Environmental Factors Influencing Benthic Polychaete Distributions in a Subtropical Lagoon

2018 ◽  
Vol 52 (4) ◽  
pp. 58-74
Author(s):  
Anthony Cox ◽  
Daniel Hope ◽  
M. Angelica Zamora-Duran ◽  
Kevin B. Johnson
Keyword(s):  
Indian River Lagoon ◽  
Nutrient Inputs ◽  
Polychaete Species ◽  
Fine Grained ◽  
Principle Components Analysis ◽  
Indian River ◽  
Components Analysis ◽  
Benthic Sediments ◽  
Elevated Water ◽  
Definition Of

AbstractFine-grained organic-rich sediments (FGORS) in the Indian River Lagoon (IRL), Florida, sometimes called “muck,” contain elevated water, silt-clay, and organic matter contents and are abundant as a result of anthropogenic nutrient inputs. Many polychaetes inhabit the benthic sediments of estuaries and tolerate various degrees of FGORS. FGORS composition can be variable, and its effects on infaunal life such as polychaetes may depend upon concentration and composition. The IRL Cox Muck Index (CMI) is proposed as a mechanism for assigning a single value to the complex composition of muck and found to be a useful tool for summary and comparison. CMI has negative correlations with polychaete density (R2 = 0.2, p < 0.001), richness (R2 = 0.57, p < 0.001), and diversity (R2 = 0.55, p < 0.001) based on multiple regression of principle components (PCs) derived from principle components analysis (PCA). Sediment with CMI of <1 fails to meet the definition of IRL muck in at least one parameter and is assumed capable of sustaining some metazoan life. The CMI range of 0.1‐0.2 supports the most robust polychaete community. The polychaete species Diopatra cuprea, Glycera americana, Alitta succinea, and Pectinaria gouldii persisted in the IRL above 0.6 CMI. An environmental dredging project removed muck sediments midway through this study and polychaete recovery following dredging was monitored. At one site, an area of Turkey Creek with abundant muck, the CMI was significantly reduced from 1.4 to 0.8 (p < 0.001). The developing polychaete community at these stations included G. americana and A. succinea. At the end of the study, there were increases in overall polychaete community density, richness, and diversity to 1,000 m−2, S = 3, H = 0.55, respectively.

Environmental Dredging to Remove Fine-Grained, Organic-Rich Sediments and Reduce Inputs of Nitrogen and Phosphorus to a Subtropical Estuary

2018 ◽  
Vol 52 (4) ◽  
pp. 42-57 ◽  
Author(s):  
Austin L. Fox ◽  
John H. Trefry
Keyword(s):  
Water Depth ◽  
Interstitial Water ◽  
Indian River Lagoon ◽  
Benthic Fluxes ◽  
Nitrogen And Phosphorus ◽  
Overlying Water ◽  
Fine Grained ◽  
Total Inventory ◽  
Indian River ◽  
Subtropical Estuary

AbstractEnvironmental dredging of fine-grained, organic-rich sediments, locally referred to as Indian River Lagoon (IRL) muck, have been promoted as an integral part of restoring the IRL, Florida, to a healthy ecosystem. In Turkey Creek, a tributary to the IRL, ~300 metric tons of N and ~70 metric tons of P were removed with 160,000 m3 of wet muck and sand via environmental dredging during 2016 and 2017. Within the established dredged area, muck removal efficiency was ~63%; some areas were not dredged deep enough to remove all the muck. An additional 24,000 m3 of muck located outside the dredged area were not removed due to the presence of docks and seawalls. Prior to dredging, benthic fluxes of dissolved N (as ammonium) and P (as phosphate) from sediments to the overlying water, adjusted to 25°C, averaged 11 mg N/m2/h and 2.5 mg P/m2/h, respectively. Where IRL muck was removed to expose the underlying sand or mixed sand and muck, benthic fluxes of N and P were 20- to 30-fold lower after dredging. Subsequent disturbances, including Hurricane Matthew in October 2016, redistributed residual muck, leaving the dredged area 26% muck-free. Where muck was incompletely dredged or reintroduced by slumping, fluxes returned to predredging values within 6 months as equilibrium was reestablished between sediments and interstitial water. Dredging produced a 50% increase in water depth and basin volume with positive increases in salinity and the total inventory of dissolved oxygen. This deeper basin also serves as a sediment trap that will sequester future inputs of muck and mitigate future benthic fluxes of N and P by reducing the transport of muck into the IRL.

Psychometric Definition of Rorschach Determinant Component Structure

1998 ◽  
Vol 14 (2) ◽  
pp. 116-123 ◽  
Author(s):  
Raymond M. Costello
Keyword(s):  
Lower Order ◽  
Three Dimensions ◽  
Comprehensive System ◽  
Empirical Examination ◽  
Component Structure ◽  
Exner's Comprehensive System ◽  
Factor Analytic ◽  
Confirmatory Factor ◽  
Components Analysis ◽  
Definition Of

This is an empirical examination of Experienced Stimulation (es) and Experience Actual (EA) from Exner's Comprehensive System (CS) for Rorschach's Test, spurred by Kleiger's theoretical critique. Principal components analysis, Cronbach's α, and inter-item correlational analyses were used to test whether 13 determinants used to code Rorschach responses (M, FM, m, CF+C, YF+Y, C'F+C', TF+T, VF+V, FC, FC', FV, FY, FT) are best represented as a one, two, or more-dimensional construct. The 13 determinants appear to reflect three dimensions, a “lower order” sensori-motor dimension (m + CF+C + YF+Y + C'F+C' + TF+T + VF+V) with a suggested label of Modified Experienced Stimulation (MES), a “higher order” sensori-motor dimension (FM + FV + FY + FT) with a suggested label of Modified Experience Potential (MEP), and a third sensori-motor dimension (M+FC+FC') for which the label of Modified Experience Actual (MEA) is suggested. These findings are consistent with Kleiger's arguments and could lead to a refinement of CS constructs by aggregating determinants along lines more theoretically congruous and more internally consistent. A RAMONA model with parameters specified was presented for replication attempts which use confirmatory factor analytic techniques.

Dynamics of microcystins and saxitoxin in the Indian River Lagoon, Florida

Harmful Algae ◽  
2021 ◽  
Vol 103 ◽  
pp. 102012
Author(s):  
Abdiel E. Laureano-Rosario ◽  
Malcolm McFarland ◽  
David J. Bradshaw ◽  
Jackie Metz ◽  
Rachel A. Brewton ◽  
...  
Keyword(s):  
Indian River Lagoon ◽  
Indian River

scholarly journals Metabolomic and Genetic Analysis of Biomarkers for Peroxisome Proliferator-Activated Receptor α Expression and Activation

2007 ◽  
Vol 21 (9) ◽  
pp. 2136-2151 ◽  
Author(s):  
Yueying Zhen ◽  
Kristopher W. Krausz ◽  
Chi Chen ◽  
Jeffrey R. Idle ◽  
Frank J. Gonzalez
Keyword(s):  
Mass Spectrometry ◽  
Ultra Performance Liquid Chromatography ◽  
Urinary Biomarkers ◽  
Xanthurenic Acid ◽  
Peroxisome Proliferator ◽  
Peroxisome Proliferator Activated Receptor ◽  
Flight Mass Spectrometry ◽  
Positive Ions ◽  
Components Analysis ◽  
Definition Of

Abstract Peroxisome proliferator-activated receptor α (PPARα) is a nuclear receptor with manifold effects on intermediary metabolism. To define a set of urinary biomarkers that could be used to determine the efficacy of PPARα agonists, a metabolomic investigation was undertaken in wild-type and Pparα-null mice fed for 2 wk either a regular diet or a diet containing the PPARα ligand Wy-14,643 ([4-chloro-6-(2,3-xylidino)-2-pyrimidinylthio] acetic acid), and their urine was analyzed by ultra-performance liquid chromatography coupled with time-of-flight mass spectrometry. Principal components analysis of 6393 accurate mass positive ions revealed clustering as a single phenotype of the treated and untreated Pparα (−/−) mice plus two additional discrete phenotypes for the treated and untreated Pparα (+/+) mice. Biomarkers of PPARα activation were identified from their accurate masses and confirmed by tandem mass spectrometry of authentic compounds. Biomarkers were quantitated from raw chromatographic data using appropriate calibration curves. PPARα urinary biomarkers highly statistically significantly elevated by Wy-14,643 treatment included 11β-hydroxy-3,20-dioxopregn-4-en-21-oic acid (&gt;3700-fold), 11β,20-dihydroxy-3-oxopregn-4-en-21-oic acid (50-fold), nicotinamide (&gt;2-fold), nicotinamide 1-oxide (5-fold), 1-methylnicotinamide (1.5-fold), hippuric acid (2-fold), and 2,8-dihydroxyquinoline-β-d-glucuronide (3-fold). PPARα urinary biomarkers highly statistically significantly attenuated by Wy-14,643 treatment included xanthurenic acid (1.3-fold), hexanoylglycine (20-fold), phenylpropionylglycine (4-fold), and cinnamoylglycine (9-fold). These biomarkers arise from PPARα effects on tryptophan, corticosterone, and fatty acid metabolism and on glucuronidation. This study underscores the power of mass spectrometry-based metabolomics combined with genetically modified mice in the definition of monogenic metabolic phenotypes.

scholarly journals Bloom dynamics and chemical defenses of benthic cyanobacteria in the Indian River Lagoon, Florida

Harmful Algae ◽  
2017 ◽  
Vol 69 ◽  
pp. 75-82 ◽  
Author(s):  
Jennifer M. Sneed ◽  
Theresa Meickle ◽  
Niclas Engene ◽  
Sherry Reed ◽  
Sarath Gunasekera ◽  
...  
Keyword(s):  
Indian River Lagoon ◽  
Chemical Defenses ◽  
Benthic Cyanobacteria ◽  
Indian River

scholarly journals Bivalve Feeding on the Brown Tide Aureoumbra lagunensis in a Shallow Coastal Environment

2021 ◽  
Vol 8 ◽  
Author(s):  
Eve Galimany ◽  
Jessica Lunt ◽  
Christopher J. Freeman ◽  
I. Segura-García ◽  
M. Mossop ◽  
...  
Keyword(s):  
Clearance Rate ◽  
Indian River Lagoon ◽  
Brown Tide ◽  
Bivalve Species ◽  
Clearance Rates ◽  
Interspecific Differences ◽  
Brown Tides ◽  
Indian River ◽  
Aureoumbra Lagunensis ◽  
Fish And Shellfish

Brown tides formed by Aureoumbra lagunensis decrease light penetration in the water column and are often followed by hypoxic events that result in the loss of fish and shellfish. To understand the ability of bivalve filter feeders to control and prevent A. lagunensis blooms, we exposed eastern oysters (Crassostrea virginica), hooked mussels (Ischadium recurvum), and hard clams (Mercenaria mercenaria) to a naturally co-occurring brown tide in the Indian River Lagoon (IRL), Florida, United States. Bivalves were exposed in the laboratory to multiple concentrations (104 to 106 cells mL–1) of isotopically labeled (13C and 15N) A. lagunensis cells. The standard clearance rate (herein clearance rate) of each bivalve species was calculated using flow cytometry to quantify A. lagunensis cell removal. The highest clearance rates were at 104 cells mL–1, but values varied across bivalve species (2.16 ± 0.30, 3.03 ± 0.58, and 0.41 ± 0.12 L h–1 for C. virginica, I. recurvum, and M. mercenaria, respectively). Although clearance rates decreased with increasing bloom concentrations, bivalves were still consuming algal cells at all concentrations and were retaining and assimilating more cells at the highest concentrations, as revealed by δ13C and δ15N values. We highlight interspecific differences among bivalve species in the removal of A. lagunensis, supporting the importance of healthy and diverse filter feeding communities in estuaries, especially as threats of brown tides and other HABs are increasing in the Anthropocene.

scholarly journals Insomnia among Egyptian Samples of University Students and Employees

2014 ◽  
Vol 8 (2) ◽  
pp. 377
Author(s):  
Ahmed Abdel-Khalek ◽  
Maysa al Nyal ◽  
Hanan Saeed
Keyword(s):  
University Students ◽  
Prevalence Rate ◽  
Age Groups ◽  
Female Students ◽  
Principle Components Analysis ◽  
Female Employees ◽  
Males And Females ◽  
Components Analysis ◽  
Male University Students ◽  
Two Age Groups

The aim of this study was to estimate the prevalence of insomnia, differences between males and females, and between two age groups, and to explore the factorial structure of the Arabic Scale of Insomnia (ASI). Samples of university students (n=500) and employees (n=457) of both sexes were recruited. Female university students obtained the highest mean total score on the ASI, followed by female employees, male university students, and finally male employees. The salient significant differences were between female students and male employees and between male and female employees. Despite the differences in the prevalence rate of insomnia between the four groups, they all agreed on that the least prevalence rate was for the item: “I feel depressed when it is time for me to go to bed, whereas the highest prevalence rate was for the item: “My interrupted sleep annoys me.” Principle components analysis yielded three factors for each group. Most of their names were not identical. The most salient finding of this study was the statistically significant sex differences in insomnia in favor of women. It was concluded that is it important to introduce counseling for those who obtained high scores on the ASI. 

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