Midwest Fish & Wildlife Conference 2019

AUTHORS: Cory Suski, University of Illinois; Kim Fredricks, Upper Midwest Environmental Sciences Center

ABSTRACT: Carbon dioxide is a commonly occurring, natural compound that is found in aquatic environments. Recently there has been an interest in using zones of elevated carbon dioxide to act as a movement deterrent for both invasive fishes and invertebrates. Despite the promise of this tool to aid in the control of aquatic nuisance species, there are a number of questions and concerns that arise with its use, particularly related to impacts on non-target organisms and the receiving environment. The current talk will provide an overview of carbon dioxide in aquatic environments, and show how carbon dioxide can impact both invertebrates and vertebrates, ranging from physiological disturbances to ion disequilibrium to behavioral changes. The impacts of elevated carbon dioxide on the receiving environment will be discussed, along with summary of factors influencing individual variation to high CO₂. Directions for future research and unanswered questions will also be outlined. Together, this presentation will provide an overview of how elevated carbon dioxide can impact aquatic ecosystems, and how it can function as a non-physical deterrent for aquatic invasive species.

AUTHORS: Aaron Cupp, U.S. Geological Survey; David Smith, U.S. Army Corps of Engineers; Cory Suski, University of Illinois; Kim Fredricks, U.S. Geological Survey

ABSTRACT: Carbon dioxide (CO₂) is being developed as a new fisheries control chemical. Several recent studies have demonstrated that fish consistently avoid areas of elevated CO₂ when given access to other freshwater sources. Results from these studies suggest that resource managers could apply CO₂ at pinch-point or other key management locations within rivers to block upstream migration of invasive fishes (e.g. Asian carps, sea lamprey, round goby). A full-scale demonstration of this deterrent technology is being planned for 2019 at a navigational lock to better determine the costs, effectiveness, safety and overall feasibility of CO₂ as a fish deterrent method. In addition to using CO₂ as a behavioral deterrent, other recent studies have also demonstrated that CO₂ is an effective non-selective piscicide (fish toxicant). Carbon dioxide injected under-ice using various delivery methods was effective at reducing the overwinter survival of several non-native cyprinids. Further development of CO₂ as a piscicide could give managers an inexpensive, safe, and effective method to control invasive fish populations. Results from previous studies using CO₂ as a behavioral deterrent and piscicide will be discussed with specific focus on upcoming field studies aimed at transitioning CO₂ into a useful management tool.

AUTHORS: David L. Smith, Aaron Cupp, Christa Woodley, Aaron Urbanczyk – U.S. Army Engineer R&D Center

ABSTRACT: In the United States the Asian carps threaten the Great Lakes via the Illinois Waterway.  The United States Army Corps of Engineers and partners are investigating the use of carbon dioxide   based deterrence barrier.  Carbon dioxide acts as an anesthetic that leads to immobilization and death in fishes.  We have been developing carbon dioxide response rules for Bighead carp  (Hypophthalmichthys nobilis) in a laboratory.  We are applying those rules in a hydrochemodynamic numerical model representing a carbon dioxide barrier at Brandon Road Lock and Dam, a component of the Illinois Waterway.  We explore fish response to the carbon dioxide barrier using a fish movement model.  In the model we implemented rules driven by variable water velocities and carbon dioxide concentrations and produced a movement track.  We measured fish numbers that that would 1) leave the barrier in the downstream direction, 2) become immobilized, and 3) successfully pass the barrier.   The results suggest that a carbon dioxide barrier is another fish deterrence technology that has applicability in the management of invasive species.  However, additional research and development is required to better understand fish response to carbon dioxide gradients and cost of deploying an operational barrier. 

AUTHORS: Brandon J. Wu, Rene C. Reyes, Christopher L. Hart – U.S. Bureau of Reclamation; Kevin K. Kumagai, HTI-VEMCO USA, Inc.; Scott A. Porter, Michael R. Trask – U.S. Bureau of Reclamation

ABSTRACT: As an integral part of the Central Valley Project, the U.S. Department of the Interior, Bureau of Reclamation (Reclamation), Tracy Fish Collection Facility (TFCF; Byron, California) functions to salvage fish from Sacramento-San Joaquin River Delta water exported south by the C.W. “Bill” Jones Pumping Plant.  Predation by resident piscivorous fish is a contributing factor to fish loss at the TFCF and Striped Bass (Morone saxatilis) are generally considered the most prevalent piscivorous fish species within the facility.  To improve fish salvage and meet requirements mandated by the most recent National Marine Fisheries Service Biological Opinion, Reclamation is investigating the use of carbon dioxide (CO₂) as an anesthetic to remove predatory fish from the TFCF system.  The treatment of various water conveyance channels and components of the TFCF with CO₂ has demonstrated that elevated CO₂concentrations (50–350 mg/L) increase the number and size of Striped Bass in collection tanks (salvaged), suggesting that this application is feasible and effective.  In addition, acoustically tagged Striped Bass appeared to exhibit an avoidance response to elevated CO₂ concentrations.  The removal of acoustically tagged and wild Striped Bass during CO₂ treatment allowed for calculation of removal efficiency as well as estimation of Striped Bass population within the TFCF system at the time of testing.  Efforts are currently underway to estimate optimal CO₂ concentration for removal of Striped Bass based on removal efficiency and 96-hour post treatment survival.  Preliminary results suggest that the optimal CO₂ concentration for Striped Bass removal is approximately 165 mg/L.  Future efforts will focus on increasing removal efficiency in TFCF collection tanks as well as developing methods to direct piscivorous fish out of the facility to a location where there is no impact on salvageable fish.

AUTHORS: Emily K. Tucker, Cory D. Suski – University of Illinois at Urbana-Champaign

ABSTRACT: Carbon dioxide (CO₂) has been proposed as a non-physical deterrent to prevent the movement of fishes in freshwater systems. Previous studies have shown that fish of different species tend to avoid CO₂ at 50,000-75,000 µatm, but there is also wide variation between individual fish in the amount of CO₂ required to elicit avoidance. In many of these previous studies, fish were tested for CO₂ avoidance individually. Many fish species, including bigheaded carp, are frequently found in groups, and it is not known if the response of groups of fish to CO₂ exposure is consistent with the response of individuals. Therefore, the purpose of our study was to define CO₂ avoidance in fish that are part of a social group relative to when tested individually. Bluegill were first tested individually in a "shuttle box" choice assay, to define their initial avoidance threshold. All bluegill were then assigned to groups for a social network assay to determine the social personality type of each fish. Finally, each social group was tested together in the shuttle box to define the CO₂ avoidance threshold of the group. Results indicate that fish in a social group that are exposed to CO₂ will shuttle at an average of 6 times lower partial pressures of CO₂ (pCO₂) than fish tested individually, and that fish in groups had significantly less individual variation in CO₂ avoidance thresholds than fish that were not in groups. However, social personality type was not associated with shuttling behavior. Our results indicate that individual variation in CO₂ avoidance is greatly reduced when fish are in social groups. This has important implications for the use of CO₂ in fisheries management, as less CO₂ might be needed to deter groups of fish relative to deterring individuals.

AUTHORS: Jim Stoeckel, Rebecca Tucker, Hisham Abdelrahman – Auburn University; Aaron Cupps, Ann Allert, Kim Fredricks – U.S. Geological Survey; Seth Herbst, Sara Thomas – Michigan Department of Natural Resources; Brian Roth, Michigan State University

ABSTRACT: Reduction of invasive crayfish is a major challenge facing natural resource managers.  We evaluated the ability of carbon dioxide to induce red swamp crayfish (Procambarus clarkii) to leave ponds, and the ability of terrestrial shelters to facilitate collection after emergence.  We placed 100 red swamp crayfish in ~14 x 14 m experimental ponds at Auburn University, Alabama.  Tanks equipped with regulators and diffusers were used to inject CO₂ into experimental ponds whereas control ponds received no CO₂.  Silt fencing was installed around ponds such that the bottom 2 feet was folded on the ground to serve as shelter, whereas the upper foot was installed vertically on fence posts to serve as a barrier.  Carbon dioxide was elevated to =200 mg/L in experimental ponds while pH was depressed to ~5.5.  Dissolved oxygen remained > 5 mg/L.  Greater than 50% of crayfish emerged within 6 hours.  Of these, 95% remained in sheltered areas underneath the folded fencing. They did not burrow under the fencing and were easily collected.  When a small inflow of non-carbonated fresh water was provided to a pond to simulate an underwater spring, crayfish sought shelter within this small inflow area.  Only 6% exited the pond even though CO₂ quickly reached = 200 mg/L in the surrounding waters.  Results thus far show that carbon dioxide can cause a large proportion of crayfish to emerge from ponds and seek terrestrial shelter within a short time.  Small inflows of non-carbonated water from inlets or springs can provide refuges that may severely limit emergence.  However, if these refuge areas can be identified, they may facilitate removal via trapping or seining.  Results from an invaded retention-pond trial in Michigan are currently being analyzed and will also be presented.

AUTHORS: Diane Waller, USGS Upper Midwest Environmental Sciences Center; Michelle Bartsch, Upper Midwest Environmental Sciences Center; Eric Lord, Upper Midwest Environmental Sciences Center.

ABSTRACT: Tools to control dreissenid mussel (Dreissena polymorpha and D. bugensis) populations currently rely heavily on chemical molluscicides that can be both costly and have the potential to be environmentally harmful if misused. Carbon dioxide may be a more cost-effective and environmentally neutral option for controlling dreissenid mussel populations. Past studies have demonstrated that carbon dioxide is lethal to several species of invasive molluscs, including zebra mussels, Asian clams (Corbicula fluminea), and New Zealand mud snails (Potamopyrgus antipodarum). We evaluated the effects of various treatment regimens [i.e., exposure duration and pCO₂(partial pressure of carbon dioxide)] on mortality, byssal thread formation and attachment, and narcotization behavior of adult zebra mussels. Percent mortality and time to death were determined at three temperatures across a range of pCO₂ levels (70,000 – 250,000 µm). Our results indicated that elevated PCO₂ exposure induced narcotization and reduced attachment of zebra mussels within 24 h. Time to death was inversely correlated with water temperature and pCO₂ and ranged from 3 – 13 d. The potential application of carbon dioxide into an integrated pest management program for dreissenid mussels will be discussed.

AUTHORS: Michelle Bartsch, Diane Waller – US Geological Survey, Upper Midwest Environmental Sciences Center

ABSTRACT: The potential use of carbon dioxide (CO₂) as a control tool for Asian carp and dreissenid mussels has prompted investigation into the effects of elevated pCO2, under different scenarios, on native unionid mussels. We measured the lethal and sublethal responses of juvenile fat mucket (Lampsilis siliquoidea) and the federally endangered Higgins’ eye (L. higginsii) mussels to elevated pCO₂ in acute (96 h) and chronic (28 d) exposures. The lethal and sublethal responses included: survival, growth, byssal thread formation, behavior, and gene expression. In acute exposures, juvenile mussel survival was 100% after exposure to concentrations of 178 to 457 mg/L CO₂. However, burial behavior and byssal thread formation were adversely affected during CO₂ exposure. Juvenile mussels recovered after a one-week post-exposure period as >40% of fat mucket reburied and >60% had produced new byssal threads. During chronic exposures to lower CO₂ concentrations (32 to 118 mg/L), significant mortality of juveniles occurred at =60 mg/L CO₂. Sublethal effects of carbon dioxide on growth were evidenced by reduced shell growth and body condition (dry tissue weight: shell length). Expression of chitin synthase, key for shell formation, was downregulated at 28 days of exposure. The results indicate that the response of freshwater mussels to elevated pCO2 will vary with exposure pattern. Acute exposure to even extremely high pCO2 appears to be less harmful to juvenile mussels compared to extended exposure to sublethal concentrations of CO₂.