Jan Jeffrey Hoover

• Research Fisheries Biologist at US Army Engineer Research and Development Center

Silver carp, Hypophthalmichthys molitrix, escaped into the Lower Mississippi River (LMR) over 50 years ago, established reproductive populations, and spread across much of the Mississippi River Basin. Demographic rates of silver carp are needed to inform decisions on control and management of this invasive species, but have not been published for t...

This is a short article from In-Fisherman magazine describing and illustrating the third (pineal) eye of the Paddlefish, Polyodon spathula. Article summarizes the first anatomical study of the organ, suggests a possible function, and provides a method for skeletonizing Paddlefish rostra.

The effects of agriculture and flood control practices accrued over more than a century have impaired aquatic habitats and their fish communities in the Mississippi Alluvial Valley, the historic floodplain of the Lower Mississippi River prior to leveeing. As a first step to conservation planning and adaptive management, we developed and tested a co...

The Bonnet Carre' Spillway diverts water from the Mississippi River through a floodway into brackish Lake Pontchartrain to reduce river stages at New Orleans and prevent flood damage. Pallid Sturgeon Scaphirhynchus albus, a federally listed species under the Endangered Species Act, and Shovelnose Sturgeon Scaphirhynchus platorynchus, listed under t...

The Bonnet Carre’ Spillway diverts water from the Mississippi River through a floodway into Lake Pontchartrain to reduce river stages at New Orleans and prevent flood damages. Pallid Sturgeon, a federally listed species under the Endangered Species Act, and Shovelnose Sturgeon, listed under the Similarity of Appearance rule, are entrained through t...

The prominent rostrum of the North American Paddlefish, supported by a lattice-like endoskeleton, is highly durable, making it an important candidate for bio-inspiration studies. Energy dissipation and load-bearing capacity of the structure from extreme physical force has been demonstrated superior to that of man-made systems, but response to conti...

• While invasions of large rivers by exotic fish species are well documented, assessing actual or potential impacts on native species is a challenge. Rapid assessments may be possible through the application of a combination of bioenergetic and population dynamic models. • Paddlefish (Polyodon spathula) is a native species in the central USA with a...

Measuring burst speeds of fish has long been problematic due to the lack of in‐situ measurements. Using boat‐mounted cameras, we recorded video of invasive Silver Carp Hypophthalmichthys molitrix, in the field leaping from the water and measured their leap height, horizontal distance, angle of escape, and estimated their escape velocity. Leap chara...

Paddlefish, Polyodon spathula, are behaviorally, morphologically, and physiologically adapted for prolonged free-swimming at moderately high speeds but not for maneuverability which makes them prone to impacts from submerged structures. These structures include low-head dams, weirs, dikes, levees, high-head dams, dredges, diversions, intakes, and v...

This work presents a transdisciplinary, integrated approach that uses computational mechanics experiments with a flow network strategy to gain fundamental insights into the stress flow of high-performance, lightweight, structured composites by investigating the rostrum of paddlefish. Although computational mechanics experiments give an overall dist...

Synthetic biology has the potential for a broad array of applications. However, realization of this potential is challenged by the paucity of relevant data for conventional risk assessment protocols, a limitation due to to the relative nascence of the field, as well as the poorly characterized and prioritized hazard, exposure, and dose–response con...

Bio-structures have been optimized by nature to possess remarkable resiliency and strength yet retain a light-weight composition. The hierarchical geometrical arrangements that are prevalent in bio-structures, coupled with heterogeneous constituents, present uncertainty as to what dictates the structural response. Although computational mechanics e...

Short-term movements of adult Polyodon spathula (Paddlefish) are well-documented, but long-term movements are underreported. In this study, we describe extraordinary distances traveled by 4 Paddlefish that were captured, tagged, and released in Moon Lake, a remote oxbow lake in Coahoma County, MS. After 8-24 months at large, the 4 fish were recaptu...

Abundance estimates are essential for assessing the viability of populations and the risks posed by alternative management actions. An effort to estimate abundance via a repeated mark‐recapture experiment may fail to recapture marked individuals. We devised a method for obtaining lower bounds on abundance in the absence of recaptures for both panmi...

An evaluation of a proposed technology to prevent invasive species migration using a treatment chamber using chlorination.

Management and recovery of endangered sawfishes are challenged by the uncertainty of species determination. Frequently, dried rostra (saws) are the only material available to represent an historical occurrence, yet traditional methods of species identification of data-deficient rostra (rostral tooth counts) are unreliable. We evaluated utility of m...

Although the movement of invasive bighead carp (Hypophthalmichthys nobilis) and silver carp (H. molitrix) in the Upper Mississippi River system is dependent on their ability to swim through its numerous lock-and-dams, the swimming performance of adults of these species is at present unknown. Using a large (2,935-L) mobile swim tunnel, the swimming...

PURPOSE: Empirical swim speed data are needed to manage invasive bigheaded or " Asian " carps (Figure 1). However, such data are limited within the scientific literature. The large size and active temperament of the carp combined with current legislative restrictions concerning transport, make them difficult to acclimatize and test in traditional l...

Bighead Carp Hypophthalmichthys nobilis and Silver Carp H. moli-trix are native in the Yangtze River and extremely important economically and culturally as food fishes; however, the two species have declined due to overfish-ing and anthropogenic modifications to hydrology and water quality. Bighead Carp and Silver Carp were imported to North Americ...

Two Hypophthalmichthys molitrix (silver carp) were collected in the Pearl River on 6 September 2012 during a natural fish kill in the decommissioned lock chamber of Lock-and-Dam No. 1 located at river kilometer (RKM) 47.5 in St. Tammany Parish, 9.4 km NW of the city of Pearl River, LA. Fish were a male 987 mm TL, 10.9 kg, and a female 1042 mm TL, 1...

On 24 February 2014, commercial fishers caught an unusually large Hypophthalmichthys nobilis (Bighead Carp) from an oxbow lake in northwestern Mississippi. We examined it to determine age, gonadal development, and fecundity. The specimen was 1316 mm total length, 49.7 kg, and 11 years old. It had asymmetric ovaries that collectively represented 15....

Tested was the hypothesis that juvenile Atlantic sturgeon (Acipenser oxyrinchus oxyrinchus) would exhibit no response in short-term survival or swimming performance when exposed to varying concentrations of suspended sediment simulating dredge plumes in waterways where this species may be impacted by dredging operations. Sediment collected from Sav...

The purpose of this report is to present preliminary data regarding the use of videography to estimate Silver Carp burst swimming speeds. The authors document the use of videotaped Silver Carp leaping behavior as a means of estimating, in-situ, burst swimming speeds, fish leap height, and horizontal distance traveled during a leap.

Section 7(a)(1) of the Endangered Species Act (ESA) requires all federal agencies to use their authority as appropriate to carry out programs for the conservation (i.e., recovery) of endangered and threatened species. For more than a decade, the U.S. Army Corps of Engineers (USACE) has worked with the U.S. Fish and Wildlife Service (USFWS) and stat...

The electrosensory capabilities of the rostrum of the paddlefish (Polyodon spathula) were investigated previously. However, the structure-property relationship associated with the rostrum has yet to be explored. In this study, the stellate bone properties of the rostrum are examined as a function of spatial location on the rostrum using nanoindenta...

We observed a large adult Paddlefish entrained from the Mississippi River through the Bonnet Cane spillway, south Louisiana, which was injured and underweight. We captured, measured (23 metrics), and tagged the fish. After it had spent a week at large on the fioodway, we recaptured and released it back into the Mississippi River. The specimen was r...

Paddlefish (Polyodontidae), sturgeon (Acipenseridae) and bigheaded carps (Cyprinidae: Hypophthalmichthys spp.) are taxa shared by the Yangtze and Mississippi River Basins. In the Yangtze, native paddlefish (Psephurus gladius) are functionally extinct, sturgeon are maintained through stocking, and bigheaded carps (H. nobilis and H. molitrix) declini...

The Paddlefish rostrum enhances swimming due to unique construction, variable form, and large size. We measured 5-min critical swim speed, Ucrit, of 66 young-of-year (4.9-9.6 cm EFL) and 20 yearlings (21.6-28.2 cm EFL) in 100-L and 1200-L swim tunnels, correlating results with rostrum size, body shape, and caudal lobe asymmetry. Ucrit of young-of-y...

Borrow-pit lakes encompass about a third of the lentic water habitats (by area) in the active floodplain of the Lower Mississippi River, yet little is known about their fish assemblages. We investigated whether fish assemblages supported by borrow-pit lakes resembled those in oxbow lakes to help place the ecological relevance of borrow-pit lakes in...

Harvesting of liver samples for toxicologic and other laboratory analyses is frequently undertaken in free-ranging fish to evaluate accumulations of various pollutants and chemicals. However, commonly used, lethal techniques for collecting liver tissues are unacceptable when dealing with protected species. We report the use of a nonlethal, single-e...

The lower portion of the Sacramento River, California, has been highly engineered to protect low‐lying surrounding communities from annual flood events. While engineered floodplains have provided adequate protection for the surrounding communities, there remain unintended consequences to migratory fish that become stranded during high flow events....

Three floodways along the lower Mississippi River were operated during the 2011 flood: New Madrid, Morganza, and Bonnet Carre. There was concern that the federally endangered pallid sturgeon (Scaphiryhnchus albus) would be entrained through the floodways resulting in injury or death. Varying levels of sampling effort were conducted in each floodway...

The lower portion of the Sacramento River has been highly engineered to protect low lying surrounding communities from annual flood events. While engineered flood plains have provided adequate protection for the surrounding communities, there remain unintended consequences to migratory fish which become stranded during high flow events. In April 20...

Fecundity was estimated for two pallid sturgeon, Scaphirhynchus albus, from the Lower Mississippi River (LMR). Sturgeon measured 827 and 886 mm fork length, weighed Document Type: Research Article DOI: http://dx.doi.org/10.1111/j.1439-0426.2011.01931.x Affiliations: Environmental Laboratory, US Army, Engineer Research and Development Center, Vicksb...

EnviroFish is both a modeling approach and a computer software. As a modeling approach, EnviroFish estimates the value of floodplain habitat suitable for fish reproduction under a given set of hydrologic and hydraulic conditions. As a software, EnviroFish is a Java computer program facilitating the application of the modeling approach. This manual...

The Lower Mississippi River (LMR) flows between six states beginning at the confluence of the Ohio River down to the Gulf of Mexico. Like most great rivers, the LMR has been impacted from river regulation for flood control and navigation. Despite these activities, the LMR remains free-flowing and supports the most productive floodplain fishery in N...

A specially designed net was used to study fish entrainment and injury through towboat propellers in 13 pools of the Upper Mississippi and Illinois rivers. The net was attached to the stern of a 48.8-m-long towboat with twin propellers (in Kort propulsion nozzles), and sampling typically took place while the towboat pushed 15 loaded barges upstream...

Summary Sturgeon are threatened by dredging, but there is no established protocol for determining risk of entrainment to different populations of wide-ranging species. We demonstrate that laboratory evaluations of swimming performance for individual populations are an effective way to describe susceptibility of entrainment. Using a Blazka-type swim...

Summary Critical swimming speeds of sturgeon are presumably lower in vertically uniform, rectilinear flow than in heterogeneous boundary-layer flow. Movement in rectilinear flow of the water column necessitates frequent high-energy free-swimming, while movement in boundary-layers near the bottom of the river permits a variety of lower energy behavi...

EnviroFish is both a modeling approach and a computer software. As a modeling approach, EnviroFish estimates the value of floodplain habitat suitable for fish reproduction under a given set of hydrologic and hydraulic conditions. As a software, EnviroFish is a Java computer program facilitating the application of the modeling approach. This manu...

The invasive silver carp (Hypophthalmichthys molitrix) has become pervasive in much of the Mississippi River, its tributaries, and in connected lakes and wetlands. As an increasingly abundant planktivore, it competes directly for food with native fishes. Its greatest impact may be in connected backwater lakes and wetlands, which due to their high p...

Thirty-six sturgeon (Scaphirhynchus spp.) were captured from the lower Mississippi River using baited trot-lines, anesthetized using tricaine methanesulfonate, and subjected to endoscopic evaluation of their coelom (coelioscopy) on the river bank. Using a 2.7 mm rod-lens telescope and gravity–fed sterile saline infusion, gender and reproductive sta...

White sturgeon, Acipenser transmontanus (Richardson), are at risk of entrainment from dredging, with young-of-the-year fish at greatest risk. To evaluate this entrainment risk, swimming performance trials were conducted in a laboratory swim tunnel with hatchery-reared juvenile white sturgeon with varying experience levels including: naïve (only tes...

The Topeka shiner (Notropis topeka) is imperiled by extensive changes in stream hydrology. Responses of shiners to changes or variation in stream hydraulics, however, have not been quantified, hampering conservation efforts. We quantified swimming endurance and behavior for Topeka shiners in a laboratory swim tunnel. Sustained swimming (>200 min) w...

Juvenile paddlefish (Polyodon spathula) exhibit conspicuous variation in the shape of their rostra and caudal fins. We quantified morphological variation for a composite collection of young-of-year paddlefish (N = 55, 61.9-403.7 mm total length) using nine measurements of the rostrum, body, and caudal fin. Sheared principal component analysis of mo...

The Danube and Mississippi Rivers are sharing experiences to overcome similar challenges in protecting fish populations.

Habitat models are used to evaluate impacts of water resource development activities such as flood control and navigation projects, and environmental benefits of restoration or mitigation projects. These models generally take the form of an index ranging from 0.0 (poor habitat) to 1.0 (optimum habitat), referred to as a Habitat Suitability Index (H...

The impacts to Gulf and pallid sturgeon from a proposed Mississippi River water diversion into the swamps bordering Lake Maurepas were evaluated. Gulf sturgeon were unlikely to be affected by the diversion due to characteristics of their life history. Adult and subadult pallid sturgeon were relatively abundant in the proposed project area and could...

Delta streams, forming in the floodplains of large river systems, are widespread throughout the United States. Delta streams are most prevalent in the Mississippi Embayment, also referred to as the lower Mississippi River Basin. The alluvial flood-plain deposits are typically rich in organic material. Consequently, most delta streams have been alte...

This study summarizes recent observations of silver carp, Hypopthalmichthys molitrix, in small wetlands of the Lower Mississippi River and suggests management actions for their control based on wetland hydrology and pattern of fish movements.

Pallid sturgeon (Scaphirhynchus albus) captured in the Middle and Lower Mississippi River (i.e. below St. Louis, MO, USA) are morphologically very similar to shovelnose sturgeon (Scaphirhynchus platorynchus). Available empirical data are limited to a few studies based on low sample sizes from disjointed populations. Geneticists are currently search...

Trotlines were used to capture pallid sturgeon in the free-flowing Mississippi River, which extends from the Gulf of Mexico to the mouth of the Missouri River. Trotlines were baited with worms, and set overnight usually along the channel border. The pectoral fin rays of 165 pallid sturgeon caught in the Mississippi River were aged; 118 were from th...

Sturgeon specimens encountered in the wild that exhibit visible signs of gross physical trauma often look to the naked eye to be in otherwise good condition. Visible morphological anomalies were observed in 9.1% of 176 pallid (Scaphirhynchus albus) and 4.6% of 4904 shovelnose (Scaphirhynchus platorynchus) sturgeon specimens captured in the Middle (...

Gut contents of shovelnose and pallid sturgeon from the lower and middle Mississippi River were obtained by colonic flushing, a safe and easily implemented alternative to gastric lavage. Diets of both species were dominated numerically by immature Trichoptera, Ephemeroptera, and Diptera. Primary prey, based on volume, for shovelnose sturgeon were T...

The gut contents of 12 museum specimens of the federally (USA) endangered Alabama sturgeon were analyzed. This collective series represents 32% of the known museum specimens. Gut contents were dominated by aquatic insects and fishes. At the taxonomic level of insect orders, Dipterans (174.3/fish) were the most numerically abundant food item consume...

SummaryA multiyear study of pallid sturgeon distribution and relative abundance was conducted in the lower and middle Mississippi river (LMR and MMR, respectively). The LMR and MMR comprise the free-flowing Mississippi River extending 1857 river kilometers (rkm) from its mouth at the Gulf of Mexico upstream to the mouth of the Missouri River. A tot...

Many vertebrate predators consume a wide variety of prey types, depending upon availability and vulnerability. In contrast, striped bass, Morone saxatilis, that have been introduced to Lake Texoma (Oklahoma-Texas, U.S.A.) use a very limited array of fish (mostly clupeids of the genus Dorosoma) as prey. As a large, mobile predator, M. saxatilis shou...

This document is a report of the Aquatic Nuisance Species Research Program. ANSRP Bulletin. Volume 4-1.

We examined oral grasping behavior, a unique and relatively unknown method of maintaining station against flow, in nine species of North American cyprinids to determine whether oral grasping was used by a range of cyprinid species and to further investigate the relationship between oral grasping and water velocity. Fish were subjected to a stepwise...

Erik Stokstad's article “Can well-timed jolts keep out unwanted exotic fish?” (News Focus, 11 July, p. [157][1]) was an excellent summary of the work being done to create effective electrical barriers to the movement of aquatic nuisance fishes. It will challenge resource managers to think beyond

The effect of fin ray removal on swimming performance was evaluated for shovelnose sturgeon Scaphirhynchus platorynchus from the lower Mississippi River. Immediately upon collection, the marginal pectoral fin ray was removed from some fish, and others were left unclipped as a control group. Fish were promptly returned to the laboratory and held in...

The round goby, Neogobius melanostomus, a native of Eurasia, is spreading throughout the waters of North America. Native to the Black Sea and Caspian Sea systems, the round goby appeared in the St. Clair River, ONT-MI in 1990, and subsequently in the Great Lakes during 1993-1996 (Charlebois et al. 1997). Particular concern exists for the population...

Small floodplain pools (less than 2 m deep, less than 500 sq m) are inhabited by some of the least common fishes in large river systems: species adapted morphologically and physiologically to shallow, periodically hypoxic water with wide variation in temperature (Baker, Killgore, and Kasul 1991; Hoover and Killgore 1998). They are also inhabited by...

We evaluated fish species composition relative to dissolved oxygen concentrations in Mercer Bayou, a vegetated impoundment in southwest Arkansas. Sampling stations were distributed among three reaches that varied in dissolved oxygen concentrations ranging from 0.2 to 7.5 mg/l. Hypoxia was pronounced at the downstream reach of the bayou because of s...

Paddlefish rostra vary in size and shape suggesting existence of multiple morphotypes. Measurements for 118 adult paddlefish from a Mississippi delta river indicate that the rostrum becomes shorter, narrower, and straighter as a fish grows. Negative allometric growth of rostra, and high variation within size classes, may obscure existence of distin...

PURPOSE: Benefits of restoring riverine backwaters using weirs or other types of water control structures are evaluated. This approach allows: (a) site-specific characterization of backwater fish assemblages ; (b) development of quantitative models of habitat quality ; and (c) incremental estimation of habitat benefits of weirs with different crest...

During early life stages, fish in the Mississippi River system may become stranded by shoreline drawdowns induced by the passage of commercial vessels. We examined the stranding of larval shovelnose sturgeon Scaphirhynchus platorynchus, paddlefish Polyodon spathula, and bigmouth buffalo Ictiobus cyprinellus and of juvenile blue catfish Ictalurus fu...

Hatchery-reared, juvenile pallid sturgeon (Scaphirhynchus albus) were subjected to swimming stamina tests in a 100-L Blazka-type swim tunnel at 17-20 C. Endurance was measured at fixed velocities ranging from 10-70 cm/sec, and sustained, prolonged, and burst swimming speeds were identified for two size groups: 17.0-20.5 and 13.0-16.8 cm FL. Maximum...

The Corps of Engineers has a central role in restoring aquatic ecosystems. Under the authority of the 1986 Water Resource Development Act and subsequent amendments, the Corps can modify or construct projects to restore fish and wildlife habitat, as well as assist states and other non-Federal agencies with ecosystem and watershed planning (Table 1)....

Bottomland hardwood wetlands are conspicuous features of many river systems in the lower Mississippi River basin. They occur on alluvial floodplains that are inundated in winter and spring. These forested wetlands are highly productive and support diverse aquatic communities. Despite their importance to riverine ecosystems, extensive tracts of bott...

Swimming performance and behavior of five adult (57—69 cm fork length) shovelnose sturgeon, Scaphirhynchus platorynchus, were studied in a 945-L swim tunnel at 16° C. Fifteen-minute critical swimming speeds ranged from 65 to 116 cm s. Sturgeon swam volitionally at low speeds (5—30 cm s), but at higher speeds (40—120 cm s) sturgeon alternated betwee...

Stomach contents of 17 paddlefish, collected in the Mississippi delta, yielded 41 specimens of riffle beetle, Stenelmis spp. The specimens provide documentation of riffle beetles in the Big Sunflower River and the first record of Stenelmis parva in Mississippi.