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Avian research may require investigators to capture birds for many reasons, including to collect measurements and attach leg bands or transmitters. The effectiveness and efficiency of capture techniques varies by species, habitat, and time of year. Rails are particularly challenging to capture because of their secretive behavior and the dense vegetation they inhabit. As such, basic natural history questions for many rail species remain unanswered. We paired audio lures with modified noose carpets to capture and study 69 Yuma Ridgway's rails (Rallus obsoletus yumanensis) in the southwestern United States during 2016–2018. We compared results with other more commonly used capture methods, and our results show that noose carpets paired with audio lures can be an effective tool to capture rails, thereby facilitating studies of their ecology and life history. Noose carpets are easy to use, cheap to build and maintain, and effective over a wide range of conditions. This method could be used to capture rails other than the Yuma Ridgway's rail by adjusting the noose size, noose line weight, and audio lures to match the target species. Published 2020. This article is a U.S. Government work and is in the public domain in the USA. We used audio lures and modified noose carpets to efficiently capture Yuma Ridgway's rails, thereby facilitating studies of their ecology and life history. Noose carpets are easy to use, cheap to build and maintain, and effective over a wide range of conditions. This method could be modified easily to capture rails other than the Yuma Ridgway's rail by adjusting the noose size, fishing line weight, and audio lures to match the species of interest. [ABSTRACT FROM AUTHOR]

Trip limits are frequently used as a management measure to control or reduce harvest by restricting harvest to a maximum amount. The goal of trip limits is often to lengthen the fishing season relative to the annual catch limit by slowing the landings rate or incentivizing fishers to target another species. Two recent commercial trip limits implemented in the southeastern USA were examined to determine the accuracy of the predicted changes in harvest. For South Atlantic Snowy Grouper Hyporthodus niveatus, analysts accurately predicted the change in landings (weight) that could be expected per trip in response to a trip limit increase but did not account for an increased number of trips early in the fishing season. An increased number of trips resulted in higher landings causing Snowy Grouper to reach the quota and close earlier than desired. For Gulf of Mexico Gray Triggerfish Balistes capriscus, analysts underestimated the predicted change in landings per trip that could be realized from implementing a trip limit (numbers of fish). The Gray Triggerfish analysis failed to account for fishers retaining larger individual fish on average after the trip limit was implemented, resulting in higher landings than predicted. When examining per-fish trip limits, it is recommended that other potential changes in fishing behavior, such as changes in the mean weight of fish being retained or increased effort, be considered. The results of this study could be used to improve the effectiveness of trip limits as a management tool. [ABSTRACT FROM AUTHOR]

Five commercial diets and two formulated feeds were fed to initial-feeding Yellowstone cutthroat trout Oncorhynchus clarkii bouvieri fry and Snake River cutthroat trout O. clarkii spp. (currently being petitioned for classification as O. clarkii behnkei) fry for 18 weeks from June 16 to October 18, 2006, to evaluate fish performance. Eyed eggs from Yellowstone and Snake River cutthroat trout were received from the Yellowstone River State Fish Hatchery and Jackson National Fish Hatchery, respectively. Each diet was fed to four tanks of each subspecies of cutthroat trout (7 diets x 4 tanks/diet x 2 cutthroat trout subspecies = 56 tanks). Skretting Nutra-Plus provided optimal fish weight, total length, survival, and feed conversion for Yellowstone cutthroat trout. The weight and total length of Snake River cutthroat trout were also greatest when fish were fed Skretting Nutra-Plus. Skretting Nutra-Plus is no longer available, but Skretting/Bio-Oregon Bio-Vita is very similar; this feed and similar premium feeds from other manufacturers should be considered for future cutthroat trout propagation programs. [ABSTRACT FROM AUTHOR]

This article provides a quantitative review of the type, number, and estimated weight of the fish stocked by the 50 state agencies and the U.S. Fish and Wildlife Service in the United States in 2004. I examined trends in the light of data from earlier reports dating back to 1931. Among other things, this analysis shows that 1.7 billion fish were stocked by these agencies in 2004, representing 104 types of fish weighing an estimated 19.8 million kg. This was the largest number of types of fish (species, subspecies, and hybrids) and the largest total weight of fish ever stocked for those years for which information was available. Because many fish are being stocked at larger sizes, the total number of fish stocked in 2004 was in fact lower than in the first half of the twentieth century. Reflecting a long-term trend, most of the stocking was done by state agencies. The majority of the fish stocked (by estimated weight) were in western states and the most commonly stocked fish by this measure were coldwater sportfish, especially rainbow trout (Oncorhynchus mykiss). [ABSTRACT FROM AUTHOR]

Little information exists regarding the biological attributes and stock dynamics of flathead catfish Pylodictis olivaris in lotic systems throughout the northern United States. We examined the population abundance, annual survival, growth, condition, size structure, and age structure of flathead catfish in the lower St. Joseph River, Michigan, to direct future management efforts in this system and increase our knowledge of northern flathead catfish stocks. Fish were collected by means of electrofishing during June through September 2002 and 2003. Population abundance was estimated at 5,452 individuals (range, 3,985-7,277 fish), and annual survival was estimated at 67%. Analysis of pectoral spine cross sections revealed that growth was greatest for fish younger than age 6 (range, 83-98 mm/year) and decreased among older age-classes (range, 18-70 mm/year). Relative weight was greatest for individuals less than 300 mm total length (TL; 115%) and declined with increasing fish length. The size structure and age structure of flathead catfish were dominated by fish less than 400 mm TL and younger than age 4 (89% and 79%, respectively), although individuals greater than 1,100 mm TL and up to age 17 were present in the population. Relative stock density estimates indicated that 58% of fish greater than the minimum stock size were of quality length, while flathead catfish of preferred, memorable, and trophy sizes represented 28, 7, and 1% of fish collected, respectively. Despite their presence on the northern fringe of the species' geographic distribution, the flathead catfish in the lower St. Joseph River exhibited biological characteristics and stock dynamics that were similar to those reported for other lightly exploited stocks throughout the midwestern United States. [ABSTRACT FROM AUTHOR]

Wild harvests of yellow perch Perca flavescens have failed to keep up with the strong market demand for the fish. Moreover, yellow perch has many attributes that make it attractive for commercial aquaculture in the USA. One drawback to yellow perch culture in the north-central region of the United States is that low winter water temperatures inhibit somatic growth. In this study, yellow perch juveniles were stocked at three densities (30, 60, and 90 per tank) in 600-L tanks in Auburn, Alabama, in early January and maintained throughout the winter until mid-April. Water in the tanks was circulated through an earthen pond and returned to the research system by means of a water pump. Tanks were aerated by means of submersible air diffusers and a regenerative air blower. Fish were offered a commercial, slow-sinking feed at 5% of body weight, and temperature was measured hourly by a remote data logger. Survival was greater than 99% in all treatments. When water temperature was below 20°C, absolute growth was 0.06, 0.05, and 0.04 g/d for the low-, medium-, and high-stocking density treatments, respectively. When water temperature was above 20°C, absolute growth was 0.58, 0.48, and 0.46 g/d for the low-, medium-, and high-stocking density treatments, respectively. Yellow perch juveniles survived well and grew well in Alabama during fall and spring seasons when temperatures were above 20°C. [ABSTRACT FROM AUTHOR]

This study shows the effect of production variables on assimilation of foods by golden shiners, Notemigonus crysoleucas, in ponds was examined in concurrent 8-week feeding trials at the University of Arkansas at Pine Bluff (UAPB) and Texas A&M University (TAMU). Ten 0.04-ha ponds per site were fertilized with defatted rice bran and stocked with golden shiners (initial weight = 1.3 g) at a rate of 750,000/ha (UAPB) or 375,000/ha (TAMU). Fish in five ponds per site were fed a nutritionally complete prepared diet at 4% of body weight, while fish in the remaining ponds were not fed. As similation of natural foods by “unfed” fish was compared to that of fish fed the prepared diet at each site. Standard production data (weight gain, Secchi depth, dissolved oxygen [DO]) were compared to stable carbon isotope ratio (d13 C) data as an index of fish performance (weight change or fish d13C, resulting from assimilation of various food sources). Fish weight change and fish isotope ratio were regressed separately against independent variables (feed amount, Secchi depth, DO, fed/unfed dummy variable, and study site dummy variable) to determine their relation ships. Natural productivity was consistently lower at TAMU than at UAPB, while temperature and minimum DO were similar between sites. Weight gains of fed and unfed fish at TAMU were higher than those of fed and unfed fish at UAPB. The d13C of fed and unfed fish at UAPB changed little during the study and did not allow discrimination among their food sources. The d13 C of fed fish at TAMU ap proached that of the prepared diet, while that of unfed fish resembled that of the plankton and rice bran. Prepared diet quantity and the study site significantly (P < 0.1) affected fish weight change, but Secchi depth and minimum DO did not. Weight gain increased with increasing diet input up to a maximum value, then declined with additional inputs. Minimum DO, plankton isotope ratio, and the fed/unfed and site variables significantly affected fish isotope ratio. [ABSTRACT FROM PUBLISHER]

The article discusses the "Saw Kill Eel" project by Hudson River Estuary Program of New York State Department of Environmental Conservation and biology professors from Bard College in New York and Simon's Rock College in Massachusetts. The project aims to boost the number of American eels, one of North America's slipperiest and most imperiled fish. The team of researchers, educators, and students will be collecting the eels from Saw Kill creek in Bard campus by April to measure and tag them before releasing the fish upstream.