Reservoirs are mostly managed at local scales as spatially independent units. A basin‐scale perspective may increase awareness at a broader scope and generate insight not evident at local scales. We examined the array of reservoir attributes and fisheries in the Mississippi Basin to identify management opportunities. The basin is the third largest in the world and includes over 1,700 reservoirs >100 ha, the most of any river basin. Our bird's‐eye view shows a piecemeal approach where reservoirs are mostly administered at the local level. Basin‐wide or catchment coordination to holistically address problems that recur across the basin is mostly lacking. A basin‐wide coordination arrangement could facilitate various facets of reservoir management. We reviewed governance arrangements in major river basins across the globe and concluded that the basin‐wide administrative layer we encourage for the Mississippi Basin may already exist in some basins but may not be directly applicable everywhere.

Chase boats are used to assist in the capture of Blue Catfish Ictalurus furcatus because they often surface relatively far from the electrofishing boat (electrofisher) when incapacitated by low‐frequency, pulsed DC. We conducted this study to determine how chase boat use affects size‐related and capture efficiency metrics of Blue Catfish, and we concurrently examined possible confounding effects of sample duration and velocity on these metrics. We used DC at 15 pulses/s in 5‐ or 10‐min runs during four trials that were stratified by reservoir zone, season, and macrohabitat over a 2‐year period in Pool 10 of the Arkansas River (Lake Dardanelle, Arkansas). We captured 4,330 fish in 96 samples and analyzed the catch data by size‐group (all fish; >199, >299, and >509 mm). We compared samples of fish captured by an electrofisher alone with those collected by the electrofisher in combination with a chase boat (chase+). The electrofisher‐only protocol captured a greater proportion of fish less than 300 mm compared to the chase+ protocol, but length‐frequency distributions of larger‐size fish did not differ. Overall catch was greater for the chase+ protocol, with the difference generally increasing by size‐group except for the largest fish. Catch efficiency was greater for 5‐ versus 10‐min samples for both protocols, with the relative difference increasing as fish size increased. Calculated values of the proportional size distribution of quality‐size fish were sufficiently similar among all combinations of protocol and duration for management purposes. The practical implication is that an electrofisher‐only protocol can be used to collect representative samples of Blue Catfish, but the use of a chase boat increases the average catch per boat.

Understanding patterns in trace element concentrations and water quality within river systems provides a foundation to evaluate retrospective movements and habitat use of fish. Because trace elements are incorporated into calcified structures of fishes relative to water concentrations, baseline maps have application for fisheries management, including for rare species such as sturgeons. Therefore, trace elements [strontium (Sr), barium (Ba), manganese (Mn), zinc (Zn), and magnesium (Mg)], strontium isotopes ( 87 Sr/ 86 Sr), dissolved oxygen and salinity were measured in the Pearl River and Lake Pontchartrain watersheds, within Mississippi and Louisiana, USA for application in assessing riverine use by Gulf Sturgeon Acipenser oxyrinchus desotoi. Water samples were collected during the summerfall period when juvenile Gulf Sturgeon were anticipated to be present and analyzed by solution and multi-collector inductively coupled plasma mass spectrometry. Trace element to calcium (Ca) ratios in Sr, Ba, Zn, and Mg were distinguishable between the upper Pearl River and the Bogue Chitto River tributary, and the upper Pearl River and lower Pearl River. For most trace elements and 87 Sr/ 86 Sr, there was a gradual increase from upper river regions to lower river regions, and large differences between freshwater and saline areas. Lake Pontchartrain watershed rivers were not easily differentiated, but regions of low dissolved oxygen concentrations in the lower reaches suggest available Gulf Sturgeon habitat may be seasonally limited. Therefore, maps of water microchemistry in the Pearl River watershed allow for retrospective analyses of fish watershed use.

The Blue Catfish Ictalurus furcatus is a popular sport fish in its native range and a prolific invasive species in its nonnative range. Low‐frequency electrofishing (LFE) is effective for sampling Blue Catfish, and development of standardized LFE protocols for sampling Blue Catfish is critical for monitoring and management of their populations. However, standardized sampling for Blue Catfish can be difficult because their habitat use is variable among seasons and habitats, and LFE is affected by a suite of abiotic factors. To quantify this variation, our objectives were to determine how Blue Catfish LFE catch (1) differs during spring and summer sampling seasons, (2) is affected by environmental variables, and (3) relates to their habitat use. To do so, we conducted a telemetry study and systematic random LFE sampling in Lake Dardanelle, Arkansas, in the spring and summer of 2016. We compared the numbers, capture rates, and size structure (proportional size distribution index of quality‐size fish) of telemetry‐located and LFE‐captured Blue Catfish in distinct habitats and found that habitat use was heterogeneous but capture rates were proportional to habitat use. Blue Catfish catch increased with conductivity and decreased with flow velocity; catch also differed among habitat types, among reservoir zones, and between seasons (spring/summer). Understanding how spatiotemporal differences in habitat use contextualize the effects of LFE catch will improve sampling protocols for Blue Catfish.