Publications

Water nutrient management efforts are frequently coordinated across thousands of water bodies, leading to a need for spatially extensive information to facilitate decision making. Here we explore potential applications of a machine learning model of river low-flow total phosphorus (TP) concentrations to support landscape nutrient management. The model was trained, validated, and then...

Lake Ontario Lake Trout (Salvelinus namaycush) rehabilitation has been annually assessed with fishery independent surveys since 1983, in an effort to evaluate program benchmarks and compare observations with management objectives. These surveys provide information on the abundance, strain composition, and condition of the adult Lake Trout stock, as well as information on levels of...

Sea lamprey, a destructive invasive species in the Great Lakes in North America, is among very few fishes that rely on oral suction during migration and spawning. Recently, soft pressure sensors have been proposed to detect the attachment of sea lamprey as part of the monitoring and control effort. However, human decision is still required for the recognition of patterns in the measured...

Fall bottom trawl (fall BT) and lakewide acoustic (AC) surveys are conducted annually to generate indices of pelagic and benthic prey fish densities in Lake Michigan. The fall BT survey has been conducted each fall since 1973 using 12-m trawls at depths ranging from 9 to 110 m at fixed locations distributed across seven transects; this survey estimates densities of seven prey fish...

Understanding the timing and drivers of migration can be beneficial for improving response efforts aimed at reducing invasive species densities. Efforts by management agencies to remove grass carp (Ctenopharyngodon idella), an invasive species to the Laurentian Great Lakes, have been ongoing in Lake Erie tributaries since 2018. To bolster efforts, deployment of a non-physical barrier has...

In large lake systems the nearshore habitat is an intermediate zone between the shoreline and offshore, is an important nursery for larval fish, and is highlighted as an area in need of research in the Laurentian Great Lakes. In this study, we used two long-term monitoring programs to characterize the nearshore zooplankton community composition using seasonal data (May – October) and to...

River-to-lake transitional areas are biogeochemically active ecosystems that can alter the amount and composition of dissolved organic matter (DOM) as it moves through the aquatic continuum. However, few studies have directly measured carbon processing and assessed the carbon budget of freshwater rivermouths. We compiled measurements of dissolved organic carbon (DOC) and DOM in several...

Phragmites australis is a cosmopolitan grass species common in wetland ecosystems across the world. In much of North America, the non-native subspecies of Phragmites threatens wetland biodiversity, hinders recreation, and is a persistent problem for natural resource managers. In other parts of the world, populations are in decline, as Reed Die-Back Syndrome (RDBS) plagues some Phragmites...

In 2022, the Lake Superior fish community was sampled with daytime bottom and surface trawls at 71 nearshore locations in May-June and 35 offshore locations in July, and at 51 Coordinated Science and Monitoring Initiative (CSMI) locations in July-October with bottom trawls, surface trawls, mid-water trawls and acoustics that were previously sampled in 2011 and 2016. Nearshore bottom...

Seasonal hypolimnetic hypoxia has been documented in Lake Erie’s central basin since the 1950s. Ship-based surveys to monitor hypoxia have been conducted since the 1980s, but they occur at a relatively low frequency and focus on the deeper areas of the central basin. To better document the seasonal development of stratification and the consequent occurrence of hypoxia, we deployed eight...

Stocking of hatchery-reared fishes has been used with variable success as a management action to promote the recovery of populations and species. The practice has been controversial for several reasons, including uncertainty about whether the hatchery rearing experience may affect reproduction after release. Fine-scale acoustic telemetry was used during three spawning seasons to test...

Phragmites australis (common reed) has a cosmopolitan distribution and has been suggested as a model organism for the study of invasive plant species. In North America, the non-native subspecies (ssp. australis) is widely distributed across the contiguous 48 states in the United States and large parts of Canada. Even though millions of dollars are spent annually on Phragmites management