Flocculation and Sedimentation in the ACE Basin, South Carolina

Milligan, Timothy G.; Kineke, Gail C.; Blake, A. C.; Alexander, Clark; Hill, Paul S.

doi:10.2307/1352881

Cited by 26 publications

(20 citation statements)

References 33 publications

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“…ETM are typically created by interactions between river flow and tidal forcing and are located at the boundary of the salt wedge (i.e., approximately station 3) (38). They are characterized as regions where there are elevated concentrations of flocculent material and suspended solids (7,44). Our findings that the TSS content was substantially higher and the ratio of OS content to TSS content was lower in the ACE Basin estuary (Table 2) than in the NI estuary suggested that flocculent material and/or riverine debris, and not microbially derived debris, was primarily responsible for most of the observed turbidity in the ACE Basin estuary.…”

Section: Discussionmentioning

confidence: 72%

Contrasting Patterns of Phytoplankton Community Pigment Composition in Two Salt Marsh Estuaries in Southeastern United States

Noble

Tymowski²,

Fletcher

et al. 2003

Appl Environ Microbiol

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Phytoplankton community pigment composition and water quality were measured seasonally along salinity gradients in two minimally urbanized salt marsh estuaries in South Carolina in order to examine their spatial and temporal distributions. The North Inlet estuary has a relatively small watershed with minimal fresh water input, while the Ashepoo, Combahee, and Edisto (ACE) Basin is characterized by a relatively greater influence of riverine drainage. Sampling stations were located in regions of the estuaries experiencing frequent diurnal tidal mixing and had similar salinity and temperature regimens. Phytoplankton community pigment composition was assessed by using high-performance liquid chromatography (HPLC) and multivariate statistical analyses. Shannon diversity index, principal-component, and cluster analyses revealed that phytoplankton community pigments in both estuaries were seasonally variable, with similar diversities but different compositions. The temporal pigment patterns indicated that there was a relatively weak correlation between the pigments in ACE Basin and the relative persistence of photopigment groups in North Inlet. The differences were presumably a consequence of the unpredictability and relatively greater influence of river discharge in the ACE Basin, in contrast to the greater environmental predictability of the more tidally influenced North Inlet. Furthermore, the timing, magnitude, and pigment composition of the annual phytoplankton bloom were different in the two estuaries. The bloom properties in North Inlet reflected the predominance of autochthonous ecological control (e.g., regenerated nutrients, grazing), and those in ACE Basin suggested that there was greater influence of allochthonous environmental factors (e.g., nutrient loading, changes in turbidity). These interestuarine differences in phytoplankton community structure and control provide insight into the organization of phytoplankton in estuaries.Processes and mechanisms that determine the spatial and temporal patterns of phytoplankton have been a central focus of marine research for decades. This research has led to the identification of biotic and abiotic factors that regulate primary productivity and the development of models that describe phytoplankton growth dynamics under specific environmental conditions (4). Phytoplankton communities are multispecies communities which are highly complex in terms of their diversity and dynamics. Successional shifts in phytoplankton community structure are primarily due to changes in environmental variables (e.g., degree or type of nutrient limitation) and/or shifts in higher trophic levels (e.g., micro-versus mesozooplankton) (23,35,40,54,56). How phytoplankton community composition changes with environmental variables and/or preferential grazing by herbivores is not well understood, particularly in estuarine ecosystems. Identifying the ecological variables that regulate phytoplankton community structure is essential for facilitating the development of broad hypotheses underlying our...

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Section: Discussionmentioning

confidence: 72%

Contrasting Patterns of Phytoplankton Community Pigment Composition in Two Salt Marsh Estuaries in Southeastern United States

Noble

Tymowski²,

Fletcher

et al. 2003

Appl Environ Microbiol

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“…A change in floc size or abundance due to advection is distinguishable when floc size is decoupled from bottom stress (Jago et al 2006). Resuspension is distinguishable by coupling between floc size and seabed stress (Milligan et al 2001, Fugate & Friedrichs 2003). Aggregation occurs when turbulence is low to moderate, and particle concentration is large ).…”

Section: Particle Size and Packagingmentioning

confidence: 99%

“…Hill et al (2001) reported that marine aggregates or flocs break up when turbulent stress is at or above 0.1 Pa. Deposition occurs when stress is low enough for flocs to settle from the water column, and is associated with decreases in concentration and overall particle size. As a suspension settles, however, a temporary increase in concentration near the seabed can occur (Milligan et al 2001, Voulgaris & Meyers 2004, Mikkelsen et al 2006, Hill et al 2011.…”

Section: Particle Size and Packagingmentioning

confidence: 99%

Size, settling velocity and density of small suspended particles at an active salmon aquaculture site

Law¹,

Hill²,

Maier³

et al. 2014

Aquacult. Environ. Interact.

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Scientific understanding of aquaculture interactions with the environment is limited, especially concerning the far-field transport and possible impacts of particulate wastes. A pilot study was carried out in southwest New Brunswick, Canada, in November 2008 to determine the size, settling velocity, and density of suspended particles at an active salmon aquaculture cage site. The model of Khelifa & Hill (2006) was fit to size-versus-settling velocity data to estimate the fractal dimension of flocs and the density of the component particles within flocs. Flocs had a larger fractal dimension and smaller component−particle density than in other studies, suggesting that particles from the aquaculture operation may be incorporated into suspended flocs with average settling velocities of 1 mm s −1. Variability in particle size and packaging was interpreted in the context of near bed velocity, tidal stage, and wind speed and direction. This analysis indicated that advection dominated observed variations in particle size and packaging. Indicators of resuspension, aggregation, disaggregation, and deposition were not detected in the time series. Advection of flocs away from the study site provides a mechanism to transport wastes over distances greater than 1 km prior to deposition; thus a settling class of 1 mm s −1 should be considered in depositional models of aquaculture wastes.

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“…La velocidad de caída del grano está relacionada con partículas con un d50 entre 9 y 55 µm según la ecuación de Stokes, lo que está en concordancia con la granulometría superficial. Además, bajos valores del número de Rouse (n < 1) están relacionados con el predominio del transporte de sedimentos en suspensión (Milligan et al, 2001), esto se produce cuando los valores de la velocidad de caída del grano son mucho menores que la velocidad de corte.…”

Section: Discussionunclassified

Distribución vertical de sedimentos en suspension en la zona de desembocadura del Rio Magdalena, Colombia

Higgins¹,

Restrepo²,

Díaz³

et al. 2017

lajar

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), and high values in shear stress (1.1-5.8 Pa) were obtained. It can be said therefore that in the River Magdalena predominates sediment transport in suspension. The values of bottom sediment transport calculated with the three formulations represent lower rates to 5% of total sediment transport. The formulation of Meyer-Peter & Müller (1948) underestimate the transport of bottom sediment due to the conditions under which it was originally calibrated, while Nielsen (1992) and Ribberink (1998) formulations can generate better estimates, because they were originally calibrated with fine sediment, similar to the sediment type reported in the study area.

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Flocculation and Sedimentation in the ACE Basin, South Carolina

Cited by 26 publications

References 33 publications

Contrasting Patterns of Phytoplankton Community Pigment Composition in Two Salt Marsh Estuaries in Southeastern United States

Contrasting Patterns of Phytoplankton Community Pigment Composition in Two Salt Marsh Estuaries in Southeastern United States

Size, settling velocity and density of small suspended particles at an active salmon aquaculture site

Distribución vertical de sedimentos en suspension en la zona de desembocadura del Rio Magdalena, Colombia

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