Geology Reports⌕ Search

USGS · 1000795

Patterns of organochlorine contamination in lake trout from Wisconsin waters of the Great Lakes

Abstract

To investigate spatial and temporal patterns of organochlorine contamination in lake trout from Wisconsin waters of the Great Lakes, we examined laboratory contaminant analysis data of muscle tissue samples from Lake Michigan (n = 317) and Lake Superior (n = 53) fish. Concentrations of polychlorinated biphenyls (PCBs), chlordane, and dieldrin, reported as mg/kg wet weight in 620 mm to 640 mm mean length Lake Michigan lake trout, decreased over time. Mean total PCB concentration declined exponentially from 9.7 in 1975 to 1.9 in 1990. Total chlordane concentration declined 63 percent from 0.48 in 1983 to 0.18 in 1990, and dieldrin declined 52 percent during this same period, from 0.21 to 0.10. The bioaccumulation rate of PCBs is significantly lower for lake trout inhabiting Lake Michigan's midlake reef complex, compared to lake trout from the nearshore waters of western Lake Michigan. Organochlorine compound concentrations were greater in Lake Michigan lake trout than Lake Superior fish. Lake Superior lean lake trout and siscowet exhibited similar rates of PCB bioaccumulation despite major differences in muscle tissue lipid content between the two subspecies. The lack of a significant difference in the PCB bioaccumulation rates of lean trout and siscowet suggests that lipid content may not be an important factor influencing PCB bioaccumulation in lake trout, within the range of lipid concentrations observed. Relative concentrations of the various organochlorine contaminants found in lake trout were highly correlated, suggesting similar mass balance processes for these compounds. Evidence presented revealing spatial and temporal patterns of organochlorine contamination may be of value in reestablishing self-sustaining populations of lake trout in Lake Michigan.

Explore related subjects

Keep this discovery

Explore connections, maps & timelines

BibTeXRIS

Michael A. Miller, Charles P. Madenjian, Robert G. Masnado. 1992. Patterns of organochlorine contamination in lake trout from Wisconsin waters of the Great Lakes. https://doi.org/10.1016/s0380-1330(92)71333-1

Cite the original work for its findings. Save a collection to share your selection of sources.

KEEP EXPLORING

Related USGS reports

Groundwater nutrient contributions to surface water in the upper Maumee River basin

Harmful algal blooms triggered by nutrient loading have negatively affected Lake Erie water quality for decades, but the role groundwater plays in transporting nutrients to tributary streams is unclear. Here, we apply a multi-scale approach to investigate groundwater nitrogen (N) and phosphorus (P) dynamics at the field scale, along a groundwater flow path, and at the Maumee River basin scale. Unsaturated zone monitoring indicates that macropore flow is the primary mechanism for N and P leaching with nitrate and orthophosphate (OP) concentrations from macropore samplers more than double those from soil-matrix samplers. Shallow (< 4.5 m) groundwater nitrate concentrations indicate the timing of saturated-zone nitrate fluxes is crop dependent with more nitrate mobilized during the maize growing season whereas concentrations below soybeans can remain elevated (> 3 mg/L) through winter months. A three-end-member hydrograph analysis for the upper Maumee River basin indicates that tile drains transport most subsurface N and P with greater than 15,000 kg per day of nitrate transported between January and May. Orthophosphate concentrations in tile drainage at an edge-of-field site correlate well with concentrations in a nearby tributary of the Maumee River. While runoff is the dominant source of OP loading, tile drainage and groundwater discharge contributed an estimated 36% of OP load during a 2018–2022 analysis period with most subsurface loading occurring between January and March. These findings highlight how best management practices (such as cover crops and tile drainage control structures) can be used to help limit leaching and tile effluent during the nongrowing season.

Indiana↗

Application of novel encounter and predation models to the natural behavior of slimy sculpin Cottus cognatus

Sculpins play a critical mid-trophic role in lacustrine food webs, converting production by benthic and migrating pelagic invertebrates into biomass available to higher trophic levels. Although sculpin diets and habitat choices are relatively well described, much less is known about their in situ behavior which governs trophic interactions and, in part, prey behavior. We measured the natural behavior of slimy sculpin Cottus cognatus in Lake Champlain using video data originally collected to quantify Mysis diluviana abundance in benthic habitat. After characterizing slimy sculpin movement behaviors according to body size, we incorporated these data into encounter and predation rate models at the individual and population levels, the latter based on bottom trawl data from Lake Champlain. Saltatory movement varied with body length in terms of distance traveled, duration traveled, and duration at rest, but strike distances at prey did not vary across individual sculpins. Slimy sculpin predation rate increased with depth and was limited by pursuit time rather than prey availability, and their populations exerted predation rates on Mysis up to 5 predation events/m 2 /day. Assessment of benthic predation risks affords the opportunity to test hypotheses about the role of predation risk in Mysis diel vertical migration (DVM), and DVM more broadly. Furthermore, the methods we describe here can easily be employed for other benthic fishes such as the invasive round goby Neogobius melanostomus .

New York, Vermont↗

Thermal habitat use of lake trout in Lake Erie

Understanding the thermal habitat use of fish populations is vital for effective rehabilitation or management, particularly in the face of climate change, given limited thermal tolerances of some species. In Lake Erie, lake trout ( Salvelinus namaycush ) rehabilitation efforts by means of stocking have been ongoing for four decades. However, high water temperatures and lengthening periods of stratification may be hindering reestablishment efforts by contributing to unfavorable conditions for spawning and natural recruitment. We used acoustic telemetry to quantify weekly temperature occupancy of adult lake trout in Lake Erie and evaluated whether temperature occupancy differed relative to fish total length and sex. We found that lake trout occupied water temperatures similar to temperatures occupied by other Great Lakes lake trout populations during summer stratification. During fall, lake trout in Lake Erie occupied warmer temperatures than Lake Huron populations but similar temperatures to Lake Ontario populations. Occupied temperatures decreased with increasing body size during a 7-week period of mid- to late-summer stratification, but not during early summer or fall. Male and female lake trout did not differ in weekly temperature occupancy during any season. These findings reveal similarities with successfully reproducing populations, which suggest that adult temperature occupancy is unlikely to be a major impediment to natural recruitment in Lake Erie.

Lake Erie↗