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Research about Laurentian Great Lakes

Source-linked reports with geographic coverage including Laurentian Great Lakes.

At least 19 recordsLinked to original sources
USGS2026

Availability of dark daytime refuge may limit mysid abundance in the Laurentian Great Lakes

The zooplankton Mysis diluviana is a major component of the Laurentian Great Lakes food web and has recently declined in abundance in both lakes Michigan and Huron. Drivers of these declines are not well understood. Here, we explore the hypothesis that recent increases in water clarity have contributed to the decline of M. diluviana (mysids) by limiting the availability of daytime dark refuge from visual predators. Using Secchi depth data from 1996 to 2021, we estimate that dark refuge has decreased substantially in lakes Michigan and Huron where mysids have declined, but dark refuge has remained more stable in lakes Ontario and Superior where mysid populations did not decline. Results from a 2021 uncrewed surface vessel hydroacoustic survey and lake-wide, net-based sampling in lakes Michigan and Huron revealed significantly more mysids in areas with dark refuge, such as Lake Michigan’s northern basin. Conversely, Lake Huron contains sparse dark refuge consistent with low mysid densities in that lake. Higher water clarity leading to increased predation may be a primary driver of mysid declines in the Great Lakes.

Laurentian Great Lakes↗
USGS2026

Two hundred years of historical spawning and nursery data for coregonine fishes in the Laurentian Great Lakes

Historical data can provide critical ecological information for species across the globe, many of which are facing unprecedented rates of ecosystem change. Yet, historical information related to freshwater species, especially fishes, remains scattered, often in original formats, and underutilized for informing conservation and restoration activities. Here, we present a Data Descriptor called Coregonine Spawning History (CORHIST), a database designed to house diverse data related to past spawning and nursery areas for fishes in the family Salmonidae, subfamily Coregoninae (ciscoes and whitefishes), in the Laurentian Great Lakes and their tributaries. Data for 11 species of coregonines historically occurring in the Great Lakes are included in CORHIST. Over 3,400 occurrence records at the coordinate scale have been entered, over 2,200 of which are for Cisco ( Coregonus artedi ) and Lake Whitefish ( C. clupeaformis )—two focal species for which there is either multinational conservation interest or restoration efforts underway in the Laurentian Great Lakes. CORHIST is already proving useful for several studies developing habitat suitability models and delineating spatial units for conservation or restoration planning.

Laurentian Great Lakes↗
USGS2025

Lake sturgeon behavioral diversity in the Laurentian Great Lakes: Migratory patterns across populations and habitats

Background Characterizing the diversity of migration behaviors from the individual to the population level is essential for understanding how organisms respond to environmental variation and how these responses affect survival and habitat use. Lake sturgeon ( Acipenser fulvescens ) is a species of special concern in the Laurentian Great Lakes that are long-lived and generally classified as intermittent, adfluvial spawners. Observations of lake sturgeon movements at ecologically relevant spatiotemporal scales have shown that migration behavior often varies among individuals within the same population. However, studies on individual populations, particularly when focused only on a part of the life cycle (e.g., often spawning), provide just a partial understanding of the species’ full migratory scope and processes underlying expression of different migratory behaviors. To better understand lake sturgeon migratory diversity, we characterized and compared migratory behaviors of six lake sturgeon populations occupying environments that varied in habitat availability and connectivity in different Laurentian Great Lakes. Methods Sequence analysis combined with agglomerative hierarchical clustering and visual inspection of daily location data were used to identify distinct lake sturgeon migratory behaviors present in each population. Results Seven distinct migratory behaviors were identified based on differential patterns of lake and river use that encompass spawning and other seasonal periods. Behaviors were categorized as annual spring river, intermittent spring river, intermittent two-step, annual summer river, annual winter river, and annual interlake migrants along with river residents. The presence and frequency of migratory behaviors varied substantially among populations. Conclusions Our study demonstrated that migratory diversity is a general feature of lake sturgeon life history that may be partially shaped by habitat availability and connectivity. Given these results, we propose a conceptual model that links habitat availability and connectivity to migratory diversity and predict a positive association between them. This updated framework provides a cohesive basis for understanding lake sturgeon migratory behavior across variable ecological contexts in the Laurentian Great Lakes and will help promote future research to refute or refine the model.

Laurentian Great Lakes↗
USGS2025

Ten lessons for controlling invasive species: Wisdom from the long-standing sea lamprey control program on the Laurentian Great Lakes

Sea lamprey ( Petromyzon marinus ) control in the Laurentian Great Lakes of North America is among the largest and most successful control programs of an invasive species anywhere on the planet. The effort began more than 75 years ago; it unites multiple nations, states, and provinces with the common goal of controlling this invasive species and protecting a valuable fishery. The science-based control program is administered by the Great Lakes Fishery Commission (GLFC), a body arising from a treaty signed by the United States and Canada. In the present article, we share 10 lessons learned from decades of successful sea lamprey control with the hopes of informing ongoing and future control programs targeting biological invasions. The 10 lessons we identified are to act boldly in times of crisis, to maintain the social license, to invest in capacity building, to break down the silos, to support fundamental science, to diversify your portfolio of control measures, to strive for continuous improvement, to confront the trade-off between information and action, to keep your foot on the gas, and to keep your eyes on the prize. The GLFC has long fostered a framework that uses some military strategy and verbiage that extends across the lessons (e.g., know your enemy). Other lessons are more nascent as the GLFC reenvisions its relationship with Indigenous peoples and governments in a path to reconciliation where two-eyed seeing is being embraced. Through adaptive management, horizon scanning methods, and embracing implementation science, the lessons learned about sea lamprey control will continue to evolve, which is itself a lesson. We submit that the lessons shared in the present article will help guide invasive species control programs spanning taxa, ecosystems, and regions.

Laurentian Great Lakes↗
USGS2025

Sustaining Namāēw (Lake Sturgeon): Partner-led climate adaptation for Indigenous fisheries in the Laurentian Great Lakes

Namāēw (Menominee; Lake Sturgeon Acipenser fulvescens ) have long supported Indigenous culture and food sovereignty but have declined by over 80% in the Laurentian Great Lakes, exacerbating their sensitivity to climate change. Following interest from Indigenous leaders, we initiated a partnership-driven effort to (1) assess climate effects and (2) develop potential adaptation options for Namāēw using a participatory, transdisciplinary approach that combines multiple ways of knowing. Through a literature review and nine semistructured conversations with officials from Indigenous Nations and organizations in the Great Lakes, we identified central themes including access, culture, and fish persistence. Other concerns included habitat, food web shifts, and water quality. Prominent adaptation themes involved population assessments, stocking, regulations, habitat restoration, interagency coordination, and cultural advocacy. These findings underscore the importance of partnership-driven research to support Indigenous fisheries through knowledge coproduction and equitable adaptation. Our approach provides a model to inform stewardship planning for fisheries that are facing global change.

Laurentian Great Lakes↗
USGS2025

Visioning and conceptual framework for coordinating Great Lakes connecting waters research and monitoring

The Laurentian Great Lakes are connected via naturally occurring straits and rivers: St. Marys River, Straits of Mackinac, St. Clair-Detroit River System, Niagara River, and the St. Lawrence River. Despite the historical ecological and economic importance of these waters, international agreements (e.g., Great Lakes Water Quality Agreement) only recently explicitly named the Great Lakes Connecting Waters (GLCWs), requiring governments to address the challenges of adequate restoration and protection from historical use and degradation. Standardized research and monitoring activities are needed; however, there is no established mechanism for coordination across the GLCWs. A three-day summit in 2023 convened experts to form the initial framework for a GLCWs Collaborative to increase standardizations and knowledge transfer. Participants drafted a governance structure and priorities following the principles of collective impact but allowed for place-based specificity for local connecting water organizations. Priorities and suggestions for success included: 1) co-development of the collaborative with all rights holders, stakeholders, and surrounding communities; 2) investment in research and technology specific to GLCWs; 3) investment in information transfer and training; 4) increased communication; and 5) better integration into existing Great Lakes research, monitoring, and funding programs. Expanding participation in all local GLCWs organizations with principles of inclusivity was identified as a larger collaborative goal. Next steps in the development of a GLCWs Collaborative include increased communication and formation of working groups and obtaining funding for a dedicated organization to begin supporting activities (communication, facilitation, logistics). By using a deliberate process for establishment, the potentially slower time frame for establishment may result in increased participation and success.

Laurentian Great Lakes↗
USGS2025

Integrating acoustic telemetry research into management: successes and challenges in the Laurentian Great Lakes

In the Laurentian Great Lakes, the application of acoustic telemetry to track fish movements has evolved into an important part of multijurisdictional management. Nevertheless, barriers remain in translating telemetry research into management or conservation actions. Here, we synthesize acoustic telemetry literature within the Great Lakes basin to explore factors that have contributed to successes and failures of integrating research with the needs of decision-making processes. Collaboration between researchers and managers, facilitated by consistent opportunities for stakeholder engagement, stood out as one of the most effective means of integration. For example, 79% (95 of 127) of articles published (up to 2023) included co-authorship by both government and academic organizations. Case studies on lake sturgeon ( Acipenser fulvescens ), walleye ( Sander vitreus ), and sea lamprey ( Petromyzon marinus ) further highlight how telemetry has informed management through collaborative engagement among researchers, stakeholders, and managers, as well as ongoing challenges. By exploring facets of acoustic telemetry research and connections to conservation and fisheries concerns, we identify pathways to reduce knowledge–action gaps widely applicable within and outside of the Great Lakes.

Laurentian Great Lakes↗
USGS2024

Reconstructing half a century of coregonine recruitment reveals species-specific dynamics and synchrony across the Laurentian Great Lakes

Understanding how multiple species and populations vary in their recruitment dynamics can elucidate the processes driving recruitment across space and time. Lake Whitefish ( Coregonus clupeaformis ) and Cisco ( C. artedi ) are socioecologically important fishes across their range; however, many Laurentian Great Lakes populations have experienced declining, poor, or sporadic recruitment in recent decades. We integrated catch and age data from 38 long-term surveys across each of the Great Lakes and Lake Simcoe, resulting in a combined time series spanning 1960–2019. We estimated Lake Whitefish and Cisco year-class strength (YCS) in each lake using longitudinal mixed-effects regressions of relative cohort abundance. We subsequently quantified interspecific, spatial, and temporal synchrony in YCS using correlation and dynamic factor analyses. Lake Whitefish YCS was positively spatially synchronous on average, and YCS in all six lakes was elevated during the 1980s–1990s. In contrast, Cisco YCS was sporadic, not spatially synchronous, and highly variable around long-term, lake-specific means. YCS was not synchronous between species in any lake. Collectively, our analyses demonstrate that these species exhibit differential recruitment dynamics that may be regulated by species-specific factors. Results from this study can be leveraged in future research on the causes and consequences of cross-species, cross-basin recruitment variability.

Laurentian Great Lakes↗
USGS2024

Origin of the Laurentian Great Lakes fish fauna through upward adaptive radiation cascade prior to the Last Glacial Maximum

The evolutionary histories of adaptive radiations can be marked by dramatic demographic fluctuations. However, the demographic histories of ecologically-linked co-diversifying lineages remain understudied. The Laurentian Great Lakes provide a unique system of two such radiations that are dispersed across depth gradients with a predator-prey relationship. We show that the North American Coregonus species complex (“ciscoes”) radiated rapidly prior to the Last Glacial Maximum (80–90 kya), a globally warm period, followed by rapid expansion in population size. Similar patterns of demographic expansion were observed in the predator species, Lake Charr ( Salvelinus namaycush ), following a brief time lag, which we hypothesize was driven by predator-prey dynamics. Diversification of prey into deep water created ecological opportunities for the predators, facilitating their demographic expansion, which is consistent with an upward adaptive radiation cascade. This study provides a new timeline and environmental context for the origin of the Laurentian Great Lakes fish fauna, and firmly establishes this system as drivers of ecological diversification and rapid speciation through cyclical glaciation.

Communications Biology↗
USGS2024

Assessing and implementing the concept of Blue Economy in Laurentian Great Lakes fisheries: Lessons from coupled human and natural systems

Inland fisheries often receive little to no attention in global discussions about sustainable development. The consequences of overlooking inland fisheries in sustainability dialogues are increasingly problematic as fisheries stressors (e.g., overharvest, species invasion, climate change, habitat modification) intensify. Elevating the global profile of inland fisheries requires an approach for quantifying and clearly conveying the ecological, economic, and societal values of these systems. One such approach involves the Blue Economy, a multifaceted concept initially used to describe the intersection of marine conservation and sustainable use of marine resources for economic growth. Although conceptually powerful, the Blue Economy has rarely been applied to inland waters and fisheries. To address this knowledge gap, we conceptualized Laurentian Great Lakes fisheries from a Blue Economy perspective. In particular, we evaluated the utility of the coupled human and natural systems (CHANS) framework for characterizing the ecological, economic, and societal values of Laurentian Great Lakes fisheries and associated contributions to the Blue Economy (e.g., human livelihoods, food security, recreation, conservation, economic prosperity). There are numerous opportunities to leverage CHANS methods (e.g., metacoupling, telecoupling) and associated mathematical models to advance fisheries science, inform fisheries management, and ultimately move toward a Blue Economy in the Laurentian Great Lakes. To that end, we demonstrated applications of CHANS methods, discussed strategies for communicating with stakeholders, and provided insights for navigating challenges to developing a Blue Economy in the Laurentian Great Lakes—a model that could be used in the African Great Lakes and other large ecosystems in the world.

Laurentian Great Lakes↗
USGS2023

FishPass sortable attribute database: Phenological, morphological, physiological, and behavioural characteristics related to passage and movement of Laurentian Great Lakes fishes

In-stream barriers pose threats to fishes, including habitat loss, constraints on migration, and reduced connectivity between populations. Despite many negative consequences, barriers can serve to protect native species by limiting the spread of invasive species. For example, in the Laurentian Great Lakes, physical barriers have long been used to control invasive sea lamprey ( Petromyzon marinus ) populations by limiting access to potential upstream spawning and rearing habitat. Selective fish passage systems could solve this management trade-off, termed the “connectivity conundrum”, but must efficiently pass multiple native or desirable species while blocking invasive species. Designing such fish passage systems requires an understanding of the attribute dimensions of the fish community, specifically, the phenology, morphology, physiology, and behaviour of each species. Here, we describe the first comprehensive collection of sortable attributes associated with fish passage. The integrated database consists of 21 biological attributes that influence the movement and passage of 220 species in the Great Lakes, including native species, established non-native species, and unestablished but potentially invasive fishes. Data coverage varies with species, taxonomic orders, and attribute dimensions. Behavioural attributes were typically underrepresented in the literature, and the ecology of potential invaders was not well understood. The synthesis described herein is a critical step towards a holistic approach to fish passage design and may help to inform management actions related to population connectivity. The database is openly accessible online and is expected to be updated periodically.

Laurentian Great Lakes↗
USGS2023

Intra-lake trends and inter-lake comparisons of Mysis diluviana life history variables and their relationships to food limitation

The opossum shrimp, Mysis diluviana , is an important member of the offshore food webs of the Laurentian Great Lakes, but its response to ecosystem changes that have occurred over the past several decades is not well understood. We combined the data of four long-term sampling programs, adding several years of data (post and prior) to previously published analyses to offer a longer-term, cross-basin analysis of M. diluviana populations in the Great Lakes from 1997 to 2019. Densities were high in lakes Superior and Ontario (summer values 100–300/m 2 ), high and variable but declining (from 200–300/m 2 in 1997–2004 to less than 100/m 2 in 2017–2019) in Lake Michigan, low (∼20–50/m 2 since 2005) in Lake Huron, and very low in shallower eastern Lake Erie (<1/m 2 ). Biomass showed similar trends. Life history parameters (mortality, fecundity, and growth) were consistently highest in eastern Lake Erie, followed by lakes Ontario, Michigan, Huron, and Superior. Generation time was 1 year in Lake Erie and 2 years in the other lakes. Cross-basin relationships between annual M. diluviana areal densities and food indices (chlorophyll-a concentration and zooplankton biomass) were non-linear, increasing with food levels up to about 250 mysids/m 2 and about 650 mg dry wt/m 2 . Annual growth rates were also positively correlated to both food indices in the four deep lakes, but fecundity and mortality rates were not. Our results suggest food availability is a primary factor predicting M. diluviana density and biomass. Density-dependent mortality and fish predation could explain some of the inter-lake differences, but these relationships could benefit from further investigations.

Laurentian Great Lakes↗
USGS2023

A science and management partnership to restore coregonine diversity to the Laurentian Great Lakes

Similar to many freshwater ecosystems, the Laurentian Great Lakes of North America have undergone numerous anthropogenic stressors resulting in considerable loss of biodiversity and habitat. Among Great Lakes fishes, the coregonine sub-family has endured the most extensive declines, including extinction of several species ( Coregonus johannae, C. alpenae , and C. kiyi orientalis ) and at least 10 instances of local extirpations of other species ( C. nigripinnis, C. reighardi, C. zenithicus, C. hoyi , and C. artedi ) across all 5 lakes, much of which occurred prior to the 1960s owing to overfishing, interactions with non-indigenous species, and habitat loss. Despite these declines, no federal-, provincial-, or state-mandated actions were ever implemented to conserve coregonine diversity, potentially because so much of the coregonine declines occurred prior to the enactment of federal conservation legislation. Possible explanations for inaction since enactment of that legislation include insufficient data on biological vulnerability or threats, unresolved taxonomy, and limited support from the fishery management agencies and their stakeholders prior to the 2000s. In recent decades, however, several fishery management agencies have undertaken efforts to re-introduce coregonine diversity. These efforts helped lead to development of a science-based framework to restore coregonines that was universally endorsed by fishery managers representing eight U.S. states, four U.S. tribal organizations, and the province of ON, Canada, in May 2018. The basin-wide framework is based on principles of conservation biology and adaptive management. We describe details of its key steps, including planning, restoring, and evaluating, while also describing recent implementation efforts to develop methods, improve available resources, and enhance coordination across the basin. Although our paper describes a regional effort to restore native coregonines, our adaptive-management approach could be used by other multi-agency stakeholders seeking to conserve or restore native fishes.

Laurentian Great Lakes↗
USGS2022

Exposure and effects of bioaccumulative contaminants of emerging concern in tree swallows nesting across the Laurentian Great Lakes

Contaminants of emerging concern (CECs) are a loosely defined group of chemicals whose wide-spread usage or presence in the environment has occurred more recently or for which there has been relatively little research done until recently. Many of these CECs are not currently regulated. The National Toxicology Program within the U.S. Department of Health and Human Services estimates that about 2000 CECs are introduced each year (https://ntp.niehs.nih.gov/about/). An unknown number may pose a risk to human or animal health. The Phase 1 (2010 – 2014) CEC work in birds, which is the subject of this report, assessed exposure across the Great Lakes to polybrominated diphenyl ethers (PBDEs), perfluorinated compounds (PFASs), and polycyclic aromatic hydrocarbons (PAHs), and put those exposures into context with data from biologically relevant endpoints such as reproductive success, as well as, physiological response indicators (bioindicators) to assess possible effects. The group of chemicals included in Phase 1 were mainly those chemicals that bioaccumulate in tissues. Phase 2 (2015 – 2019) CEC work with tree swallows was expanded to include CECs whose occurrence in the environment is more temporary or seasonal, and that do not necessarily bioaccumulate. These are often called pseudo-persistent, because, while they are not long-lived in the environment, there are often daily inputs via waste water treatment plants, and run-off from farm fields and storm drainages, thereby making them available to biota year-round. These include pharmaceuticals, personal care products, and newer pesticides including herbicides. Tree swallow work on these less persistent CECs will be reported in the future, however see other Appendices in this report for information on some of these types of CECs (Appendices A, B, D).

Laurentian Great Lakes↗
USGS2021

Enhanced susceptibility of methylmercury bioaccumulation into seston of the Laurentian Great Lakes

Mercury concentrations in the Laurentian Great Lakes waters are among the lowest reported in the literature, while game fish concentrations approach consumption advisory limits, particularly in Lakes Superior, Huron, and Michigan, indicating efficient methylmercury transfer from water to game fish. To determine if increased transfer efficiency is evident within the lower food web, we measured (2010–2018) mercury and dissolved organic carbon (DOC) in water, and in size-sieved seston, dietary tracers (carbon and nitrogen isotope ratios), phytoplankton methylmercury bioaccumulation, and methylmercury biomagnification between increasing seston size fractions. We observed consistently low filter-passing methylmercury (<0.010 ng L –1 ) and comparatively variable DOC (1.1 to 3.4 mg L –1 ) concentrations. Methylmercury biomagnification factors between size-sieved seston were similar between lakes. Bioaccumulation factors in phytoplankton were among the highest in the literature (log 5.5 to 6.1), exceeding those in oceans, smaller lakes, and streams, and was influenced by DOC. Higher bioaccumulation rates increase the susceptibility of methylmercury accumulation into the food web. Because mercury is dominantly delivered to the Great Lakes through the atmosphere and the biota therein is highly susceptible to methylmercury uptake, we propose that the Laurentian Great Lakes are excellent sentinels to trace the success of efforts to decrease global mercury emissions (e.g., Minamata Treaty) in the future.

Environmental Science and Technology↗
USGS2021

Eradication of sea lampreys from the Laurentian Great Lakes is possible

Eradication has been achieved for many vertebrate pest control programs, primarily on small, isolated islands, but has never been considered a practical goal for invasive sea lampreys in the Laurentian Great Lakes. Our objective was to examine evidence relevant to the feasibility of setting eradication as a management goal for Great Lakes sea lampreys. Bomford and O'Brien (1995) listed six conditions for successful eradication of a vertebrate pest; here we examine evidence that these conditions are likely to be met for Great Lakes sea lampreys, with a focus on the first condition: that removal of the pest through control can exceed their rate of replenishment . We analyzed two data sets – one empirical and one synthetic – to estimate stock-recruitment relationships and calculate the exploitation rate necessary for extinction. The empirical data set included the effect of existing lampricide control and suggested an exploitation rate of 59%, in addition to lampricide control, would be sufficient for eventual eradication. The synthetic data set, derived from a simulation of stream-level recruitment dynamics in the absence of lampricide control, suggested that an overall exploitation rate of 90% would be sufficient. We suggest that both of these targets could be achieved. Meeting the other conditions will depend on the scale of the eradication effort, and on development of an exploitation strategy, such as genetic biocontrol, that can target sea lampreys in presently invulnerable habitats. Overall, we concluded that eradication of sea lampreys from the Great Lakes should not be dismissed as a prospective goal.

Laurentian Great Lakes↗
USGS2021

Assessing the assumptions of classification agreement, accuracy, and predictable healing time of sea lamprey wounds on lake trout

Sea lamprey control in the Laurentian Great Lakes relies on records of sea lamprey wounds on lake trout to assess whether control efforts are supporting fisheries management targets. Wounding records have been maintained for 70 years under the assumption that they are a reliable and accurate reflection of sea lamprey damage inflicted on fish populations. However, two key assumptions underpinning the use of these data need thorough evaluation: sea lamprey wounds follow a predictable healing progression, and individuals classify wounds accurately and reliably. To assess these assumptions, we conducted a workshop where experienced professionals examined lake trout with known sea lamprey wounds. For most lake trout, pictures were taken at regular intervals during the healing process. Our evaluation of wound pictures found high variability in healing times and wound progressions that did not conform to the currently used classification system. Participants’ wound classification agreement and accuracy were low and misclassification rates were high for most wound types. Training provided during the workshops did not markedly improve these metrics. We assessed wound classification accuracy for the first time and found assumptions of high accuracy and agreement are not met. We recommend misclassification rates be incorporated into models using wound data, sensitivity analyses be conducted to assess the potential impact of wound misclassification on estimates of key metrics (such as sea lamprey-induced mortality for lake trout), and alternative biomarkers be developed to quantify wound status with greater accuracy and precision.

Laurentian Great Lakes↗