For more information on the USGS-the Federal source for science about the Earth, its natural and living resources, natural hazards, and the environment-visit http://www.usgs.gov/ or call 1-888-ASK-USGS.For an overview of USGS information products, including maps, imagery, and publications, visit http://www.usgs.gov/pubprod/.Any use of trade, firm, or product names is for descriptive purposes only and does not imply endorsement by the U.S. Government.Although this information product, for the most part, is in the public domain, it also may contain copyrighted materials as noted in the text. Permission to reproduce copyrighted items must be secured from the copyright owner. AbstractThe Comprehensive Sturgeon Research Project is a multiyear, multiagency collaborative research framework developed to provide information to support pallid sturgeon recovery and Missouri River management decisions. The project strategy integrates field and laboratory studies of sturgeon reproductive ecology, early life history, habitat requirements, and physiology. The project scope of work is developed annually with collaborating research partners and in cooperation with the U.S. Army Corps of Engineers, Missouri River Recovery Program-Integrated Science Program. The project research consists of several interdependent and complementary tasks that involve multiple disciplines.The project research tasks in the 2014 scope of work emphasized understanding of reproductive migrations and spawning of adult pallid sturgeon and hatch and drift of larvae. These tasks were addressed in three hydrologically and geomorphologically distinct parts of the Missouri River Basin: the Lower Missouri River downstream from Gavins Point Dam, the Upper Missouri River downstream from Fort Peck Dam and downstream reaches of the Milk River, and the Lower Yellowstone River. The project research is designed to inform management decisions related to channel re-engineering, flow modification, and pallid sturgeon population augmentation on the Missouri River and throughout the range of the species. Research and progress made through this project are reported to the U.S. Army Corps of Engineers annually. This annual report details the research effort and progress made by the Comprehensive Sturgeon Research Project during 2014.

Channel Catfish Ictalurus punctatus is an important species among anglers in North America. Channel Catfish management strategies vary greatly in the United States and Canada, and there are few examples of regulations aimed at improving size structure in the literature. The goal of this study was to model the response of Channel Catfish to changes in regulations that meet specific management objectives. We modeled a suite of regulations to determine if minimum length limits or a protected slot limit could be used to improve size structure or avoid growth overfishing of Channel Catfish in a large river. We modeled three minimum length limits (304, 356, and 406 mm) and a 356–456‐mm protected slot limit to assess the effectiveness of each at delaying or eliminating growth overfishing and increasing the number of quality‐sized fish in the Missouri River, Nebraska. Our models indicated a 406‐mm minimum length limit could be used to avoid growth overfishing until exploitation rates were greater than 45% and that both minimum length limits and slot limits could be used to increase the number of quality‐sized fish by up to 4 times the number under current regulations. Received April 6, 2015; accepted October 27, 2015

Diagram showing the Sturgeon Information Management System that accommodates and integrates multiple disparate data types by using a suite of software to accommodate various data formats and the demand for near real-time updates .

Floodplain connectivity has been identified as an important element of river ecosystem function for enhancing biological productivity, yet most of the world's large rivers have been managed to reduce river-floodplain connectivity to protect human interests. Flow events in the Missouri River basin during the summers of 2010 and 2011 offered a unique opportunity to investigate the influence of floodplain connectivity on fish communities. The floods created aquatic habitats not generally available on the main stem and the magnitude and duration of the 2011 event have not occurred since the main-stem dams were closed. Therefore, the objectives were to: (1) document species use on available floodplain habitats and assess age-0 fish presence, (2) compare spatial and temporal distribution of fish species, and (3) evaluate fish community responses at different discharges. Age-0 fish dominated the fish community during the 2010 and 2011 floods, representing 90% and 94% of all fish collected each year. Species composition during the 2011 flood was different above and below the Platte and Missouri rivers confluence (ANOSIM; r ¼ 0.211; p < 0.001) and between individual sites (r ¼ 0.667; p < 0.001) but did not change temporally (r ¼ 0.086; p ¼ 0.244).Comparison of the age-0 fish community response to varying water levels also differed (r ¼ 0.619; p ¼ 0.038) annually. The effects of this flood on the fish community of the Missouri River initially appear to have been beneficial for the native fish community; however, continued research and evaluation will verify the flood's effects.

Trotlines have historically been used by commercial fishers to target ictalurids and have recently been shown to be effective for collecting sturgeons Scaphirhynchus spp. However, little is known about the gear–fish interaction after trotlines are deployed. Therefore, the objectives of this study were to determine whether trotlines equipped with Lindgren‐Pitman (LP) hook timers could withstand harsh riverine conditions and whether catch rates, retention rates of hooked fish, capture times of targeted species, and bycatch would be affected. Our results showed no difference between standardized trotlines and trotlines with hook timers and indicated that 31% of pulled hook timers resulted in no fish being collected. Hook timers were activated by 69% of all the fish collected. The majority of fish collected were shovelnose sturgeon S. platorynchus (77%), of which 70% activated the timer. The fork length of the shovelnose sturgeon that did activate the timer (571.0 ± 60.1 mm [mean ± SE]) did not differ from that of fish that did not (542.4 mm). Overall, 43% of the hook timers were activated within the first 2 h of deployment and an additional 19% in the next 2‐h period; 54% of the fish were collected prior to sunset. Our study shows that hook timers can be a valuable tool that will aid in the interpretation of trotline catches. Received March 16, 2011; accepted June 14, 2011