Geology topics

Katelyn M. Lawson

Publications and source records attributed to Katelyn M. Lawson.

6 recordsLinked to original sources

USGS2025

Behavioral responses of Silver Carp to underwater acoustic deterrent sounds

Objective Invasive carps continue to spread across the Mississippi River basin, posing significant ecological risk. Identifying technologies to slow their dispersal is critical. The use of sound has been proposed as a method to modify the behavior of Silver Carp Hypophthalmichthys molitrix , offering a nonstructural deterrent strategy. Methods Silver Carp implanted with acoustic transmitters were released into earthen ponds equipped with telemetry arrays. The fish were exposed to a 30-min playback of three underwater sounds (chirp saw, chirp square, and 100-hp boat motor). Movement trajectories were analyzed using a two-state hidden Markov model to estimate the effects of environmental and experimental variables on fish behavior. Results The results of the hidden Markov model supported two behavioral states. State 1 was characterized by longer step lengths (distance between positions) and greater directional persistence in turning angle (change in direction between two intervals), indicative of heighted activity. State 2 was defined by shorter step lengths and less directional persistence, suggesting reduced activity. Silver Carp that were exposed to the chirp square sound had an increased likelihood of entering state 1, whereas the 100-hp boat motor sound promoted transitions to state 2. Conclusions Underwater sounds distinctly influenced the movement of Silver Carp in earthen ponds. The chirp square sound elicited heightened activity levels, demonstrating potential for use in acoustic deterrent applications. However, the response of Silver Carp to these sounds may be influenced by the size of the study environment or the absence of natural drivers of fish behavior, such as food or reproduction. This study contributes to the development of nonstructural, species-specific deterrent systems by identifying sounds that influence the behavior of invasive carps. The application of sound-based methods may play a critical role in integrated pest management strategies for invasive carps, potentially limiting their spread while minimizing effects on native species.

Transactions of the American Fisheries Society↗

USGS2023

Cryptic tolerant fish species and their potential effect on index of biotic integrity (IBI) scores

Indices such as the Index of Biotic Integrity (IBI) are often used by management agencies to estimate the abstract property of stream health. These indices are usually predicated on the belief that certain fish species are tolerant to environmental perturbation while others are sensitive. Species are usually designated as either tolerant or sensitive in these analyses based on inherent ecological or taxonomic characteristics. However, previous literature has shown that certain species from ecological or taxonomic “sensitive” groups experience increased abundance in degraded streams. We term such species “cryptic tolerants”. Using a stream fish assemblage dataset of 433 unique sample locations across the state of Alabama and the National Landcover Dataset, our objectives were to 1) identify the most common cryptic tolerant species, 2) investigate how cryptic tolerant species might inflate indices of stream health, and 3) compare an alternative measure of stream health in which species are statistically defined rather than defined using the traditional trait-based approach. We identified cryptic tolerants using Nonmetric Multidimensional Scaling in six ecoregions. A series of regressions revealed that the proportion of cryptic tolerant species decreased in response to an increasing proportion of forested land in catchments while the proportion of true sensitives increased in all ecoregions except for the Cumberland Plateau. An index that simply used the percentage of statistically defined, non-tolerant species generally had lower p-values and higher r 2 values than IBI scores when both were regressed against percentage of forest in catchment. However, both indices had low degrees of correlation with expected disturbance, indicating a univariate index may be inadequate to characterize stream health. Our results highlight a potential issue with applying the IBI to diverse southeastern systems in the United States, which may be alleviated by designating species sensitivity based on empirical response to disturbance rather than taxonomic or ecological characteristics.

Alabama↗

USGS2022

Effects of shady environments on fish collective behavior

Despite significant efforts devoted to understanding the underlying complexity and emergence of collective movement in animal groups, the role of different external settings on this type of movement remains largely unexplored. Here, by combining time series analysis and complex network tools, we present an extensive investigation of the effects of shady environments on the behavior of a fish species (Silver Carp Hypophthalmichthys molitrix ) within earthen ponds. We find that shade encourages fish residence during daylight hours, but the degree of preference for shade varies substantially among trials and ponds. Silver Carp are much slower and exhibit lower persistence in their speeds when under shade than out of it during daytime and nighttime, with fish displaying the highest persistence degree and speeds at night. Furthermore, our research shows that shade affects fish schooling behavior by reducing their polarization, number of interactions among individuals, and the stability among local neighbors; however, fish keep a higher local degree of order when under shade compared to nighttime positions.

Scientific Reports↗

USGS2021

An assessment of fish herding techniques: Management implications for mass removal and control of silver carp

We assessed the effectiveness of herding techniques on adult Silver Carp Hypophthalmichthys molitrix in a tributary to the Missouri River. Sites (600 m) were contained using block nets and treated with one of five herding techniques: (1) a method commonly used by commercial fishers in the United States (commercial technique), (2) pulsed-DC electrofishing (electric technique), (3) broadband sound administered with underwater speakers (sound technique), (4) both sound and electric in combination (combination technique), and (5) solely the boat, with no added stimulus (control). Treatments were administered at sites with repeated 20-min runs (3×) in a slow, bank-to-bank pattern downstream through a 4.5-m opening between the block net and shoreline. Herding effectiveness was quantified by run category (cumulative for the second and third runs) using adaptive resolution imaging sonar. Mean herding effectiveness of the combination technique was three to four times greater than that of the other techniques regardless of the number of runs included. The effectiveness of the combination technique was significantly greater than the sound technique and control with inclusion of the second run and the commercial technique with inclusion of the third run. All herding techniques, excluding the combination technique, were statistically similar to the control. Inclusion of the second run was advantageous for all techniques, as herding effectiveness increased 54–103%, whereas inclusion of the third run was less beneficial (9–17% increase). Repeated runs allowed fish additional time to vacate the sample reach, but behavioral responses (i.e., acclimation or sensitization) were likely technique dependent. This study describes which techniques are most effective for herding Silver Carp and provides insight for improving mass removal efforts.

Missouri↗

USGS2021

Non-native poeciliids in hot water: The role of thermal springs in facilitating invasion of tropical species

Livebearers in the family Poeciliidae are some of the most widely introduced fishes. Native poeciliid translocations within the U.S. are mostly due to deliberate stocking for mosquito control. Introductions of exotic poeciliids, those not native to the U.S., are more likely to be due to release from aquaria or escape from farms. Many of these non-natives originate from warm climate regions, contrasting with the relatively cold climates in the U.S. Thus, thermal springs may increase the possible range of these species. Our primary objective was to examine the importance of climate and thermal springs in affecting the distribution of translocated and non-native poeciliids in the U.S. This objective was addressed using a national database of poeciliid introductions. Records were dominated by a handful of states and most introductions led to established populations. While translocated mosquitofish were found across many states and climates, non-natives were found almost exclusively in warm climate states and territories (e.g., Florida, Hawaii, Puerto Rico), especially where air temperatures remained above freezing. Outside warm climate states, 46% of established non-native populations were located at thermal spring sources. These results indicate that thermal springs extend the distribution of non-natives, but were relatively unimportant for translocated poeciliids.

Hydrobiologia↗

USGS2017

Distribution and status of five non-native fish species in the Tampa Bay drainage (USA), a hot spot for fish introductions

The Tampa Bay region of Florida (USA) is a hot spot for non-native freshwater fishes. However, published information on most non-native fishes in the basin is not current. Systematic sampling efforts targeting non-native fishes in the region were conducted from 2013–2015 by the University of Florida Tropical Aquaculture Laboratory. Data from these recent surveys were analyzed, along with historic and new data from published and unpublished sources, to assess current fish distributions and determine status. We focus on five of the non-native species sampled: pike killifish Belonesox belizanus Kner, 1860, green swordtail Xiphophorus hellerii Heckel, 1848, southern platyfish Xiphophorus maculatus (Günther, 1866), Mayan cichlid Mayaheros urophthalmus (Günther, 1862), and Jack Dempsey Rocio octofasciata (Regan, 1903). All five were found to have reproducing populations in the basin, each showing broader distributions than previously indicated. Non-native populations of four of the species have persisted in the Tampa Bay region since at least the 1990s. In contrast, the presence of Mayan cichlid in the basin was not confirmed until 2004. Based on numbers, distributions, and years of persistence, these five species all maintain established populations. Pike killifish and Mayan cichlid are established and spreading throughout multiple habitat types, while green swordtail, southern platyfish, and Jack Dempsey are localized and found primarily in more marginal habitats (e.g., small ditches and first order tributary streams). Factors affecting continued existence and distributions likely include aquaculture, biotic resistance, and thermal and salinity tolerances. We also clarify non-native species status determination using a multi-agency collaborative approach, and reconcile differences in terminology usage and interpretation.

Florida↗