Anadromous Sturgeons: Habitats, Threats, and Management

2007 ◽  
Keyword(s):  
South Carolina ◽  
Brackish Water ◽  
Data Sets ◽  
Water Interface ◽  
Atlantic Sturgeon ◽  
Gill Net ◽  
Large Numbers ◽  
Class Strength ◽  
Study Designs ◽  
Acipenser Oxyrinchus

<em>Abstract</em>.—The anadromous Atlantic sturgeon <em>Acipenser oxyrinchus</em> once supported an important commercial fishery throughout its range (northern Florida, USA, to Labrador, Canada). All surviving populations are apparently depleted, presumably due to overfishing, pollution, and dam construction. A complete moratorium on the fishery has been established in U.S. waters. Unfortunately, population status is unknown for nearly all systems. Several 1994–2001 data sets from South Carolina rivers were examined for their potential in development of recruitment (year-class abundance) indices. Because Atlantic sturgeon often begin leaving their natal systems at age 2, after which they occupy other systems and then presumably return to natal areas at sexual maturity several years later, a valid river-specific abundance index must be based on either age0–1 or adult fish. Working with three former commercial Atlantic sturgeon fishermen to collect adults in two rivers during the spring and fall of 1998 resulted in collection of only 39 fish in 13 nominal age-classes. In another river, 2 years of monthly sampling with multipanel, anchored gill nets and otter trawls at eight stations throughout the estuary produced only 31 juvenile Atlantic sturgeon. Neither of these study designs provided adequate sample sizes. However, sampling in a clean-bottom section at the freshwater–brackish water interface of the Edisto River with a modified drift gill net produced large numbers of small Atlantic sturgeon. More than 3,000 juveniles have been collected and tagged since 1994. The 1,331 nominal age-1 Atlantic sturgeon that were captured displayed a distinct bimodal length frequency distribution, supporting the hypothesis that there are both spring and fall spawning events. A period of record drought impeded sampling efforts during a portion of this study. However, when flows and bottom configurations allow nets to be fished at the freshwater–brackish water interface, the gears and methods employed in the Edisto River can produce an age-1 Atlantic sturgeon catch per unit effort that is high enough to be used in estimating relative year-class strength.

Anadromous Sturgeons: Habitats, Threats, and Management

2007 ◽  
Keyword(s):  
Negative Impact ◽  
Open Water ◽  
Abundant Species ◽  
Lake Sturgeon ◽  
Disposal Site ◽  
Atlantic Sturgeon ◽  
Sediment Dispersal ◽  
Gill Net ◽  
Longnose Sucker ◽  
Acipenser Oxyrinchus

<em>Abstract.</em>—In 1999 and 2000, gill-net sampling was used to determine the effect of sediment deposition (sand) on the relative abundance (catch per unit effort [CPUE]) of Atlantic sturgeon <em>Acipenser oxyrinchus</em> and lake sturgeon <em>A. fulvescens</em> frequenting the Île Madame open-water disposal site using a before–after and control–impact sampling design. A total of 1,108 fish of 11 different species were captured in the vicinity of the sediment disposal site. Sauger <em>Sander canadensis</em>, longnose sucker <em>Catostomus catostomus</em>, Atlantic sturgeon and lake sturgeon were the four most abundant species. Atlantic sturgeon CPUE was significantly higher in 1999 than in 2000, while lake sturgeon CPUE was similar in both years. After sediment disposal operations, we observed a significant decrease (3–7 times lower) in the Atlantic sturgeon CPUE at the impacted station compared to the control stations: CPUE dropped from 5.8 to 0.8 fish/ station-day in 1999 and from 1.8 to 0.5 fish/station-day in 2000. A significant reduction in CPUE values was also noted in the sediment dispersal area downstream from the disposal site after dumping. For both years, lake sturgeon CPUE at the impacted station was not significantly different from control stations after sediment disposal. These results suggest site avoidance and a negative impact of sediment disposal operations for Atlantic sturgeon but not for lake sturgeon. Management implications of these results are discussed in relation to sediment disposal operations in the St. Lawrence estuarine transition zone, an important habitat for both sturgeon species.

scholarly journals The Anadromous Hickory Shad (Clupeiformes: Clupeidae, Alosa mediocris [Mitchill 1814]): Morphometric and Meristic Variation

2019 ◽  
Author(s):  
Jordan P. Smith ◽  
Michael S. Brewer ◽  
Roger A. Rulifson
Keyword(s):  
South Carolina ◽  
Meristic Characters ◽  
Gill Rakers ◽  
Morphometric Characters ◽  
Linear Relationships ◽  
Gill Net ◽  
Information Gap ◽  
Large Numbers ◽  
Meristic Counts ◽  
Meristic Variation

AbstractThe anadromous Hickory Shad Alosa mediocris (Mitchill, 1814) (Clupeiformes: Clupeidae) is reviewed, specifically regarding morphometric and meristic variation. Despite its long history as recognized species, few descriptions of Hickory Shad morphometric and meristic characters exist in the literature. Most authors of the historic literature have failed to provide capture location for specimens, analyze large numbers of Hickory Shad, or document how morphometric and meristic characters of the species vary spatially. To address this information gap, a total of 717 mature Hickory Shad were collected from 23 different locations in Maryland, Delaware, Virginia, North Carolina, South Carolina, Georgia, and Florida using electroshocking, gill net, or rod and reel. All specimens were frozen, thawed, and 17 morphometric characters and four meristic characters were examined; a random subset (n = 463) were analyzed for an additional four meristic counts of gill rakers. Overall specimens ranged from 206-389 mm SL with a mean + SD of 278.41 + 27.69 mm, 232-435 mm FL with a mean of 310.98 + 30.35 mm, and 272-508 mm TL with a mean of 365.62 + 35.52 mm. The linear relationships between FL and TL, and FL and SL, were investigated and found to be: TL = 1.169*FL + 1.660 (n=705, r2=0.995) and SL = 0.909*FL - 4.274 (n=717, r2=0.992). Substantial differences in character means for many morphometric measurements were found between male and female specimens, suggesting strong sexual dimorphisms relating to shape. However, meristic characters did not show differences in character means by sex. No one morphometric measurement could distinguish Hickory Shad from other morphologically similar clupeids, but the meristic count of gill rakers on the lower limb of the first arch were important to separate Hickory Shad (19-22) from American Shad A. sapidissima (Wilson, 1811), Alewife A. pseudoharengus (Wilson, 1811), and Blueback Herring A. aestivalis (Mitchill, 1814).

scholarly journals A New Method for Landmark-Based Studies of the Dynamic Stability of Growth, with Implications for Evolutionary Analyses

2021 ◽  
Author(s):  
Fred L. Bookstein
Keyword(s):  
Growth Regulation ◽  
Pattern Analysis ◽  
Developmental Time ◽  
Dynamical Stability ◽  
New Method ◽  
Data Sets ◽  
Data Set ◽  
Landmark Data ◽  
Study Designs ◽  
Changes Over Time

AbstractA matrix manipulation new to the quantitative study of develomental stability reveals unexpected morphometric patterns in a classic data set of landmark-based calvarial growth. There are implications for evolutionary studies. Among organismal biology’s fundamental postulates is the assumption that most aspects of any higher animal’s growth trajectories are dynamically stable, resilient against the types of small but functionally pertinent transient perturbations that may have originated in genotype, morphogenesis, or ecophenotypy. We need an operationalization of this axiom for landmark data sets arising from longitudinal data designs. The present paper introduces a multivariate approach toward that goal: a method for identification and interpretation of patterns of dynamical stability in longitudinally collected landmark data. The new method is based in an application of eigenanalysis unfamiliar to most organismal biologists: analysis of a covariance matrix of Boas coordinates (Procrustes coordinates without the size standardization) against their changes over time. These eigenanalyses may yield complex eigenvalues and eigenvectors (terms involving $$i=\sqrt{-1}$$ i = - 1 ); the paper carefully explains how these are to be scattered, gridded, and interpreted by their real and imaginary canonical vectors. For the Vilmann neurocranial octagons, the classic morphometric data set used as the running example here, there result new empirical findings that offer a pattern analysis of the ways perturbations of growth are attenuated or otherwise modified over the course of developmental time. The main finding, dominance of a generalized version of dynamical stability (negative autoregressions, as announced by the negative real parts of their eigenvalues, often combined with shearing and rotation in a helpful canonical plane), is surprising in its strength and consistency. A closing discussion explores some implications of this novel pattern analysis of growth regulation. It differs in many respects from the usual way covariance matrices are wielded in geometric morphometrics, differences relevant to a variety of study designs for comparisons of development across species.

Comparison of iterative desmearing procedures for one-dimensional small-angle scattering data

2011 ◽  
Vol 44 (1) ◽  
pp. 32-42 ◽  
Author(s):  
Thomas Vad ◽  
Wiebke F. C. Sager
Keyword(s):  
Small Angle ◽  
Incident Beam ◽  
Scattering Data ◽  
Data Sets ◽  
Convergence Criteria ◽  
Small Momentum Transfer ◽  
One Dimensional ◽  
Noise Filter ◽  
Large Numbers ◽  
Angle Scattering

Two simple iterative desmearing procedures – the Lake algorithm and the Van Cittert method – have been investigated by introducing different convergence criteria using both synthetic and experimental small-angle neutron scattering data. Implementing appropriate convergence criteria resulted in stable and reliable solutions in correcting resolution errors originating from instrumental smearing,i.e.finite collimation and polychromaticity of the incident beam. Deviations at small momentum transfer for concentrated ensembles of spheres encountered in earlier studies are not observed. Amplification of statistical errors can be reduced by applying a noise filter after desmearing. In most cases investigated, the modified Lake algorithm yields better results with a significantly smaller number of iterations and is, therefore, suitable for automated desmearing of large numbers of data sets.

Contemporary and historical effective population sizes of Atlantic sturgeon Acipenser oxyrinchus oxyrinchus

2018 ◽  
Vol 20 (2) ◽  
pp. 167-184 ◽  
Author(s):  
John Waldman ◽  
S. Elizabeth Alter ◽  
Douglas Peterson ◽  
Lorraine Maceda ◽  
Nirmal Roy ◽  
...  
Keyword(s):  
Atlantic Sturgeon ◽  
Effective Population ◽  
Population Sizes ◽  
Acipenser Oxyrinchus

scholarly journals Atlantic sturgeon movements in relation to a cutterhead dredge in the James River, Virginia

2021 ◽  
Author(s):  
Matthew Balazik ◽  
Safra Altman ◽  
Kevin Reine ◽  
Alan Katzenmeyer
Keyword(s):  
Water Quality ◽  
Field Study ◽  
Technical Note ◽  
Atlantic Sturgeon ◽  
James River ◽  
Acipenser Oxyrinchus ◽  
Reduced Water

This technical note describes a field study investigating the movements of federally endangered Atlantic sturgeon, Acipenser oxyrinchus oxyrinchus (ATS), during the summer and fall of 2017 near a cutterhead dredge working in the James River, Virginia, to provide data addressing the concern about the potential impacts of dredging activities (for example, excavation, transit, disposal, sounds, reduced water quality) on the ATS.

Evaluation of the Risk of Therapy-Associated Complications in Survivors of Hodgkin Lymphoma

Hematology ◽  
2007 ◽  
Vol 2007 (1) ◽  
pp. 192-196 ◽  
Author(s):  
Lois B. Travis
Keyword(s):  
Hodgkin Lymphoma ◽  
Health Care Providers ◽  
Late Effects ◽  
Disease Risk ◽  
Risk Measures ◽  
Epidemiologic Study ◽  
Incidence Rates ◽  
Care Providers ◽  
Large Numbers ◽  
Study Designs

Abstract Given the improvements in survival of patients with Hodgkin lymphoma (HL) in the last three decades, quantification of the late effects of successful treatment has become critical. Since the highest incidence rates of HL occur at ages 20 to 34 years, large numbers of patients remain at lifelong risk for the late effects of treatment. Deaths due to second cancers are now the most common cause of mortality among long-term survivors of HL, followed by cardiac disease. Risk measures of these and other late sequelae, however, can vary markedly between investigations, depending on the types of treatment, the rigor with which epidemiologic study designs are applied, ascertainment of events of interest, the duration and completeness of follow-up, and consideration of competing risks. Further, numerous influences apart from therapy can affect late effects, including patient age, sex, race, lifestyle factors (tobacco, alcohol, diet), comorbidities, and the underlying cancer process. In the future, it will become increasingly important for health-care providers to be able to critically evaluate the risk of late effects in HL survivors, which will include a working knowledge of various epidemiologic study designs and risk measures and an ability to judiciously review the medical literature. In this article, the methods, significance and caveats in calculating and reporting risks of complications of treatment for HL are reviewed.

Atlantic sturgeon Acipenser oxyrinchus surfacing behaviour

2018 ◽  
Vol 92 (4) ◽  
pp. 929-943
Author(s):  
L. M. Logan-Chesney ◽  
M. J. Dadswell ◽  
R. H. Karsten ◽  
I. Wirgin ◽  
M. J. W. Stokesbury
Keyword(s):  
Atlantic Sturgeon ◽  
Acipenser Oxyrinchus

Anadromous Sturgeons: Habitats, Threats, and Management

2007 ◽  
Keyword(s):  
Large Scale ◽  
Atlantic Coast ◽  
The United States ◽  
Management Plan ◽  
Commercial Fishing ◽  
Atlantic Sturgeon ◽  
Coastal Fisheries ◽  
Number Of Factors ◽  
Acipenser Oxyrinchus ◽  
The U.S

<em>Abstract.</em>—Large-scale commercial fisheries for Atlantic sturgeon <em>Acipenser oxyrinchus</em> in the late 1880s eventually led to substantial reductions in the population size. The coastwide Atlantic sturgeon population of the United States has not recovered to the levels seen prior to the 1900s. A number of factors have contributed to the slow recovery or continued decline of Atlantic sturgeon populations, including continued commercial fishing and the targeting of females for caviar, bycatch in other fisheries, and changes in habitat due to dam construction and water quality degradation. The Atlantic States Marine Fisheries Commission (ASMFC) developed the first coastwide management plan for Atlantic sturgeon in 1990. In response to the shortcomings of that plan, the ASMFC applied new standards and the authority granted to it by the U.S. Congress to adopt a coastwide moratorium on all harvesting in 1998. A federal status review conducted in 1998 concluded that the continued existence of Atlantic sturgeon was not threatened given the situation at the time. Since then, monitoring programs have indicated varying levels of relative abundance in several water bodies along the Atlantic coast. The U.S. government is responsible for undertaking a status review to document any changes since the last review and determining whether those findings warrant a threatened or endangered listing for the species. The government’s findings may have far-reaching effects on many other Atlantic coastal fisheries.

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