Browsing by Subject "silver carp"

Now showing 1 - 4 of 4
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    Acoustic and chemical conditioning and retention for behavioral deterrence in invasive bigheaded carps (Hypophthalmichthys molitrix and H. nobilis)
    (2023-05) Culotta, Jackie
    Invasive bigheaded carps (Hypophthalmichthys molitrix and H. nobilis) are two aquatic invasive species that are expanding their range throughout the Mississippi River Basin. These carp display negative phonotaxis to broadband sound and thus acoustic deterrents have shown promise for managing their populations. Numerous dams block direct upstream access for the carp; however, fish can bypass these physical obstructions by swimming though navigational locks. Nonphysical acoustic deterrents have the advantage of not effecting navigation, are relatively inexpensive, and could be tuned above the hearing range of non-ostariophysian fishes. Fish also react negatively to high levels of carbon dioxide, and it has been proposed to combine these two stimuli into one deterrent system to reduce potential habituation to long term acoustic playbacks and increase barrier efficacy. Here, the possible synergies of combining these two stimuli into integrated deterrent systems are evaluated.
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    Behavior and Bioacoustics of Invasive Silver and Bighead Carp
    (2016-05) Vetter, Brooke
    Invasive silver (Hypophthalmichthys molitrix) and bighead (H. nobilis) carp (collectively bigheaded carp) dominate the Mississippi River Drainage, outcompete native species, and continue to expand northward. Silver carp demonstrate an unusual jumping behavior to boat traffic. Understanding this response is important from a behavioral standpoint and critical to developing effective control methods. Experiments in outdoor concrete ponds (10 x 5 x 2 m), investigated the impact of pure tones (500 – 2000 Hz) and a recording from an outboard motor (0.06 – 10 kHz) on bigheaded carp swimming. Speakers broadcasting the sound stimuli were placed at either end of the concrete pond and bigheaded carp behavior was assessed using overhead cameras. Silver carp were consistently directed away (mean: 11.8 ± 1.3 consecutive responses) from the broadband sound (outboard motor recording) and the bighead carp were more responsive, exhibiting a median of 20.0 consecutive responses (1st Q: 12.0, 3rd Q: 23.0). However, both species were less reactive and habituated quickly to pure tones (after 1-2 trials). Field observations of silver carp jumping frequency, orientation, and direction in response to fast moving (16 – 40 km/hr) boats suggest that jumping is non-random, as the fish primarily move away from (79.8%) and behind the boat (> 90%), avoiding the area directly astern (< 4 m) in the most turbulent part of the wake. Finally, broadband sound (> 150 dB) stimulated wild silver carp to jump in a small tributary of the Illinois River. The fish demonstrated a different pattern than those reacting to the fast moving boats, with carp jumping all around the slow moving boat. This research suggests that sound can be used to alter the behavior of bigheaded carp with implications for deterrent barriers or other uses (e.g., herding fish to increase harvest).
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    An ensonified bubble curtain blocks 4 species of invasive carp in a laboratory flume but also deters other fish, while sound alone is less effective overall and does not target carp
    (2022-03-18) Feely, Jane; Sorensen, Peter; feely033@umn.edu; Feely, Jane; University of Minnesota - Minnesota Aquatic Invasive Species Research Center
    Four species of invasive carp from Asia are advancing up the Mississippi River through its locks and dams (LDs) and threatening to profoundly alter its ecosystems. It has been hypothesized that sensory stimuli could be projected into locks to block carp movement through LDs. Sound has garnered special attention because carp are members of Ostariophysi, a group of fish with an exceptional sense of hearing. Further, it has been found that a broadband cyclic sound is especially effective at blocking bighead and common carp and that when projected into an air curtain to create an ensonified bubble curtain (EBC), blockage rates for these species exceed 90%. However, whether an EBC might especially effective at blocking all carps, and what its effects might be on native non-ostariphysians and why, has not been addressed. To answer these questions, this study examined the responses of 10 fishes including 4 invasive carps (common, bighead, silver, grass), 2 native Ostariophysi (channel catfish, golden shiners), and 4 native non-ostariophysians (rainbow trout, largemouth bass, bluegill sunfish, lake sturgeon) in a darkened laboratory flume while either a cyclic sound was played on its own, or projected into an air curtain. The EBC blocked all 4 carps 92-97% of the time without habituation, but 5 native fish were also partially blocked. In contrast, sound alone only blocked 2 carps and affected the other fishes to varying extents. An EBC appears uniquely well-suited to blocking carp invasions if native fish movement is a secondary concern.
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    Hearing Thresholds and the Impact of Anthropogenic Noise in Four Invasive Fishes: Silver (Hypophthalmichthys molitrix), Bighead (H. nobilis), Black (Mylopharyngodon piceus), and Grass (Ctenopharyngodon idella) Carp
    (2018-10) Nissen, Andrew
    Due to extensive ecological impacts, aggressive range expansion, and their potential to enter the Laurentian Great Lakes, silver (Hypophthalmichthys molitrix) and bighead (H. nobilis) carp are primary targets for fisheries management. One promising measure to prevent their further dispersal is the use of acoustic deterrents because carp exhibit negative responses to sound. However, for an acoustic deterrent to be effective the sound level emitted needs to be above the hearing sensitivity for any target species, yet not too high to be detrimental to fish hearing. In this study, auditory evoked potentials (AEPs) were used to determine the impacts of exposure to high intensity sound on the hearing of silver and bighead carp. Auditory temporary threshold shifts (TTS) of up to 32 dB re 1 μPa SPLrms following sound exposure were observed between 0.2 – 2 kHz for both silver and bighead carp and sensitivity to some frequencies remained elevated up to 96-hrs following exposure. As there is often overlap of detectable frequency ranges among different species, there is the potential for acoustic deterrent signals to effectively target multiple fishes. Therefore, auditory thresholds were also determined for the invasive grass (Ctenopharyngodon idella) and black (Mylopharyngodon piceus) carp. Auditory thresholds were measured from 0.2 - 4 kHz with the greatest sensitivity between 0.3 - 0.4 kHz for both species. This study indicates that acoustic deterrents could impact carp hearing and that such deterrents may also be detectable by other invasive fishes in the area, such as grass and black carp. These findings will be used to increase the long-term efficacy of acoustic deterrents aimed at preventing the range expansion of invasive carps.