primarily related to host feeding behavior as well as spatial and seasonal distribution of invertebrate and vertebrate larval hosts. A progressive increase in the abundance of Echinorhynchus through midage or through life is associated with a stable intake of an invertebrate diet, including the infected intermediate host, in larger volumes by older fish. Loss of the latter two patterns is affected by destabilizing the above trend through total or partial replacement of the invertebrate diet with a piscivorous one.

An examination of the PCB: lipid relationship among individual fish

1997 ◽  
Vol 54 (5) ◽  
pp. 1031-1038
Author(s):  
C A Stow ◽  
L J Jackson ◽  
J F Amrhein
Keyword(s):  
Salmo Trutta ◽  
Lake Michigan ◽  
Oncorhynchus Tshawytscha ◽  
Lake Trout ◽  
Coho Salmon ◽  
Salvelinus Namaycush ◽  
Rainbow Trout Oncorhynchus Mykiss ◽  
Strong Linear Correlation ◽  
Brown Trout Salmo Trutta ◽  
The Relationship

We examined data from 1984 to 1994 for five species of Lake Michigan salmonids to explore the relationship between total PCB concentration and percent lipid. When we compared mean species lipid and PCB values, we found a strong linear correlation. When we compared values among individuals, we found modest positive PCB:lipid associations in brown trout (Salmo trutta), chinook salmon (Oncorhynchus tshawytscha), coho salmon (Oncorhynchus kisutch), and rainbow trout (Oncorhynchus mykiss) collected during spawning, but positive associations were not apparent among nonspawning individuals. Lake trout (Salvelinus namaycush) exhibited no discernible PCB:lipid relationship. Our results are not incompatible with previous observations that contaminants are differentially partitioned into lipids within a fish, but these results do suggest that lipids are not a major factor influencing contaminant uptake.

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.

Endohelminths of salmonids from two localities in eastern Lake Michigan, with emphasis on Echinorhynchus salmonis

1989 ◽  
Vol 67 (6) ◽  
pp. 1604-1607 ◽  
Author(s):  
Patrick M. Muzzall
Keyword(s):  
Chinook Salmon ◽  
Salmo Trutta ◽  
Lake Michigan ◽  
Oncorhynchus Tshawytscha ◽  
Lake Trout ◽  
Coho Salmon ◽  
Oncorhynchus Kisutch ◽  
Salvelinus Namaycush ◽  
Salmo Gairdneri ◽  
Brown Trout Salmo Trutta

Adult salmonids (101 chinook salmon, Oncorhynchus tshawytscha; 7 coho salmon, Oncorhynchus kisutch; 56 lake trout, Salvelinus namaycush; 6 steelhead, Salmo gairdneri; and 2 brown trout, Salmo trutta) were collected from eastern Lake Michigan (Ludington and Manistee, Michigan) in July–September 1986, and examined for helminths. Eight species (three Cestoda, three Nematoda, two Acanthocephala) were found in the digestive tract and other viscera. Echinorhynchus salmonis and Eubothrium salvelini were the most common helminths found. The intensity of E. salmonis significantly increased as chinook salmon became older and longer.

Spatiotemporal patterns in trophic niche overlap among five salmonines in Lake Michigan, USA

2020 ◽  
Vol 77 (6) ◽  
pp. 1059-1075 ◽  
Author(s):  
Matthew S. Kornis ◽  
David B. Bunnell ◽  
Heidi K. Swanson ◽  
Charles R. Bronte
Keyword(s):  
Brown Trout ◽  
Chinook Salmon ◽  
Lake Michigan ◽  
Lake Trout ◽  
Coho Salmon ◽  
Niche Overlap ◽  
Trophic Niche ◽  
Ecosystem Change ◽  
Forage Base ◽  
Overlap Analysis

Native lake trout (Salvelinus namaycush) and introduced Chinook salmon (Oncorhynchus tshawytscha), coho salmon (Oncorhynchus kisutch), steelhead (Oncorhynchus mykiss), and brown trout (Salmo trutta) are major predators in Lake Michigan’s complex ecosystem and collectively support a valuable recreational fishery, but declines in their primary prey, alewife (Alosa pseudoharengus), have raised ecological and management concerns about competition and prey allocation. We applied niche overlap analysis to evaluate competition among salmonine predators during rapid forage base change in Lake Michigan. δ13C and δ15N stable isotope ratios indicated that lake trout had a unique trophic niche from inclusion of offshore and benthic prey, with <29% lake-wide niche overlap with Chinook salmon, coho salmon, and steelhead. Brown trout had moderate overlap with other species (45%–91%), while Chinook salmon, coho salmon, and steelhead had high overlap (71%–98%). Regional differences in isotopic signatures highlighted the potential importance of subsystem differences in fish diets in large aquatic systems. The uniqueness of the lake trout niche, and broadness of brown trout and steelhead niches, suggest these species may be resilient to forage base changes. This study further demonstrates how niche overlap analysis can be applied to tease apart competitive interactions and their response to ecosystem change.

PCB Uptake by Five Species of Fish in Lake Michigan, Green Bay of Lake Michigan, and Cayuga Lake, New York

1982 ◽  
Vol 39 (5) ◽  
pp. 700-709 ◽  
Author(s):  
A. L. Jensen ◽  
S. A. Spigarelli ◽  
M. M. Thommes
Keyword(s):  
New York ◽  
Brown Trout ◽  
Lake Michigan ◽  
Lake Trout ◽  
Coho Salmon ◽  
Metabolic Parameters ◽  
Lake Whitefish ◽  
Bioenergetic Model ◽  
Green Bay ◽  
Cayuga Lake

We applied a bioenergetic model to describe uptake of polychlorinated biphenyls (PCBs) by lake trout (Salvelinus namaycush), brown trout (Salmo trutta), lake whitefish (Coregonus clupeaformis), coho salmon (Oncorhynchus kisutch), and chinook salmon (Oncorhynchus tshawytscha) in Lake Michigan; lake trout and lake whitefish in Green Bay of Lake Michigan; and lake trout in Cayuga Lake, New York. The model describes PCB uptake in terms of metabolism, food consumption, size, and growth. Concentrations of PCBs differ significantly among species; for the same species there are large differences among habitats. The pattern of PCB uptake by brown trout is different from that of the other species. Application of the model with uptake and metabolic parameters estimated by Norstrom et al. describes the trend in the brown trout data; to describe uptake for other species we increased the exponent of weight for metabolism γ. An increase in γ changes the shape of the relation between PCB concentration and body weight from asymptotic to non-asymptotic. In all species tested except brown trout, uptake of PCBs was not asymptotic and concentrations did not approach an equilibrium; accumulation of contaminants was first rapid, decreased toward a plateau, and then began a second rapid increase. Simulation studies indicate that differences in PCB concentrations among species and in the same species among different environments result from differences in metabolic parameters, exposure, size, and rate of growth.Key words: PCBs, bioenergetic model, contaminant uptake, toxicology, fish, Great Lakes, salmon, trout, whitefish

Effects of Dressing and Cooking on DDT Concentrations in Certain Fish from Lake Michigan

1972 ◽  
Vol 29 (5) ◽  
pp. 525-529 ◽  
Author(s):  
Robert E. Reinert ◽  
Donald Stewart ◽  
Harry L. Seagran
Keyword(s):  
Yellow Perch ◽  
Oil Content ◽  
Lake Michigan ◽  
Lake Trout ◽  
Coho Salmon ◽  
Corn Oil ◽  
Perca Flavescens ◽  
Salvelinus Namaycush ◽  
The Body ◽  
Coregonus Hoyi

Concentrations of DDT residues were highest in parts of the body with the highest oil content in four species of fish from Lake Michigan: yellow perch (Perca flavescens), bloater (Coregonus hoyi), lake trout (Salvelinus namaycush), and coho salmon (Oncorhynchus kisutch). Dressing reduced the DDT residues and oil content by more than 90% in yellow perch but had little effect in the other three species. The concentration of DDT residues in bloaters was changed little by smoking but was reduced 64–72% by other methods of cooking: from 8.0 ppm (raw) to 2.2 ppm after frying in corn oil; from 10.7 to 3.9 ppm after frying in lard; and from 9.1 to 3.2 ppm after broiling. The concentration of DDT residues in fillets of yellow perch changed only from 0.3 ppm (raw) to 0.4 or 0.5 ppm after baking, frying, or broiling.

A spatially explicit bioenergetics measure of habitat quality for adult salmonines: Comparison between Lakes Michigan and Ontario

1995 ◽  
Vol 52 (7) ◽  
pp. 1572-1583 ◽  
Author(s):  
Doran M. Mason ◽  
Andrew Goyke ◽  
Stephen B. Brandt
Keyword(s):  
Growth Rate ◽  
Habitat Quality ◽  
Chinook Salmon ◽  
Lake Michigan ◽  
Oncorhynchus Tshawytscha ◽  
Lake Trout ◽  
Ecosystem Change ◽  
Spatially Explicit ◽  
Consumption Rates ◽  
Species Specific

We used spatially explicit modeling to compare habitat quality for chinook salmon, Oncorhynchus tshawytscha, and lake trout, Salvelinus namaycush, in Lakes Michigan and Ontario. This grid-based approach predicts a predator's physiological growth response, growth rate potential, from measured physical and biological environmental conditions and is a species-specific measure of habitat quality. Underwater acoustics was used to map prey spatial distributions, abundances, and sizes. A foraging model defined predator consumption rates from prey data. A bioenergetics model calculated growth rate potential based on consumption rates and prevailing thermal conditions. We compared habitat quality between lakes using both the mean growth rate potential and the volume (or proportion) of water capable of supporting positive growth rates. Mean growth rate potential for both chinook salmon and lake trout was similar between the lakes despite known differenes in the prey species composition and abundance. However, Lake Michigan provided a greater volume of water capable of supporting growth for both chinook salmon (26%) and lake trout (21%) compared with that for Lake Ontario (19% for both species). Our measure of habitat quality based on species-specific physiological requirements should provide a tool to compare ecosystems and quantify ecosystem change.

Residues of DDT in Lake Trout (Salvelinus namaycush) and Coho Salmon (Oncorhynchus kisutch) from the Great Lakes

1974 ◽  
Vol 31 (2) ◽  
pp. 191-199 ◽  
Author(s):  
Robert E. Reinert ◽  
Harold L. Bergman
Keyword(s):  
Lake Erie ◽  
Lake Michigan ◽  
Lake Trout ◽  
Coho Salmon ◽  
Marked Decrease ◽  
Life Stage ◽  
Oncorhynchus Kisutch ◽  
Salvelinus Namaycush ◽  
Spawning Season ◽  
Spawning Run

Concentrations of DDT residues were higher in lake trout (Salvelinus namaycush) from southern Lake Michigan in 1966–70 (average 18.1 ppm in fish 558–684 mm long) than in lake trout of the same size-class from Lake Superior in 1968–69 (4.4 ppm), and higher in adult coho salmon (Oncorhynchus kisutch) from Lake Michigan in 1968–71 (averages for different year-classes, 9.9–14.0 ppm) than in those from Lake Erie in 1969 (2.2 ppm). Residues were significantly higher in lake trout from southern Lake Michigan than in those from the northern part of the lake. In lakes Michigan and Superior, the levels increased with length of fish and percentage oil. In Lake Michigan coho salmon, the residues remained nearly stable (2–4 ppm) from September of the 1st yr of lake residence through May or early June of the 2nd yr, but increased three to four times in the next 3 mo. Residues in Lake Erie coho salmon did not increase during this period, which preceded the spawning season. Although the concentrations of total residues in whole, maturing Lake Michigan coho salmon remained unchanged from August 1968 until near the end of the spawning season in January 1969, the residues were redistributed in the tissues of the spawning-run fish; concentrations in the loin and brain were markedly higher in January than in August. This relocation of DDT residues accompanied a marked decrease in the percentage of oil in the fish, from 13.2 in August to 2.8 in January. Concentrations of residues were relatively high in eggs of both lake trout (4.6 ppm) and coho salmon (7.4–10.2 ppm) from Lake Michigan. The percentage composition of the residues (p,p′DDE, o,p′/DDT, p,p′DDT, and p,p′DDT) did not differ significantly with life stage, size, age, or locality, or date of collection of lake trout or coho salmon.

Species Succession and Fishery Exploitation in the Great Lakes

1968 ◽  
Vol 25 (4) ◽  
pp. 667-693 ◽  
Author(s):  
Stanford H. Smith
Keyword(s):  
Great Lakes ◽  
Brook Trout ◽  
Oncorhynchus Tshawytscha ◽  
Lake Trout ◽  
Coho Salmon ◽  
The United States ◽  
Sea Lamprey ◽  
Species Interaction ◽  
Selective Predation ◽  
Fish Stocks

The species composition of fish in the Great Lakes has undergone continual change since the earliest records. Some changes were caused by enrichment of the environment, but others primarily by an intensive and selective fishery for certain species. Major changes related to the fishery were less frequent before the late 1930's than in recent years and involved few species. Lake sturgeon (Acipenser fulvescens) were overexploited knowingly during the late 1800's because they interfered with fishing for preferred species; sturgeon were greatly reduced in all lakes by the early 1900's. Heavy exploitation accompanied sharp declines of lake herring (Leucichthys artedi) in Lake Erie during the 1920's and lake whitefish (Coregonus clupeaformis) in Lake Huron during the 1930's. A rapid succession of fish species in Lakes Huron, Michigan, and Superior that started about 1940 has been caused by selective predation by the sea lamprey (Petromyzon marinus) on native predatory species, and the resultant shifting emphasis of the fishery and species interaction as various species declined. Lake trout (Salvelinus namaycush) and burbot (Lota lota), the deep-water predators, were depleted first; this favored their prey, the chubs (Leucichthys spp.). The seven species of chubs were influenced differently according to differences in size. Fishing emphasis and predation by sea lampreys were selective for the largest species of chubs as lake trout and burbot declined. A single slow-growing chub, the bloater, was favored and increased, but as the large chubs declined the bloater was exploited by a new trawl fishery. The growth rate and size of the bloater increased, making it more vulnerable to conventional gillnet fishery and lamprey predation. This situation in Lakes Michigan and Huron favored the small alewife (Alosa pseudoharengus) which had recently become established in the upper Great Lakes, and the alewife increased rapidly and dominated the fish stocks of the lakes. The successive collapses of various stocks after periods of stable production may give some indication of their sustainable yield. The sea lamprey is being brought under control in Lakes Superior, Michigan, and Huron; lake trout are being established; and chinook salmon (Oncorhynchus tshawytscha), coho salmon (O. kisutch), kokanee salmon (O. nerka), and the splake, a hybrid of lake trout and brook trout (Salvelinus fontinalis), are being introduced to reestablish a new species balance. Fish stocks are in a state of extreme instability in these lakes. Careful control of stocking programs and fisheries, and coordination of management among the various states of the United States and the province of Canada (Ontario) which manage the fish stocks, will be required to restore and maintain a useful fishery balance.

Density, growth, and change in density of coho salmon and rainbow trout in three Lake Michigan tributaries

1983 ◽  
Vol 61 (5) ◽  
pp. 1120-1127 ◽  
Author(s):  
L. M. Carl
Keyword(s):  
Rainbow Trout ◽  
Growth Rates ◽  
Lake Michigan ◽  
Coho Salmon ◽  
Daily Growth ◽  
Salmon Fry ◽  
Daily Change ◽  
Early Fall ◽  
Growth And Change ◽  
Downstream Movement

Coho salmon spawning peaked in the late fall. Spawning densities ranged from fewer than 5 coho salmon per hectare up to 90 fish per hectare. Subyearling coho salmon densities ranged from 10 to 60 fish per 100 m2 in June and dropped to 5–20 fish by early fall. Coho salmon fry increased in length from 40 mm in early May, to over 120 mm by smolt out-migration in the following April. Coho salmon instantaneous daily change in density coefficients ranged from 0.004 to 0.019 and were dependent on initial coho density. Daily coho salmon growth rates ranged from 0.38 to 0.60 mm per day and were not dependent on initial coho salmon density. Downstream movement of rainbow trout fry began in May, and continued into July. In the spring 10–20 yearlings and one to five 2-year-olds per 100 m2 were present. Most fry emerged in June at a size of 25 mm and grew to 85 mm by fall. Daily growth rates varied from 0.23 to 0.45 mm per day for yearling rainbow trout and were not correlated with rainbow trout density.

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