Feasibility of implementing an integrated long-term database to advance ecosystem-based management in the Laurentian Great Lakes basin.

The North American Great Lakes have been experiencing dramatic change during the past half-century, highlighting the need for holistic, ecosystem-based approaches to management. To assess interest in ecosystem-based management (EBM), including the value of a comprehensive public database that could serve as a repository for the numerous physical, chemical, and biological monitoring Great Lakes datasets that exist, a two-day workshop was organized, which was attended by 40+ Great Lakes researchers, managers, and stakeholders. While we learned during the workshop that EBM is not an explicit mission of many of the participating research, monitoring, and management agencies, most have been conducting research or monitoring activities that can support EBM.

Realized thermal niche approach eliminates temperature bias in bioenergetic model estimates.

Bioenergetics models estimate ectotherm growth, production, and prey consumption - all key for effective ecosystem management during changing global temperatures. Based on species-specific allometric and thermodynamic relationships, these models typically use the species' lab-derived optimum temperatures (physiological optimum) as opposed to empirical field data (realized thermal niche) that reflect actual thermal experience. Yet, dynamic behavioral thermoregulation mediated by biotic and abiotic interactions may provide substantial divergence between physiological optimum and realized thermal niche temperatures to significantly bias model outcomes.

Host species and habitat shape fish-associated bacterial communities: phylosymbiosis between fish and their microbiome.

Background: While many studies have reported that the structure of the gut and skin microbiota is driven by both species-specific and habitat-specific factors, the relative importance of host-specific versus environmental factors in wild vertebrates remains poorly understood. The aim of this study was to determine the diversity and composition of fish skin, gut, and surrounding water bacterial communities (hereafter referred to as microbiota) and assess the extent to which host habitat and phylogeny predict microbiota similarity. Skin swabs and gut samples from 334 fish belonging to 17 species were sampled in three Laurentian Great Lakes (LGLs) habitats (Detroit River, Lake Erie, Lake Ontario).

Burkholderia spp.-based biopesticide controls wireworms (Coleoptera: Elateridae) in potatoes.

Wireworms (Coleoptera: Elateridae) are economically significant pests of potatoes (Solanum tuberosum), damaging the marketable portion of the crop by feeding and tunneling into tubers. While conventional potato growers use the few registered synthetic insecticides to control wireworms, certified organic growers are left with less options due to the limited effectiveness of the available insecticides. Biologically derived pesticides provide an additional alternative for both systems.

Watercraft decontamination practices to reduce the viability of aquatic invasive species implicated in overland transport.

Recreational boating activities enable aquatic invasive species (AIS) dispersal among disconnected lakes, as invertebrates and plants caught on or contained within watercraft and equipment used in invaded waterbodies can survive overland transport. Besides simple preventive measures such as "clean, drain, dry", resource management agencies recommend decontaminating watercraft and equipment using high water pressure, rinsing with hot water, or air-drying to inhibit this mode of secondary spread. There is a lack of studies assessing the efficacy of these methods under realistic conditions and their feasibility for recreational boaters.

Subsidy accessibility drives asymmetric food web responses.

Global change is fundamentally altering flows of natural and anthropogenic subsidies across space and time. After a pointed call for research on subsidies in the 1990s, an industry of empirical work has documented the ubiquitous role subsidies play in ecosystem structure, stability, and function. Here, we argue that physical constraints (e.

Evaluation of muscle lipid extraction and non-lethal fin tissue use for carbon, nitrogen, and sulfur isotope analyses in adult salmonids.

Rationale: Chemical lipid extraction or using alternative tissues such as fish fin as opposed to muscle may alter isotopic ratios and influence interpretations of δ C, δ N, and previously unassessed δ S values in stable isotope analyses (SIA). Our objectives were to determine if lipid extraction alters these isotope ratios in muscle, if lipid normalization models can be used for lipid-rich salmonids, and if fin isotope ratios are comparable with those of muscle in adult salmonids.

Methods: In six adult salmonid species (n = 106) collected from Lake Ontario, we compared three isotope ratios in lipid-extracted (LE) muscle with bulk muscle, and LE muscle with fin tissue, with paired t-tests and linear regressions.

Application of machine learning to identify predators of stocked fish in Lake Ontario: using acoustic telemetry predation tags to inform management.

Understanding predator-prey interactions and food web dynamics is important for ecosystem-based management in aquatic environments, as they experience increasing rates of human-induced changes, such as the addition and removal of fishes. To quantify the post-stocking survival and predation of a prey fish in Lake Ontario, 48 bloater Coregonus hoyi were tagged with acoustic telemetry predation tags and were tracked on an array of 105 acoustic receivers from November 2018 to June 2019. Putative predators of tagged bloater were identified by comparing movement patterns of six species of salmonids (i.

Long-term retention of acoustic telemetry transmitters in temperate predators revealed by predation tags implanted in wild prey fish.

Bloater Coregonus hoyi (n = 48) were implanted with V9DT-2x predation transmitters and monitored on 105 acoustic receivers in eastern Lake Ontario for >6 months. Twenty-three predation events were observed, with predator retention of tags ranging from ≤1 to ≥194 days and 30% of retentions lasting >150 days. Long tag retention times raise concerns for acoustic telemetry analysis and the health of piscivorous predators retaining tags.

Effects of intracoelomic transmitter implantation on metabolic rate, swimming performance, growth and survival in juveniles of two salmonids.

In this study, we investigated the effects of acoustic tag implantation on standard and routine metabolic rate (SMR and RMR, estimated via oxygen consumption), critical swimming speed (U ), survival and growth in juveniles of rainbow trout Oncorhynchus mykiss and lake trout Salvelinus namaycush. Tag burdens ranged from 1.8% to 7.

Benefits of Turbid River Plume Habitat for Lake Erie Yellow Perch (Perca flavescens) Recruitment Determined by Juvenile to Larval Genotype Assignment.

Nutrient-rich, turbid river plumes that are common to large lakes and coastal marine ecosystems have been hypothesized to benefit survival of fish during early life stages by increasing food availability and (or) reducing vulnerability to visual predators. However, evidence that river plumes truly benefit the recruitment process remains meager for both freshwater and marine fishes. Here, we use genotype assignment between juvenile and larval yellow perch (Perca flavescens) from western Lake Erie to estimate and compare recruitment to the age-0 juvenile stage for larvae residing inside the highly turbid, south-shore Maumee River plume versus those occupying the less turbid, more northerly Detroit River plume.

Novel molecular approach demonstrates that turbid river plumes reduce predation mortality on larval fish.

Turbidity associated with river plumes is known to affect the search ability of visual predators and thus can drive 'top-down' impacts on prey populations in complex ecosystems; however, traditional quantification of predator-prey relationships (i.e. stomach content analysis) often fails with larval fish due to rapid digestion rates.

Validation of rapid assimilation of PCBs following IP dosing in the round goby (Neogobius melanostomus).

The assimilation of polychlorinated biphenyls (PCBs) in round gobies (Neogobius melanostomus) after intraperitoneal (IP) injection was compared to PCBs bioaccumulated by the same fish through natural exposure ("native" PCBs). Lipid equivalent corrected dorsal muscle: whole body concentration ratios for native PCB 153 averaged 1.16 ± 0.

Seasonal variation in mercury and food web biomagnification in Lake Ontario, Canada.

Seasonal variation in mercury (Hg) concentrations and food web structure was assessed for eastern Lake Ontario. Hg concentrations, measured in 6 species of invertebrates and 8 species of fishes, tended to be highest in the spring and lowest in the summer for most biota. Yellow perch (Perca flavescens) exhibited significant ontogenetic shifts in diet and Hg, although such patterns were not evident for other species.

T-maze learning in weanling lambs.

A major advantage of sheep models in experimental studies of neurodevelopmental disorders (e.g., with prenatal neurotoxicant exposure) is that the equivalent of all three trimesters of human brain development occurs in sheep entirely in utero.

Resource switching in fish following a major food web disruption.

Dreissenid mussels (Dreissena polymorpha and D. bugensis) have re-engineered Great Lakes ecosystems since their introduction in the late 1980s. Dreissenids can have major indirect impacts on profundal habitats by redirecting nutrients and energy away from pelagic production (which supplies profundal production) and depositing nutrients and energy in the nearshore zones that they occupy.

Eyeblink classical conditioning in the preweanling lamb.

Classical conditioning of eyeblink responses has been one of the most important models for studying the neurobiology of learning, with many comparative, ontogenetic, and clinical applications. The current study reports the development of procedures to conduct eyeblink conditioning in preweanling lambs and demonstrates successful conditioning using these procedures. These methods will permit application of eyeblink conditioning procedures in the analysis of functional correlates of cerebellar damage in a sheep model of fetal alcohol spectrum disorders, which has significant advantages over more common laboratory rodent models.

Eyeblink classical conditioning and interpositus nucleus activity are disrupted in adult rats exposed to ethanol as neonates.

Neonatal exposure to ethanol in rats, during the period of brain development comparable to that of the human third trimester, produces significant, dose-dependent cell loss in the cerebellum and deficits in coordinated motor performance. These rats are also impaired in eyeblink conditioning as weanlings and as adults. The current study examined single-unit neural activity in the interpositus nucleus of the cerebellum in adults following neonatal binge ethanol exposure.

Selective and enduring deficits in spatial learning after limited neonatal binge alcohol exposure in male rats.

Background: In rats, heavy bingelike alcohol exposure during the neonatal brain growth spurt [postnatal days (PD) 4-9] can impair development of spatial learning. This study tested whether binge exposure limited to the latter half of this period (PD 7-9) produced selective spatial learning deficits that endured into adulthood.

Methods: On PD 7 to 9, Long-Evans rats were given intubations of alcohol (5.