JournalTOCs

Journal of Great Lakes Research
Journal Prestige (SJR): 1.222

Citation Impact (citeScore): 2
Number of Followers: 7

Hybrid journal (It can contain Open Access articles)
ISSN (Online) 0380-1330
Published by Elsevier

[3147 journals]

Risk-based classification and interactive map of watersheds contributing
anthropogenic stress to Laurentian Great Lakes coastal ecosystems
- Abstract: Publication date: Available online 3 April 2019Source: Journal of Great Lakes ResearchAuthor(s): George E. Host, Katya E. Kovalenko, Terry N. Brown, Jan J.H. Ciborowski, Lucinda B. JohnsonAbstractWe describe development anthropogenic stress indices for coastal margins of the Laurentian Great Lakes basin. Indices were derived based on the response of species assemblages to watershed-scale stress from agriculture and urbanization. Metrics were calculated for five groups of wetland biota: diatoms, wetland vegetation, aquatic invertebrates, fishes, and birds. Previously published community change points of these assemblages were used to classify each watershed as ‘least-disturbed’, ‘at-risk’, or ‘degraded’ based on community response to these stressors. The end products of this work are an on-line map utility and downloadable data that characterize the degree of agricultural land use and development in all watersheds of the US and Canadian Great Lakes basin. Discrepancies between the observed biological condition and putative anthropogenic stress can be used to determine if a site is more degraded than predicted based on watershed characteristics, or if remediation efforts are having beneficial impacts on site condition. This study provides a landscape-scale evaluation of wetland condition that is a critical first step for multi-scale assessments to help prioritize conservation or restoration efforts.
Correction to photo credit for JGLR 45(1) cover photo
- Abstract: Publication date: April 2019Source: Journal of Great Lakes Research, Volume 45, Issue 2Author(s):
Phosphorus and nitrogen loading to Lake Huron from septic systems at Grand
Bend, ON
- Abstract: Publication date: Available online 21 March 2019Source: Journal of Great Lakes ResearchAuthor(s): Simon Baer, William Robertson, John Spoelstra, Sherry SchiffAbstractGroundwater nutrient loading to L. Huron was assessed along a 1.7 km section of beach at Grand Bend, ON, Canada, where septic systems are used for wastewater disposal. The artificial sweetener acesulfame (ACE) was detected in all groundwater samples (7–842 ng/L, n = 78), revealing that the entire surficial aquifer was impacted by septic system wastewater. Nitrate concentrations (3.5 ± 1.4 mg/L, n = 78) were correlated with ACE (r2 = 0.54), indicating that septic systems contribute to nitrate loading in the aquifer. Chloride was also elevated (37 ± 11 mg/L, n = 78), but was not correlated with ACE (r2 = 0.008), indicating a non wastewater source was dominant, likely road salt. Soluble reactive phosphorus (SRP) values were low (5.3 ± 9.3 μg/L, n = 77) and were not correlated with ACE (r2 = 0.006). Sediment profiling below two of the septic system drain-fields, showed that the sand grains had distinct secondary coatings containing P, indicating that mineral precipitation reactions played a role in limiting P concentrations present in the aquifer. Groundwater nutrient loading to the lake was estimated at 13,000 kg N/year from NO3− and 1.9 kg P/year from SRP. These amounts are insignificant compared to nutrient loading from a stream that drains an agricultural catchment and discharges to the lake at the north end of the study site (Parkhill Creek). This calls into question, in some cases, the rationale of decommissioning properly functioning septic systems as a mitigation measure for reducing nutrient loading to nearby water courses.
Non-seismic soft-sediment deformation structures from Late Pleistocene
lacustrine deposits of Lake Van (Eastern Turkey): Storm and overloading
effect
- Abstract: Publication date: Available online 21 March 2019Source: Journal of Great Lakes ResearchAuthor(s): Serkan Üner, Azad Sağlam Selçuk, Erman ÖzsayınAbstractSoft-sediment deformation structures of different types and sizes are frequently observed in the lacustrine deposits of Lake Van. According to sedimentary features and regional factors, these structures are categorized as non-seismic originated and seismically-induced, soft-sediment deformation structures. Well-preserved non-seismic originated, soft-sediment deformation structures were observed in fine-grained sandy and silty deposits at three locations (Çatakdibi, Yumrutepe, and Yukarıışıklı), and occur at different stratigraphic horizons, exhibiting morphological variability as they consist of load, flame, and slump structures. The formation mechanisms of these structures are determined by the characteristics of their sedimentary facies and environmental conditions. Overloading, caused by rapid coarse sediment deposition or underwater landslides, and storm waves are identified as triggering mechanisms, while rapid sediment accumulation and underwater mass movements caused by volcanogenic shakes are the conditions responsible for the formation of non-seismic soft-sediment deformation structures, in terms of regional geodynamics.
Evaluating visible derivative spectroscopy by varimax-rotated, principal
component analysis of aerial hyperspectral images from the western basin
of Lake Erie
- Abstract: Publication date: Available online 21 March 2019Source: Journal of Great Lakes ResearchAuthor(s): Joseph D. Ortiz, Dulci M. Avouris, Stephen J. Schiller, Jeffrey C. Luvall, John D. Lekki, Roger P. Tokars, Robert C. Anderson, Robert Shuchman, Michael Sayers, Richard BeckerAbstractThe Kent State University (KSU) spectral decomposition method provides information about the spectral signals present in multispectral and hyperspectral images. Pre-processing steps that enhance signal to noise ratio (SNR) by 7.37–19.04 times, enables extraction of the environmental signals captured by the National Aeronautics and Space Administration (NASA) Glenn Research Center's, second generation, Hyperspectral imager (HSI2) into multiple, independent components. We have accomplished this by pre-processing of Level 1 HSI2 data to remove stripes from the scene, followed by a combination of spectral and spatial smoothing to further increase the SNR and remove non-Lambertian features, such as waves. On average, the residual stochastic noise removed from the HSI2 images by this method is 5.43 ± 1.42%. The method also enables removal of a spectrally coherent residual atmospheric bias of 4.28 ± 0.48%, ascribed to incomplete atmospheric correction. The total noise isolated from signal by the method is thus
Assessment of mercury mobilization potential in Upper St. Lawrence River
riparian wetlands under new water level regulation management
- Abstract: Publication date: Available online 11 March 2019Source: Journal of Great Lakes ResearchAuthor(s): Evie S. Brahmstedt, Hao Zhou, Erin M. Eggleston, Thomas M. Holsen, Michael R. TwissAbstractMercury is a contaminant of concern in freshwater ecosystems. Riparian wetlands in the Upper St. Lawrence River (USLR) are dominated by monotypic (Typha spp.) marshes due to water level management since 1958. A new management plan will make water levels more closely resemble natural fluctuations and restore riparian wetland biodiversity by eroding some existing marshes. If Typha abundance is reduced there is potential for Hg, from legacy atmospheric deposition, contained in hydric soils to become mobilized into the food web. To evaluate this potential, the capacity of sixteen USLR wetlands to support Hg-methylating microbes was determined by quantifying total Hg, C, N, S, P and organic matter content in conjunction with genomic analysis in hydric soils from four riparian wetland types: barrier beaches, drowned river mouths, protected embayments, and open embayments. Drowned river mouth hydric soils contained significantly (p 
Assessment of site-specific agricultural Best Management Practices in the
Upper East River watershed, Wisconsin, using a field-scale SWAT model
- Abstract: Publication date: Available online 4 March 2019Source: Journal of Great Lakes ResearchAuthor(s): Katherine R. Merriman, Prasad Daggupati, Raghavan Srinivasan, Brett HayhurstAbstractThe Great Lakes “Priority Watershed” effort targeted the Upper East River watershed, a 116.5-km2 tributary watershed to Wisconsin's Green Bay, to reduce its sediment and nutrients loads from agricultural sources. A Soil and Water Assessment Tool (SWAT) model was created to determine the effectiveness of agricultural Best Management Practices (BMPs) funded through the Great Lakes Restoration Initiative. The model was calibrated at the monthly time-step for flow, sediment, dissolved reactive phosphorus (DRP), total phosphorus (TP), nitrate, and total nitrogen (TN). Field- and watershed-scale sediment and nutrient reductions were calculated due to the implementation of 74 BMP combinations on dairy and cash grain rotations. Modeling results indicated that when multiple BMPs were placed on a field, especially those including filter strips and grassed waterways, sediment and nutrient loads generally were reduced more than single BMP implementation. The most effective in-field practice at reducing DRP and TP on dairy fields was a combination of 5 different BMPs: cover crops, crop rotation, nutrient management plan, reduced tillage, and a filter strip. Conservation cover was the single most effective practice at reducing sediment and nutrient yields. Sediment and nutrient loads decreased at the watershed scale as the quantity and coverage of BMPs increased. When all contracted BMPs were simulated at the watershed scale, sediment loads were reduced 2%, while TP, DRP, TN and nitrate loads were reduced 20%, 9%, 24%, and 17%, respectively. Modeling scenarios also indicated that over-winter manure storage was important to keep soluble nutrients out of waterways.
Laboratory evaluation of spawning substrate type on potential egg
predation by round goby (Neogobius melanostomus)
- Abstract: Publication date: Available online 15 February 2019Source: Journal of Great Lakes ResearchAuthor(s): Andrew J. Miano, John Paul Leblanc, John M. FarrellAbstractSpawning habitat structure may protect demersal eggs of broadcast spawning species from depredation. Egg predation by round goby (Neogobius melanostomus) is commonly referenced as a concern associated with their invasion of the Laurentian Great Lakes. Whereas nest-building species have received some attention in egg predation studies, broadcast spawning species may be particularly vulnerable as they do not guard their eggs. This study used a 2 × 7 factorial experiment to investigate how substrate characteristics influenced the rate that fertilized eggs are lost when exposed to round goby. Eggs for two recreationally important broadcast spawning species, northern pike (Esox lucius) and muskellunge (Esox masquinongy), were placed within spawning habitat treatments (bare, silt, sand, rubble, gravel, filamentous algae, and submerged aquatic vegetation) representing a range (least to most complex) of habitat complexity. Regardless of substrate type, egg loss was similar between the two esocid species. Across all substrates and species, the number of eggs lost varied two-fold over the 24-hour experiment, with the lowest rate of egg loss observed in the most complex substrate (submerged aquatic vegetation) and the highest over the least complex substrates (bare and silt). Both northern pike and muskellunge are known to spawn over structurally complex submerged aquatic vegetation and filamentous algae. Although eggs spawned over these substrates likely offer some protection from predation, eggs that settle over less complex ancillary habitats may face higher predation risk.
Nitrogen dry deposition to Lake Superior and Lake Michigan
- Abstract: Publication date: Available online 14 February 2019Source: Journal of Great Lakes ResearchAuthor(s): Theresa A. Foley, Eric A. BettertonAbstractNitrate (NO3−) levels in Lake Superior have increased from historic levels of about 5 μM to its current concentration of about 25 μM. The atmosphere makes a substantial contribution to the nitrogen budgets for Lake Superior and Lake Michigan. This study provides a more well-defined estimate of nitrogen dry deposition rates derived from the measurement of over-water concentrations, and in situ meteorological measurements, which were input into the Resistance Model. We obtained a nitrogen dry deposition rate of [(3.41 ± 2.26) × 107 kg N/yr; (5.90 ± 3.91) kg N/ha/yr] over Lake Michigan, and [(1.54 ± 1.06) × 107 kg N/yr; (1.87 ± 1.27) kg N/ha/yr] over Lake Superior. Nitric acid (HNO3), which originates from the combustion of fossil fuels, contributes 84% of the total nitrogen dry deposition to Lake Michigan; and 66% to Lake Superior. Ammonia (NH3), which originates from agricultural activities and gasoline combustion, is the second highest contributor of nitrogen dry deposition to both lakes: contributing 13% to Lake Michigan and 32% to Lake Superior. The nitrogen dry deposition is approximately 68% of the nitrogen wet deposition over Lake Superior, and approximately 80% of wet deposition over Lake Michigan. The over-water dry deposition velocity of HNO3 and NH3 were also evaluated. We obtained morning deposition velocities of 0.099 cm/s for NH3 and 0.095 cm/s for HNO3; and afternoon values of 0.137 cm/s for NH3 and 0.132 cm/s for HNO3. Another key finding is that the atmospheric concentrations of nitrogen compounds near Lake Michigan and Lake Superior have decreased since 2003.
Status of Mysis diluviana in Lake Ontario in 2013: Lower abundance but
higher fecundity than in the 1990s
- Abstract: Publication date: Available online 7 February 2019Source: Journal of Great Lakes ResearchAuthor(s): Toby J. Holda, Lars G. Rudstam, Kelly L. Bowen, Brian C. Weidel, James M. Watkins, Patrick J. Sullivan, Jeremy P. Holden, Michael J. ConnertonAbstractMysis diluviana is a major component of prey fish diets in the Great Lakes, so annual production of M. diluviana is important for understanding and modeling energy flow through Great Lakes food webs. However, only three lake-wide measurements of M. diluviana annual production in Lake Ontario are currently available (1971, 1990, 1995). During 2013, lake-wide coverage of Lake Ontario was achieved during four periods from April to November. Annual mean density and biomass of M. diluviana in 2013 were 99 #/m2 (SE: 8) and 318 mg dw/m2 (SE: 28) – approximately half of values observed in 1990s. M. diluviana comprised 13–30% of offshore zooplankton biomass in each period. Reproduction peaked in fall, with mean brood size of 32 embryos (range: 11–49), at least 10% larger than in 1990s. Generation time was two years from embryo to initial reproduction. Growth rates were 0.052 mm/d for the age-0 cohort and 0.027 mm/d for the age-1 cohort. Age-0 growth rate was significantly higher than in 1980s–90s (0.035 mm/d). Annual production in 2013 was 0.85 g dw/m2/yr (SE: 0.03) which was 30–40% of values observed in 1990 and 1995 (2.23 and 2.53 g/m2/yr). Annual production to biomass ratio (P/B) in 2013 was 2.65 /yr which was 80–85% of values observed in 1990 and 1995 (3.24 and 3.11 /yr), but this difference was not statistically significant. Our results suggest that changes in annual production over time can be estimated using changes in biomass over time and a mean P/B ratio.
Pond sediments on nesting islands in eastern Lake Ontario provide insights
into the population dynamics and impacts of waterbird colonies
- Abstract: Publication date: Available online 7 February 2019Source: Journal of Great Lakes ResearchAuthor(s): Emily M. Stewart, Mina Vu, Neal Michelutti, Kathryn Hargan, Christopher Grooms, Linda E. Kimpe, Jules M. Blais, John P. SmolAbstractMarked increases in ring-billed gulls and double-crested cormorants in the Laurentian Great Lakes during the last century have garnered attention over their ecological impacts, sparking debates about management strategies. However, monitoring data are generally sparse and of short duration for these colonies, hampering the ability to place recent changes within long-term context. Sediment records from ponds immediately surrounded by colonies on nesting islands can be used to track past bird populations, as they release wastes with geochemical signals that can be tracked using traditional paleolimnological methods, such as diatoms and stable isotopes of nitrogen (δ15N). Here, we provide new information about waterbird nesting histories on islands in eastern Lake Ontario that are of interest to wildlife managers. In all bird-impacted ponds, eutrophic diatom assemblages and elevated sediment chlorophyll-a coincided with high signatures of δ15N in the recent sediments, signifying bird influence. An absence of significant bird impacts in the oldest portion of one sediment core indicates that the current cormorant colony size (>2000 birds) is unprecedented over the ~150-year record. Diatoms and sediment chlorophyll-a also responded to even a small, short-duration cormorant nesting event on an actively managed reference island. Collating our findings with those from four previously studied sediment cores from nearby islands, we show that cormorants are unlikely to have occupied eastern Lake Ontario in their current numbers within the past ~150 years. However, ring-billed gulls have likely used several islands in the area for most of the 20th century (and perhaps earlier) until present.
Winds of change – Predicting water-based recreationists' support and
opposition for offshore wind energy development in the Great Lakes
- Abstract: Publication date: February 2019Source: Journal of Great Lakes Research, Volume 45, Issue 1Author(s): Michael D. Ferguson, Samantha L. Powers, Nate Trauntvein, Jeffrey B. Jacquet, Alan R. Graefe, Andrew J. MowenAbstractThis study examined the factors influencing water-based recreationists' perceptions of support and opposition towards off-shore wind energy development (OWD) on Lake Erie. Much of the proposed or future Lake Erie OWD infrastructure may either be within or adjacent to public lands, waters, and protected areas, raising concerns about the potential environmental and social impacts upon recreation stakeholders. The limited body of OWD research within the United States has suggested there are numerous factors that may influence overall perceptions of support and opposition such as political orientation and beliefs in climate change. Moreover, recent research has proposed that the perceived recreation impact of OWD may be the most important predictor of support and opposition. This study confirmed this premise and found the perceived recreation impact of OWD to be the strongest predictor of support. Results of a multiple linear regression suggested that political orientation (β = 0.135), beliefs in the anthropogenic causation of climate change (β = 0.207), beliefs in the occurrence of climate change (β = 0.213), and the perceived recreation impact of OWD among water-based recreationists (β = 0.439) were significant predictors of support for OWD on Lake Erie (R2 = 0.46). Study findings corroborated previous research which suggested that regional climate change beliefs and political attitudes may influence support for OWD. From a policy and management standpoint, study results highlight the importance of assessing and communicating recreation experience and use impacts when planning, developing, and managing OWD and related decisions in the United States.
Spatial ecology of reintroduced walleye (Sander vitreus) in Hamilton
Harbour of Lake Ontario
- Abstract: Publication date: February 2019Source: Journal of Great Lakes Research, Volume 45, Issue 1Author(s): J.L. Brooks, J.D. Midwood, L.F.G. Gutowsky, C.M. Boston, S.E. Doka, J.A. Hoyle, S.J. CookeAbstractMany coastal embayments in the Laurentian Great Lakes have been subjected to extensive human physical modification and pollution that has led to the loss of freshwater biodiversity. For example, Hamilton Harbour is a large coastal embayment situated at the western end of Lake Ontario, with a long history of industrial and urban development that has resulted in the loss and degradation of aquatic habitat and the extirpation of several fish species. To restore the fish community in Hamilton Harbour, several attempts have been made to increase apex predator biodiversity by reintroducing native walleye (Sander vitreus). To assess how reintroduced (i.e., stocked) walleye use Hamilton Harbour, we used acoustic telemetry to characterize the residency of individuals within the boundaries of the harbour as well as their seasonal space use, with a focused interest on the spring spawning period. During the 1 yr tracking period tagged walleye spent an average of 357 days (range 135–365 days) within the harbour. Most individuals (12/15) remained within the harbour during the entire spring spawning period, and over half of the tagged fish departed (n = 7) at the end of summer and beginning of fall. Core use areas appeared to gradually shift more easterly as the seasons progressed from winter to summer. Results from this study indicate that stocked fish are resident within Hamilton Harbour for most of the year, including the reproductive period, which suggests that stocking efforts to re-establish walleye populations may be an effective restoration strategy if recruitment is successful.
Trophic ecology of salmonine predators in northern Lake Huron with
emphasis on Atlantic salmon (Salmo salar)
- Abstract: Publication date: February 2019Source: Journal of Great Lakes Research, Volume 45, Issue 1Author(s): Brandon S. Gerig, Dominic T. Chaloner, Sean A. Cullen, Roger Greil, Kevin Kapucinski, Ashley H. Moerke, Gary A. LambertiAbstractPacific salmon were introduced to the Great Lakes in the 1960s and now support major recreational fishery. Population declines resulting from invasive species have prompted agencies to consider diversifying sport fisheries through stocking. Atlantic salmon are native to Lake Ontario, but a small fishery has developed in northern Lake Huron since the 1990s that appears suited to the Lake Huron food web leading to requests for increased stocking by anglers and consideration by agencies. However, no study has evaluated the trophic ecology of Atlantic salmon in relation to other salmonine predators in northern Lake Huron. In this study, we used stable isotopes of carbon (δ13C) and nitrogen (δ15N), along with mercury (Hg) concentrations to assess resource use, niche overlap, and contaminant accumulation in Atlantic salmon compared to select Lake Huron predators. Atlantic salmon exhibited considerable niche overlap with Chinook and coho salmon but were strongly differentiated from lake trout. In addition, we observed that Atlantic salmon had similar Hg concentrations as coho but were lower than both Chinook salmon and lake trout. Based upon the relationship between fish size, δ15N, and Hg, Atlantic salmon bioaccumulate Hg similarly to Pacific salmon but likely have lower consumptive demands than Chinook salmon. Continued attention should be placed on understanding how Atlantic salmon fit into the current Lake Huron food web in order to evaluate the long-term efficacy of the Atlantic salmon stocking program.
Predicting the potential distribution of the non-native Red Swamp Crayfish
Procambarus clarkii in the Laurentian Great Lakes
- Abstract: Publication date: February 2019Source: Journal of Great Lakes Research, Volume 45, Issue 1Author(s): Rachel M. Egly, Gust M. Annis, W. Lindsay Chadderton, Jody A. Peters, Eric R. LarsonAbstractThe ongoing threat of introduction of invasive species, including crayfish, to the Laurentian Great Lakes has motivated the development of predictive models to inform where these invaders are likely to establish. Our study is among the first to apply regional freshwater-specific GIS layers to species occurrence data to predict ecosystem suitability to invasions, specifically for the red swamp crayfish, Procambarus clarkii, in the Great Lakes. We combined a database of crayfish species occurrences with the Great Lakes Aquatic Habitat Framework (GLAHF) GIS layers to model habitats suitable to invasion by P. clarkii using boosted regression trees and physiological information for this species. We developed a model of all suitable crayfish habitat across the Great Lakes, then constrained this habitat to areas anticipated to be suitable for P. clarkii based on known physiological limitations of this species. Specifically, P. clarkii requires a minimum temperature of 15 °C for copulation and oviposition, with peak reproduction occurring at temperatures of 20–23 °C. We identified 2% of the Great Lakes as suitable for P. clarkii establishment and 0.88% as optimal for this crayfish, primarily located on the southern coastlines of lakes Michigan and Erie and shallow bays including Saginaw Bay (Lake Huron), Green Bay (Lake Michigan), and Henderson Bay (Lake Ontario). These predictions of where P. clarkii is likely to establish populations can be used to identify areas where education, outreach, compliance, and law enforcement efforts should seek to prevent new introductions of this crayfish and help prioritize locations for surveillance to detect newly established populations.
Phenology and species diversity in a Lake Huron ichthyoplankton community:
Ecological implications of invasive species dominance
- Abstract: Publication date: February 2019Source: Journal of Great Lakes Research, Volume 45, Issue 1Author(s): Timothy P. O'Brien, Stacey Ireland, Edward F. Roseman, Andrew S. Briggs, William W. TaylorAbstractIchthyoplankton communities are dynamic and vary spatiotemporally based on factors such as wind, water currents, and phenology. Nonetheless, ichthyoplankton are an indicator of spawning success in fish populations and examining their community diversity and composition can serve to provide information on ecosystem integrity. Although some ichthyoplankton species may be transient, understanding their distribution in space and time provides information on species composition, abundance, and habitat use during critical early life stages. We sampled the spring-summer ichthyoplankton community during 2008 and 2009 in northern Lake Huron to determine species succession, abundance, and species diversity along physical and environmental gradients. Seasonal succession of species was similar during both years, indicating well-defined patterns in spawning by northern Lake Huron fish populations. Invasive alewife, rainbow smelt, and round goby were the dominant species during both years, with native stickleback species also abundant. Shannon Entropy (H′) increased with increasing water temperature until late summer when H′ declined. H′ decreased with increasing bottom depth and distance to tributary mouth indicating the important ecological role of these habitat features during early life stages. Although ichthyoplankton diversity was comparable to or higher than that reported for other areas of the Great Lakes, the prominence of invasive species in our study is reflective of the disturbed state of the Lake Huron fish community, despite large reductions in invasive planktivorous fish since 2004. Continued monitoring of ichthyoplankton communities will be important for measuring the impacts of species invasions or other ecosystem stressors on fish community structure in the Great Lakes.
Relative contributions of nearshore and wetland habitats to coastal food
webs in the Great Lakes
- Abstract: Publication date: February 2019Source: Journal of Great Lakes Research, Volume 45, Issue 1Author(s): Michael E. Sierszen, Lee S. Schoen, Jessica M. Kosiara, Joel C. Hoffman, Matthew J. Cooper, Donald G. UzarskiAbstractHydrologic linkages among coastal wetland and nearshore areas allow coastal fish to move among the habitats, which has led to a variety of habitat use patterns. We determined nutritional support of coastal fishes from 12 wetland-nearshore habitat pairs using stable isotope analyses, which revealed differences among species and systems in multi-habitat use. Substantial (proportions > 0.30) nutrition often came from the habitat other than that in which fish were captured. Nearshore subsidies to coastal wetlands indicate wetlands are not exclusively exporters of energy and materials; rather, there is reciprocity in the mutual energetic support of nearshore and wetland food webs. Coastal wetland hydrogeomorphology influenced the amount of multi-habitat use by coastal fishes. Fishes from systems with relatively open interfaces between wetland and nearshore habitats exhibited less nutritional reliance on the habitat in which they were captured, and higher use of resources from the adjacent habitat. Comparisons of stable isotope analyses of nutrition with otolith analyses of occupancy indicated nutritional sources often corresponded with habitat occupancy; however, disparities among place of capture, otolith analyses, and nutritional analyses indicated differences in the types of support those analyses inform. Disparities between occupancy information and nutritional information can stem from movements for support functions other than foraging. Together, occupancy information from otolith microchemistry and nutritional information from stable isotope analyses provide complementary measures of the use of multiple habitats by mobile consumers. This work underscores the importance of protecting or restoring a diversity of coastal habitats and the hydrologic linkages among them.
Contemporary abundance patterns of Cyclotella sensu lato diatom taxa in
Lake Superior: Assessing responses to physical and chemical gradients and
potential links to climate change
- Abstract: Publication date: February 2019Source: Journal of Great Lakes Research, Volume 45, Issue 1Author(s): Amy R. Kireta, Jasmine E. SarosAbstractMany studies attribute shifts in relative abundances of Cyclotella sensu lato diatom taxa in freshwater lakes over the past 150 years to climate change. Although abundances of several of these taxa have also changed in Lake Superior over the last century, the specific drivers are currently unclear. This study used multiple linear regression to analyze long-term planktonic monitoring data to identify drivers of changing cell densities of six Cyclotella sensu lato species, four shown to be responsive to climate-driven change in smaller lakes and two species with similar morphology to two previously assessed taxa: Discostella stelligera and the morphologically similar D. pseudostelligera, Lindavia comensis and the morphologically similar L. delicatula, Lindavia ocellata, and Lindavia bodanica. Assessed variables associated with climate-driven physical change included surface water temperature and light availability, with turbidity and thermocline depth as indicators of the light environment. One to three variables explained 8–61% variation for each of 5 taxa from 2001 to 2011, significant predictive variables were not identified for D. stelligera. Multiple linear regression identified nutrients, including nitrate, phosphorus, and silica, as essential in explaining distributions of all the other assessed taxa. A physical variable associated with climate explained changes of one taxon: L. ocellata, which increased with lower water temperatures. Climate-driven species responses were not as apparent as in other systems; specifically, changes in the light environment of this clear lake did not explain abundance changes in any of the taxa. Multiple and complex environmental variables drive Cyclotella sensu lato abundance patterns in Lake Superior, possibly suggesting ecotype formation.
Temporal and spatial changes in bacterial diversity in mixed use
watersheds of the Great Lakes region
- Abstract: Publication date: February 2019Source: Journal of Great Lakes Research, Volume 45, Issue 1Author(s): Mahi M. Mohiuddin, Steven R. Botts, Athanasios Paschos, Herb E. SchellhornAbstractEnvironmental water monitoring is an important responsibility of municipal governments. In this study, we partnered with several municipalities in an extensive sampling program to investigate the effects of spatiotemporal and environmental factors on bacterial diversity in a complex watershed ecosystem containing specific environments including creeks, a river, canals, stormwater outfalls and freshwater lakes of the Niagara Peninsula. Samples were collected using standard municipal protocols and bacterial DNA extracted from these samples was sequenced using high-throughput DNA sequencing targeting the V3–V4 regions of the 16S rRNA gene. Average taxonomic richness and alpha diversity differed significantly between samples collected from lakes and creeks (P 
Validation of a diatom-based index of water quality confirms its utility
in monitoring of the Lake Erie's nearshore area
- Abstract: Publication date: February 2019Source: Journal of Great Lakes Research, Volume 45, Issue 1Author(s): Václava Hazuková, Jeffrey R. Johansen, Gerald V. SgroAbstractWe conducted a validation of the Planktonic Diatom Index (PDI) to demonstrate the utility of a water quality index for the monitoring of Lake Erie's nearshore pelagial zone. Using a large, independent dataset from the Western and Central Basins of Lake Erie for validation ensures realistic assessment of the performance of the index. Diatom-based biomonitoring allows for the inference of integrative information about water quality based on diatom species composition. The PDI is based on the assumption that phosphorus, an established proxy for eutrophication, is instrumental in the structuring of diatom communities. In this study, PDI scores and measured total phosphorus were significantly correlated (r2 = 0.34, r2 = 0.63 outliers removed). However, when samples were considered on a basin-wide basis, the PDI scores were not significantly predicted by measured total phosphorus in the Western Basin. We suggest that snapshot phosphorus measurements are less likely to represent the overall condition in the highly variable, eutrophic Western Basin. When multiple phosphorus measurements were averaged over time, the relationship with the integrative PDI scores was more apparent (r2 = 0.52). Through validation with an independent dataset, we show that the PDI is likely a monitoring tool that provides a robust assessment of water quality in the pelagial zone of the nearshore waters in Lake Erie.
Investigating the restoration of Lake Urmia using a numerical
modelling approach
- Abstract: Publication date: February 2019Source: Journal of Great Lakes Research, Volume 45, Issue 1Author(s): H. Hamidi-Razi, M. Mazaheri, M. Carvajalino-Fernández, J. Vali-SamaniAbstractWe assessed the effectiveness of multiple hydrologic restoration scenarios for Lake Urmia, as well as the variation of its salinity regime under no intervention, using a 2D shallow water model. Tested scenarios, proposed by Urmia Lake Restoration Program Committee, include: Preservation of current lake status (no intervention), complete closing of Shahid Kalantari causeway, dyke construction in the southern part of Lake Urmia, water transfer from Zarrinehrood River to Siminehrood River and reduction of agricultural water consumption by best agricultural practices. Results indicate that neither the closure of the causeway nor the construction of the southern dyke would significantly improve lake conditions when compared to preservation of current lake status. The water transfer alternative doesn’t seem to have any effect on the current lake conditions either. However, the reduction on water diversions by improving agricultural practices in the lake's basin leads to a partial restoration of the lake in terms of water level, surface area and volume. If current conditions persist, salinity in the northern part of Lake Urmia will reach supersaturation levels (340 g/L), generating further salt deposits.
Modeling the impacts of climate change on the thermal and oxygen dynamics
of Lake Volta
- Abstract: Publication date: February 2019Source: Journal of Great Lakes Research, Volume 45, Issue 1Author(s): Deborah Darko, Dennis Trolle, Ruby Asmah, Karsten Bolding, Kwaku A. Adjei, Samuel N. OdaiAbstractClimatic changes influence the thermal and oxygen dynamics of a lake and thus its ecological functioning. The impacts of climatic changes on tropical lakes are so far poorly studied and the extent of the effects is therefore uncertain, most investigations describing only potential effects. In this study, we applied the one-dimensional lake ecosystem model GOTM-ERGOM to quantify the effects of climate change on thermal stratification, oxygen dynamics, and primary production in meso-oligotrophic Lake Volta. GOTM-ERGOM was calibrated and validated using two years of observed data. The validated model was used to evaluate a series of future climate change scenarios. The model simulations showed good agreement with observed water temperature, dissolved oxygen and chlorophyll-a and indicated intensified stratification and reduced oxygen levels in the productive water layers of the lake. However, the longer-lasting stratification (prolonged stability) did not translate into permanent stratification. A relatively small (1 m) upward shift of thermocline depth resulted in an 8%–12% volume loss of the oxygen-rich upper mixed layer, which may be significant for the fisheries of the lake as it diminishes the size of suitable fish habitats. Light limitation of primary production renders the lake somewhat resilient to intensive algae blooms, as traceable in both the present and in the future climate scenarios. In the long term, the ongoing climate change may affect riparian communities that depend on the lake's fisheries for their livelihood. In consequence, future lake management strategies for implementation need to account for the impacts of future climate change.
Stratification and mixing in large floodplain lakes along the lower Amazon
River
- Abstract: Publication date: February 2019Source: Journal of Great Lakes Research, Volume 45, Issue 1Author(s): Pétala Bianchi Augusto-Silva, Sally MacIntyre, Conrado de Moraes Rudorff, Alicia Cortés, John Michael MelackAbstractLarge, shallow lakes are common in the extensive floodplains throughout the tropics. To determine controls on their mixing dynamics, we instrumented 5 stations in two shallow, connected tropical lakes on the lower Amazon floodplain with meteorological and temperature sensors. A tight relation between changes in thermal structure and LMO/h (the ratio of the Monin-Obukhov length scale to the depth of the actively mixing layer) indicates the sensitivity of thermal structure to wind speed relative to heating and cooling. Four regimes led to variations in mixing: (i) high solar radiation with light winds in the mid-morning to early afternoon resulted in shallow stratification, 0 
Nearshore-offshore exchanges in multi-basin coastal waters: Observations
and three-dimensional modeling in Lake Erie
- Abstract: Publication date: February 2019Source: Journal of Great Lakes Research, Volume 45, Issue 1Author(s): Reza Valipour, Yerubandi R. Rao, Luis F. León, David DepewAbstractNearshore-offshore exchanges through upwelling events and subsequent formation of internal Kelvin waves and coastal-jets are expected in the multi-basin coastal waters of Lake Erie; however, these phenomena have yet to be confirmed in the field or numerically modeled. Here, we demonstrate these physical processes in Lake Erie through extensive field data analysis and high-resolution three-dimensional hydrodynamic modeling. The validated model successfully reproduces dominant physical processes in the offshore and nearshore waters including surface seiches (~14 h), near-inertial waves (~17 h) and upwelling events (5–10 days). We show that upwelling events are the predominant nearshore physical processes, and are energized when winds accelerate the epilimnetic waters to the south, causing the thermocline front to move up into the north shore. After the wind subsides, the elevated thermoclines simultaneously form two separate cyclonically propagating internal Kelvin waves in the central and the eastern basins following by two coastal-jets at phase speeds of 0.22 ms−1 and 0.37 ms−1 within 5–15 km off the shoreline, respectively. The predominant south-west winds limit the presence of Kelvin waves only to the northern parts of each basin, where the bathymetry allows, and disappear when shoreline morphology no longer maintain these waves due to nonzero cross-shore transports at the coastal boundary layer. Intrusions of hypolimnetic waters through upwelling events contribute 10–30% to the net cross-shore transport, and are most pronounced in May and June when the offshore thermocline is shallow. The intermittent strong westward nearshore currents by Kelvin waves are in the opposite direction of seasonal eastward currents.
The putative Saginaw impact structure, Michigan, Lake Huron, in the light
of gravity aspects derived from recent EIGEN 6C4 gravity field model
- Abstract: Publication date: February 2019Source: Journal of Great Lakes Research, Volume 45, Issue 1Author(s): Jaroslav Klokočník, Jan Kostelecký, Aleš BezděkAbstractThe hypothetical impact structure in the Saginaw Bay (Michigan, USA, Lake Huron) has been tested by the gravity data derived from the recent gravity field model EIGEN 6C4 (expanded to degree and order 2190, with ground resolution of ~9 km). The following gravity field aspects were used: the gravity disturbances/anomalies, second derivatives of the disturbing potential (Marussi tensor), two of three gravity invariants, their specific ratio (known as 2D factor), the strike angles, and the virtual deformations. These gravity aspects are sensitive in various ways to the underground density contrasts. For the Saginaw Bay area, we confirm that we do not see any typical impact crater in terms of gravity disturbance or the radial second order derivative, possibly because of the thick layer of the ice located at the place and time of the impact. But the “combed” strike angles (one type of the gravity aspects we use) disclose a trace of high pressure to the SE/S/SW of the Bay and may be due to an impacting body. Thus, we provide circumstantial evidence of the Younger Dryas impact hypothesis.
Commentary: Achieving phosphorus reduction targets for Lake Erie
- Abstract: Publication date: February 2019Source: Journal of Great Lakes Research, Volume 45, Issue 1Author(s): Robyn S. Wilson, Margaret A. Beetstra, Jeffrey M. Reutter, Gail Hesse, Kristen M. DeVanna Fussell, Laura T. Johnson, Kevin W. King, Gregory A. LaBarge, Jay F. Martin, Christopher WinslowAbstractHarmful Algal Blooms (HABs), which were largely absent from Lake Erie from the 1980s until the mid-late 1990s, have been growing steadily worse in intensity. While much of the phosphorus loading into the lake prior to 1972 was caused by point-source pollution, approximately 88% to 93% of current loading comes from nonpoint sources, of which agriculture is the dominant land use. A reduction target of 860 metric tons, or 40% of the total phosphorus spring loading in 2008, has been set with the expectation that such a reduction could limit the size and associated impact of HABs in 9 out of every 10 years. We review the effectiveness of recommended practices aimed at reducing phosphorus loss in agriculture and pair this knowledge with behavioral data on likely adoption to identify how best to achieve the reduction target. The data suggests that the target is feasible as a majority of the farming population is willing to consider many of the recommended practices. However, increases in adoption over time have been minimal, and farmers will need better cost-benefit information, site-specific decision support tools, and technical assistance in order to more rapidly adopt and execute the placement of recommended practices. A combination of voluntary and mandatory approaches may be needed, but policies and programs promoting voluntary adoption should be designed to better target known barriers and maximize voluntary program effectiveness.
The application of decision support tools and the influence of local data
in prioritizing barrier removal in lower Michigan, USA
- Abstract: Publication date: Available online 31 January 2019Source: Journal of Great Lakes ResearchAuthor(s): Hsien-Yung Lin, Kelly Robinson, Austin Milt, Lisa WalterAbstractWeb-based decision support tools (DSTs) can be useful to facilitate decision-making processes for managing complex natural resource systems. However, the alignment of DSTs with the objectives in governmental policies or management plans and the influence of limited local data on the outputs of these tools may reduce the use of DSTs by decision makers. In this study, we examined the outcomes of web-based DSTs when different types of local data were incorporated and demonstrated a way to incorporate outputs from multiple DSTs or local inventories to benefit barrier removal decisions. Restoring habitat connectivity in rivers in northwest lower Michigan, USA, was used as a case study due to the abundance of local inventory data and web-based DSTs. We found that, when compared to prioritizations made using local data, some DSTs could produce similar outcomes (in barriers selected, cost, and the benefit for migratory fish) with limited data, but the trade-offs among users' objectives might influence the cost and effectiveness of DSTs' outputs. Improving the ability of DSTs to incorporate objectives consistent with policy and stakeholders' values (e.g., restore certain species or sedimentation control) across management scales can help close the gap between tool recommendations and management decisions while making the barrier removal prioritization process transparent and efficient.
Perchlorate in environmental waters of the Laurentian Great Lakes
watershed: Evidence for uneven loading
- Abstract: Publication date: Available online 28 January 2019Source: Journal of Great Lakes ResearchAuthor(s): D.R. Van Stempvoort, J. Struger, S.J. BrownAbstractA database of nearly 500 analyses of perchlorate in water samples from the Laurentian Great Lakes (LGL) watershed is presented, including samples from streams, from the Great Lakes and their connecting waters, with a special emphasis on Lake Erie. These data were assessed to test an earlier hypothesis that loading of perchlorate to the LGL watershed is relatively uniform. Higher perchlorate concentrations in streams in more developed and urban areas appear to indicate higher rates of loading from anthropogenic sources in these areas. Variable perchlorate concentrations in samples from Lake Erie indicate transient (un-mixed) conditions, and suggest loss by microbial degradation, focused in the central basin of that lake. Interpretation of the data included estimation of annual loading by streams in various sub-watersheds, and simulations (steady state and transient state) of the mass balance of perchlorate in the Great Lakes. The results suggest uneven loading from atmospheric deposition and other sources.
Transitions in microbial communities along a 1600 km freshwater
trophic gradient
- Abstract: Publication date: Available online 15 January 2019Source: Journal of Great Lakes ResearchAuthor(s): Mark J. Rozmarynowycz, Benjamin F.N. Beall, George S. Bullerjahn, Gaston E. Small, Robert W. Sterner, Sandra S. Brovold, Nigel A. D'souza, Susan B. Watson, Robert Michael L. McKayThis study examined vertically-resolved patterns in microbial community structure across a freshwater trophic gradient extending 1600 km from the oligotrophic waters of Lake Superior to the eutrophic waters of Lake Erie, the most anthropogenically influenced of the Laurentian Great Lakes system. Planktonic bacterial communities clustered by Principal Coordinates Analysis (PCoA) on UniFrac distance matrices into four groups representing the epilimnion and hypolimnion of the upper Great Lakes (Lakes Superior and Huron), Lake Superior's northern bays (Nipigon and Black bays), and Lake Erie. The microbes within the upper Great Lakes hypolimnion were the most divergent of these groups with elevated abundance of Planctomycetes and Chloroflexi compared to the surface mixed layer. Statistical tests of the correlation between distance matrices identified temperature and sample depth as the most influential community structuring parameters, reflecting the strong UniFrac clustering separating mixed-layer and hypolimnetic samples. Analyzing mixed-layer samples alone showed clustering patterns were correlated with nutrient concentrations. Operational taxonomic units (OTU) which were differentially distributed among these conditions often accounted for a large portion of the reads returned. While limited in coverage of temporal variability, this study contributes a detailed description of community variability that can be related to other large freshwater systems characterized by changing trophic state.Graphical abstract
Monitoring shallow benthic fish assemblages in the Laurentian Great Lakes
using baited photoquadrats: Enhancing traditional fisheries monitoring
methods
- Abstract: Publication date: Available online 11 January 2019Source: Journal of Great Lakes ResearchAuthor(s): Krista M. Robinson, Tracy L. Galarowicz, Patrick O'Neill, W. Lindsay Chadderton, Randall M. Claramunt, Matthew E. Herbert, Andrew TuckerAbstractPhotoquadrats and underwater video surveys are standard non-destructive monitoring methods in marine ecosystems and are becoming more common in freshwater systems. The high water clarity found in most of the Laurentian Great Lakes make them ideally suited for photoquadrat sampling. We compared the effectiveness of baited photoquadrats to monitor benthic fish communities of shallow, littoral habitats of northern Lake Michigan. We compared our results with baited minnow traps, a technique commonly used to monitor benthic fish communities in freshwater ecosystems. Photoquadrats baited with lake trout (Salvelinus namaycush) eggs, the most effective attractant, proved to be an efficient tool for sampling round goby (Neogobius melanostomus) relative abundance and resulted in higher round goby catches than in photoquadrats baited with a commercially available fish attractant or unbaited photoqudrats. This method allowed sites to be surveyed rapidly (requiring
Spatial and temporal variations in water temperature in a high-altitude
deep dimictic mountain lake (Nam Co), central Tibetan Plateau
- Abstract: Publication date: Available online 6 January 2019Source: Journal of Great Lakes ResearchAuthor(s): Junbo Wang, Lei Huang, Jianting Ju, Gerhard Daut, Yong Wang, Qingfeng Ma, Liping Zhu, Torsten Haberzettl, Jussi Baade, Roland MäusbacherAbstractWater temperature and the related thermal structure and stratification of a lake are very important to lake ecosystems because of their significant effects on the vertical exchanges of dissolved and particulate matter. In this study, we present high resolution, seasonal variations in water temperature at different depths of a large deep lake on the central Tibetan Plateau. The results show that Nam Co is a typical dimictic lake whose thermal stratification begins and ends in early June and early November, respectively. Increases in the water temperature during spring and the establishment of thermal stratification in the eastern small sub-basin occur approximately one month prior to the main basin which is likely caused by the different morphometry, different water transparency during spring, and the possible presence of a spring thermal bar. The Schmidt stability of the water column is directly controlled by surface water temperature. During the ice-covered period, the homogeneous water temperature exhibits a continuous increasing trend from approximately 0.5 °C to 3.5 °C. The daily mean surface water temperature of the main open lake area is highly correlated to the air temperature but shows a hysteresis effect of approximately 38 days, which shows the significant heat storage in such a large deep lake. Nam Co is a typical lake in this area in terms of its altitude, water depth and climatic conditions, so our results have broader significance for limnological and paleolimnological studies of similar lakes on the Tibetan Plateau.
Morphometric differentiation and gene flow in emerald shiners (Notropis
atherinoides) from the lower Great Lakes and the Niagara River
- Abstract: Publication date: Available online 6 January 2019Source: Journal of Great Lakes ResearchAuthor(s): John J.V. Lang, Randal J. Snyder, Mark D. Clapsadl, Pawel Michalak, Lin Kang, Alicia Pérez-FuentetajaAbstractDifferences in habitat (e.g., water velocity, prey, and predator regimes) are a driving force causing adaptive divergence among fish populations. This study used geometric shape analysis to assess morphological differences among emerald shiner (Notropis atherinoides) populations inhabiting the Niagara River, Lake Erie, and Lake Ontario. It was expected that emerald shiners inhabiting the two lakes would have more robust bodies and smaller heads, while river emerald shiners were expected to display more fusiform bodies with larger heads. The results of this study indicate that emerald shiners from Lake Erie and the Niagara River had a more robust form on average than individuals from Lake Ontario. Specifically, emerald shiners collected from Lake Ontario displayed more streamlined bodies and larger heads than emerald shiners collected from Lake Erie and the Niagara River. In addition, this divergence in body shape has apparently occurred despite the lack of distinct genetic differentiation as measured with microsatellite variation. Our results suggest that differences in water velocity alone may not be responsible for phenotypic variation in body shape among these emerald shiner populations, and other factors such as differences in prey or predator regimes are likely involved.
The effects of riprap in enhancing the abundance and coexistence of
Gobiidae along the southern Caspian Sea coast
- Abstract: Publication date: Available online 21 December 2018Source: Journal of Great Lakes ResearchAuthor(s): Sina Zarini, Asghar Abdoli, Bahram H. KiabiAbstractMany natural coastal habitats around the world are being replaced by hard coastal defense structures as a result of rising sea levels and increasing intensity of storms. To examine the potential effects of riprap on gobies in the nearshore zone of the southern Caspian Sea, we used angling to compare their abundance and diversity in 13 riprap and natural habitats (sandy and gravel shores) from April 2012 through April 2013. In total, 819 gobies of three species, Caspian sand goby Neogobius pallasi (N = 433), round goby Neogobius melanostomus (N = 206), and Caspian goby Neogobius caspius (N = 180) were collected. No round gobies were caught from sandy shores and only two Caspian gobies were caught from gravel habitats, while all three species were abundant in riprap shores. A significant difference was observed in CPUE of all three goby species among shore types, with riprap sites having the highest abundance. PERMANOVA and nMDS demonstrated differences in goby assemblages among all three habitats. There were significant differences in round goby and Caspian goby sizes among riprap and natural habitats, while there were no significant differences in Caspian sand goby size among habitat types. In general deployment of riprap, especially in an area characterized as having natural shores with low structural complexity, could enhance the abundance and coexistence of nearshore gobies and act as a dispersal vector.
Comparison of satellite reflectance algorithms for estimating turbidity
and cyanobacterial concentrations in productive freshwaters using
hyperspectral aircraft imagery and dense coincident surface observations
- Abstract: Publication date: Available online 9 November 2018Source: Journal of Great Lakes ResearchAuthor(s): Richard Beck, Min Xu, Shengan Zhan, Richard Johansen, Hongxing Liu, Susanna Tong, Bo Yang, Song Shu, Qiusheng Wu, Shujie Wang, Kevin Berling, Andrew Murray, Erich Emery, Molly Reif, Joseph Harwood, Jade Young, Christopher Nietch, Dana Macke, Mark Martin, Garrett StillingsAbstractWe analyzed 37 satellite reflectance algorithms and 321 variants for five satellites for estimating turbidity in a freshwater inland lake in Ohio using coincident real hyperspectral aircraft imagery converted to relative reflectance and dense coincident surface observations. This study is part of an effort to develop simple proxies for turbidity and algal blooms and to evaluate their performance and portability between satellite imagers for regional operational turbidity and algal bloom monitoring. Turbidity algorithms were then applied to synthetic satellite images and compared to in situ measurements of turbidity, chlorophyll-a (Chl-a), total suspended solids (TSS) and phycocyanin as an indicator of cyanobacterial/blue green algal (BGA) abundance. Several turbidity algorithms worked well with real Compact Airborne Spectrographic Imager (CASI) and synthetic WorldView-2, Sentinel-2 and Sentinel-3/MERIS/OLCI imagery. A simple red band algorithm for MODIS imagery and a new fluorescence line height algorithm for Landsat-8 imagery had limited performance with regard to turbidity estimation. Blue-Green Algae/Phycocyanin (BGA/PC) and Chl-a algorithms were the most widely applicable algorithms for turbidity estimation because strong co-variance of turbidity, TSS, Chl-a, and BGA made them mutual proxies in this experiment.