Particulate Carbon:Nitrogen Relations in Northern Chesapeake Bay

1971 ◽  
Vol 28 (6) ◽  
pp. 911-918 ◽  
Author(s):  
David A. Flemer ◽  
Robert B. Biggs
Keyword(s):  
Chesapeake Bay ◽  
Net Primary Production ◽  
C:N Ratio ◽  
Particulate Material ◽  
Late Winter ◽  
Suspended Material ◽  
Particulate Carbon ◽  
Susquehanna River ◽  
Low Salinity ◽  
Thaw Period

The Susquehanna River annually supplies about 8.4 × 104 and 4.7 × 103 metric tons of particulate carbon (PC) and nitrogen (PN), respectively, to upper Chesapeake Bay. In the upper bay, the concentration of PN usually ranges between 0.10 and 0.30 mg liter−1 and is occasionally greater than 0.50 mg liter−1. In the lower study area, the concentration of PN stabilizes near 0.10 mg liter−1. Maximum values of the carbon:nitrogen (C:N) ratio (atomic basis) occurred in the upper bay, and highest values were associated with the late-winter thaw period of the Susquehanna River. C:N ratios of 20–30 were usual most of the year in the low salinity region, and often greater than 30 during times of maximum river discharge. In the lower study area, the ratio approached 15 throughout most of the year. In general, the reduction in the C:N ratios of the suspended material was reflected in the C:N ratios of the sediments.The high C:N ratios in the upper bay and the tidal freshwater portion of the Susquehanna River indicate a high detrital content. An estimate of net primary production would extrapolate to the fixation of PN of approximately 1600 metric tons per year in the upper bay or about 34% of that supplied by upland drainage. The major source of PN in the lower study area is probably provided by photosynthetic fixation, since the physical circulation of the estuary retards a large movement of particulate material seaward.

Suspended Sediment Discharge of the Susquehanna River to Northern Chesapeake Bay, 1966 to 1976

Estuaries ◽  
1978 ◽  
Vol 1 (2) ◽  
pp. 106 ◽  
Author(s):  
M. Grant Gross ◽  
M. Karweit ◽  
William B. Cronin ◽  
J. R. Schubel
Keyword(s):  
Chesapeake Bay ◽  
Suspended Sediment ◽  
Sediment Discharge ◽  
Susquehanna River

scholarly journals Spatiotemporal Variations Dictate Stable and Resilient Microbiome Interactions in the Chesapeake Bay

2020 ◽  
Author(s):  
Hualong Wang ◽  
Feng Chen ◽  
Chuanlun Zhang ◽  
Min Wang ◽  
Jinjun Kan
Keyword(s):  
Chesapeake Bay ◽  
Structural Equation ◽  
Regression Tree ◽  
Warm Season ◽  
Temporal Variations ◽  
Microbial Interactions ◽  
Equation Modeling ◽  
Spatiotemporal Variations ◽  
Particulate Carbon ◽  
Estuarine Ecosystem

Abstract Background: Annually reoccurring microbial populations with strong spatial and temporal variations have been identified in estuarine environments, especially in those with long residence time such as the Chesapeake Bay (CB). However, it is unclear how microbial taxa interact with each other (e.g., mutualistic and competitive interactions) and how these interactions respond to their surrounding environments. Specifically, there is a lack of understanding of how these interactions influence microbiome population dynamics, and its adaptability and resilience to estuarine gradients. Results: Here, we constructed co-occurrence networks on prokaryotic microbial communities in the Bay, which included seasonal samples from seven spatial stations along the salinity gradients for three consecutive years. Our results showed that spatiotemporal variations of planktonic microbiomes promoted differentiations of the characteristics and stability of prokaryotic microbial networks in the CB estuary. Prokaryotic microbial networks are more stable seasonally than spatially, and microbes were more strongly connected during warm season compared to the associations during cold season. In addition, microbial interactions were more stable in the lower Bay (ocean side) than those in the upper Bay (freshwater side). Interestingly, compared to the abundant groups, the rare taxa such as SAR116 clade, SAR11 clade III, and OM182 clade contributed greatly to the stability and resilience of prokaryotic microbial interactions in the Bay. Modularity and cluster structures of microbial networks varied spatiotemporally, which provided valuable insights into the ‘small world’ (a group of more interconnected species), network stability, and habitat partitioning/preferences. Multivariate regression tree (MRT) analysis and Piecewise structural equation modeling (SEM) indicated that temperature, salinity and total suspended substances directly or indirectly (through nutrient availability, particulate carbon and Chl a) affected the distribution and associations of microbial groups, such as Actinobacteria, Bacteroidetes, Cyanobacteria, Planctomycetes, Proteobacteria, and Verrucomicrobia.Conclusion: Our results shed light on how spatiotemporal variations alter the nature and stability of prokaryotic microbial networks in the estuarine ecosystem, as well as the ability of planktonic microbiomes and their interactions to resist future disturbances.

A Continuous Size Spectrum for Particulate Matter in the Sea

1967 ◽  
Vol 24 (5) ◽  
pp. 909-915 ◽  
Author(s):  
R. W. Sheldon ◽  
T. R. Parsons
Keyword(s):  
Particle Diameter ◽  
Particulate Material ◽  
Size Spectrum ◽  
Particulate Carbon ◽  
Particle Volume ◽  
Carbon And Nitrogen ◽  
Total Particle ◽  
Volume Measurements ◽  
Good Agreement

The size spectrum of particulate material in seawater can easily be expressed as total particle volume versus the logarithm of particle diameter. This appears to be the most informative way to present the data and it is also aptly suited to the classical divisions of nanno-, micro-, and macroplankton.A realistic measure of the volume of irregularly shaped particles such as phytoplankton chains could be made with a Coulter Counter. Particle volume measurements were in good agreement with estimates based on microscopic determination of particle diameter. There were also highly significant correlations between total particle volume, as indicated by the counter, and particulate carbon and nitrogen.

Seasonal variations in the Indian Ocean along 110°E. II. Particulate carbon

1969 ◽  
Vol 20 (1) ◽  
pp. 51 ◽  
Author(s):  
BS Newell
Keyword(s):  
Indian Ocean ◽  
Seasonal Variations ◽  
Combustion Method ◽  
Particulate Material ◽  
Particulate Carbon ◽  
The Indian Ocean

Particulate carbon at 0, 50, 100, 150, and 200 m was measured by a combustion method. Mineral carbon appeared to be negligible. Some particulate material escaped the Whatman GF/C filters used. The amount of suspended carbon decreased with depth at most stations from values of 20 �g/l, or more at 0 and 50 m, to 15 �g/l, at 150 m, and 10�g/l, at 150 and 200m. Higher values were found at all depths at the two southernmost stations (25-30 �g/I. at 0 and 50 m decreasing to 15 �gll. at 150 and 200 m ) and at shallow depths at the northernmost stations (20-25 �g/l. at 0 and 50m). At all stations and at all depths, least carbon occurred in March.

Satellite-measured net primary production in the Chesapeake Bay

2014 ◽  
Vol 144 ◽  
pp. 109-119 ◽  
Author(s):  
SeungHyun Son ◽  
Menghua Wang ◽  
Lawrence W. Harding
Keyword(s):  
Primary Production ◽  
Chesapeake Bay ◽  
Net Primary Production

scholarly journals Predictability of Vibrio cholerae in Chesapeake Bay

2003 ◽  
Vol 69 (5) ◽  
pp. 2773-2785 ◽  
Author(s):  
Valérie R. Louis ◽  
Estelle Russek-Cohen ◽  
Nipa Choopun ◽  
Irma N. G. Rivera ◽  
Brian Gangle ◽  
...  
Keyword(s):  
Chesapeake Bay ◽  
Vibrio Cholerae ◽  
Stream Flow ◽  
Natural Waters ◽  
Global Climate ◽  
Fluorescent Antibody ◽  
Fourfold Increase ◽  
Susquehanna River ◽  
Direct Fluorescent Antibody ◽  
Untreated Water

ABSTRACT Vibrio cholerae is autochthonous to natural waters and can pose a health risk when it is consumed via untreated water or contaminated shellfish. The correlation between the occurrence of V. cholerae in Chesapeake Bay and environmental factors was investigated over a 3-year period. Water and plankton samples were collected monthly from five shore sampling sites in northern Chesapeake Bay (January 1998 to February 2000) and from research cruise stations on a north-south transect (summers of 1999 and 2000). Enrichment was used to detect culturable V. cholerae, and 21.1% (n = 427) of the samples were positive. As determined by serology tests, the isolates, did not belong to serogroup O1 or O139 associated with cholera epidemics. A direct fluorescent-antibody assay was used to detect V. cholerae O1, and 23.8% (n = 412) of the samples were positive. V. cholerae was more frequently detected during the warmer months and in northern Chesapeake Bay, where the salinity is lower. Statistical models successfully predicted the presence of V. cholerae as a function of water temperature and salinity. Temperatures above 19°C and salinities between 2 and 14 ppt yielded at least a fourfold increase in the number of detectable V. cholerae. The results suggest that salinity variation in Chesapeake Bay or other parameters associated with Susquehanna River inflow contribute to the variability in the occurrence of V. cholerae and that salinity is a useful indicator. Under scenarios of global climate change, increased climate variability, accompanied by higher stream flow rates and warmer temperatures, could favor conditions that increase the occurrence of V. cholerae in Chesapeake Bay.

High Salinity Relay as a Postharvest Processing Strategy To Reduce Vibrio vulnificus Levels in Chesapeake Bay Oysters (Crassostrea virginica)†

2011 ◽  
Vol 74 (11) ◽  
pp. 1902-1907 ◽  
Author(s):  
CORINNE AUDEMARD ◽  
HOWARD I. KATOR ◽  
MARTHA W. RHODES ◽  
THOMAS GALLIVAN ◽  
A. J. ERSKINE ◽  
...  
Keyword(s):  
Chesapeake Bay ◽  
High Salinity ◽  
Vibrio Vulnificus ◽  
Most Probable Number ◽  
Probable Number ◽  
Low Salinity ◽  
Moderate Salinity ◽  
Salinity Increase ◽  
The Impact ◽  
Postharvest Processing

In 2009 the U.S. Food and Drug Administration (FDA) announced its intention to implement postharvest processing (PHP) methods to eliminate Vibrio vulnificus from oysters intended for the raw, half-shell market that are harvested from the Gulf of Mexico during warmer months. FDA-approved PHP methods can be expensive and may be associated with unfavorable responses from some consumers. A relatively unexplored PHP method that uses relaying to high salinity waters could be an alternative strategy, considering that high salinities appear to negatively affect the survival of V. vulnificus. During relay, however, oysters may be exposed to rapid and large salinity increases that could cause increased mortality. In this study, the effectiveness of high salinity relay to reduce V. vulnificus to <30 most probable number (MPN) per g and the impact on oyster mortality were assessed in the lower Chesapeake Bay. Two relay experiments were performed during the summer and fall of 2010. Oysters collected from three grow-out sites, a low salinity site (14 to 15 practical salinity units [psu]) and two moderate salinity sites (22 to 25 psu), were relayed directly to a high salinity site (≥30 psu) on Virginia's Eastern Shore. Oysters were assayed for V. vulnificus and Vibrio parahaemolyticus (another Vibrio species of concern) densities at time 0 prior to relay and after 7 and 14 days of relay, using the FDA MPN enrichment method combined with detection by real-time PCR. After 14 days, both V. vulnificus and V. parahaemolyticus densities were ≤0.8 MPN/g, and decreases of 2 to 3 log in V. vulnificus densities were observed. Oyster mortalities were low (≤<4%) even for oysters from the low salinity harvest site, which experienced a salinity increase of approximately 15 psu. Results, although preliminary and requiring formal validation and economic analysis, suggest that high salinity relay could be an effective PHP method.

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