Patrick M Kocovsky (Former Employee)

A comprehensive understanding of fish populations and their interactions is the cornerstone of modern fishery management and the basis for Fish Community Goals and Objectives for Lake Erie (Ryan et al. 2003). This report is responsive to U.S. Geological Survey (USGS) obligations via Memorandum of Understanding (MOU) with the Great Lakes Council of Lake Committees (CLC) to provide...

Decisions about invasive species control and eradication can be difficult because of uncertainty in population demographics, movement ecology, and effectiveness of potential response actions. These decisions often include multiple stakeholders and management entities with potentially different objectives, management priorities, and jurisdictional authority. We provide a case study of...

In 2000, the Governing Board of the American Fisheries Society (AFS) approved the first Guidelines for Authorship (GFA) in AFS publications, developed by the AFS Publications Overview Committee (POC) chaired by Mary Fabrizio. This version of the GFA document provided guidance for fisheries science publications for nearly two decades. The 2015 AFS President Donna Parish charged the POC to...

Grass Carp (Ctenopharyngodon idella) are a non-native species to North America that were first introduced for vegetation control in the 1960s. However, wild-reproducing Grass Carp can negatively impact aquatic habitats and aquatic communities by consuming substantial amounts of aquatic vegetation and increasing turbidity. Numerous fisheries techniques have been used in an attempt to...

This report presents biomass-based summaries of fish communities in western Lake Erie derived from USGS bottom trawl surveys from 2013 to 2017 during June and September. The survey design provided temporal and spatial coverage that does not exist in the interagency trawl database, and thus complemented the August Ohio-Ontario effort to reinforce stock assessments with more robust data...

Natural resource managers and ecologists often desire an understanding of spatial dynamics such as migration, dispersion, and meta-population dynamics. Network-node models can capture these salient features. Additionally, the state-variable used with many species may be appropriately modeled as a continuous variable (e.g., length) and management activities sometimes can only target...

Management of invasive species, whether prevention, population reduction, or eradication, requires assessment of the invasive species’ population status and an assessment of the probability of success of management options. Perceptions of a species’ permanence in an environment or lack thereof frequently drives how limited time, financial, and personnel resources are allocated to such...

Bighead Carp Hypophthalmichthys nobilis, Black Carp Mylopharyngodon piceus, Grass Carp Ctenopharyngodon idella, and Silver Carp H. molitrix are considered invasive species in North America and Europe. In North America, they are typically referred to collectively as “Asian carp”, a reference to their native range. The category “Asian carp” fails to acknowledge the cultural value and the...

Identifying spawning and hatching locations is vital to controlling invasive fish and conserving imperiled fish, which can be difficult for pelagically-spawning species with semi-buoyant eggs. In freshwater systems, this reproductive strategy is common among cyprinid species, such as Chinese carp species currently threatening the Great Lakes. Following the confirmation that one of these...

Silver chub (Macrhybopsis storeriana, Kirtland, 1844) is a native Cyprinid in Lake Erie, one of the Laurentian Great Lakes of North America. It is listed as endangered by the US state of New York and Canada, which has a recovery plan, and as special concern by the state of Michigan. Silver chub faces a potential threat to recovery from control efforts for invasive Grass carp...

Submerged aquatic vegetation (SAV) in clearwater systems simultaneously provides habitat for invertebrate prey and acts as refugia for small fishes. Many fishes in Lake Erie rely on shallow, heavily vegetated bays as spawning grounds and the loss or absence of which is known to reduce recruitment in other systems. The Maumee River and Maumee Bay, which once had abundant macrophyte beds...

Population availability and vessel avoidance effects on hydroacoustic abundance estimates may be scale dependent; therefore, it is important to evaluate these biases across systems. We performed an inter-ship comparison survey to determine the effect of vessel size, day-night period, depth, and environmental gradients on walleye (Sander vitreus) density estimates in Lake Erie, an...