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This study used satellite remote sensing to investigate trends in harmful algal blooms (HABs) over the last 21 years, focusing on four regions within the Laurentian Great Lakes: western Lake Erie, Green Bay, Saginaw Bay, and western Lake Superior. HABs in the water column were identified from remote sensing-derived chlorophyll concentrations, and surface HAB scums were classified based on the Normalized Difference Vegetation Index (NDVI) band ratio index. Using imagery from the Moderate Resolution Imaging Spectroradiometer sensor on the Aqua satellite (MODIS-Aqua) from 2002 to 2022, we generated daily estimates of the HAB and surface scum extents for each region, which were then averaged to generate mean annual extents. We observed a significant decline in the Saginaw Bay mean annual HAB extents over the 21-year study period. Otherwise, no significant changes were observed over this period in any region for either the HAB or surface scum mean annual extents, thus suggesting that HABs are not increasing in the Great Lakes. Despite the lack of increasing trends, the blooms are still recurring annually and causing a negative impact on the nearby communities; thus, we believe that it is crucial to continue studying Great Lakes HABs to monitor the impact of current and future abatement strategies. [ABSTRACT FROM AUTHOR]

Coregonus populations across their Holarctic range have often undergone unexplained collapses. Here, we document causes of collapse for two of the largest Coregonus populations in the world, cisco (C. artedi) in Green Bay, Lake Michigan, and Saginaw Bay, Lake Huron, during the 1950s. We used simulation models, rank‐order correlations, and historical literature to evaluate effects of overfishing, interactions with introduced rainbow smelt (Osmerus mordax), and overwinter bottom hypoxia on both cisco populations. Fully selected exploitation rates for cisco were alarmingly high (0.82–0.84), correlations and anecdotal evidence suggested negative interactions with rainbow smelt, and extensive areas of hypoxia coincident with cisco declines suggested incubation of cisco embryos was impaired regionally. Our findings suggested that negative effects of rainbow smelt were mainly responsible for the cisco population collapse in Green Bay and that overfishing and hypoxia had suppressed the Saginaw Bay cisco population before rainbow smelt caused its final collapse. [ABSTRACT FROM AUTHOR]

The Flinton Group is a metasedimentary succession of the Grenville Province in SE Ontario, potentially allowing insight into the tectono‐thermal evolution of continental crust during the Mesoproterozoic. At its Green Bay locality, Flinton Group metapelites of the staurolite zone contain abundant, post‐kinematic garnet porphyroblasts. Whereas the larger garnet crystals are typically impinged, smaller crystals are isolated from each other, occasionally exhibiting elongated shapes with apparently trigonal morphology. Central sections of the garnet population of a representative sample reveal that garnet is composed of different compositional and microstructural domains. In the largest crystals of the population, garnet contains rectangular to rhombic domains, marked by sharp increases in the concentrations of Nb, V, Ti, and Cr. These domains are associated with irregularly shaped patches, characterized by spatially heterogenous enrichments of Ca and LREE, and depletions in the contents of P, Y, MREE, and HREE, accompanied by increased densities of comparatively coarse‐grained quartz inclusions hosting apatite. Microstructural relationships indicate that these domains correspond to portions of garnet that pseudomorphed biotite, with the enrichments of Nb, V, Ti, and Cr outlining the original biotite shapes. The compositional patterns formed by Ca, P, Y, and REE indicate that apatite participated in the grain‐fluid interactions that operated during the metasomatic replacement of biotite by garnet. The statistical analyses of the garnet number and size distributions confirm that garnet initially nucleated on biotite, controlled by the kinetics of attachment and detachment processes at the garnet/biotite interface, resulting in the typical impingement habit. In situ Lu–Hf garnet geochronology applied to garnet that did not pseudomorph biotite, and hence is enriched in HREE, points to a first metamorphic event at c. 1080 ± 31 Ma. Subsequent pseudomorphism of staurolite by white mica in a Al2O3‐ and FeO‐mobile system resulted in the concomitant crystallization of a new garnet generation, forming overgrowths on the first garnet generation and nuclei in the fine‐grained matrix. Garnet that nucleated during this event grew to isolated and elongated crystals with apparently trigonal morphology, aligned in a direction c. perpendicular to the rock matrix foliation. The open‐system behaviour during this event limits the use of whole‐rock‐based geochronological and thermobarometrical applications. However, previously published in situ U–Pb ages of monazite included in the rims of the garnet crystals and in the rock matrix indicate that this event took place at c. 976 ± 4 Ma, likely associated with a period of increased hydrothermal activity late in the metamorphic history of the Grenvillian Orogeny. Diffusion geospeedometry calculations indicate that garnet growth during this hydrothermal event lasted for less than 6 Myr. [ABSTRACT FROM AUTHOR]

The open waters of large lakes can sometimes become so depleted in important metals that phytoplankton communities become either growth limited or limited in some metabolic function. Metals such as Fe, Ni, Mo, and Zn are used as co-factors for enzymes by phytoplankton in core metabolic functions, as well as metabolic pathways that allow phytoplankton to use less preferred forms of N and P (e.g. nitrates, urea, and organic phosphorus). In the Laurentian Great Lakes, metal limitation has been observed primarily in waters that are isolated from tributary inputs and sediment exchange. These are situations where the supply of metals is very low relative to demand. We hypothesized that another situation where metal limitation could occur is within algal blooms, where the demand for metals is high because preferred forms of N and P are often low or absent and the phytoplankton biomass is extremely high. As a preliminary test of this hypothesis, we performed seven laboratory incubation experiments on naturally occurring phytoplankton communities from two nearshore habitats that frequently experience blooms (Green Bay in Lake Michigan and Maumee Bay in Lake Erie). Metals and labile nutrients (inorganic N and P) were often present at low concentrations or below the method detection limit. Amendments of inorganic N (5 experiments) and P (1 one experiment) resulted in increased chlorophyll in laboratory incubations, but metal amendments alone never appeared to stimulate growth. Although we attempted to sample during conditions when we hypothesized metal limitation would be most likely, we cannot rule out the possibility that metal limitation is occurring at other times in these eutrophic nearshore areas. Further, metal availability could affect other aspects of the phytoplankton community, such as the production of cyanotoxins or the interactions between different phytoplankton taxa. Although harmful algal blooms are more likely to develop when external nutrient loads are high, while a bloom is occurring, the concentrations of key nutrients (nitrogen and phosphorus) can be very low. When key nutrients are in low abundance or absent, algae require additional metals to take advantage of poorer quality versions of these key nutrients. We hypothesized that metals might become growth-limiting in blooms, which might in turn have implications for predicting bloom toxicity. Seven experiments on phytoplankton from nearshore Great Lakes areas experiencing algal blooms did not show evidence for growth-limitation of algae, although the spatial and temporal extent of these experiments is limited. [ABSTRACT FROM AUTHOR]

Fish larvae in riverine environments often disperse (e.g., drift) from areas of egg deposition at the time of hatch. Several components of drift can be important in terms of survival including timing, distribution in the water column, and body size. The longitudinal and cross-sectional aspects of larval lake sturgeon (Acipenser fulvescens) drift from upstream spawning sites have received considerable study. However, the vertical distribution of larval lake sturgeon in the water column has not been comprehensively evaluated with respect to river size, water depth, the size of larvae in drift over the entire drift period, and the effectiveness of traditional sampling gear (D-frame nets) designed to collect larvae along the river bottom. In 2013, we sampled larval lake sturgeon drifting from upstream spawning sites in the Menominee and Oconto Rivers (Wisconsin, USA) using traditional D-frame nets and custom fabricated sampling nets that vertically partitioned the water column. Drifting larval lake sturgeon were observed from the river bottom to the top of the water column in both systems. Vertical net section was a significant predictor of total larval catch with the highest catch occurring in nets towards the center of the water column but was dependent on net location within the rivers' cross section and downstream distance from spawning locations. 42% of larvae captured across both rivers were outside of the sampling capability of the traditional D-frame nets (i.e., fish would have drifted over the top). Studies seeking to describe larval production for lake sturgeon, as well as other fish species that exhibit drift in larval dispersal, need to consider a balance between net design and sampling the vertical/cross sectional profiles of rivers. Size-based vertical drift may also have consequences for studies seeking to estimate genetic parameters (e.g., diversity and parentage). [ABSTRACT FROM AUTHOR]

Purpose: The commercial-scale production of torrefied plastic-fiber fuel pellets from waste plastics and waste fibers may offer a viable alternative to fossil fuel–based energy. In this study, the environmental impact of fuel pellets produced and consumed in Green Bay, Wisconsin, USA is evaluated and compared to the status quo of grid energy production from fossil fuels (i.e., coal or natural gas). Methods: A cradle-to-grave life cycle assessment was conducted using a functional unit of 1 kWh of energy produced using torrefied plastic-fiber fuel pellets versus production of energy from coal or natural gas. Regional data along with relevant manufacturing data was used to inform the inventory of the production of the torrefied fuel pellets, which are manufactured using waste fibers and waste plastics sourced from within 5 km of the torrefaction facility and consumed within 50 km of the facility. Since fuel pellets are produced from waste inputs and contain biogenic carbon sources, impacts were assessed with/without credit for biogenic carbon and with/without the burden of the torrefaction inputs. Results and discussion: The production of 1 kWh of energy using torrefied plastic-fiber fuel pellets was determined to produce between 0.303 and 0.757 kg CO2 eq emissions due to combustion and between 0.062 and 1.105 kg CO2 eq additional emissions as a result of the manufacturing process, with the ranges dependent upon the allocation method selected. Under a burden-free allocation due to waste materials used as inputs, along with a credit for biogenic carbon emissions, the system produces 0.365 kg CO2 eq per 1 kWh of energy; however, under a full-burden allocation with no credit for biogenic carbon emissions, 1.862 kg CO2 eq per 1 kWh of energy is produced. This highlights the differences between allocation scenarios and role of credits for biogenic carbon emissions when evaluating systems. Conclusions: The usage of torrefied plastic-fiber fuel pellets produced using waste plastics and fibers is a reasonable alternative to the status quo of waste disposal coupled with the production of grid energy from fossil fuels. In addition to the reduction in GHG emissions, the use of the process would also help to alleviate the environmental burden of waste plastics. [ABSTRACT FROM AUTHOR]

Reservoir 14C age offsets track past changes in atmospheric carbon content, air–water gas exchange, and freshwater circulation in water bodies. Determination of a freshwater reservoir correction (FWRC) is a crucial step in age-model development to provide accurate climate-proxy records. We employ published, recent water column 14C measurements from Lake Superior, and reassess unpublished and published 14C measurements of live-collected, pre-bomb bivalve shells dated from lakes Michigan, Huron, Erie, and Ontario, to provide the most comprehensive, consistent snapshot of the mid twentieth century (pre-bomb) FWRC for the Laurentian Great Lakes assembled to date. We also use mollusk/ostracod and wood shell ages from the bottom 60 cm of a 1218 cm core from Lake Erie's eastern basin to estimate a late Holocene FWRC. The FWRC for all live-collected samples were recalculated in a consistent-manner using the IntCal20 atmospheric 14C curve. The revised corrections provide modest revisions (± 10%) of published values. The revised FWRC values document a generally increasing trend along the circulation pathway from Lake Superior to Michigan, Huron, and Erie with average FWRC in 14C years of 206 ± 55 for Lake Superior, 247 ± 81 for Lake Michigan, 365 ± 41 in Green Bay, 340 ± 72 for northern Lake Huron, 321 ± 71 in Georgian Bay, to 443 ± 62 in southern Lake Huron. For Lake Erie, the average FWRC for the western basin is 455 ± 52 14C years, for the central basin 676 ± 52 14C years, and 748 ± 76 14C years for the eastern basin. In Lake Ontario, the average FWRC for the western part of the lake is 540 ± 55 14C years, smaller than the value observed for Lake Erie. The late Holocene FWRC for eastern Lake Erie is estimated between 440 ± 124 14C years and 306 ± 124 14C years, which is smaller than the pre-bomb value. This study provides a conceptual framework and statistical model to explain the observed pattern of FWRC in the Great Lakes. Higher FWRC values are encountered in basins surrounded by more carbonate bedrock and higher inflow rates, mostly from upstream lakes. On a basin-wide scale, there is a statistically significant positive linear relation for the observed FWRC, which depends on the fractional area of carbonate bedrock within each Great Lake watershed and the inflow rate to each basin, accounting for essentially all the variance in the data. [ABSTRACT FROM AUTHOR]

Estuaries, in particular freshwater estuaries, provide valuable economic, social, and ecological services, but their ecosystems are often heavily stressed. Located in the Laurentian Great Lakes basin, Green Bay is a large freshwater estuary and a prominent example of a degraded ecosystem due to intensive human interventions and rapid development. Excessive amounts of contaminants and nutrients were discharged to the bay by inflowing tributaries for almost half a century, while in contrast Green Bay's seasonal‐, morphological‐, and physically‐restricted mixing is unable to export a significant portion of those materials out of the bay, that is, Green Bay behaves as an efficient retention basin for the Lake Michigan. Consequently, several environmental and public health‐related issues have risen in Green Bay and turned the lower bay into an area of environmental concern since the 1980s. To address these challenges, restoration programs were developed, including the development of monitoring programs, scientific research, and remedial action plans. There is a consensus that accelerated loading rates of contaminated and nutrient‐rich sediments are a major driver of the environmental crisis in the bay, yet the fate and transport patterns of Green Bay sediments are not clearly understood. While field observations in Green Bay are season‐limited and costly, advanced computing techniques provided opportunities to refine our understanding of sediment dynamics in this estuarine system. This review of existing knowledge on Green Bay sediment processes can help to better understand the interplay between sediments, and physical/biogeochemical activities in estuarine systems and contributes conceptually to the restoration of degraded aquatic ecosystems. This article is categorized under:Science of Water > Hydrological ProcessesScience of Water > Water QualityWater and Life > Stresses and Pressures on Ecosystems [ABSTRACT FROM AUTHOR]

Effective fishery management in large systems relies on understanding how individual stocks contribute to a fishery over spatial and temporal scales. The current conceptual model for management of Walleye Sander vitreus in Green Bay designates Walleye in the northern and southern parts of the bay as distinct stocks, with little mixing between the northern and southern fisheries, and assumes that Walleye in both northern and southern Green Bay primarily spawn in tributaries as opposed to shoreline or offshore reef areas. We used acoustic telemetry to test this conceptual model for Walleye management in Green Bay. Telemetry indicated that the majority of Green Bay Walleye use tributaries for spawning. However, many individuals were assigned to open‐water spawning locations during consecutive years in both northern (26%) and southern (21%) Green Bay, suggesting that open‐water spawners may represent a larger proportion of the Walleye stocks than previously thought. Differential movement was observed between northern and southern portions of Green Bay, with 56% of Walleye tagged in northern Green Bay crossing receiver lines to move south compared to only 19% of Walleye tagged in southern Green Bay crossing receiver lines to move north. Walleye typically transitioned across these boundaries in summer and fall, suggesting that stock contributions to the fishery in each zone may differ seasonally. Differential movements of northern Green Bay Walleye may be influenced by broad‐scale differences in habitat and prey availability, which are likely related to the differential effects of dreissenid mussel invasion in Green Bay. Our results suggest that adjustment of monitoring efforts to account for open‐water spawners may provide a more complete picture of stock status. Additionally, more research examining potential food web effects of northern Green Bay Walleye moving into southern Green Bay may be needed to determine how these movements might influence other important species. [ABSTRACT FROM AUTHOR]

Ground water contamination from septic systems and the application of dairy cattle manure has been a long-standing problem in rural northeastern Wisconsin, especially in areas with thin soils over karstified Silurian dolostone bedrock, where as many as 60% of the wells show evidence of fecal contamination. We present the results of a citizen science supported water-isotope study in Kewaunee County, Wisconsin to evaluate aquifer recharge processes in the critical zone and to demonstrate the viability of time-series stable isotope data as a supplement to traditional water quality indicators in a contamination-prone aquifer. A meteoric water line was also constructed for Green Bay, Wisconsin, providing reasonable isotopic ranges for aquifer recharge events. Volunteer homeowners collected water samples from their domestic wells for a period of ~14 months to provide a measure of long-term isotopic variation in produced water and to determine whether event-driven responses could be identified using δ18O and δ2H isotopic values. Three shallower wells with a prior history of contamination exhibited significant seasonal variation, while the deepest well with the greatest soil thickness (above bedrock) showed less variation. For moderate precipitation events, the shallowest well showed as much as 5–13% of produced water coming from direct recharge, with smaller contributions for deeper wells. Our case study provides a clear example of how citizen science can collect useful time-series isotopic data to support groundwater recharge studies. [ABSTRACT FROM AUTHOR]

One of the largest freshwater estuarine systems on Earth, Green Bay receives freshwater runoff from its land watershed and cold-water intrusions from Lake Michigan. Southern Green Bay is a designated area of concern (AOC) due to ecosystem degradation, contaminated sediments, and poor water quality. Successful restoration of aquatic systems requires a clear understanding of their circulation and thermal regimes. Using a state-of-the-art numerical ocean model, this study examines the effect of variability in tributary inflows and the related lake intrusions on the circulation and thermal regime in Green Bay and on the mass and heat fluxes between lower- and upper–Green Bay areas. Our findings indicate that tributaries influence the circulation and thermal regime, locally and throughout the bay, and that the impact is more significant in hydrologically wet years. Model simulations showed evidence of small net transport out of lower Green Bay. This analysis of the simultaneous effects of tributary flows and lake intrusions in Green Bay can contribute to understanding the dynamics of freshwater estuaries and improve the planning of future restoration projects. [ABSTRACT FROM AUTHOR]

River-to-lake transitional areas are biogeochemically active ecosystems that can alter the amount and composition of dissolved organic matter (DOM) as it moves through the aquatic continuum. However, few studies have directly measured carbon processing and assessed the carbon budget of freshwater rivermouths. We compiled measurements of dissolved organic carbon (DOC) and DOM in several water column (light and dark) and sediment incubation experiments conducted in the mouth of the Fox river (Fox rivermouth) upstream from Green Bay, Lake Michigan. Despite variation in the direction of DOC fluxes from sediments, we found that the Fox rivermouth was a net sink of DOC where water column DOC mineralization outweighed the release of DOC from sediments at the rivermouth scale. Although we found DOM composition also changed during our experiments, alterations in DOM optical properties were largely independent of the direction of sediment DOC fluxes. We found a consistent decrease in humic-like and fulvic-like terrestrial DOM and a consistent increase in the overall microbial composition of rivermouth DOM during our incubations. Moreover, greater ambient total dissolved phosphorus concentrations were positively associated with the consumption of terrestrial humic-like, microbial protein-like, and more recently derived DOM but had no effect on bulk DOC in the water column. Unexplained variation indicates that other environmental controls and water column processes affect the processing of DOM in this rivermouth. Nonetheless, the Fox rivermouth appears capable of substantial DOM transformation with implications for the composition of DOM entering Lake Michigan. [ABSTRACT FROM AUTHOR]

The growing trend of solar photovoltaic (PV) adoption has motivated homeowners and independent solar PV plants to assume the role of electricity generators. Utility companies need to address the changes in supply and demand to formulate effective distribution plans. Monitoring the power output of the photovoltaic array is a key task in ensuring the correct estimation of the electricity production of the system. Nevertheless, the literature recognizes the obstacle that expensive on-site monitoring sensors have on the cost of small-scale and medium-scale PV applications. Mathematical models based on the estimation of power output from historical data are the most used techniques to address the need for expensive monitoring systems. Estimating the power output of a PV array depends on the cell temperature, ambient temperature, and solar irradiance. This paper proposes a machine learning model to forecast site-specific ambient temperature and solar irradiance. The results contribute to the generation of low-cost data-driven models to save money by eliminating the need to install on-site sensors. The methodology employed off-site publicly-available weather data from neighboring weather stations as an alternative to on-site measurements. A 5-layer deep neural network was trained using 5 years' worth of historical data from a remote weather station in Green Bay, WI, to predict on-site parameters for a solar array located about 45 miles away in Keshena, WI. The model was found to be suitable for site-specific ambient temperature prediction. The ozone Dobson was a key parameter for solar irradiance prediction, given that the predictive accuracy of the proposed model was limited by the size of the training data. [ABSTRACT FROM AUTHOR]

Lake whitefish (Coregonus clupeaformis (Mitchill, 1818)) is an important commercial and recreational species in the Great Lakes. Precise age estimates are important for management, and two widely used techniques for otolith preparation are thin-section and crack-and-burn, which have not been compared for lake whitefish. Sagittal otoliths were collected from 92 lake whitefish in Green Bay and Lake Michigan and aged using thin-section and crack-and-burn techniques. Otoliths were aged independently by three individuals (two novices and one expert) to assess repeatability in estimated ages. Our investigation highlights the inherent difficulty of aging lake whitefish, where thin-section produced significantly older estimated ages (6–30 years) compared to crack-and-burn (5–26 years). Percent agreement of estimated ages between preparation techniques was low for all readers within ±0 years but increased when tolerance buffers were applied. Mean coefficient of variation values from both experience levels (>10.8%) exceeded the acceptable range reported in the literature (5%–7%); however, species longevity and nature of the structure must be considered when establishing target values. Variation in estimated ages is attributed to the experience level and interpretation of structural features. Species-specific training and establishing an objective framework to identify annuli will improve precision metrics. [ABSTRACT FROM AUTHOR]

In North America, native unionid mussels are imperiled due to factors such as habitat degradation, pollution, and invasive species. One of the most substantial threats is that posed by dreissenid mussels, which are invasive mussels that attach to hard substrates including unionid shells and can restrict movement and feeding of unionids. This dreissenid mussel biofouling of unionids varies spatially in large ecosystems, such as the Great Lakes, with some areas having low enough biofouling to form effective refugia where unionid mussels might persist. Here, we measured biofouling on mussels suspended in cages over the growing season (generally first week in June to last week of August) over 3 years in nearshore areas in Lake Erie (2014–2016), Lake Michigan (Grand Traverse Bay, 2015 and Green Bay, 2016), and Lake Huron (2015). Biofouling varied substantially by years within Lake Erie, with increasingly higher biofouling rates each year. Although dreissenid mussels are present throughout these lakes, we observed very low biofouling in Grand Traverse Bay (Lake Michigan) and Saginaw Bay (Lake Huron), with no dreissenid mussels in 8 of 9 sites across these two bays. Sampling in the rivermouth of the Fox River (Wisconsin) and the Maumee River (Ohio) both showed very high biofouling in areas adjacent to the outlet of these tributaries into Green Bay and Maumee Bay (Lake Erie), respectively. These watersheds are dominated by agriculture, and we would expect high growth of primary producers (i.e., mussel food) and primary consumers (unionids and zebra mussels) in these areas compared to the other sampled bays or the open waters of the Great Lakes. [ABSTRACT FROM AUTHOR]

This interview offers rare insight covering the recent triangulation of events - technology churning and crunching more bytes, COVID presenting more supply chain and analytical challenges, and more female CIOs entering the C-suites. Anu Varma, Vice President and CIO of the Communication Solution Segment at TE Connectivity, sat down with JITCAR to offer a rare insight into the evolving CEO-CIO dynamics, particularly from the women CIO perspective in these challenging and also promising times. In the interview, Anu shares how the CEO-CIO dynamics have changed significantly in the past ten to fifteen years. She also highlights how IT is now driving the business strategy, and the CIO is trusted with business roles rather than a back-office role. As a female CIO, Anu offers unique perspectives on the challenges faced by women in the IT world, particularly at the CIO level. During Covid, she and her team embraced the supply chain challenges and turned those into an opportunity to transform IT operations at TE Connectivity. Their efforts have also driven the analytics and insight-driven culture and created more demand for analytical-driven solutions within the business. The interview also discusses several other pressing issues facing CIOs in the manufacturing industry: IT talent acquisition/retention and costs of IT and cybersecurity. The interview also discusses how business leaders can support women in balancing their work responsibilities and family obligations in IT and elsewhere. The interview was conducted by Dr. Gaurav Bansal and transcribed by Dr. Zhuoli Axelton, both from the University of Wisconsin-Green Bay. [ABSTRACT FROM AUTHOR]

Cyanobacteria blooms have been reported to be increasing worldwide. In addition to potentially causing major economic and ecological damage, these blooms can threaten human health. Furthermore, these blooms can be exacerbated by a warming climate. One approach to monitoring and modeling cyanobacterial biomass is to use processed satellite imagery to obtain long-term data sets. In this paper, an existing algorithm for estimating cyanobacterial biomass previously developed for MERIS is validated for Green Bay using cyanobacteria biovolume estimates obtained from field samples. Once the algorithm was validated, the existing MERIS imagery was used to determine the bloom phenology of the cyanobacterial biomass in Green Bay. Modeled datasets of heat flux (as a proxy for stratification), wind speed, water temperature, and gelbstoff absorption along with in situ river discharge data were used to separate bloom seasons in Green Bay from bloom seasons in nearby cyanobacteria bloom hotspots including western Lake Erie and Saginaw Bay. Of the ten-year MERIS dataset used here, the highest five years were considered "high bloom" years, and the lowest five years from biomass were considered "low bloom" years and these definitions were used to separate Green Bay. Green Bay had a strong relationship with gelbstoff absorption making it unique among the water bodies, while western Lake Erie responded strongly with river discharge as previously reported. Saginaw Bay, which has low interannual bloom variability, did not exhibit a largely influential single parameter. [ABSTRACT FROM AUTHOR]

Complex life history behaviours like spawning migrations can complicate population assessments. However, predictable aggregation of populations at certain times of year (e.g. at spawning grounds) presents an effective way to sample species that are otherwise spatially widespread. From 2014 to 2019, a mark‐recapture study on Green Bay northern pike (Esox lucius) entering a spawning wetland was used to estimate apparent survival and population size using Bayesian inference and the Cormack–Jolly–Seber model. Population estimates and apparent survival varied from 446 to 1949 and 0.22 (males in 2017) to 0.63 (males in 2015), respectively, among years. Apparent survival also increased with maximum mean daily water temperature. Estimated capture probability was consistently low across years (<30%) despite a sampling method with high capture efficiency of fish present at the wetland, suggesting Green Bay northern pike may be exhibiting low spawning site fidelity or other life history behaviours, like skipped spawning, which reduce their capture probability at a single wetland over time. Further, spawning site selection and timing may respond to water temperatures. Surveying multiple sites could further elucidate important life history traits while refining estimates of population size and structure in large systems. [ABSTRACT FROM AUTHOR]

Aquatic environments and biological communities in nearshore waters of the Laurentian Great Lakes have undergone extensive change in recent decades. The nearshore waters of northern Green Bay, Lake Michigan, have been subject to environmental change but are relatively unstudied, despite hosting important fisheries for Walleye Sander vitreus, Yellow Perch Perca flavescens, Northern Pike Esox lucius, and Smallmouth Bass Micropterus dolomieu. Our objectives were to (1) test for changes in water clarity and fish populations in northern Green Bay, Lake Michigan, during 1989–2019, (2) depict recent spatial patterns in abundance for species of management interest, and (3) test for effects of recent Great Lakes water level changes on Northern Pike recruitment. Fishes were sampled annually in August and September 1989–2019 via trawl and gill‐net surveys at index sites. Mean water clarity increased 30% over this period. Aside from Round Goby Neogobius melanostomus, total catch rate of species in trawls decreased by over 90% between the 1990s and 2010s, with significant declines for Yellow Perch and pelagic forage fishes (coincident with dreissenid mussel invasion). Fish species richness in trawl and gill‐net surveys and total gill‐net catch rates declined significantly over time. Trends in gill‐net catch rates of game fishes during 1989–2019 were species‐specific, with spatial patterns often related to availability of preferred habitat conditions. Similar fish community changes to those we observed in northern Green Bay, Lake Michigan, have been noted in other Great Lakes, many being associated with invasion of dreissenid mussels and Round Goby. Increased water levels in Lake Michigan during the 2010s had a significant positive effect on Northern Pike recruitment, which highlights the importance of varying water levels, shoreline habitat conditions, and early life processes on population dynamics of fishes reproducing in inshore habitats. [ABSTRACT FROM AUTHOR]

The Great Lakes support some of the most productive fisheries for Walleye Sander vitreus in North America, although system‐level change from overexploitation, pollution, and invasive species has dramatically changed these fisheries over time. More recently, the widespread establishment of dreissenid mussels (zebra mussel Dreissena polymorpha and quagga mussel D. bugensis) has strongly altered energy flow by sequestering nutrients in nearshore benthic habitats, thereby influencing primary, secondary, and prey fish production with implications for Walleye. While the impacts of dreissenids on the open‐water food web are well established, little is known about their influence on fish populations occupying nearshore or embayment habitats. In this study, we tested the hypothesis that ecosystem changes resulting from dreissenid mussels have altered the stable isotope ratios and displacement of Walleye in Little Bay de Noc, an embayment of Lake Michigan. Retrospective isotope analysis of fin spines over a 31‐year time series coincident with the invasion of dreissenid mussels suggests that alterations in energy dynamics have increased Walleye reliance on nearshore benthic energy. From reports of jaw‐tagged Walleye caught over the same time period, we found significant temporal changes in Walleye displacement distances from the tagging site that were strongly size dependent following the invasion of dreissenid mussels. These results potentially suggest that the spatial distribution of large Walleye shifted in response to prey availability or habitat conditions. Additionally, sex‐specific differences in Walleye displacement indicate that females move greater distances than males, possibly driven by higher energetic and reproductive demands. Our findings suggest that the largest Walleye are seasonally leaving Little Bay de Noc, potentially altering the dynamics of the sport fishery in Green Bay and impacting management programs that occur across state lines. [ABSTRACT FROM AUTHOR]

In the quest for always wanting to find better and faster ways of doing things, AI has come to be an integral part of our daily lives. There is hardly any sphere of life that is not being touched upon by AI. Given that AI is being used in a range of industries and functions from agriculture, education, music, fashion, healthcare, manufacturing, law enforcement, and even raging wars, to name a few; and impacts people of all age groups and from all walks of life, this article attempts at understanding the ethical perspectives of AI. Regardless of the function and the industry, the discussion below reminds us that since we humans are creating AI, our perspectives and biases are reflected in the tools we create. The article, which documents a panel discussion held with various experts from different domains as listed below, cautions developers to be aware of their inherent biases and ask tough questions while creating solutions that run on AI. As users and consumers of AI, we must engage in critical thinking while adopting a new AI-based solution. We provide the details from the panel discussion organized by Dr. Gaurav Bansal and Dr. Stacie Christian, both from the University of Wisconsin-Green Bay, on Jan 17, 2022. Dr. Vic Matta led the panel discussion transcription with input from all panelists. [ABSTRACT FROM AUTHOR]

Information regarding site occupancy of fish that migrate long distances during nonspawning periods together with estimates of recruitment trends for individual populations can be informative for management, especially when individuals from different spawning populations intermix and are sampled or harvested together. Tendencies for individuals from different populations to preferentially occupy specific regions increases vulnerability to anthropogenic and natural disturbances. Using mixed stock analysis (MSA), we estimated population-specific occupancy of lake sturgeon (Acipenser fulvescens) in open-water and nearshore regions of Lake Michigan across a hierarchy of spatial scales. Open-water mixture composition differed between Lake Michigan's eastern and western basins. Significant heterogeneity in habitat occupancy was also observed at microgeographic scales throughout open-water regions of Green Bay, indicating nonrandom occupancy to regions proximal to natal streams. Estimates of relative recruitment levels determined from MSA extensions indicated increasing recruitment trends for spawning populations associated with Wisconsin tributaries (Oconto–Peshtigo, Fox, and Menominee rivers). Our lake sturgeon results demonstrate the utility of genetic data for informing management efforts for spatially structured, highly migratory species. Similar analyses could prove beneficial for species with similar characteristics. [ABSTRACT FROM AUTHOR]

Length‐at‐age data are commonly used to describe growth of fish, and obtaining these data typically involves estimating ages from calcified structures (e.g., fin spines or rays, otoliths, or cleithra). Verifying the accuracy of age and growth estimates for long‐lived fish is often difficult because known‐age fish are not available for all ages in a population. Mark–recapture methods offer nonlethal alternatives for estimating growth of fish that do not require age data. However, few studies have compared growth trajectories estimated from mark–recapture data with trajectories estimated using the standard von Bertalanffy growth function (VBGF) incorporating length‐at‐age data from known‐age fish. We used a robust data set of Muskellunge Esox masquinongy sampled from Green Bay, Lake Michigan, during 1990–2018 to compare growth trajectories estimated from three mark–recapture models and a VBGF fitted to length‐at‐age data from known‐age individuals. Growth trajectories estimated with mark–recapture models were similar to trajectories estimated with a VBGF using known‐age fish. Our results suggest that using recapture of tagged fish provides a viable alternative for describing Muskellunge growth trajectories compared with using ages estimated from calcified structures, where incorrect age estimates represent an additional source of error. [ABSTRACT FROM AUTHOR]

Under the 1987 Great Lakes Water Quality Agreement, the lower Green Bay and Fox River estuary have been labeled as areas of concern due to the contamination of mercury and polychlorinated biphenyls (PCBs) from industrialization. These pollutants pose substantial health and environmental hazards for the Green Bay region. The PCBs reported in this region, including Aroclor 1242, are known to trigger carcinogenic responses in animals and mercury targets the central nervous system and vital organs. Furthermore, these compounds are extremely difficult to remove from the environment once introduced. Extensive remedial actions have been implemented including dredging sediments in the Lower Fox River from DePere to Green Bay. The purpose of this study is to assess the concentration and distribution of Aroclor 1242 and total mercury in the Green Bay region sediments and pore waters and to assess the impact of interventions and the natural rates of change previously found. [ABSTRACT FROM AUTHOR]

Oxygen depletion in bottom waters of lakes and coastal regions is expanding worldwide. To examine the causes of hypoxia, we quantified the drivers of benthic oxygen uptake in Green Bay, Lake Michigan, USA, using 2 techniques, aquatic eddy covariance and sediment core incubation. We investigated benthic oxygen uptake along a gradient in C deposition, including shallow water near the riverine source of eutrophication and deeper waters of lower Green Bay where high net sediment deposition occurs. Time-averaged eddy covariance oxygen uptake was high near the source of eutrophication (11.5 mmol m−2 d−1) and at the shallower of the high deposition sites (9.8 mmol m−2 d−1). The eddy covariance technique revealed a decrease in benthic oxygen uptake with depth at the high deposition sites. These patterns were consistent with benthic uptake being driven by the deposition of autochthonous production. Additionally, eddy covariance revealed a nearly proportional relationship between benthic oxygen uptake and current velocity at all sites. Specifically, because of the lake seiche, water velocity typically varied 3× at a site and caused a 3× variation in benthic oxygen uptake. A summer storm also doubled bottom-water velocities and caused a further doubling of uptake to 28 mmol m−2 d−1. This high sensitivity of benthic oxygen uptake to seiche-driven water velocities indicates that redox conditions in surficial cohesive sediments are highly dynamic. [ABSTRACT FROM AUTHOR]

Wayne Velicer is remembered for a mind where mathematical concepts and calculations intrigued him, behavioral science beckoned him, and people fascinated him. Born in Green Bay, Wisconsin on March 4, 1944, he was raised on a farm, although early influences extended far beyond that beginning. His Mathematics BS and Psychology minor at Wisconsin State University in Oshkosh, and his PhD in Quantitative Psychology from Purdue led him to a fruitful and far-reaching career. He was honored several times as a high-impact author, was a renowned scholar in quantitative and health psychology, and had more than 300 scholarly publications and 54,000+ citations of his work, advancing the arenas of quantitative methodology and behavioral health. In his methodological work, Velicer sought out ways to measure, synthesize, categorize, and assess people and constructs across behaviors and time, largely through principal components analysis, time series, and cluster analysis. Further, he and several colleagues developed a method called Testing Theory-based Quantitative Predictions, successfully applied to predicting outcomes and effect sizes in smoking cessation, diet behavior, and sun protection, with the potential for wider applications. With $60,000,000 in external funding, Velicer also helped engage a large cadre of students and other colleagues to study methodological models for a myriad of health behaviors in a widely applied Transtheoretical Model of Change. Unwittingly, he has engendered indelible memories and gratitude to all who crossed his path. Although Wayne Velicer left this world on October 15, 2017 after battling an aggressive cancer, he is still very present among us. [ABSTRACT FROM AUTHOR]

Small tributaries of the Great Lakes serve as important habitat during critical life stages of many fish species, though temporal and spatial dynamics of the assemblage that uses these systems are seldom investigated. This study quantifies larval and adult fish assemblages captured by fyke net and light traps among small tributary mouths of Green Bay, Lake Michigan. Ten tributaries harbored a total of 45 species representing 17 families, with the most abundant including spottail shiner (Notropis hudsonius (Clinton, 1824)) in adult assemblages and white sucker (Catostomus commersonii (Lacepède, 1803)) in larval assemblages. Larval fish assemblage structures differed over five biweekly sampling events in May and June. Adult fish assemblage structures varied among tributaries but not among spring, summer, and fall samples. Larval and adult species assemblages at these river mouths are likely influenced by hydrology, habitat structure, and species-specific ecology. Water movement may transport larvae into river mouths, as larval assemblages were dominated by species that spawn in coastal habitats. Adult species richness varied with longitude, with the greatest diversity in tributaries on the west shore. This investigation of fish assemblages highlights the spatial and temporal variation that occurs in these systems and their role in shaping fish populations in Green Bay. [ABSTRACT FROM AUTHOR]

Anthropogenic activities can cause important changes in aquatic ecosystems, such as warming due to climate change, nutrient loading from agricultural runoff and urban areas, and decreased concentrations of oxygen in bottom waters. These changes may lead to impacts on both organism performance and ecosystem functionality. Studying planktonic species that form an aquatic ecosystem's foundation is an important step towards understanding the entire food web and predicting how it may respond to a changing environment. One important planktonic species in the Laurentian Great Lakes is the invasive calanoid copepod Eurytemora carolleeae (formerly considered part of the Eurytemora affinis species complex). This study analyzes the metabolic activity of E. carolleeae from Green Bay, Lake Michigan, U.S.A. using two different methods, over a range of temperatures from 9 to 26°C. Total oxygen consumption was measured directly using a micropulse oxygen probe system, and the activity of aerobic metabolic enzymes in the electron transport system (ETS) was quantified using in vitro reduction of iodonitrotetrazolium chloride (INT). Respiration rate of E. carolleeae increases approximately linearly from 9 to 26°C. Measurements of ETS activity indicate that the copepod's metabolic enzymes have an Arrhenius activation energy of 46.5 ± 15.6 kJ/mol with a thermal maximum between 22 and 26°C. Overall, E. carolleeae ETS rates increased by approximately 7% per °C over the range 9 to 22°C. This thermal limit has implications for future performance of this species, as the combination of higher temperatures and disappearance of oxygenated colder-water refuges may limit E. carolleeae 's success in the Green Bay system following warmer climate and increased nutrient conditions. [ABSTRACT FROM AUTHOR]