Technology advancements in fisheries science can provide useful tools to support natural resource management and conservation. However, new technologies may also present challenges for decision makers due to the lack of a standardized process to assess technologies for consideration within management plans. Future technology development in fishery and water resources could benefit from a framework that assigns an appropriate technology development stage and defines the readiness for implementation. Technology Readiness Levels (TRL) are one established research and development scale used throughout engineering and related disciplines that could be applied to natural resource management tools. The TRL assess the maturity of a technology from nascent idea through a fully developed technology. Steps within this scale could provide a general framework for researchers to follow when planning and conducting studies, while similarly providing a standard scale for resource managers to assess readiness for technology transfer and implementation. The goal of this paper is to describe TRL in the context of natural resource management tools and offer this existing framework as one option to facilitate communication between researchers and managers.

Blue sucker ( Cycleptus elongatus) occurs in the Mississippi River and Gulf of Mexico drainages of North America and is negatively affected by habitat fragmentation and flow regime alteration caused by dams. During fish assemblage surveys in August of 2022, we collected five specimens of juvenile blue sucker (312-428 mm total length) in the Angelina River upstream of Sam Rayburn Reservoir in east Texas (46,335-hectare surface area) where the occurrence of the species was previously unconfirmed. Given this unexpected finding, we (1) analyzed blue sucker mesohabitat associations to compare habitats we sampled with reports in the literature, and (2) reviewed blue sucker occurrence in state, national, and global databases across historical (1950-1980) and contemporary (1981-2022) periods to assess occurrence across gradients of habitat fragmentation and streamflow regulation. The blue sucker population in the Angelina River upstream of Sam Rayburn Reservoir was previously unconfirmed but is within the native range of the species. Mesohabitats occupied by blue sucker were consistent with literature reports, including fast velocity, shallow depth, and coarse substrates. The low degree of regulation (19% of natural runoff stored by upstream reservoirs) and a high degree of habitat connectivity (287 rkm of mainstem habitat) for the Angelina River upstream of Sam Rayburn Reservoir matched range-wide patterns of persistence within relatively intact (unfragmented and unregulated) or remnant (fragmented but unregulated) riverscapes. Our review reveals that blue sucker populations might persist (1) in remnant river fragments where local habitat templates are appropriate and (2) where effects of habitat fragmentation and flow regulation are not coupled.

Social interactions have important consequences for individual fitness. Collective actions, however, are notoriously context-dependent and identifying how animals rapidly weigh the actions of others despite environmental uncertainty remains a fundamental challenge in biology. By exposing zebrafish (Danio rerio) to virtual fish silhouettes in a maze we isolated how the relative strength of a visual feature guides individual directional decisions and, subsequently, tunes social influence. We varied the relative speed and coherency with which a portion of silhouettes adopted a direction (leader/distractor ratio) and established that solitary zebrafish display a robust optomotor response to follow leader silhouettes that moved much faster than their distractors, regardless of stimulus coherency. Although recruitment time decreased as a power law of zebrafish group size, individual decision times retained a speed-accuracy trade-off, suggesting a benefit to smaller group sizes in collective decision-making. Directional accuracy improved regardless of group size in the presence of the faster moving leader silhouettes, but without these stimuli zebrafish directional decisions followed a democratic majority rule. Our results show that a large difference in movement speeds can guide directional decisions within groups, thereby providing individuals with a rapid and adaptive means of evaluating social information in the face of uncertainty.

: The U.S. Army Corps of Engineers Engineer Research and Development Center (USACE-ERDC) Environmental Lab (EL) assisted USACE, Portland District (CENWP) in updating a CE-QUAL-W2 (W2) model of Lost Creek Lake based on a previous version of W2. The model was calibrated using data from calendar year (CY) 2001 validated with data from calendar years 2003 and 2010. One set of W2 parameters were successfully applied to all calendar year types (2001 is a dry year; 2003 is a normal year; and 2010 is a wet year). This model and the corresponding results from the study provided CENWP with more refined estimates of water temperatures so that more defendable water temperature targets can be discussed with the state of Oregon. This is extremely important because the Rogue and Applegate temperature Total Maximum Daily Loads and Rogue Spring Chinook Conservation Plan require the Corps to review the Rogue Basin Project operations to determine whether improvements can be achieved to downstream temperature for the benefit of endangered fish. In addition to modeling the basic calibration for three years, a modified version of W2 was used to create a predictive model to determine the best blending of the intake ports to meet the temperature targets.

A fish barrier using elevated aqueous carbon dioxide (CO2) concentrations is proposed for Brandon Road Lock and Dam to prevent the spread of Asian carp into the Great Lakes. However, a CO2 barrier has never been assessed for potential environmental impacts, human health and safety risks, or for mechanical or structural deterioration of the lock and dam. Environmental impacts of the barrier will be modest and are restricted to the barrier vicinity. Nonetheless, significant asphyxia threats (CO2 is denser than air) exist in closed spaces (e.g., barges, ship hulls, and the lock chamber when the miter gates are closed). Potential exists for drowning or vessel sinking because CO2 bubbles reduce water density and the buoyant forces needed to float a human body or vessel. The increased risk caused by the reduction in buoyancy cannot be estimated without first knowing the design and operation of the CO2 delivery system. Lastly, elevated aqueous CO2 concentrations will increase the concrete deterioration rate. However, little information exists that can be used to estimate the potential for structural or mechanical damage. Constructing an elevated CO2 barrier is feasible at the Brandon Roads Lock and Dam; however, this comes with potentially substantial risks to human health and safety, and project integrity. More detailed studies should be conducted after the design and operation of an elevated CO2 barrier are known. DISCLAIMER: The contents of this report are not to be used for advertising, publication, or promotional purposes. Citation of trade names does not constitute an official endorsement or approval of the use of such commercial products. All product names and trademarks cited are the property of their respective owners. The findings of this report are not to be construed as an official Department of the Army position unless so designated by other authorized documents. DESTROY THIS REPORT WHEN NO LONGER NEEDED. DO NOT RETURN IT TO THE ORIGINATOR.