Lake whitefish Coregonus clupeaformis play a key role in the socioeconomics of the Laurentian Great Lakes region and serve as an important conduit of energy among trophic levels. Lake wide declines in adult abundance creates the need for improved understanding of population dynamics, currently hampered by a lack of early life history information and resolution of subpopulation structure. We predicted

Population structure can reveal the diversity, gene flow, and dispersal of a species. This information can be used to make management decisions and reveal fundamental aspects of an organism’s biology. Distinct intrinsic (e.g., biological characteristics) and extrinsic (e.g., geographical and historical events, environment, human pressures) factors can influence population structure, with significant

This paper analyzes high-resolution lidar data to estimate sediment export to the Pennsylvania Lake Erie littoral zone from lakefront bluff retreat under relatively unique lake-level conditions: approximately a decade of average lake level transitioning into a mild transgression. Analysis identifies bluff-failure patterns important to coastal hazard planning, possible feeder-bluff conservation areas

The sea lamprey (Petromyzon marinus) is an invasive species in the Laurentian Great Lakes which requires control to protect valuable fisheries. The Sea Lamprey Control Program (program) uses chemical methods (lampricides) each year to treat infested streams, but limited resources only allow control agents to target 100–125 streams annually. To provide the most cost-effective use of these resources

Previous modeling of hydrologic and nutrient budgets of lakes in Precambrian Shield regions have generally ignored groundwater as a source of water and supplier or sink of nutrients. This paper and its companion (Part 1) address this science gap by probing the role of groundwater in the nutrient balance for a restricted bay of a Precambrian Shield lake (Lake of the Woods) that experienced extensive

Nitrogen fixation (NFix) is an important, yet understudied, microbial process in aquatic ecosystems, especially in the Laurentian Great Lakes (LGL). To date, a dearth of nitrogen fixation rate measurements exists in the LGL, are from temporally isolated studies, and were collected primarily from near-shore and surface water environments. Evidence of nitrogen accumulation across the Laurentian Great

Nutrient losses from agricultural operations are a major contributor to the eutrophication of freshwaters. Although many studies have quantified diffuse nutrient losses, less is known about agricultural point-source contributions, such as bunker silos, to watershed phosphorus (P) loads. This study examined the contributions of a dairy farm bunker silo effluent to watershed soluble reactive P (SRP)

As sentinels of climate change and other anthropogenic forces, freshwater lakes are experiencing ecosystem disruptions at every level of the food web, beginning with the phytoplankton, a highly responsive group of organisms. Most studies regarding the effects of climate change on phytoplankton focus on a potential scenario in which temperatures continuously increase and droughts intersperse heavy precipitation

Among the Laurentian Great Lakes, Lake Ontario is the farthest downstream and has the longest history of environmental stress from human activities. Two sediment cores, spanning the last 300 years, from Lake Ontario were analyzed for diatom composition and geochemistry and compared with anthropogenic activities in the surrounding watershed. Despite some regional variation a clear, lake-wide record

In 2014, 94 paired neuston net samples (0.5 mm mesh) were collected from the surface waters of Lake Superior. These samples comprise the most comprehensive surface water survey for microplastics of any of the Great Lakes to date, and the first to employ double net trawls. Microplastic abundance estimates showed wide variability, ranging between 4000 to more than 100,000 particles/km2 with most locations

Innovative and robust methods are needed to evaluate the risks to native aquatic organisms exposed to organic compounds released from contaminated sediments. In the present study, we deployed semi-permeable membrane devices (SPMDs) above sediments in a contaminated harbor at a location in the Laurentian Great Lakes (i.e. Owen Sound Bay) and prepared extracts from these passive samplers for analysis

Freshwater systems are vulnerable to contamination by oil extraction and transportation. Thus, it is critical to understand how large freshwater ecosystems such as the Great Lakes will respond to released oil. In this study, we investigated differences in the microbial response to oil in the Straits of Mackinac at different times throughout the year and if crude (Bakken) and refined (non-highway diesel)

Changes in winter conditions, such as decreased ice coverage and duration, have been observed in the Laurentian Great Lakes for more than 20 years. Such changes have been hypothesized to be linked to low Coregonus spp. survival to age-1 as most cisco (Coregonus artedi) populations are autumn spawners whose embryos incubate under ice throughout the winter. The quantity of light during winter is regulated

The Maumee River watershed in the Laurentian Great Lakes Basin has been impacted by decades of pollution and habitat modification due to human settlement and development. As such, the lower 35 km of the Maumee River and several smaller adjacent watersheds comprising over 2000 km2 were designated the Maumee Area of Concern (AOC) under the revised Great Lakes Water Quality Agreement in 1987. As part

Lake Vättern is Sweden’s second largest lake and faces multiple environmental challenges such as climate change, pollutants and invasive alien species. Since its foundation in 1957, the Lake Vättern Society of Water Conservation (LVSWC) has been a local actor aiming to manage a broad range of environmental issues concerning the lake and its catchment. Stakeholders can be members of LVSWC, which also

In much of the United States and Canada, the common reed consists of both a native subspecies Phragmites australis americanus, and a highly invasive introduced subspecies P. australis australis. DNA testing is generally used to distinguish them definitively and is necessary to detect hybridization. We report a group of single nucleotide polymorphisms and indels in the nuclear NRT2 gene of Phragmites

Beginning with the first lampricide treatments of Lake Huron streams in 1960, applying lampricides and maintaining barriers to migration in Lake Huron tributaries continue to be the primary methods of controlling sea lampreys (Petromyzon marinus). In years leading up to the new millennium, sea lamprey abundance in Lake Huron remained at high levels, yet well below the pre-control adult abundance estimate

Mount Baldy dune is one of the largest active eolian dunes along the southern shore of Lake Michigan and a famous tourist attraction within the Indiana Dunes National Park. It is an anthropogenically disturbed landform where restoration efforts include native beach-grass plantings and restricted foot traffic. In July 2013, a 6-year-old boy was buried more than 3 m below the dune stoss surface after

Because little is known about the effects of currents on lake charr (Salvelinus namaycush) deposition and fate of eggs, a method to determine their role in spawning success was developed. It is suggested that an ideal strategy for lake charr egg survival is to select hydrodynamic conditions that allow for eggs to roll on lakebed and into void spaces in the substratum, whilst avoiding to be lifted from

Survival of adult fishes is critical to the conservation and management of wild populations, particularly for long-lived, slow to reproduce species. Most sturgeon species are of conservation concern, but their long lifespans and large ranges have made estimation of adult survival rates challenging. In this study, acoustic telemetry was used to track 205 lake sturgeon (Acipenser fulvescens) tagged in

The periodic application of chemical lampricides that selectively kill larval sea lampreys (Petromyzon marinus) in their nursery habitats remains a primary component of the Great Lakes Fishery Commission’s (GLFC) Sea Lamprey Control Program in the Laurentian Great Lakes. Lampricides include 3-trifluoromethyl-4-nitrophenol (TFM) and niclosamide, the 2-aminoethanol salt of 2′, 5-dichloro-4′-nitrosalicylanilide

The collapse of Diporeia spp. and invasions of dreissenid mussels (zebra, Dreissena polymorpha; quagga, D. bugensis) and round goby (Neogobius melanostomus) have been associated with declines in abundance of native benthic fishes in the Great Lakes, including historically abundant slimy sculpin (Cottus cognatus). We hypothesized that as round goby colonized deeper habitat, slimy sculpin avoided habitat

Per- and polyfluoroalkyl substances (PFAS) are a group of synthetic chemicals detected throughout the environment. To better understand the distribution of PFAS in an aquatic system (the Laurentian Great Lakes), stable isotope enrichment (δ13C and δ15N), fatty acid (FA) profiles, and PFAS were measured in various species from the Lake Ontario (LO) aquatic food web. Sampled organisms included top predator

Algal blooms in Lake Erie have worsened in recent decades and are driven by diffuse export of phosphorus (P) from a large stream network that drains predominately agricultural land. Given the diffuse nature of nonpoint source pollution, best management practices (BMPs) must target areas where P levels are high. This requires long-term watershed-wide monitoring programs that do not currently exist in

Fish population structure in previously glaciated regions is often influenced by natural colonization processes and human-mediated dispersal, including fish stocking. Endemic populations are of conservation interest because they may contain rare and unique genetic variation. While coregonines are native to certain Michigan inland lakes, some were stocked with fish from Great Lakes sources, calling

An enhanced understanding of nonpoint source (NPS) nutrient export to the lower Great Lakes is needed to inform land use and land management decisions within southern Ontario. However, this understanding is limited by a lack of long-term, temporally-intensive monitoring. To address this knowledge gap, we revisit six agriculturally-dominated subwatersheds in southern Ontario, which were intensively

Understanding dreissenid mussel population dynamics and their impacts on lake ecosystems requires quantifying individual growth across a range of habitats. Most dreissenid mussel growth rates have been estimated in nutrient rich or nearshore environments, but mussels have continued to expand into deep, cold, low-nutrient habitats of the Great Lakes. We measured annual quagga mussel (Dreissena rostriformis

Lake Ontario boasts a diverse fish community comprised of native and introduced species that support vibrant recreational, commercial and Indigenous fisheries. The effective delivery of a program to assess and control the sea lamprey (Petromyzon marinus) is crucial to achievement of Lake Ontario Fish Community Objectives of rehabilitating native fish stocks while protecting and maintaining the abundance

Sea lamprey control has been a dominant feature in the Great Lakes since the Great Lakes Fishery Commission (GLFC) formation in 1955. Review and recommendations on the sea lamprey control program are undertaken by a Sea Lamprey International Symposium (SLIS) held every twenty years beginning in 1979. In the forty-year history of the SLIS, this is the first paper on Indigenous perspectives in the published

This paper synthesizes information on the at-sea ecology of ten anadromous lampreys, with emphasis on trophic ecology. The at-sea ecology of these lampreys concerns the juvenile stage, in which growth is most rapid. Anadromous lampreys can be categorized into four groups, based on feeding modalities: 1) scavenger (Caspian lamprey, Caspiomyzon wagneri); 2) parasite-predator (Pacific lamprey, Entosphenus

The lampricides 3-trifluoromethyl-4-nitrophemol (TFM) and niclosamide have been used for over 60 years to control the invasive sea lamprey (Petromyzon marinus) population in the Laurentian Great Lakes. In this review, we summarize these findings in the context of the mode of action of both lampricides, with a focus on: (1) the physiology of uptake, bodily distribution and mode of action, detoxification

Coregonine fishes are important to Laurentian Great Lakes food webs and fisheries and are central to basin-wide conservation initiatives. In Lake Ontario, binational management objectives include conserving and restoring spawning stocks of cisco (Coregonus artedi) and lake whitefish (C. clupeaformis), but the spatial extent of contemporary coregonine spawning habitat and the environmental factors regulating

Delivery of a successful Sea Lamprey Control Program depends upon bi-national, government-funded operations and research and is contingent upon public understanding of the need for the Program and its ecosystem and economic benefits. Changing social, political, regulatory, and climatological environments present a host of strengths, weaknesses, opportunities, and threats requiring an array of responses

Lampreys are jawless fishes that evolved hundreds of millions of years ago and exhibit multiple and varied life history strategies. Rapid changes in the current climate are clear, and warming temperatures and changes in precipitation patterns over the past several decades are projected to continue into the foreseeable future. The effects of our changing climate may impact lamprey species worldwide

Mercury-contaminated fish are a serious problem in the Great Lakes basin, because mercury is a potent neurotoxin that poses a danger to both humans and wildlife. Lake Superior lake trout and walleye have the highest mercury concentrations of the five Great Lakes. Because the atmosphere is the major source of mercury to the Great Lakes, information on the over-water mercury concentration is essential

The Great Lakes are non-tidal, but experience significant water level fluctuations at hourly, seasonal, and decadal scales. A rise of 0.83 m was observed between 2013 and 2020 on Lake Erie with the annual water level near the previous record high of 174.89 m set in 1986. In response to elevated water levels, barrier beach-ridges located on the eastern shore of the Point Pelee foreland, in the Lake

Lake Michigan rose to record high water levels in the 2010s; during this time, some coastal sites experienced habitat loss rates an order of magnitude higher than during previous high water periods throughout the 20th century. The high magnitude and rapid rate of rise observed during the 2012–2020 period in combination with a slight increase in the percentage of storm waves likely accelerated habitat

We simulated bottom resuspension events in Lake Erie, using a coupled three-dimensional hydrodynamic and water quality model. Key parameters in the model, including critical bottom shear stress (τcr) and resuspension rate (α) were calibrated and validated by comparing the model output to observations. These included total suspended solid (TSS) concentrations in the bottom boundary layer (RMSE = 0.74

Eutrophication of Lake Victoria led to changes in its phytoplankton communities. However, different levels of eutrophication exist in the open lake and the bays, and between embayments. This study utilized spatial and temporal sampling of Napoleon Gulf and Murchison Bay, exhibiting different trophic conditions. Over one year, we investigated phytoplankton biomass, richness, diversity and dissimilarity

The amphipod Diporeia spp. has historically been an important component of the benthic food web of the Laurentian Great Lakes. The Great Lakes Water Quality Agreement included its population density as an indicator of ecological condition for Lake Superior, with target values of 220–320 m−2 in nearshore areas (≤100 m depth) and 30–160 m−2 in offshore areas (>100 m). To assess the status of Diporeia

The larval stage of invasive Dreissena spp. mussels (i.e., veligers) are understudied despite their seasonal numerical dominance among plankton. We report the spring and summer veliger densities and size structure across the main basin, North Channel, and Georgian Bay of Lake Huron, and seek to explain spatiotemporal variation. Monthly sampling was conducted at 9 transects and up to 3 sites per transect

Crayfish represent important links in aquatic food webs because they have diverse, omnivorous diets and are an important source of energy for fishes and birds. Crayfish have the ability to increase sediment transport through bioturbation, some are considered ecosystem engineers due to their burrowing habits, and crayfish invasions have been linked to large declines in biodiversity and changes in ecosystem

Alewife (Alosa pseudoharengus) are the preferred prey species of the top piscivore predators in the Lake Ontario food web and are an essential constituent in the bioaccumulation of persistent organic contaminants. Year-class samples collected in 2016 represent the alewife age ranges of 2015 (Age-01) sequentially dating back to 2008 (Age-08). The most abundant contaminant measured in Lake Ontario alewife

Cisco Coregonus artedi was once an important native fish in Lake Ontario; however, after multiple population crashes, the cisco stock has yet to recover to historic abundances. Rehabilitation of cisco in Lake Ontario is a fish community management objective, but the extent to which recent non-native species and pelagic food web changes have influenced cisco is not well understood. We described cisco

Ecosystem-based management relies on understanding how perturbations influence ecosystem structure and function (e.g., invasive species, exploitation, abiotic changes). However, data on unimpacted systems are scarce; therefore, we often rely on impacted systems to make inferences about ‘natural states.’ Among the Laurentian Great Lakes, Lake Superior provides a unique case study to address non-native

Invasive species can cause major disruptions in native food webs, yet the impact of species introductions and whether they will become invasive appears to be context-dependent. Rainbow smelt and alewife co-exist as invasive species in the Laurentian Great Lakes and as native species on the Atlantic coast of North America, but in Lake Champlain rainbow smelt is the dominant native forage fish and alewife

Rapids habitats are critical spawning and nursery grounds for multiple Laurentian Great Lakes fishes of ecological importance such as lake sturgeon, walleye, and salmonids. However, river modifications have destroyed important rapids habitat in connecting channels by modifying flow profiles and removing large quantities of cobble and gravel that are preferred spawning substrates of several fish species

The lampricide 3-trifluoromethyl-4-nitrophenol (TFM) has been used in liquid form to control larval sea lamprey (Petromyzon marinus) in Great Lakes tributaries since the late 1950s. In the 1980s a dissolvable TFM bar was developed as a supplemental tool for application to small tributaries as a deterrent to larvae seeking water not activated with TFM. The size, mass, and number of bars needed in some

We detail our attempts at empirical modeling of MODIS derived Chlorophyll a (Chl a) distribution on Lake Victoria in East Africa and consequently its trophic status. This was motivated by the need for Lake Victoria specific algorithms, as the current satellite based standard algorithms overestimate derived Chl a. In situ Chl a data was hence collected in three field campaigns in November 2014, March

The city of Puno in Peru is the largest producer of trout (Oncorhynchus mykiss) using intensive floating cage systems installed in Lake Titicaca. As a result, the increase in diseases and the use of antibiotics to control them during the production cycle has been documented. We study the impact of antibiotics on drinking water, trout tissues and the lake's aquatic ecosystem. Nine antibiotics were monitored:

A disconnect between scientific research and environmental management communities can be a detriment to both. In the case of Great Lakes coastal ecosystems, which are inherently complex and subject to uncertain effects of future climatic, environmental, and anthropogenic drivers, greater collaboration could be beneficial to their sustainability. We capture the challenges and opportunities identified

The Canada-U.S. State of the Strait Conference is a biennial forum with a 22-year history of assessing ecosystem status and providing advice to improve research, monitoring, and management of the Detroit River and western Lake Erie. The 2019 conference focused on assessing ecosystem health based on 61 indicators. Although there has been considerable improvement in the Detroit River since the 1960s

Lake sturgeon (Acipenser fulvescens) can migrate long distances to spawn, but many populations currently spawn in systems where the length of accessible riverine migratory habitat has been greatly reduced by dam construction. With the increased prevalence of shortened rivers, focusing on migratory dynamics in short rivers (<30 km) is beneficial to understanding the migratory needs of lake sturgeon

Three anadromous lamprey species support important commercial fisheries in the northern hemisphere, sea lamprey in the Iberian Peninsula and France, European river lamprey in the Baltic Sea countries and Russia, and Arctic lamprey in Russia. Pacific lamprey, Caspian lamprey, Korean lamprey and pouched lamprey are harvested for subsistence and local commerce on the Pacific coast of North America, and

Previous studies of the nutrient budgets of lakes in Precambrian Shield regions have generally ignored the role of groundwater as a source or sink (influx or efflux) of nutrients. This paper and its companion (Part 2) address this science gap by probing the role of groundwater in the nutrient balance for a restricted bay of a Precambrian Shield lake that has undergone extensive shoreline development

Lake Neusiedl, the largest steppe lake in Europe, is particularly sensitive to climate variations due to its extreme shallowness (zmax = 1.8 m) and low ratio of catchment to lake area (3.5 : 1). Changes in water budget, salinity and turbidity have key implications for the lake’s ecology and management. Here, we present a multi-proxy palaeolimnological reconstruction of the evolution of Lake Neusiedl

Fishes typically occupy a species-specific temperature range, with their occupied depth being related to the lake’s temperature profile. When a fish’s preferred temperature range coincides with the thermocline, the location of their preferred thermal habitat is influenced by the rise and fall of internal waves, leading to possible changes in fish depth. These internal waves are common in large, stratified

A basin-wide water quality survey for the radionuclide tritium during 2017 and 2019 provides an overview of levels in Great Lakes surface waters. All data, together with those from similar basin-wide surveys since the early 1990s, are included in the Supplemental Material. Values of tritium are lowest in Lake Superior and are highest within a region of northwestern Lake Ontario, as well as locally