Andrew K. Carlson

Otolith Microchemistry Reveals Natal Origins of Walleyes in Missouri River Reservoirs

AbstractReproductive habitats are vital for sustaining fish populations, but their location and relative natal contributions are often unknown or poorly understood. We used otolith microchemistry to examine natal origins of Walleyes Sander vitreus in Missouri River reservoirs (i.e., Lake Oahe, Lake Sharpe, Lake Francis Case, and Lewis and Clark Lake) in North Dakota and South Dakota. Water Sr:Ca and Ba:Ca were spatially heterogeneous and temporally consistent in all impoundments. Otolith Sr:Ca and Ba:Ca from age-0 Walleyes permitted the reclassification of fish to known natal habitats (i.e., tributary, embayment, main stem) and individual sites with 87% and 75% accuracy, respectively. Natal contributions were highest in tributaries, particularly those in Lake Oahe, where 32% of all adults and 77% of Lake Oahe adults hatched. Embayments and main-stem environments had high natal contributions (67–78%) in Lakes Sharpe and Francis Case and Lewis and Clark Lake, where tributaries are less abundant. Our researc...

Aquapod: Prototype design of an amphibious tumbling robot

As mobile robots decrease in size so does their ability to traverse rough terrain. New forms of locomotion beyond the basic wheel are being explored to overcome this fault. This paper expands on the mechanical design of a previous robot with a high mobility-to-size ratio. To accomplish high mobility the robot uses tumbling as its form of locomotion. By actively involving the body of the robot in the locomotion it can scale larger obstacles and will not get stuck in compliant terrain like similar sized wheeled robots. To accommodate real-world environments the new design has been waterproofed and moreover can be completely submerged in water to operate on a lake or stream floor. Additionally, this robot is equipped with a buoyancy control unit which will allow the robot to either sink or float in water, offering many unique applications in environmental monitoring and surveillance. This paper describes a first generation, radio controlled prototype of the design.

Synthesis of Ecology and Human Dimensions for Predictive Management of Bighead and Silver Carp in the United States

Prolific non-native organisms pose serious threats to ecosystems and economies worldwide. Nonnative bighead carp (Hypophthalmichthys nobilis) and silver carp (H. molitrix), collectively referred to as Asian carps, continue to colonize aquatic ecosystems throughout the central United States. These species are r-selected, exhibiting iteroparous spawning, rapid growth, broad environmental tolerance, high density, and long-distance movement. Hydrological, thermal, and physicochemical conditions are favorable for establishment beyond the current range, rendering containment and control imperative. Ecological approaches to confine Asian carp populations and prevent colonization characterize contemporary management in the United States. Foraging and reproduction of Asian carps govern habitat selection and movement, providing valuable insight for predictive control. Current management approaches are progressive and often anticipatory but deficient in human dimensions. We define predictive management of Asian carps as synthesis of ecology and human dimensions at regional and local scales to develop strategies for containment and control. We illustrate predictive management in the Upper Mississippi River System and suggest resource managers integrate predictive models, containment paradigms, and human dimensions to design effective, socially acceptable management strategies. Through continued research, university-agency collaboration, and public engagement, predictive management of Asian carps is an auspicious paradigm for preventing and alleviating consequences of colonization in the United States.

Chemistry to conservation: using otoliths to advance recreational and commercial fisheries management

Otolith chemistry is an effective technique for evaluating fish environmental history, but its utility in fisheries management has not been comprehensively examined. Thus, a review of otolith chemistry with emphasis on management applicability is presented. More than 1500 otolith chemistry manuscripts published from 1967 to 2015 are reviewed and descriptive case studies are used to illustrate the utility of otolith chemistry as a fisheries management tool. Otolith chemistry publications span a wide variety of topics (e.g. natal origins, habitat use, movement, stock discrimination and statistical theory) and species in freshwater and marine systems. Despite the broad distribution of manuscripts in a variety of fisheries, environmental and ecological journals, the majority of publications (83%, n = 1264) do not describe implications or applications of otolith chemistry for fisheries management. This information gap is addressed through case studies that illustrate management applications of otolith chemistry. Case studies cover numerous topics (e.g. natal origins, population connectivity, stock enhancement, transgenerational marking, pollution exposure history and invasive species management) in freshwater and marine systems using sport fishes, invasive fishes, endangered fishes and species of commercial and aquaculture importance. Otolith chemistry has diverse implications and applications for fisheries management worldwide. Collaboration among fisheries professionals from academia, government agencies and non-governmental organizations will help bridge the research-management divide and establish otolith chemistry as a fisheries management tool.

Otoliths as elemental tracers of walleye environmental history: insights for interjurisdictional fisheries management

ABSTRACT Carlson AK, Bailey PE, Fincel MJ, Graeb BDS. Otoliths as elemental tracers of walleye environmental history: insights for interjurisdictional fisheries management. Lake Reserve Manage. 32:329–340. Understanding fish natal origins and movement is important for managing interjurisdictional fisheries. We used otolith microchemistry to assess walleye (Sander vitreus) provenance, movement, and natal homing in Lake Oahe, an interjurisdictional reservoir fishery in North Dakota and South Dakota. Historical (1983–1989) water chemistry varied among 6 tributaries for strontium:calcium (Sr:Ca; μmol/mol) and barium:calcium (Ba:Ca) and between 2 main-stem sites for Ba:Ca. Current (2012) water chemistry was spatially heterogeneous for Sr:Ca and Ba:Ca. Both ratios were consistent between the historical and current periods in tributaries and main-stem sites. Sr:Ca and Ba:Ca of age-0 walleye otolith cores varied in proportion to water chemistry, resulting in high reclassification accuracies to habitat types (87%) and individual sites (78%). For adult walleye, contributions of South Dakota natal sites to the North Dakota population (48%, n = 30) and North Dakota natal sites to the South Dakota population (48%, n = 29) were highest for tributaries and embayments (e.g., Moreau and Cannonball rivers, Beaver Bay). Annual downstream movement was more prevalent than upstream movement, particularly during a flood in 2011. An average of 36% of North Dakota walleye and 33% of South Dakota walleye exhibited natal homing each year from 2009 to 2013. Otolith element:Ca ratios are effective natural tracers for evaluating walleye natal origins, movement within and between states, and natal homing. Otolith microchemistry is a tool for interjurisdictional walleye management in reservoirs, providing a methodology for assessing natal origins and movement and designing spatially informed habitat conservation programs and harvest regulations.

Effects of historic flooding on fishes and aquatic habitats in a Missouri River delta

Understanding the effects of disturbances on aquatic biota is important for management of the worlds rivers. Riverine deltas are among the most biologically productive ecosystems, yet the ecological effects of floods in deltas are poorly understood. Therefore, the goal of this study was to examine impacts of an historic flood in the Missouri River basin in 2011 on fishes and aquatic habitats in the Lewis and Clark Delta, located in South Dakota and Nebraska, USA. Fish community structural indices declined in the six years preceding the flood, with species richness and diversity (Fishers α) decreasing from 25 to 22 and 4.56 to 3.48, respectively. However, the fish community exhibited short-term resistance to the flood as both metrics were similar to pre-flood levels after the disturbance in 2012. Evenness (J′) declined from 0.88 to 0.73 before the flood but increased to 0.84 after the disturbance. The majority of species exhibited greater relative abundance after the flood regardless of age class (i.e., juvenile, adult), morphology (i.e., small-bodied, large-bodied), introduction history (i.e., introduced, native), or recreational importance (i.e., sport fish, non-recreational). However, the flood reduced relative abundance of juvenile freshwater drum (Aplodinotus grunniens) and white crappie (Pomoxis annularis) and did not affect the three small-bodied species that were studied, including emerald shiner (Notropis atherinoides), red shiner (Cyprinella lutrensis), and spotfin shiner (Cyprinella spiloptera). The flood decreased side channel and backwater frequency and width/area but increased sandbar abundance. Physical alterations evidently had minimal effects on structural indices of the fish community. However, an overall increase in relative abundance across species suggests that interspersed fluvial and slackwater habitats in the delta provided refuge from floodwaters during the disturbance. Maintaining habitat connectivity in deltas during and after floods is particularly important for fisheries conservation. Illustrating the ecological effects and implications of a major flood, this study contributes to the nascent field of delta ecology.

Brown trout growth in Minnesota streams as related to landscape and local factors

ABSTRACT Brown trout (Salmo trutta) are ecologically and socioeconomically important throughout the world. As such, understanding population dynamics is critical for brown trout management. Brown trout support a valuable recreational fishery in the Driftless Ecoregion of southeast Minnesota, where growth (i.e. mean back-calculated length-at-age) varies among streams but the relative effects of landscape (i.e. watershed level) and local (i.e. reach-level) factors on growth are unclear. Thus, the objective of this study was to evaluate effects of drainage area on individual brown trout growth relative to the effects of local factors (i.e. thermal regime, riparian land cover, relative abundance) to provide managers with strategies for increasing growth and the abundance of large individuals in southeast Minnesota streams. Linear mixed-effects models with combinations of these factors were compared using information-theoretic model selection and multimodel inference. Age, which explained 63% of variation in growth, differed among streams for age-1 and age-2, but not age-3 brown trout. Model averaging indicated growth of age-1 and age-2 individuals increased primarily with drainage area and secondarily with forested riparian area. Brown trout relative abundance did not affect growth, so it is realistic for managers to sustain high-quality, high-quantity brown trout populations. Overall, this synthetic landscape and local study advances brown trout management by illustrating that systems with large watersheds and forested riparian zones are suitable for management strategies (e.g. harvest regulations, habitat restoration) to increase growth and the abundance of large brown trout in socioeconomically valuable southeast Minnesota streams.

Aquapod: A small amphibious robot with sampling capabilities

Mobile robots are often proposed as a favorable substitute to human correspondence in emergency response, disaster relief, and environmental monitoring scenarios. In this work, the next iteration of the Aquapod is proposed as a method to facilitate collection of subsurface liquid samples in order to assess toxicity levels in a body of water. This amphibious small form-factor robot is equipped with a buoyancy control unit, detachable fluidic sampling unit, and a wide range of sensing and processing capabilities. The robot was designed to move and collect water samples to a maximum depth of ten meters. Its unique form of tumbling locomotion results in a versatile platform that can be used in both terrestrial and aquatic environments leveraging its high mobility-to-size ratio.

Peruvian anchoveta as a telecoupled fisheries system

Fisheries are coupled human and natural systems (CHANS) across distant places, yet fisheries research has generally focused on better understanding either fisheries ecology or human dimensions in a specific place, rather than their interactions over distances. As economic and ideational globalization accelerate, fisheries are becoming more globally connected via movements of fish products and fisheries finances, information, and stakeholders throughout the world. As such, there is a pressing need for systematic approaches to assess these linkages among global fisheries, their effects on ecosystems and food security, and their implications for fisheries science and sustainability. Use of the telecoupling framework is a novel and insightful method to systematically evaluate socioeconomic and environmental interactions among CHANS. We apply the telecoupling framework to the Peruvian anchoveta (Engraulis ringens) fishery, the world’s largest single-species commercial fishery and a complex CHANS. The anchoveta fishery has diverse and significant telecouplings, socioeconomic and environmental interactions over distances, with the rest of the world, including fishmeal and fish oil trade, monetary flow, knowledge transfer, and movement of people. The use of the telecoupling framework reveals complex fishery dynamics such as feedbacks (e.g., profit maximization causing fishery overcapitalization) and surprises (e.g., stock collapse) resulting from local and long-distance ecological and socioeconomic interactions. The Peruvian anchoveta fishery illustrates how the telecoupling framework can be used to systematically assess the magnitude and diversity of local and distant fisheries interactions and thereby advance knowledge derived from traditional monothematic research approaches. Insights from the telecoupling framework provide a foundation from which to develop sustainable fisheries policy and management strategies across local, national, and international levels in a globalized world.

Trophy Northern Pike: The Value of Experimentation and Public Engagement

ABSTRACT Northern pike (Esox lucius) are ecologically and socioeconomically important throughout Canada and the northern United States. In Minnesota, USA, large northern pike were historically abundant, but size-selective harvest and poor growth (i.e., stunting), in combination with thermal warming and prey resource limitation, have hindered development of fisheries with trophy individuals (≥ 43 inches) in recent decades. Despite strong interest of fisheries managers and public stakeholders in trophy management, historical approaches to improve population size structure (e.g., stocking, removal of small individuals, minimum length limits, liberalized creel limits) were largely unsuccessful. Currently, more than 100 Minnesota water bodies are managed under a series of special and experimental regulations (e.g., protected slot limits, minimum length limits, maximum length limits) intended to enhance size structure and promote trophy angling. These regulations have improved size structure in some lakes, yet trophy management can be improved by diversifying harvest regulations and enhancing public engagement strategies. It is particularly important to minimize or eliminate harvest of trophy individuals; protect and restore critical habitats; maintain high-energy prey resources; limit density of small individuals; experimentally evaluate regulation effects; and actively engage the public in the management process. Overall, fisheries managers can sustain trophy fisheries for present and future generations by solidifying the nexus among northern pike research, management, and human dimensions.