Journal of Great Lakes Research最新文献

A comparison of phytoplankton development in Lake Baikal, Siberia, and Rybinsk Reservoir, Volga River, European Russia, using stability indices

IF 2.4 3区环境科学与生态学 Q3 ENVIRONMENTAL SCIENCES

Journal of Great Lakes Research

Pub Date : 2025-02-01 DOI: 10.1016/j.jglr.2024.102493

Natalya Mineeva , Nina Bondarenko

Based on observations of 2009–2022, the state of phytoplankton and its main taxa was analyzed in Lake Baikal (Siberia, Russia) and Rybinsk Reservoir (European Russia), two large freshwater lake reservoirs. Data were collected during periods of phytoplankton seasonal maxima which determine the total level of their annual production. The development of phytoplankton was assessed by biomass expressed in units of wet weight for Lake Baikal and units of chlorophyll a for the Rybinsk Reservoir. To assess the sustainability of biomass, its coefficients of variation, deviation from the mean value, and population stability index were calculated. These metrics did not reveal any definite inter-annual trends in the state of phytoplankton, but showed sharp changes in the level of community resistance in years with different trophic state. In both water bodies, a decrease in stability was observed under conditions atypical for the ecosystem. In the oligotrophic Lake Baikal, the most unstable situation was noted in highly productive years with the mass development of diatoms in the spring plankton. In the moderately eutrophic Rybinsk Reservoir, its resistance decreased in low productivity years with a weak summer development of phytoplankton and cyanobacteria due to the unfavorable weather conditions. The proposed approach will be of interest for assessing the stability of other aquatic ecosystems.

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引用次数: 0

Role of tributary cyanobacterial and nutrient transport and sediment processes on cyanobacterial bloom initiation in Lake Superior nearshore

IF 2.4 3区环境科学与生态学 Q3 ENVIRONMENTAL SCIENCES

Journal of Great Lakes Research

Pub Date : 2025-02-01 DOI: 10.1016/j.jglr.2024.102409

Rebecca M. Kreiling , Carrie E. Givens , Anna C. Baker , Richard L. Kiesling , Eric D. Dantoin , Patrik M. Perner , Shelby P. Sterner , Kenna J. Gierke , Paul C. Reneau

Watershed fluxes of suspended sediment (SS), nutrients, in particular phosphorus (P), and cyanobacteria may play a role in driving cyanobacterial blooms along the southwestern shore of oligotrophic Lake Superior. To understand how tributary loads contribute to nearshore blooms, we sampled two southwestern shore tributaries, Bois Brule and Siskiwit Rivers. We collected water-quality samples to compute nutrient and sediment loads and to assess cyanobacteria community composition from the tributaries to the nearshore. We collected suspended and streambed sediment to assess the capacity for sediment to store and transport bioavailable P and to assess cyanobacteria community composition. Storm flows drove export of SS, total P, and total nitrogen, with the majority of total P being particulate P. Equilibrium P concentrations revealed that SS sorbed P as it is moved through the stream network across sites and seasons and was a potential source of P to the nearshore. However, streambed sediment in the Bois Brule and Siskiwit River watersheds were P sinks during summer, which potentially delayed transport of dissolved P to the lake. The cyanobacteria community varied spatially and temporally relating to multiple environmental variables including nutrients (P, N, and C) and specific conductivity. Cyanobacteria capable of producing cyanotoxins were present in tributaries and found across multiple environmental compartments indicating a potential for fluvial flow to the nearshore. This study demonstrated that streamflow is a primary driver of total nutrient and sediment loading in both watersheds, which indicates the potential for algal loading to the nearshore via suspended sediment or water.

{"title":"Role of tributary cyanobacterial and nutrient transport and sediment processes on cyanobacterial bloom initiation in Lake Superior nearshore","authors":"Rebecca M. Kreiling , Carrie E. Givens , Anna C. Baker , Richard L. Kiesling , Eric D. Dantoin , Patrik M. Perner , Shelby P. Sterner , Kenna J. Gierke , Paul C. Reneau","doi":"10.1016/j.jglr.2024.102409","DOIUrl":"10.1016/j.jglr.2024.102409","url":null,"abstract":"<div><div>Watershed fluxes of suspended sediment (SS), nutrients, in particular phosphorus (P), and cyanobacteria may play a role in driving cyanobacterial blooms along the southwestern shore of oligotrophic Lake Superior. To understand how tributary loads contribute to nearshore blooms, we sampled two southwestern shore tributaries, Bois Brule and Siskiwit Rivers. We collected water-quality samples to compute nutrient and sediment loads and to assess cyanobacteria community composition from the tributaries to the nearshore. We collected suspended and streambed sediment to assess the capacity for sediment to store and transport bioavailable P and to assess cyanobacteria community composition. Storm flows drove export of SS, total P, and total nitrogen, with the majority of total P being particulate P. Equilibrium P concentrations revealed that SS sorbed P as it is moved through the stream network across sites and seasons and was a potential source of P to the nearshore. However, streambed sediment in the Bois Brule and Siskiwit River watersheds were P sinks during summer, which potentially delayed transport of dissolved P to the lake. The cyanobacteria community varied spatially and temporally relating to multiple environmental variables including nutrients (P, N, and C) and specific conductivity. Cyanobacteria capable of producing cyanotoxins were present in tributaries and found across multiple environmental compartments indicating a potential for fluvial flow to the nearshore. This study demonstrated that streamflow is a primary driver of total nutrient and sediment loading in both watersheds, which indicates the potential for algal loading to the nearshore via suspended sediment or water.</div></div>","PeriodicalId":54818,"journal":{"name":"Journal of Great Lakes Research","volume":"51 1","pages":"Article 102409"},"PeriodicalIF":2.4,"publicationDate":"2025-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143129561","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}

引用次数: 0

Connecting tributary mercury loads to nearshore and offshore sediments in Lake Superior 将支流汞负荷与苏必利尔湖近岸和离岸沉积物联系起来

IF 2.4 3区环境科学与生态学 Q3 ENVIRONMENTAL SCIENCES

Journal of Great Lakes Research

Pub Date : 2025-02-01 DOI: 10.1016/j.jglr.2024.102381

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

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.

{"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}

引用次数: 0

Food web structure of the Lake Superior fish community in 2021–2022

IF 2.4 3区环境科学与生态学 Q3 ENVIRONMENTAL SCIENCES

Journal of Great Lakes Research

Pub Date : 2025-02-01 DOI: 10.1016/j.jglr.2024.102486

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

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 Mysis 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 Mysis, with less reliance on Diporeia 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.

{"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}

引用次数: 0

Stable isotope analysis of western Lake Superior predatory fishes, part one: Trophic niche overlap

IF 2.4 3区环境科学与生态学 Q3 ENVIRONMENTAL SCIENCES

Journal of Great Lakes Research

Pub Date : 2025-02-01 DOI: 10.1016/j.jglr.2024.102441

Jessica Hanson , Morgann Gordon , Nick Peterson , Ryan Lepak , Cory Goldsworthy , Valerie Brady , Thomas Hrabik , Joel Hoffman

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 (Salvelinus namaycush) and walleye (Sander vitreus), 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 (δ¹³C, δ¹⁵N). Within a species, we did not find consistent differences in either δ¹³C or δ¹⁵N values by sex, collection year, capture location, or length. Among species, the range in δ¹⁵N 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 δ¹³C values indicated dietary reliance on a mix of pelagic and benthic prey. Combined, the δ¹³C and δ¹⁵N 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.

{"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}

引用次数: 0

LiDAR-derived measurements of rapid coastal change along Wisconsin’s Lake Superior coast (2009–2019) 威斯康星州苏必利尔湖沿岸海岸快速变化的激光雷达测量结果（2009-2019 年）

IF 2.4 3区环境科学与生态学 Q3 ENVIRONMENTAL SCIENCES

Journal of Great Lakes Research

Pub Date : 2025-02-01 DOI: 10.1016/j.jglr.2024.102366

C.J. Roland, L.K. Zoet

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

\times

10⁶ m³ of net erosion, corresponding to a normalized mean erosion rate of 3.9 m³ yr⁻¹ per m of coastline. The mean bluff toe retreated 6.8 ± 5.6 m over this time period (0.7 ± 0.4 m yr⁻¹), while the mean bluff crest retreated 2.9 ± 5.7 m over this time period (0.3 ± 0.4 m yr⁻¹), leading to widespread bluff steepening. Coastal erosion rates exhibited a strong lithological dependence, with sandier bluffs losing 7.0 ± 4.9 m³ yr⁻¹ per m of coastline while more clay-rich bluffs eroded at a rate of 3.2 ± 2.3 m³ yr⁻¹ 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.

{"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}

引用次数: 0

Cyanobacteria in cold waters: A study of nearshore cyanobacteria assemblages in Lake Superior 冷水中的蓝藻：苏必利尔湖近岸蓝藻群研究

IF 2.4 3区环境科学与生态学 Q3 ENVIRONMENTAL SCIENCES

Journal of Great Lakes Research

Pub Date : 2025-02-01 DOI: 10.1016/j.jglr.2024.102425

Kirill Shchapov , E. Todd Howell , Tara George , Sapna Sharma

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. Pseudanabaena limnetica, Dolichospermum flos-aquae and Limnothrix 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.

蓝藻藻华通常与温暖、富营养化的湖泊有关，由于其对生态和公共健康的潜在破坏而受到广泛关注。最近，在寡营养湖泊（包括大型冷水湖泊苏必利尔湖）中也观察到了蓝藻藻华。尽管最近取得了一些进展，但针对苏必利尔湖北部近岸浮游植物群的研究还很有限，自 2019 年以来，该地区出现了孤立的蓝藻水华。2019 年，我们对 10 个近岸监测站的蓝藻群进行了研究，以了解潜在的藻华形成类群及其与水质的关系。我们观察到蓝藻的多样性，其中春季密度最高，秋季生物量最大。在不同地点和不同季节，藻类中最常见的物种是藻蓝蛋白和藻蓝蛋白。变异分区分析表明，与气象因素相比，水质条件对蓝藻密度和生物量的影响更大，尤其是在营养盐输入增加和暴风雨过后的地区。然而，目前蓝藻在研究区域浮游植物总生物量中所占比例还不到 15%。我们的监测数据和最近关于北岸蓝藻藻华的报告表明，目前的藻华并不普遍。尽管如此，我们还是发现了多种蓝藻类群，其中大多数都能产生蓝藻毒素。考虑到导致蓝藻藻华的各种因素在全球范围内的不确定性，以及影响苏必利尔湖的大规模气候变化，建议采取积极主动的方法来评估藻华风险。这应包括数据生成工作（如频繁的浮游植物监测和已报告的藻华调查），以支持未来以管理蓝藻藻华为重点的合作计划。

{"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}

引用次数: 0

Reducing bias in Coregonus artedi abundance estimates using stationary up-looking acoustics

IF 2.4 3区环境科学与生态学 Q3 ENVIRONMENTAL SCIENCES

Journal of Great Lakes Research

Pub Date : 2025-02-01 DOI: 10.1016/j.jglr.2024.102456

Ryan C. Grow , Eric Berglund , Friedrich Fischer , Michael D. Rennie

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 (Coregonus artedi) 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.

{"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}

引用次数: 0

Seasonal population characteristics and gut contents of the invasive mysid, Hemimysis anomala, in Milwaukee Harbor, Lake Michigan

IF 2.4 3区环境科学与生态学 Q3 ENVIRONMENTAL SCIENCES

Journal of Great Lakes Research

Pub Date : 2025-02-01 DOI: 10.1016/j.jglr.2024.102462

Sierra N. Wachala , John Janssen , Erica B. Young , John A. Berges

The invasive mysid, Hemimysis anomala, 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 (Bosmina longirostris, Bythotrephes longimanus, Cercopagis pengoi, Daphnia galataea mendotae, Daphnia pulex, Dreissena veliger larvae, Keratella cochlearis, Leptodiaptomus ashlandii, and Limnocalanus macrurus). 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⁻¹), reaching 10–12 mm by early spring. Immunochemical gut analyses showed Hemimysis to be generalist feeders, consuming all nine species tested. Most trapped individuals (58 %) had empty guts, suggesting that Hemimysis cleared their guts before recovery. No differences in diet were seen among sexes/developmental stages, or across seasons. We also compared Hemimysis 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.

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引用次数: 0

Genetic pedigree analyses of Arctic grayling offspring produced to initiate the Michigan reintroduction program

IF 2.4 3区环境科学与生态学 Q3 ENVIRONMENTAL SCIENCES

Journal of Great Lakes Research

Pub Date : 2025-02-01 DOI: 10.1016/j.jglr.2024.102492

Kim T. Scribner , Jeannette Kanefsky , Nicholas Sard , Dan Sampson

Measures of genetic diversity among individuals within and between broodstock year classes of Arctic Grayling (Thymallus arcticus) 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 diversity including heterozygosity and allelic diversity were high, while inbreeding coefficients (F_IS), and estimates of inter-individual relatedness (R_XY) 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.

{"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}

引用次数: 0