Sarah E. Janssen , Michael T. Tate , Eric D. Dantoin , Christopher T. Filstrup , Euan D. Reavie , Robert M. Stewart , Chris Robinson , Craig J. Allan , Dale M. Robertson , David P. Krabbenhoft
{"title":"Connecting tributary mercury loads to nearshore and offshore sediments in Lake Superior","authors":"Sarah E. Janssen , Michael T. Tate , Eric D. Dantoin , Christopher T. Filstrup , Euan D. Reavie , Robert M. Stewart , Chris Robinson , Craig J. Allan , Dale M. Robertson , David P. Krabbenhoft","doi":"10.1016/j.jglr.2024.102381","DOIUrl":"10.1016/j.jglr.2024.102381","url":null,"abstract":"<div><div>Lake Superior has a vast and largely undeveloped watershed in comparison to the other Great Lakes, which makes it challenging to study mercury (Hg) sources and cycling. To examine Hg inputs to Lake Superior, we conducted an expansive binational assessment in 40 watersheds from a diverse range of landcover types. We further paired tributary Hg data to sediment source portfolios in the nearshore and offshore zones of Lake Superior through partnership with the Great Lakes Sediment Surveillance Program. We observed that total Hg loads were highest in the spring driven by the combination of elevated Hg concentrations and increased water discharge from snowmelt. In addition, total Hg concentrations in tributaries from remote, heavily forested regions, such as Pukaskwa National Park and the Minnesota Northshore, were higher than the Southshore and Thunder Bay regions. Methylmercury concentrations and loads were more spatially dependent, often corresponding to regions with more wetlands (e.g., Michigan Upper Peninsula). We estimated that the total Hg tributary load to Lake Superior in 2021 was 126 kg per year. To further examine the fate of watershed Hg sources, we examined sediments from 28 sites in Lake Superior using Hg stable isotopes. At open water sites, precipitation was the primary Hg source to sediments, but within nearshore sites Hg originated predominantly from watershed runoff. This work further defines the sources and fate of Hg within Lake Superior and highlights how Hg delivery is intrinsically tied to varying hydrologic regimes.</div></div>","PeriodicalId":54818,"journal":{"name":"Journal of Great Lakes Research","volume":"51 1","pages":"Article 102381"},"PeriodicalIF":2.4,"publicationDate":"2025-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141692477","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Ariel N. Edwards , Shawn P. Sitar , Ashley H. Moerke , Jonathan P. Doubek , Daniel L. Yule , Dray D. Carl , Cory A. Goldsworthy , Ian C. Harding , S. Ben Michaels , Eric K. Berglund , Seth A. Moore , Brandon S. Gerig
{"title":"Food web structure of the Lake Superior fish community in 2021–2022","authors":"Ariel N. Edwards , Shawn P. Sitar , Ashley H. Moerke , Jonathan P. Doubek , Daniel L. Yule , Dray D. Carl , Cory A. Goldsworthy , Ian C. Harding , S. Ben Michaels , Eric K. Berglund , Seth A. Moore , Brandon S. Gerig","doi":"10.1016/j.jglr.2024.102486","DOIUrl":"10.1016/j.jglr.2024.102486","url":null,"abstract":"<div><div>The trophic linkages and ecological requirements of the Lake Superior fish community have not been assessed on a whole lake scale in over a decade. Here, we investigated the trophic dynamics across multiple species and habitat zones of Lake Superior. From April to October of 2021 and 2022, a total of five piscivore, four planktivore, and six benthivore species were collected by region and length class during bottom-trawl, standard gillnet, commercial cisco gillnet, and recreational angler surveys. To assess trophic linkages, stomach contents were measured to estimate biomass consumed and a multivariate analysis was used to assess diet composition by species, length, and region. We found a high degree of interconnectedness in the Lake Superior food web, with <em>Mysis</em> as a critical diet item for most fishes. Native piscivore diets varied by region and with ontogeny. Lake charr were important habitat couplers in the lake, exhibiting a diverse diet and opportunistic foraging strategy. Conversely, Pacific salmon were more restricted in their foraging. Planktivores and benthivores primarily consumed <em>Mysis</em>, with less reliance on <em>Diporeia</em> compared to previous studies. Lake whitefish and cisco were the exception to this pattern, with broader bathymetric depth distributions represented in their diets. We found the food web to be supported by a predominantly native species assemblage, with redundancies at all trophic levels.</div></div>","PeriodicalId":54818,"journal":{"name":"Journal of Great Lakes Research","volume":"51 1","pages":"Article 102486"},"PeriodicalIF":2.4,"publicationDate":"2025-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143129595","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Jessica Hanson , Morgann Gordon , Nick Peterson , Ryan Lepak , Cory Goldsworthy , Valerie Brady , Thomas Hrabik , Joel Hoffman
{"title":"Stable isotope analysis of western Lake Superior predatory fishes, part one: Trophic niche overlap","authors":"Jessica Hanson , Morgann Gordon , Nick Peterson , Ryan Lepak , Cory Goldsworthy , Valerie Brady , Thomas Hrabik , Joel Hoffman","doi":"10.1016/j.jglr.2024.102441","DOIUrl":"10.1016/j.jglr.2024.102441","url":null,"abstract":"<div><div>Characterizing food web interactions between introduced and native fish predators is important to quantify niche overlap, assess predator–prey balance, and support fisheries management. Lake Superior provides an ideal setting to investigate potential trophic overlap between native top predators, lake trout (<em>Salvelinus namaycush</em>) and walleye (<em>Sander vitreus</em>), and a diverse assemblage of introduced salmonids. Angler-caught fish were used to measure trophic position and niche overlap between predatory fishes in the western arm of Lake Superior based on carbon and nitrogen stable isotope ratios (δ<sup>13</sup>C, δ<sup>15</sup>N). Within a species, we did not find consistent differences in either δ<sup>13</sup>C or δ<sup>15</sup>N values by sex, collection year, capture location, or length. Among species, the range in δ<sup>15</sup>N values was >5 ‰, indicating that these species occupy ∼2 trophic positions, with dietary reliance ranging from primarily invertebrates to primarily fish, whereas the range in δ<sup>13</sup>C values indicated dietary reliance on a mix of pelagic and benthic prey. Combined, the δ<sup>13</sup>C and δ<sup>15</sup>N values revealed siscowet lake trout as the apex predator having a distinct trophic niche, while walleye and lean lake trout were intermediate trophic position predators with overlapping isotopic niches, and introduced salmonids were the lowest trophic position predators with overlapping trophic niches. Overlapping trophic niches indicated similar resource reliance and habitat occupancy among native lake trout and walleye, as well as among introduced salmonids, but less so between native and introduced predators.</div></div>","PeriodicalId":54818,"journal":{"name":"Journal of Great Lakes Research","volume":"51 1","pages":"Article 102441"},"PeriodicalIF":2.4,"publicationDate":"2025-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143129597","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Eddie Kostelnik , Julie R. Peller , Dror L. Angel , Muruleedhara N. Byappanahalli , Bharath Ganesh Babu , Mary Anne Evans
{"title":"Synthetic microfibers are ubiquitous in benthic algae from the Laurentian Great Lakes","authors":"Eddie Kostelnik , Julie R. Peller , Dror L. Angel , Muruleedhara N. Byappanahalli , Bharath Ganesh Babu , Mary Anne Evans","doi":"10.1016/j.jglr.2025.102527","DOIUrl":"10.1016/j.jglr.2025.102527","url":null,"abstract":"<div><div>Synthetic microfibers are a class of microplastics routinely released into environmental media from domestic laundry and wastewater treatment plant effluent. Areas of high human population density discharge immense amounts of synthetic microfibers that pollute and accumulate in sediments, surface waters, algae, and other parts of the ecosystem. Synthetic microfibers are abundant in the Laurentian Great Lakes of North America, but their movement and fate are not well understood. Macroalgae effectively sequester microfibers; however, it is unknown if quantities of synthetic microfibers differ in benthic algae of the Great Lakes based on human population density or algal type (such as Cladophora or charophytes). Presented here is a 4-year study that investigated benthic algae samples from four of the Laurentian Great Lakes: Lakes Michigan, Huron, Ontario, and Erie. Synthetic microfibers were isolated and quantified in the algal samples, and values were analyzed with respect to algal type, lake, and population density. The average estimated number of synthetic microfibers per kg (dry weight) of benthic algae in each lake ranged from 1.6 <span><math><mrow><mo>×</mo></mrow></math></span> 10<sup>4</sup> to 2.0 <span><math><mrow><mo>×</mo></mrow></math></span> 10<sup>4</sup>. Microscopic analysis suggested a possible interaction between epiphytic diatoms and benthic macroalgae (<em>Cladophora</em>), which may help to explain the ability of the algae to sequester microfibers regardless of algal type. The results also suggest a lack of correlation between human population density and number of synthetic microfibers in benthic algae, which could imply facile movement and distribution of microfibers in large bodies of water, that includes the aquatic food web of macroinvertebrates and fish communities.</div></div>","PeriodicalId":54818,"journal":{"name":"Journal of Great Lakes Research","volume":"51 2","pages":"Article 102527"},"PeriodicalIF":2.4,"publicationDate":"2025-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143631890","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Kirill Shchapov , E. Todd Howell , Tara George , Sapna Sharma
{"title":"Cyanobacteria in cold waters: A study of nearshore cyanobacteria assemblages in Lake Superior","authors":"Kirill Shchapov , E. Todd Howell , Tara George , Sapna Sharma","doi":"10.1016/j.jglr.2024.102425","DOIUrl":"10.1016/j.jglr.2024.102425","url":null,"abstract":"<div><div>Cyanobacterial blooms, often associated with warm, eutrophic lakes, are of widespread concern owing to their potential disruption of ecological and public health. Recently, cyanobacterial blooms have been observed in oligotrophic lakes, including Lake Superior, a large cold-water system. Despite recent developments, limited research has targeted phytoplankton assemblages in the northern Lake Superior nearshore, where isolated cyanobacteria blooms have emerged since 2019. In 2019, the cyanobacteria assemblage at 10 nearshore monitoring stations was examined to understand potential bloom-forming taxa and their association with water quality. We observed a diverse cyanobacteria assemblage, with highest densities in spring and biomass in fall. <em>Pseudanabaena limnetica</em>, <em>Dolichospermum flos-aquae</em> and <em>Limnothrix</em> sp. were the most prevalent species across sites and seasons. Variation partitioning analysis revealed that water quality conditions were more influential drivers of cyanobacteria density and biomass than meteorological factors, particularly in regions with elevated nutrient inputs and following stormy conditions. However, at present, cyanobacteria compose <15 % of the total phytoplankton biomass in the study areas. Our monitoring data and recent reports of cyanobacteria blooms on the north shore, suggests that current blooms are not widespread. Nonetheless, we found a diverse array of cyanobacteria taxa, with most capable of producing cyanotoxins. Considering the global uncertainty in the factors contributing to cyanobacteria blooms, in association with the large-scale climatic changes affecting Lake Superior, a proactive approach to assessing risks of blooms is suggested. This should include data-generating efforts (e.g., frequent phytoplankton monitoring and reported blooms investigations) to support future collaborative initiatives focused on managing cyanobacterial blooms.</div></div>","PeriodicalId":54818,"journal":{"name":"Journal of Great Lakes Research","volume":"51 1","pages":"Article 102425"},"PeriodicalIF":2.4,"publicationDate":"2025-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142249744","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Ryan C. Grow , Eric Berglund , Friedrich Fischer , Michael D. Rennie
{"title":"Reducing bias in Coregonus artedi abundance estimates using stationary up-looking acoustics","authors":"Ryan C. Grow , Eric Berglund , Friedrich Fischer , Michael D. Rennie","doi":"10.1016/j.jglr.2024.102456","DOIUrl":"10.1016/j.jglr.2024.102456","url":null,"abstract":"<div><div>Mobile hydroacoustic surveys using ship-based down-looking transducers are widely used to estimate densities for ecologically and economically important pelagic fishes. However, this method likely underestimates densities of some surface-oriented species due to biases associated with the acoustic surface exclusion zone and ship avoidance behaviours. We compared cisco (<em>Coregonus artedi</em>) density estimates from a stationary up-looking platform survey to a standard down-looking acoustic survey. Both systems were deployed during the fall cisco spawn in Thunder Bay, Lake Superior 2020–2022. Cisco density estimates from the stationary up-looking platform were on average 6.7 times higher in the upper water column (∼1–10 m) and 2 times higher over the entire water column (∼1–45 m) than those from standard mobile surveys. Ship avoidance behaviour associated with mobile surveys was apparent in the upper water column; median cisco densities observed by the platform fell from ∼36 to ∼9 fish/ha when the ship passed near the platform. Abundance estimates from the platform when not influenced by ship avoidance provided higher quota estimates than the standard survey in 2020 and 2022, but were similar in 2021. A multi-day deployment of the platform tracked a progressive daily increase in fish densities, highlighting the sensitivity of mobile survey results to the day they are conducted, often dictated by environmental conditions. Our results show promise in applying stationary acoustic deployments in fisheries surveys, with improved accuracy and reduced effort compared to mobile acoustic surveys in the management and monitoring of pelagic fishes in the Great Lakes.</div></div>","PeriodicalId":54818,"journal":{"name":"Journal of Great Lakes Research","volume":"51 1","pages":"Article 102456"},"PeriodicalIF":2.4,"publicationDate":"2025-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143129448","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Sierra N. Wachala , John Janssen , Erica B. Young , John A. Berges
{"title":"Seasonal population characteristics and gut contents of the invasive mysid, Hemimysis anomala, in Milwaukee Harbor, Lake Michigan","authors":"Sierra N. Wachala , John Janssen , Erica B. Young , John A. Berges","doi":"10.1016/j.jglr.2024.102462","DOIUrl":"10.1016/j.jglr.2024.102462","url":null,"abstract":"<div><div>The invasive mysid, <em>Hemimysis anomala,</em> is abundant along harbor breakwalls in Lake Michigan, forming large swarms, but we know little of its population dynamics or diet in these novel environments. We examined abundance, body length, and sex/developmental stage in animals collected using lighted funnel traps in Milwaukee Harbor, WI, from summer 2021 to spring 2022. We applied novel immunochemical analysis to examine gut contents using purified polyclonal antisera raised against nine putative zooplankton prey (<em>Bosmina longirostris, Bythotrephes longimanus</em>, <em>Cercopagis pengoi</em>, <em>Daphnia galataea mendotae</em>, <em>Daphnia pulex, Dreissena</em> veliger larvae, <em>Keratella cochlearis</em>, <em>Leptodiaptomus ashlandii,</em> and <em>Limnocalanus macrurus</em>). Population dynamics differed from those described in other Great Lakes; mid-late summer populations were dominated by juveniles (< 6 mm), and small (∼7 mm) adult males (80–90 %) with few reproductive females (5–10 %). Males did not die after reproducing and adults grew through winter (0.011–0.015 mm d<sup>−1</sup>), reaching 10–12 mm by early spring. Immunochemical gut analyses showed <em>Hemimysis</em> to be generalist feeders, consuming all nine species tested. Most trapped individuals (58 %) had empty guts, suggesting that <em>Hemimysis</em> cleared their guts before recovery<em>.</em> No differences in diet were seen among sexes/developmental stages, or across seasons. We also compared <em>Hemimysis</em> directly sampled from pelagic swarms, to those recovered from benthic traps. There were no differences in size or sex/developmental stage of individuals between traps and swarm populations, refuting the idea that swarming serves a reproductive function, but there were differences in prey found in guts between individuals in swarms and from traps, suggesting swarming is associated with feeding.</div></div>","PeriodicalId":54818,"journal":{"name":"Journal of Great Lakes Research","volume":"51 1","pages":"Article 102462"},"PeriodicalIF":2.4,"publicationDate":"2025-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143129452","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Kim T. Scribner , Jeannette Kanefsky , Nicholas Sard , Dan Sampson
{"title":"Genetic pedigree analyses of Arctic grayling offspring produced to initiate the Michigan reintroduction program","authors":"Kim T. Scribner , Jeannette Kanefsky , Nicholas Sard , Dan Sampson","doi":"10.1016/j.jglr.2024.102492","DOIUrl":"10.1016/j.jglr.2024.102492","url":null,"abstract":"<div><div>Measures of genetic diversity among individuals within and between broodstock year classes of Arctic Grayling (<em>Thymallus arcticus</em>) were quantified as part of a large inter-disciplinary effort to repatriate the species into Michigan fluvial habitats. Genetic pedigree analysis of 200 juveniles from each of the 2019 and 2021 year classes indicated that 205 and 218 adults from a natural stream population in central Alaska contributed to offspring genotyped. Because broodstock sampling occurred in the same stream location each year and adults were not marked, 22.4 % of successful adults were estimated to have contributed to offspring genotyped in both years, indicating that the local adult population was philopatric to the spawning site and of moderate size. Measures of genetic <u>diversity</u> including heterozygosity and allelic diversity were high, while inbreeding coefficients (F<sub>IS</sub>), and estimates of inter-individual relatedness (R<sub>XY</sub>) of offspring genotyped within and between year classes were low. Collectively, results indicate that crosses conducted among adults to establish broodstock year classes had achieved restoration program goals of creating a genetically diverse domestic broodstock to use for future repatriation efforts.</div></div>","PeriodicalId":54818,"journal":{"name":"Journal of Great Lakes Research","volume":"51 1","pages":"Article 102492"},"PeriodicalIF":2.4,"publicationDate":"2025-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143129457","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Andrew W. Wood , Jake D. Callaghan , Reane Loiselle , Robert M. McManus , Sandra S. Brovold , Holly A. Wellard Kelly , Elizabeth E. Alexson , Robert W. Sterner , Matthew J. Hudson , Cody S. Sheik
{"title":"Spatiotemporal dynamics of cyanobacterium Dolichospermum lemmermannii populations in a bloom-prone region of Lake Superior","authors":"Andrew W. Wood , Jake D. Callaghan , Reane Loiselle , Robert M. McManus , Sandra S. Brovold , Holly A. Wellard Kelly , Elizabeth E. Alexson , Robert W. Sterner , Matthew J. Hudson , Cody S. Sheik","doi":"10.1016/j.jglr.2024.102455","DOIUrl":"10.1016/j.jglr.2024.102455","url":null,"abstract":"<div><div>Cyanobacterial Harmful Algal Blooms (cHABs) are increasingly common in marine and freshwater environments, including the Laurentian Great Lakes (LGL). Lake Superior has seen two large-scale cyanobacterial blooms (2012 and 2018) along the Wisconsin shoreline west of the Apostle Islands, caused by the cyanobacterium <em>Dolichospermum lemmermannii.</em> The drivers of bloom formation in Lake Superior are not yet certain, with many factors known to trigger blooms elsewhere in the LGL being absent in Lake Superior. Furthermore, little is known about <em>D. lemmermannii</em>’s spatial structure or phenology. Thus, we sought to track the seasonal population dynamics of <em>D. lemmermannii</em> to shed light on its growth, physiology, and abundance. In 2021, we used 16S rRNA amplicon and shotgun metagenomic sequencing to characterize spatiotemporal patterns of <em>D. lemmermannii</em> abundance and diversity along the bloom-prone Wisconsin shore of Lake Superior. In 2022, we performed net tows and direct colony counts in another localized area. No large-scale bloom event was observed during either year, though several smaller localized blooms were observed. <em>D. lemmermannii</em> abundances were low at nearly all sites and sampling times. Spikes in abundance occurred in July and September, particularly near Siskiwit Bay, a hotspot of bloom formation. We also observed a seasonal shift in heterocyte and akinete abundance indicative of late-season nutrient limitation. Most striking was the seasonal turnover of <em>D. lemmermannii</em> strains, suggesting strain adaptation to specific environmental conditions. These results offer valuable and actionable insights for managers and provide a foundation for additional work to clarify drivers of bloom formation in Lake Superior.</div></div>","PeriodicalId":54818,"journal":{"name":"Journal of Great Lakes Research","volume":"51 1","pages":"Article 102455"},"PeriodicalIF":2.4,"publicationDate":"2025-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143129596","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"LiDAR-derived measurements of rapid coastal change along Wisconsin’s Lake Superior coast (2009–2019)","authors":"C.J. Roland, L.K. Zoet","doi":"10.1016/j.jglr.2024.102366","DOIUrl":"10.1016/j.jglr.2024.102366","url":null,"abstract":"<div><div>Coastal landscapes are highly dynamic, and comprehensive measurements of morphological change are important for improved coastal management. Past assessments of morphological change along Wisconsin’s Lake Superior coast were limited in either their spatial coverage or their ability to incorporate three-dimensional changes due to their reliance on 2D transect-based or plan-form measurements. Here, we quantified erosion and deposition for 74 km of Wisconsin’s Lake Superior coastline using airborne LiDAR data collected in 2009 and 2019, spanning a transition from below-average to near-record water elevations. We used open-source methods to generate new 1-m resolution DEM’s and semi-automatically delineated bluff toes and crests. The study reach experienced 3.03 ± 0.59 <span><math><mo>×</mo></math></span> 10<sup>6</sup> m<sup>3</sup> of net erosion, corresponding to a normalized mean erosion rate of 3.9 m<sup>3</sup> yr<sup>−1</sup> per m of coastline. The mean bluff toe retreated 6.8 ± 5.6 m over this time period (0.7 ± 0.4 m yr<sup>−1</sup>), while the mean bluff crest retreated 2.9 ± 5.7 m over this time period (0.3 ± 0.4 m yr<sup>−1</sup>), leading to widespread bluff steepening. Coastal erosion rates exhibited a strong lithological dependence, with sandier bluffs losing 7.0 ± 4.9 m<sup>3</sup> yr<sup>−1</sup> per m of coastline while more clay-rich bluffs eroded at a rate of 3.2 ± 2.3 m<sup>3</sup> yr<sup>−1</sup> per m of coastline. Aggradational reaches were limited to Wisconsin Point. Our findings indicate that Wisconsin’s Lake Superior coast is eroding at rates similar to other soft coastal cliff systems and there is substantial spatial variability in erosion rates. As of 2019, bluff slopes had increased and bluff crest retreat is expected to continue to achieve stable slope angles.</div></div>","PeriodicalId":54818,"journal":{"name":"Journal of Great Lakes Research","volume":"51 1","pages":"Article 102366"},"PeriodicalIF":2.4,"publicationDate":"2025-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141050419","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}