Northern Lake Michigan Research Articles

Lake Michigan Beach-Ridge and Dune Development, Lake Level, and Variability in Regional Water Balance

A sequence of northern Lake Michigan beach ridges records lake-level fluctuations that are probably related to changes in late Holocene climate. Historically, episodes of falling and low lake level associated with regional drought led to the formation of dune-capped beach ridges. The timing of prehistoric ridge formation, estimated by radiocarbon dating of plant macrofossils from early-successional dune species, shows that return periods of inferred drought, averaged for time intervals of 100 to 480 yr, ranged between 17 and 135 yr per drought during the last 2400 yr. In five of ten of these time intervals, the average return period ranged between 17 and 22 yr per drought. These intervals of frequent ridge formation and drought were associated with the development of parabolic dunes, which is indicative of high lake level and moist climate. This seeming paradox suggests that unusually moist decades alternated with unusually dry decades during these time intervals. Regional water balance probably varied less during the time intervals when ridges formed less often and the lake produced no evidence of high level.

Progress Toward Lake Trout Restoration in Lake Michigan

Progress toward lake trout restoration in Lake Michigan is described through 1993. Extinction of the native lake trout fishery by sea lamprey predation, augmented by exploitation and habitat destruction, resulted in an extensive stocking program of hatchery-reared lake trout that began in 1965. Sea lamprey abundance was effectively controlled using selective chemical toxicants. The initial stocking produced a measurable wild year class of lake trout by 1976 in Grand Traverse Bay, but failed to continue probably due to excessive exploitation. The overall lack of successful reproduction lakewide by the late 1970s led to the development and implementation in 1985 of a focused inter-agency lakewide restoration plan by a technical committee created through the Lake Committee structure of the Great Lakes Fishery Commission. Strategies implemented in 1985 by the plan included setting a 40% total mortality goal lakewide, creating two large refuges designed to encompass historically the most productive spawning habitat and protect trout stocked over their home range, evaluating several lake trout strains, and setting stocking priorities throughout the lake. Target levels for stocking in the 1985 Plan have never been reached, and are much less than the estimated lakewide recruitment of yearlings by the native lake trout stocks. Since 1985, over 90% of the available lake trout have been stocked over the best spawning habitat, and colonization of the historically productive offshore reefs has occurred. Concentrations of spawning lake trout large enough for successful reproduction, based on observations of successful hatchery and wild stocks, have developed at specific reefs. Continued lack of recruitment at these specific sites suggests that something other than stotk abundance has limited success. Poor survival of lake trout eggs, assumed to be related to contaminant burden, occurred in the late 1970s and early 1980s, but survival has since increased to equal survival in the hatchery. A recent increase in lamprey wounding rates in northern Lake Michigan appears to be related to the uncontrolled build-up of lampreys in the St. Marys River a tributary of Lake Huron. If left uncontrolled, further progress toward restoration in the Northern Refuge may be limited.

Factors Affecting the Recruitment of Lake Whitefish in Two Areas of Northern Lake Michigan

Stock-recruitment and integrated recruitment models incorporating biotic and abiotic factors were developed for lake whitefish populations in northern Green Bay and the North Shore areas of Lake Michigan. Abundance and recruitment indices were calculated for the 1961-1985 year classes based on lake whitefish catch and effort data from the commercial fishery in each area. Previous research indicates that spawning stock abundance, winter ice cover, and spring temperatures are important in determining the egg and larval abundance and survival of lake whitefish. Therefore, spawning stock abundance, ice cover, winter wind velocity, and spring water and air temperature variables were used as model inputs in regression modeling. The biotic/abiotic recruitment model for northern Green Bay hindcasted lake whitefish recruitment as a function of spawning stock abundance and the number of days that ice cover exceeded 40% during egg incubation. This regression model (R 2 = 0.62) demonstrated improved hindcasting ability of historic recruitment when compared to the Beverton-Holt (R 2 = 0.37) or the Ricker (R 2 = 0.33) stock-recruitment models for the 1961-1985 cohorts. The biotic/abiotic recruitment model for the North Shore hindcasted lake whitefish recruitment as a function of average air temperature in May after larval emergence, the number of days that ice concentration exceeded 70% during egg incubation, and spawning stock abundance. The regression model (R 2 = 0.57) also demonstrated improved hindcasting ability of historical recruitment when compared with Beverton-Holt (R 2 = 0.09) or the Ricker (R 2 = 0.13) stock-recruitment models. Results of this study indicate that biotic/abiotic recruitment models were more successful in hindcasting recruitment than solely biologically based stock-recruitment relationships. Consideration of significant abiotic variables will be useful in the management of lake whitefish stocks in the Great Lakes by improving forecasts of recruitment.

A model for 137Cs and other tracers in lake sediments considering particle size and the inverse solution

A numerical model for the time-dependent behavior of particle-associated tracers in sediments has been developed. The model is based on the advection-diffusion equation for a tracer and includes a sediment density that increases with depth as a modified power function, and a diffusion coefficient that follows a half-Gaussian function versus depth with maximal diffusivity at the sediment-water interface. The solution procedure is based on finite elements or finite differences. The density function is developed from soil mechanics concepts and includes mixing effects through a Young's modulus that is increased in the top layer according to a half-Gaussian function. The new density function provides a better fit to 15 out of 17 sediment cores from Lake Michigan than a frequently used exponential expression. The tracer model provides an excellent fit for the 137Cs distributions in all of the 17 Lake Michigan cores that were investigated. Our fit to the 137Cs profile of a southern Lake Michigan core that has been examined by others, is significantly better than previous fits, particularly near the top of the core. From two different forms of the governing equation for a tracer, and the resultant fits to experimental data, it appears that 137Cs is associated with colloidal and 210Pb with settling particles. A previously developed time domain method to extract the historical input record of a tracer from its sedimentary profile, influenced by mixing, has been further improved by including m depth and n time intervals, where m ⩾ n, and by fitting the influx to a polynomial. The improved method is demonstrated for the Cd input to a northern Lake Michigan core (NLM84B). Although the time resolution obtained ( ∼ 5 yr) is better than the previous resolution ( ∼ 15 yr), it is clear that the method needs to undergo further development in order to decrease the error of the reconstructed influx and particularly to avoid negative fluxes.

Reappearance of Spoonhead Sculpins ( Cottus Ricei) in Lake Michigan

Spoonhead sculpins ( Cottus ricei) were collected at night in bottom trawls during fall 1990 in Lake Michigan. Specimens were collected at depths from 9 to 91 m at three sites in northern Lake Michigan and at one site in southern Lake Michigan. These specimens represent the first documented collection of this species in Lake Michigan since 1973.

Analysis of Thermal Features of Lake Michigan from AVHRR Satellite Images

The seasonal dynamics of thermal features in Lake Michigan were studied using numerous sea surface temperature images acquired from the NOAA Advanced Very High Resolution Radiometer from May–December, 1990. In southern Lake Michigan, the vernal thermal front moved offshore and to the north between 7 May 1990 and 11 June 1990. Inshore of the front, surface temperatures were > 10.0°C while offshore surface temperatures remained < 4.5°C. In northern Lake Michigan, thermal fronts were not prevalent until late June. Southern Green Bay consistently contained the warmest water in Lake Michigan and exceeded 15.0°C in May. Warm bay-water frequently mixed with cooler lake-water through the channels at the north end of the bay. Warm water plumes remained intact for several days with S/SW winds but were quickly obliterated by a N/NE wind. Upwelling was most conspicuous along the eastern shore of the lake. Depending on wind direction, upwelled water formed broad continuous nearshore bands or isolated patches of relatively cold water. Evidence of upwelling 1–3 days after the instigating wind event suggested oscillations of internal waves. Our study shows that the frequent acquisition of satellite images is useful to describe significant thermal features in a large lake.

"Unmixing" of cesium-137, lead, zinc, and cadmium records in lake sediments

The inverse Berger-Health model to unmix sedimentary records of particle-associated tracers, originally used for {sup 18}O records of particle-associated tracers, originally used for {sup 18}O records in deep-sea sediments, is extended to include radioactive materials, environmental pollutants, compaction of sediments, and error analysis. The method is applied to the fallout tracer {sup 137}Cs, and to Pb, Zn, and Cd in sediment cores from Lake Michigan. The reconstructued {sup 137}Cs input records from northern Lake Michigan. The reconstructed {sup 137}Cs input records from northern Lake Michigan are in good agreement with {sup 137}Cs fallout data. The unmixed influx records of Pb, Zn, and Cd show excellent agreement with input records reconstructed previously by a frequency domain method, thus supporting the validity of the approach. Assuming that tracer concentrations as well as sedimentation and mixing parameters are known with sufficient accuracy, and that the forward model is correct, the ultimate limitation of this or any other reconstruction method lies in the finite depths of the physical sampling intervals.

Deep crustal structure of the Precambrian basement beneath northern Lake Michigan, midcontinent North America

A deep seismic-reflection profile in northern Lake Michigan, midcontinent North America, provides a cross section of the crust across the 1850 Ma Penokean orogen, in which an Early Proterozoic island-arc complex was deformed between two converging Archean continental masses. The island-arc crust is about 40 km thick and has a few kilometres of intensely reflective rocks near its base, above which it is variably reflective to transparent. The Archean terranes have thicker crust, as much as 50 km, the lower 20-25 km of which is strongly reflective. Abrupt offsets of Moho near terrane boundaries may have been preserved since accretion during the Penokean orogeny.

Transparency Calibrations for Lake St. Clair and Lake Michigan

Extensive measurements of water transparency using a Sea Tech transmissometer and total suspended solids (TSM) were made in the southern basin of Lake Michigan and in Lake St. Clair. The relationship between transparency and TSM in each lake can be expressed very well by a single equation. The similarity in the slopes of the lines for the two lakes suggests that the physical properties of the particles suspended in the water are very similar, while the large difference between the intercepts is due to the presence in Lake St. Clair of very fine material (particle diameter less than one micron) which is not present in Lake Michigan. Attempts to use the transparency measurements to identify different particle populations in Lake Michigan as a function of time, station, and sample depth were unsuccessful. Limited data from northern Lake Michigan, Lake Huron, and Lake Superior suggest that the material in Lake Huron is similar to that in the southern basin of Lake Michigan while the observations in northern Lake Michigan more closely resemble those from Lake Superior.

Midwater and epibenthic behaviors of Mysis relicta Loven: observations from the Johnson-Sea-Link II submersible in Lake Superior and from a remotely operated vehicle in northern Lake Michigan

Midwater and epibenthic behaviors of <i>Mysis relicta</i> Loven: observations from the <i>Johnson-Sea-Link II</i> submersible in Lake Superior and from a remotely operated vehicle in northern Lake Michigan

Side-Scan Sonar Mapping of Lake Trout Spawning Habitat in Northern Lake Michigan

Native stocks of lake trout Salvelinus namaycush were virtually or completely extirpated from the lower four Great Lakes by the early 1960s. The failure of early attempts to reestablish self-sustaining populations of lake trout was attributed partly to the practice of stocking hatcheryreared juveniles at locations and over substrates that had not been used in the past for spawning by native fish. Subsequent attempts to improve the selection of stocking locations were impeded by the lack of reliable information on the distribution of substrates on historical spawning grounds. Here we demonstrate the potential of side-scan sonar to substantially expand the data base needed to pinpoint the location of substrates where lake trout eggs, fry, or juveniles could be stocked to maximize survival and help ensure that survivors returning to spawn would encounter suitable substrates. We also describe the substrates and bathymetry of large areas on historical lake trout spawning grounds in the Fox Island Lake Trout Sanctuary in northern Lake Michigan. These areas could be used to support a contemporary self-sustaining lake trout population in the sanctuary and perhaps also in adjacent waters.

Genetic Differentiation among Lake Trout Strains Stocked into Lake Ontario

The lake trout Salvelinus namaycush is the focus of an international effort by fishery management agencies to restore this once-native species to Lake Ontario. Evaluation of reproductive success and comparisons among stocked lake trout strains require genetic markers. We used allozyme variation to make genetic comparisons among strains of lake trout stocked into Lake Ontario. Forty-two proteins presumed to be encoded by 102 loci were resolved electrophoretically; 18 loci were polymorphic. Among 16 samples from five principal origins (Finger Lakes, Great Lakes basin, northern New York–Adirondack, Manitoba, and mixed origins–Lake Ontario), the average observed heterozygosity was 0.029, and the proportion of polymorphic loci was 0.125. Significant differences occurred among the 16 samples at all 18 possible locus comparisons. The average Fst value was 0.14. Hierarchical analysis indicated that the variation among samples within an origin was greatest within the Great Lakes basin, which included the greatest number of samples and represented the largest geographic area. Most variation observed among samples, however, occurred among origins. The 1983 and 1984 hatchery year classes produced from the 1978 Seneca brood stock did not differ significantly. The 1981 Seneca brood stock more closely resembled the sample of wild lake trout from Seneca Lake than progeny from the 1978 brood stock. The closer affinity of the 1981 brood stock to wild Seneca lake trout may be due to the larger number of wild adults from Seneca Lake used to found these fish than was used to establish the 1978 brood stock. Siscowet (“fat”) and “lean” lake trout from Lake Superior were significantly different from each other; however, the level of variation between them was not greater than that among samples from other origins, and thus did not support recognition of siscowet lake trout as a distinct subspecies. The Jenny Lake strain possessed a genetic affinity to the siscowet sample from Lake Superior. Historical reports about the origin of this strain suggest that siscowet lake trout from northern Lake Michigan may have been used to found this strain. Therefore, the Jenny Lake strain may serve as a gene source for the establishment of the siscowet lake trout in Lake Ontario. The substantial differentiation among lake trout strains reported here supports the feasibility of using allozyme markers to identify the parental sources of naturally produced young.

Modeling radiotracers in sediments: Comparison with observations in Lakes Huron and Michigan

A comprehensive model for the activity of radionuclides in sediments is presented. The model is based on the advection‐diffusion equations for sediment solids and a radioactive tracer. Mixing, caused by deposit feeders, is taken into account by a half‐Gaussian (HG), integrated Gaussian (IG), or exponential (EX) diffusion coefficient with a maximum value D0 at the sediment‐water interface and an effective mixing depth m, where m = σ(HG), zm (IG), or a (EX). Compaction is described by an exponential bulk sediment density. The differential equations are solved by finite differences, in particular, the Crank‐Nicolson method for the time‐dependent case (Cs‐137). Estimation of the mixing parameters D0 and m is carried out efficiently by minimizing chi‐square for measured and calculated steady state Pb‐210 activities. The derived mixing depths of zm = 4.6 ± 0.1 cm (station 14) and a = 0.8 ± 0.1 cm (station 18) for the cores from Lake Huron are in good agreement with the organism distributions. The corresponding D0 values are 12 ± 2 and 1.5 ± 0.5 cm2/yr, respectively, where the latter number is lower than a previous lower limit estimate (≥ 3.3 cm2/yr), based on 1974 data. These diffusion coefficients are in excellent agreement with those inferred from the densities of Pontoporeia and tubificid oligochaetes (9.3 and 1.6 cm2/yr, respectively). Compared with southern Lake Michigan, there appears to be less sediment focusing in northern Lake Michigan, where the ratios of measured to atmospheric Cs‐137 inventories have an average value of 0.89 and range from 0.32 to 1.41 for six cores from the deep basin. When these ratios are used to correct the Pb‐210 fluxes, we obtain an atmospheric Pb‐210 flux of 0.99 ± 0.06 dpm/cm2/yr. Because of its more realistic activity profiles, we consider the present model to be generally better than previous models.

Simulation of Harvest Strategies for a Fluctuating Population of Lake Whitefish

A simulation model was developed to evaluate the performances of two harvest management strategies, constant effort and constant quota, in relation to the magnitude and variability of annual yield for a population of lake whitefish (Coregonus clupeaformis) in northern Lake Michigan. The model consisted of an age-structured, dynamic pool model incorporating a stock-recruitment function subject to environmental variability. Trap-net and gill-net selectivity functions specified the fishing mortality rates operating on each cohort. A constant effort policy produced relatively larger sustainable yields than a constant quota policy. However, the constant quota policy ont-performed the effort policy in terms of reducing the variability in annual yield. The model incorporates the effects of different potential fishing efforts that might be expended in pursuit of the quota. A high risk of population collapse was associated with quota management if a large quota was combined with a high potential fishing effort.

Population Statistics, Yield Estimates, and Management Considerations for Two Lake Whitefish Stocks in Lake Michigan

Lake whitefish (Coregonus clupeaformis) were tagged at North and Moonlight bays (NMB), Wisconsin and Big Bay de Noc (BBN), Michigan, and commercial catches were sampled in 1975-1980 to determine discreteness, distribution, biological statistics, and equilibrium yield per recruit for lake whitefish stocks in Green Bay and northern Lake Michigan. Discrete stocks were associated with the spawning grounds at NMB and BBN and fish from the NMB stock were migratory, whereas fish from the BBN stock were not. Age-3 lake whitefish dominated the commercial harvest from the BBN stock, but ages 3-5 comprised the majority of the harvest from the NMB stock. The 1972 and 1975 year classes were more abundant than other year classes in the 1975-1980 harvest from the NMB stock, whereas the 1976 year class was more abundant in the 1979-1980 harvest from the BBN stock. Mortality rates were higher for fish from the BBN stock (84%) than for fish from the NMB stock (65%), and fish of Age-7 and older experienced lower mortality rates than younger ages. Fishing caused a larger proportion of the total mortality in the BBN stock than in the NMB stock. The population size of the NMB stock was roughly 3-4 times larger than the BBN stock. Estimated yield per recruit was greater for the BBN stock than for the NMB stock and indicated that increasing the minimum size limit would reduce yield per recruit for both stocks but would increase the biomass of spawners and spawning frequency - substantially so in BBN. We concluded that management steps to delay age at recruitment to the fishery and increase the biomass would benefit the BBN stock but possibly not the NMB stock. Increased fishing effort on either population would not be beneficial for the stocks.

Microgeographic Genetic Organization of Populations of Largemouth Bass and Two Other Species in a Reservoir

GERKING, S. D. 1953. Evidence for the concept of home range and territory in stream fishes. Ecology 34:347-365. IMHOF, M., R. LEARY AND H. E. BOOKE. 1980. Population or stock structure of lake whitefish, Corregonus clupeaformis, in northern Lake Michigan as assayed by isozyme electrophoresis. Canad. J. Fish. Aquat. Sci. 37:783-793. KUDRNA, J. J. 1965. Movement and homing of sunfish in Clear Lake. Proc. Iowa Acad. Sci. 72:263271. KozHov, M. 1963. Lake Baikal and its life. Monogr. Biol. 11.

Systematics of Bangia (Rhodophyta) in North America. I. Biogeographic trends in morphology

A total of eight species of Bangia have been recognized from North America but only one or two are presently included in taxonomic works. To clarify the systematics of this genus, 84 sites were sampled throughout its range, including south-east Alaska to the Baja Peninsula, Newfoundland to northern Georgia and Lake Michigan to Lake Ontario. Filament length and pigmentation proved to be of little value in differentiating populations. In contrast, significant differences were found when filament diameters were grouped according to the basin from which the samples were collected (P < 0. 001). The mean in situ diameters of monospore releasing filaments from the Pacific, Atlantic and Great Lakes were 157, 91.6 and 75.3 μm, respectively. Similar size differentials were observed for male and female plants in the field. In addition, growth in culture under controlled or varied conditions resulted in a similar trend of basin-based differences in filament diameters for asexual germlings, mature asexual plants or conchocelis filaments. The asexual monospore-releasing plants had average diameters remarkably similar to those of field-collected plants: 163, 91.6 and 74.4 μm for Pacific, Atlantic and Great Lakes filaments, respectively. At least five populations were sampled at each of the type localities of B. enteromorphoides Dawson, B. maxima Gardner and B. vermicularis Harvey. There appears to be no basis for continuing to recognize these populations as being separate from those of the rest of the Pacific. In summary, there are minimally two species of Bangia in North America, representing the populations of the Atlantic (B. atropurpurea (Roth) C. Ag.) and the Pacific (B. vermicularis). The small size of the Great Lakes plants may indicate incipient speciation and hence a new variety may be warranted.

Spatial and Temporal Distribution of Benthic Diatoms in Northern Lake Michigan

Benthic diatom communities were sampled from natural substrates along a depth tran- sect in northern Lake Michigan to examine spatial and seasonal distribution patterns and define assemblages of associated taxa. Information-theory diversity, evenness, and richness were signifi- cantly higher in deep assemblages than in shallow assemblages, with the boundary falling between 5 and 10 m in winter and fall, 10 and 20 m in spring, and 20 and 31 m in summer. Planktonic taxa are abundant on benthic substrates in the deep zone, primarily as dead fallout. In shallow water, large numbers of living planktonic taxa overwinter beneath the ice on benthic substrates. Cluster analysis of samples was used to identify and define diatom assemblages from deep, mid- depth, and shallow water. The deep-water assemblage contains motile and nonmotile benthic species that have been reported from alpine and boreal oligotrophic lakes. The mid-depth assemblage is rich in epipsammic taxa. The shallow-water assemblages contain cosmopolitan taxa that are collected often in nearshore plankton samples. These shallow assemblages do not persist throughout the year as do the deep and mid-depth assemblages. Cluster analysis of taxa provides further definition of species associations and the degree of cor- relation among species. Correlations among benthic taxa are strengthened when planktonic taxa are removed from the analysis, indicating that plankton fallout represents an addition of information which is poorly related to distribution of the benthic species. The most stable and diverse community is found at the deepest sampling depths where environ- mental conditions are most stable, the mid-depth community exists in fluctuating but predictable conditions, and the shallow assemblages occur in the zone of maximum physical fluctuation or natural stress. Substrate types are correlated with the species assemblages, but the high diversity of substrate types in shallow water does not support the most diverse assemblage. The discrete species assem- blages seen in an oligotrophic area of this large dimictic lake apparently respond sensitively to tem- porally and spatially dynamic environmental parameters.

Distribution and Abundance of Pink Salmon in Michigan Tributaries of the Great Lakes, 1967–1980

Abstract By 1980, some 24 years after introduction of an odd-year-spawning stock into Lake Superior, pink salmon Oncorhynchus gorbuscha have spawned in at least 56 tributaries of Lake Superior, 5 of northern Lake Huron, and 11 of northern Lake Michigan. Abundance trends in Lake Superior have been sharply upward. Pink salmon in lakes Huron and Michigan have not shown such an increase, probably because relatively few generations have reproduced there. The occurrence of 2- and 3-year-old spawners suggests that magnitude of the spawning runs will be more stable than on the West Coast where all pink salmon mature at 2 years. The amount of interaction of pink salmon with other Great Lakes fishes is uncertain, but we judge that their interaction with stream fishes will be negligible.

Examination of the surface microlayer of lake michigan using scanning electron microscopy

The top 280 ~m of water from Lake Michigan was studied in order to determine the types of particles and organisms present in the surface microlayer. The microlayer was sampled by dipping an aluminum screen into the water horizontal to the surface at stations located in Southern and Northern Lake Michigan. Surface microlayer and corresponding subsurface samples were collected in April and July, 1980.