June sucker (Chasmistes liorus), listed as S2 (imperiled) and N1 (critically imperiled) in Utah's 2015 Wildlife Action Plan, were recently downlisted from endangered to threatened (USFWS 2021), due largely to increased abundance of spawning adults, successful hatchery operations, and the completion of extensive habitat restoration efforts. However, despite the increased abundance of spawning adults, recruitment of wild individuals to the adult population remains exceedingly rare (Wolff et al. 2013; Clark Barkalow and Urioste 2022), as the recent increase in abundance is largely due to highly successful hatchery operations. Recent survival studies indicate extremely low survival of June sucker less than 200mm, with a rapid increase in survival as individuals grow from 200 to 300mm (Fonken et al. 2023), suggesting a predation bottleneck is limiting recruitment of wild individuals to the population. Fishes can avoid predation either by occupying complex habitats in which their probability of being detected and captured by predators is reduced, or by altering their behavior in the presence of predators to avoid detection. Ongoing restoration projects in spawning tributaries (i.e., Hobble Creek and the Provo River Delta) have targeted the restoration of vegetated refugia to improve juvenile June sucker survival. Many fishes across a diversity of classes and families produce alarm substances that, when detected in the water column, cause conspecifics to demonstrate a fright response by either seeking refuge habitats or reducing movement to avoid detection (reviewed by Brown 2003). The presence of alarm substance producing cells have been found in the epidermis of several species of Catostomids and other members of the Cypriniformes order (Pfeiffer 1977). As such, it is likely that June sucker, as members of the Catostomidae family, also produce and react to alarm substances to reduce susceptibility to predation. Copper pollution occurs widely across the globe, as copper is produced from many anthropogenic activities, including mining, brake pad wear, and different pesticides (Davis et al. 2001; McIntyre et al. 2012). While high concentrations of copper can be directly toxic to fishes and other taxa, even low concentrations of copper can have indirect toxic effects on fishes. Specifically, copper has been demonstrated to inhibit the ability of juvenile fish to detect the presence of their alarm substance in the water column, suggesting copper can increase the susceptibility of juvenile fishes to predation (McIntyre et al. 2012). Copper pollution may be of particular importance to June sucker in Utah Lake and its tributaries for two reasons. First, the watershed surrounding Utah Lake has experienced rapid human population growth, providing the conditions for increased copper runoff from roads in the surrounding watershed (Davis et al. 2001). Second, copper-sulfate (CuSO4) based products have recently been deployed to combat harmful algal blooms in marinas around Utah Lake. If either or both of these sources have elevated copper concentrations in the lake sufficiently to inhibit June sucker's ability to detect their alarm substance, copper pollution could be driving artificially elevated predation mortality on wild-hatched June sucker, thereby limiting recovery. References: Brown, G.E., 2003. Learning about danger: chemical alarm cues and local risk assessment in prey fishes. Fish and Fisheries, 4(3), pp.227-234. Clark Barkalow, S.L. and Urioste, A.D., 2022. Investigating origins of unmarked June sucker using elemental microchemistry. Report the the June Sucker Recovery Implementation Program. American Southwest Ichthyological Researchers, Albuquerque. Davis, A.P., Shokouhian, M. and Ni, S., 2001. Loading estimates of lead, copper, cadmium, and zinc in urban runoff from specific sources. Chemosphere, 44(5), pp.997-1009. Fonken, D.R., Conner, M.M., Walsworth, T.E. and Thompson, P.D., 2023. Benefits of stocking fewer but larger individuals with implications for native fish recovery. Canadian Journal of Fisheries and Aquatic Sciences, 80(3), pp.439-450. McIntyre, J.K., Baldwin, D.H., Beauchamp, D.A. and Scholz, N.L., 2012. Low level copper exposures increase visibility and vulnerability of juvenile coho salmon to cutthroat trout predators. Ecological Applications, 22(5), pp.1460-1471. Pfeiffer, W., 1977. The distribution of fright reaction and alarm substance cells in fishes. Copeia, pp.653-665. US Fish and Wildlife Service, 2021. Endangered and Threatened Wildlife and Plants; Reclassification of the Endangered June Sucker to Threatened with a Section 4(d) Rule, 86 FR 192, 192-212. Wolff, B.A., Johnson, B.M. and Landress, C.M., 2013. Classification of hatchery and wild fish using natural geochemical signatures in otoliths, fin rays, and scales of an endangered catostomid. Canadian Journal of Fisheries and Aquatic Sciences, 70(12), pp.1775-1784.

1.Characterize the copper concentrations in habitats of Utah Lake, the Provo River Delta, and Hobble Creek. 2.Examine the effect of dissolved copper on the behavioral response of juvenile June sucker to their predator alarm substance.

This project will take place at the Technical and Experimental Aquatics Laboratory (TEAL) located within the Millville Aquatic Research Facility (Utah State University, Millville Utah). The 60' x 30' facility features multiple recirculating, and flow through, aquaculture and treatment tanks. This is a dead-end facility; the effluent from treatment tanks undergoes mechanical filtration (<40 µm) and UV sterilization before release into a settling pond. TEAL has well-water that is conducive for June Sucker husbandry. Additionally, TEAL is within 10 miles of UDWR's Logan Fish Hatchery, which produces June Sucker for Utah Lake restocking programs. The proximity to UDWR personnel will help facilitate collaboration between entities and will reduce logistical restraints regarding the transfer of June Sucker to the research facility. Additionally, we will collect water samples from multiple locations around Utah Lake, including the Provo River Delta, Hobble Creek, Utah Lake State Park Marina, and open water outside of the state park marina. With the recent downlisting of June Sucker, responsible management agencies and stakeholders are working to identify the management actions necessary to achieve population status that would warrant delisting of the June sucker. As the recruitment bottleneck of young June suckers is a primary limitation on recovery, determining the role dissolved copper may be playing in predation mortality is critical.

This project supports the June Sucker Recovery Implementation Program by determining whether copper pollution from dispersed watershed sources or acute water quality treatment sources may be limiting June sucker survival and recruitment. Specifically, this study is directly related to recovery plan elements (USFWS 1999): 3.3 Protect June sucker from impacts of nonnative species 3.3.1 Determine measures and alternatives necessary to protect June sucker from nonnative impacts. 3.3.2 Minimize nonnative impacts 3.5 Improve water quality in Utah Lake. 3.5.1 Determine and reduce or eliminate specific impacts of water quality on June sucker in Utah Lake. 3.5.3 Monitor impacts of water quality changes on June sucker. Additionally, this project can inform conservation and recovery plans of other native Catostomids (e.g., green sucker Pantosteus virescens, bluehead sucker Catostomus discobolus) and Leuciscids (e.g., roundtail chub Gila robusta).

Not applicable

This project can inform water quality management efforts by determining whether copper toxicity is a concern to June sucker recovery. This can inform the timing and distribution of copper-sulfate based algaecide treatments, and whether additional stormwater runoff treatment needs to be considered in the Utah Lake watershed.

This project will be conducted in partnership with UDWR and the JSRIP, and fish collection will come from the Logan Fish Hatchery. Thus, collection permits are already in place as part of UDWR's Section 7 Consultation with the USFWS. We will follow International Animal Care and Use Committee (IACUC) guidelines, and will need to apply for an IACUC permit from Utah State University. This project will add no additional time or effort for UDWR personnel.

Environmental Concentrations of Copper: Three water samples will be collected three times from each of four sites around Utah Lake: Utah Lake State Park marina, Utah Lake (offshore from Skipper Bay), Provo River Delta, and Hobble Creek. We will collect samples at three time periods throughout the year to assess the temporal variation in Cu concentrations. Water samples will be analyzed by the University of Utah's ICP-MS Metals and Strontium Isotope Facility. Fish Behavior Experiments: Treatment Fish - Sixty June Sucker <200mm TL (preferably age-0) from the Logan Fish Hatchery, will be transported to the hatchery at the Technical and Experimental Aquatics Laboratory (TEAL) located in Millville, UT. Fish will be acclimated to hatchery well-water and 30 fish will be stocked into each of two 300 gallon holding tanks. One holding tank will be randomly designated as the control group and the other as the copper treatment group. Control Treatment - One fish will be transferred from the 300 gallon holding tank to one of two 40 gallon aquaria supplied with aeration and pea gravel substrate. Fish will be allowed to acclimate to treatment aquariums for a minimum of 11 minutes before the start of treatment to reduce any fright-bias (Bain et al. 1985; Nemec et al. 2021). After 11 minutes, 0.5 µg epidermal protein/L of aquarium water, acting as "alarm substance", will be introduced to each tank (Sandahl et al. 2007). A top-down positioned camera and a side-view camera will record fish behavior. We will measure the vertical and horizontal location of individuals in the tanks for the three minutes immediately before the addition of the alarm substance, for three minutes immediately following the addition of the alarm substance, and then for three minutes beginning ten minutes after the alarm substance is introduced. Frames taken every 3 seconds from the videos will be assessed for the fish's relative position within the tank as compared to the previous frame, allowing for the quantification of movement rates. After treatment, fish will be transferred to a separate, 300 gallon post-treatment holding tank. These methods will be repeated for the 29 remaining fish in the control group. Cu Treatment - Cu will be added to the two treatment tanks to create a concentration of 20 µg Cu/L (McIntyre 2010). One fish will be transferred to one of two 40 gallon aquaria supplied with aeration and pea gravel substrate and will be left to acclimate for 11 minutes to reduce fright-bias and receive exposure of Cu for the 10 minutes necessary to fully induce alarm substance sensory inhibition (Baldwin et al. 2003). The same treatment protocol and data recording will be conducted as listed in the Control treatment. Data Analysis: The data collection protocol outlined above will result in 60 location observations per time frame (before, immediately after, and ten minutes after introduction of the alarm substance) per individual. From these data, we will calculate the vertical position for each image, and the rate of movement between sequential images. We will compare the vertical position and movement rates among time frames and treatments using linear mixed effects models. Additionally, we will examine step-change analyses to characterize the strength of the behavioral response of individuals with differential copper exposures when presented with the alarm substance. References: Bain, M.B., Finn, J.T., and Booke, H.E., 1985. A quantitative method for sampling riverine microhabitats by electrofishing. North American Journal of Fisheries Management, 5(3b), pp. 489--493. Baldwin, D. H., Sandahl, J. F., Labenia, J. S., and Scholz, N. L., 2003. Sublethal effects of copper on coho salmon: impacts on nonoverlapping receptor pathways in the peripheral olfactory nervous system. Environmental Toxicology and Chemistry: An International Journal, 22(10), pp. 2266-2274. McIntyre, J. K., 2010. Linking sublethal copper neurotoxicity to population survival in coho salmon (Oncorhynchus kisutch). Dissertation. University of Washington. Nemec, Z.C., Lee, L.N., and Bonar, S.A., 2021. Development and evaluation of habitat suitability criteria for native fishes in three Arizona streams. North American Journal of Fisheries Management, 41(3), pp. 661--677. Sandahl, J. F., Baldwin, D. H., Jenkins, J. J., and Scholz, N. L., 2007. A sensory system at the interface between urban stormwater runoff and salmon survival. Environmental science & technology, 41(8) pp: 2998-3004.

We will assess the copper concentrations in open water and marina habitats in Utah Lake, as well as in stillwater habitats of the Provo River Delta and Hobble Creek three times during summer and fall of 2024 to assess background levels of copper experienced by June sucker in the environment.

June Sucker Recovery Implementation Program, Utah Division of Wildlife Resources, Timothy Walsworth- Assistant Professor USU Dept of Watershed Sciences

The results of this project will help inform the effect, if any, that copper concentrations have on June Sucker predator avoidance. This information can be used my managers to direct watershed restoration efforts and the potential need for stormwater mitigation.

Currently, intensive restoration efforts are being undertaken in Utah Lake to support the June Sucker population. However, identifying additional factors that might limit recruitment of young June suckers could enhance recovery efforts. Investigating spatial-temporal variations in Cu concentrations, and how it relates to June Sucker predator avoidance, will allow managers and stakeholders to determine any necessary steps in mitigating against these effects. These management actions could entail: stormwater treatment, buffer strip restoration, and algaecide treatment alternatives.