Preliminary Investigation of the Extent of Sediment Contamination in the Lower Grand River

A preliminary investigation of the nature and extent of sediment contamination in the lower Grand River was performed. Three areas in the lower Grand River exceeded sediment quality guidelines for heavy metals and selected organic chemicals. The locations and parameters of concern are listed below: Harbor Island (G20). Exceeds sediment PEL values for chromium, lead, nickel, and DDE in the top core section. Deeper core sections were extensively contaminated with heavy metals. Spring Lake (G6). Exceeds sediment PEL values for chromium, lead, cadmium, nickel, and DDE. Grand Haven (G12). Exceeds sediment PEL values for chromium and nickel. The sediments at this location exhibited a statistically significant level of toxicity to amphipods when compared to the control

A comparison study of Colilert and qPCR methods at Pere Marquette Beach, Muskegon County, MI

Pere Marquette Beach serves as the primary attraction for tourism and coastal recreation in Muskegon, MI. Because beaches attract many people daily, it is important to monitor beach water quality for pathogens that may cause waterborne disease. Molecular-based methods are emerging as replacements for culture-based techniques for monitoring beaches. Culture-based methods require 18-hour incubation while Quantitative Polymerase Chain Reaction (qPCR) can yield results in two hours. My research examines the correlation between the culture-based Colilert-18® method and qPCR measurements of E. coli at a Lake Michigan beach in Muskegon County, MI. While Colilert 18 is a defined substrate method and measures culturable cells, the qPCR method quantifies both living and nonliving DNA. Regression analysis (R2) was used to correlate analytical results and the Index of Agreement (IA) was employed to evaluate method comparability. This research demonstrates the equivalency of both methods for E. coli measurements at Pere Marquette beach (R2 = 0.8012; IA = 0.71). The significant positive difference between the methods suggests that current guidelines for beach warnings and closures need to be revised to reflect the presence of nonviable DNA/cells in beach water. This study was important for assessing the applicability of qPCR for providing same-day results for pathogens at local beaches

Measuring Streambank Erosion: A Comparison of Erosion Pins, Total Station, and Terrestrial Laser Scanner

Streambank erosion is diffcult to quantify; models and field methods are needed to assess this important sediment source to streams. Our objectives were to (1) evaluate and compare three techniques for quantifying streambank erosion: erosion pins, total station, and laser scanning, (2) spatially assess streambank erosion rates in the Indian Mill Creek watershed of Michigan, USA, and (3) relate results with modeling of nonpoint source pollution. We found large absolute and relative errors between the different measurement techniques. However, we were unable to determine any statistically significant differences between techniques and only observed a correlation between total station and laser scanner. This suggests that the three methods have limited comparability and differences between measurements were largely not systemic. Further, the application of each technique should be dependent on site conditions, project goals, desired resolution, and resources. The laser scanner collected high-resolution data on clear, barren streambanks, but the erosion pin and total station were more representative of complex vegetated banks. Streambank erosion rates varied throughout the watershed and were influenced by fluvial processes. We estimate that streambank erosion contributed 28.5% of the creek’s total sediment load. These findings are important to address sources of watershed impairments related to sedimentation, as choosing an applicable technique for individual purposes can help reduce the challenges and costs of a streambank erosion study

The Impact of Environmental Parameters on Microcystin Production in Dialysis Bag Experiments

It is important to understand what environmental parameters may regulate microcystin (MC) production and congener type. To determine if environmental conditions in two hydraulically connected lakes can influence MC production and congener ratios, we incubated dialysis bags containing phytoplankton from mesotrophic/eutrophic Muskegon Lake into hypereutrophic Bear Lake (Michigan, USA) and vice versa. Strong cyanobacteria growth was observed in all dialysis bags with Bear Lake phytoplankton in July and August. Phytoplankton communities were dominated by Aphanizomenon aphanizomenoides, Microcystis wesenbergii, Limnothrix redekei. MC concentrations were correlated with M. wesenbergii and A. aphanizomenoides biovolume. MC concentrations in bags incubated in the Muskegon Lake with Bear Lake water were significantly higher than the other bags. The higher light intensity and total nitrogen concentration may have caused the increase of MC production. The MC-LR/MC-RR ratios varied with sample origin but not with lake of incubation, indicating that physical environmental factors (water temperature and turbidity) were not the reasons for different toxin production ratios. Differences in total phosphorus concentrations might be one reason for the dissimilarity of the MC-LR/MC-RR ratio between the two lakes. The higher light intensity and NO3-N concentration in Muskegon Lake are two factors contributing to an increase of MC production

Sex differences in contaminant concentrations of fish: a synthesis

Abstract A comparison of whole-fish polychlorinated biphenyl (PCB) and total mercury (Hg) concentrations in mature males with those in mature females may provide insights into sex differences in behavior, metabolism, and other physiological processes. In eight species of fish, we observed that males exceeded females in whole-fish PCB concentration by 17 to 43 %. Based on results from hypothesis testing, we concluded that these sex differences were most likely primarily driven by a higher rate of energy expenditure, stemming from higher resting metabolic rate (or standard metabolic rate (SMR)) and higher swimming activity, in males compared with females. A higher rate of energy expenditure led to a higher rate of food consumption, which, in turn, resulted in a higher rate of PCB accumulation. For two fish species, the growth dilution effect also made a substantial contribution to the sex difference in PCB concentrations, although the higher energy expenditure rate for males was still the primary driver. Hg concentration data were available for five of the eight species. For four of these five species, the ratio of PCB concentration in males to PCB concentration in females was substantially greater than the ratio of Hg concentration in males to Hg concentration in females. In sea lamprey (Petromyzon marinus), a very primitive fish, the two ratios were nearly identical. The most plausible explanation for this pattern was that certain androgens, such as testosterone and 11-ketotestosterone, enhanced Hg-elimination rate in males. In contrast, long-term elimination of PCBs is negligible for both sexes. According to this explanation, males not only ingest Hg at a higher rate than females but also eliminate Hg at a higher rate than females, in fish species other than sea lamprey. Male sea lamprey do not possess either of the above-specified androgens. These apparent sex differences in SMRs, activities, and Hg-elimination rates in teleost fishes may also apply, to some degree, to higher vertebrates including humans. Our synthesis findings will be useful in (1) developing sex-specific bioenergetics models for fish, (2) developing sex-specific risk assessment models for exposure of humans and wildlife to contaminants, and (3) refining Hg mass balance models for fish and higher vertebrates.http://deepblue.lib.umich.edu/bitstream/2027.42/134637/1/13293_2016_Article_90.pd

Environmental context and contaminant biotransport by Pacific salmon interact to mediate the bioaccumulation of contaminants by stream-resident fish

1. The extent to which environmental context mediates the uptake of biotransported contaminants by stream-resident organisms is not understood. For example, there is no clear understanding of the extent to which contaminant type, instream characteristics, or resident fish identity interact to influence the uptake of contaminants deposited by Pacific salmon (Oncorhynchus spp.) during their spawning runs. 2. To address this uncertainty, we sampled four stream-resident fish species from 13 watersheds of the Laurentian Great Lakes in locations with and without salmon across a gradient of instream and watershed characteristics. We determined the polychlorinated biphenyl (PCB) and mercury (Hg) concentration along with the stable isotope ratio of C and N for each stream-resident fish. 3. We found that stream-resident fish PCB concentrations were 24-fold higher in reaches with salmon and were positively related to δ15N. In contrast, stream-resident fish Hg concentrations were similar or lower in reaches with salmon and either exhibited a negative or no relationship with δ15N. 4. Based upon AICc, stream-resident fish exhibited species-specific PCB concentrations that were positively related to salmon PCB flux. Hg burdens exhibited an interaction between fish length and salmon Hg flux – as salmon Hg inputs increased, Hg levels decreased with increasing resident fish length. We found no support for models that included the mediating influence of instream or watershed factors. Salmon eggs are enriched in PCBs but have very low Hg concentrations, so our results may be driven by the consumption of salmon eggs by stream-resident fish. 5. Synthesis and applications. Our results highlight that contaminants bioaccumulate differently depending on contaminant type, species identity, and the trophic pathway to contamination. Consequently, consideration of the recipient food web and route of exposure is critical to understanding the fate of biotransported contaminants in ecosystems. The transfer of contaminants by migratory organisms represents an understudied stressor in ecology. Effective management of biotransported contaminants will require the delineation of “hot-spots” of biotransport and implementation of best management practices in those watersheds that receive contaminants from spawning salmon

Oil and PCB interactions on the uptake and excretion in midges

Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/47989/1/128_2005_Article_BF01625535.pd

Assessment of E. coli and Microcystins in Cladophora Mats in the Nearshore Waters of Grand Traverse Bay, Little Traverse Bay, and Saginaw Bay

An assessment of the ability of Cladophora mats to sequester E. coli and microcystin LR and RR was conducted in the near-shore waters of Grand Traverse Bay (7 sites), Little Traverse Bay (2 sites), and Saginaw Bay (8 sites). The sampling locations were at public beach access points where Cladophora mats were previously observed. The goals of this research were to determine the spatial and temporal variability of E. coli populations in Cladophora mats in these recreational waters and if cyanotoxins (microcystin LR and RR) are sequestered in the detached algae. The collection of Cladophora samples was coordinated with local beach monitoring programs to facilitate the comparison with ambient water bacteria concentrations. This project provided important data for the assessment of public health impacts and the development of beach management programs to address the problems associated with Cladophora accumulations. Based on the results from this investigation, Saginaw Bay appears to be more heavily impacted by detached Cladophora than Grand Traverse/Little Traverse Bays. Mean E. coli concentrations in detached Cladophora were higher in Saginaw Bay (2,796 cfu/g dwt) than Grand Traverse Bay/Little Traverse Bay (1,775cfu/g dwt); however, the difference was not statistically significant (Mann-Whitney ρ=0.40). Cladophora deposits exhibited spatial and temporal variability in both systems. At most beaches in Grand Traverse Bay, Cladophora deposits were limited to small pockets at 1 location. Clinch Park had only one site with Cladophora on the last sampling event and two locations at the Traverse City State Park were free of detached algal accumulations. In contrast, Cladophora deposits in Saginaw Bay covered approximately 1 meter (m) of the shoreline at most beaches. Two locations in Saginaw Bay also had no accumulations of Cladophora during the study period (White’s Beach and Pinconning Park). Differences in Cladophora accumulation between Saginaw Bay and Grand Traverse Bay/Little Traverse Bay may be attributed to higher total phosphorus levels in Saginaw Bay. Levels of E. coli in detached Cladophora in both systems were similar to concentrations previously reported in the Great Lakes (1,000 cfu/g dwt – 60,000 cfu/g dwt). In Saginaw Bay, the highest levels of E. coli in detached Cladophora were consistently found at beaches near the Saginaw River. Even within individual sites, locations near tributaries and drains at Wenona Beach and South Linwood Beach were significantly higher than locations farther away from a point source. This relationship also was noted in Grand Traverse Bay, where the location near Mitchell Creek at the Traverse City State Park, had elevated E. coli concentrations in detached Cladophora compared to the other beach locations. These results suggest that Cladophora can trap bacteria from point sources and also be stimulated by nutrient discharges. Two locations, Pinconning Park and White’s Beach, had very limited Cladophora growth. Both locations had Chara growing on the lake bottom. Chara is known to exhibit allelopathic activity that can limit the growth of other aquatic plants. No correlation was found between E. coli levels in the open water (designated beach monitoring locations) and the near-shore zone, where the detached Cladophora samples were taken. As noted in previous studies, Cladophora appears to hold trapped E. coli and does not release the entrained bacteria into the offshore water. This investigation was the first to document the accumulation of microcystins in the detached Cladophora of Saginaw Bay. Total microcystins in detached Cladophora had a grand mean of 57 μg/g dwt for the study period. Saginaw Bay has a history of Microcystis blooms in the late vi summer months that produce both microcystin LR and RR. Since Microcystis has a high requirement for sunlight, cyanobacteria may become stressed when they are trapped in the detached algae mats. While accidental ingestion by humans of microcystins trapped in Cladophora is unlikely, these compounds can act as skin irritants. Walking through Cladophora accumulations to get to deeper water may provide sufficient exposure to cause irritation in sensitive individuals if microcystins are present. Although the data suggest that swimming areas (1 m depth) are not impacted by the E. coli accumulations in detached Cladophora, entrained bacteria and cyanotoxins may pose a hazard to children playing in the nearshore water and beach sand. Current regulations discourage beach grooming and altering the nearshore zone. The presence of elevated bacteria and microcystin levels in the nearshore environment of Saginaw Bay suggests that the current policy should be reevaluated to balance potential impacts to public health with the ecosystem services provided by coastal wetlands

Factors influencing internal P loading in a western Michigan, drowned river-mouth lake

Originally published in: J. N. Am. Benthol. Soc., 2006, 25(2):304–312 Release of P from lake sediments may account for a significant portion of a lake’s total P (TP) load. Previous studies using sediment cores showed that ;65% of the total P load entering Spring Lake, Michigan, came from the sediments, and that an alum concentration of 24 mg Al/L effectively inactivated P release in experimental sediment-core tubes. In 2004, we studied the influence of alum concentration and sediment resuspension on P release rates from the sediments. Based on laboratory incubations using alum concentrations of 0, 5, 10, 15, 20, and 25 mg/L, we determined that P release rates at alum concentrations 15 mg/L were no different than at release rates at concentrations of 25 mg/L. Resuspension of sediments substantially increased TP concentrations, even at high alum concentrations, but total soluble P concentrations remained low in the water when alum was present. Alum application may be an effective tool to reduce P flux from sediments in shallow lakes, but external P load reduction must accompany alum application to address the long-term impacts associated with cultural eutrophication