scholarly journals Correspondence between environmental gradients and summer littoral fish assemblages in low salinity reaches of the Chesapeake Bay, USA

1999 ◽  
Vol 177 ◽  
pp. 197-212 ◽  
Author(s):  
CM Wagner ◽  
HM Austin
Keyword(s):  
Chesapeake Bay ◽  
Fish Assemblages ◽  
Environmental Gradients ◽  
Low Salinity ◽  
Littoral Fish

Spatial and seasonal variation in littoral fish assemblages of four estuarine lagoons on the Mexican Pacific coast

2021 ◽  
pp. 102000
Author(s):  
Yureidy Cabrera-Páez ◽  
Consuelo M. Aguilar-Betancourt ◽  
Gaspar González-Sansón ◽  
Angel Hinojosa-Larios
Keyword(s):  
Seasonal Variation ◽  
Pacific Coast ◽  
Fish Assemblages ◽  
Mexican Pacific ◽  
Littoral Fish ◽  
Spatial And Seasonal Variation

scholarly journals Effects of Shoreline Urbanization on Littoral Fish Assemblages

2001 ◽  
Vol 17 (2) ◽  
pp. 127-138 ◽  
Author(s):  
Perry F. Trial ◽  
Frances P. Gelwick ◽  
Mark A. Webb
Keyword(s):  
Fish Assemblages ◽  
Littoral Fish

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.

Fish assemblages in coastal lagoons in land-uplift succession: The relative importance of local and regional environmental gradients

2009 ◽  
Vol 81 (2) ◽  
pp. 247-256 ◽  
Author(s):  
Martin Snickars ◽  
Alfred Sandström ◽  
Antti Lappalainen ◽  
Johanna Mattila ◽  
Kajsa Rosqvist ◽  
...  
Keyword(s):  
Fish Assemblages ◽  
Environmental Gradients ◽  
Coastal Lagoons ◽  
Relative Importance ◽  
Land Uplift

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.

scholarly journals Stability of the relationships among demersal fish assemblages and environmental-trawling drivers at large spatio-temporal scales in the northern Mediterranean Sea

2020 ◽  
Vol 83 (S1) ◽  
pp. 153
Author(s):  
Bastien Mérigot ◽  
Jean Claude Gaertner ◽  
Anik Brind’Amour ◽  
Pierluigi Carbonara ◽  
Antonio Esteban ◽  
...  
Keyword(s):  
Mediterranean Sea ◽  
Environmental Changes ◽  
Fish Assemblages ◽  
Environmental Gradients ◽  
Temporal Stability ◽  
Demersal Fish ◽  
Minor Role ◽  
Carbon Biomass ◽  
Spatio Temporal ◽  
A Minor

Trawling pressure and environmental changes may affect the composition of fish assemblages. Our knowledge on large spatio-temporal patterns of demersal fish composition remains incomplete for the Mediterranean Sea. We investigated (1) the spatio-temporal stability of demersal assemblages, (2) the relationships between these assemblages and potential structuring factors (trawling pressure and environmental conditions) in order to assess the dynamic of the assemblage structure at the scale of the northern Mediterranean Sea. We analysed a dataset of 18062 hauls from 10 to 800 m depth performed annually during the last two decades across 17 Geographical Sub-Areas (GSAs) (MEDITS program). A multi-table analysis (STATICO-CoA) evidenced a strong inter-GSAs stability in the organization of assemblages, with specificities for some GSAs. The most stable structuring factors were linked to combined gradients of chlorophyll a, phytoplancton carbon biomass and temperature, inversely correlated with depth, salinity and nutrient gradients (axis 1 of the STATICO-CoA compromise, 93.74% of the total variability). A common pattern linking the distribution of species to these environmental gradients was evidenced for most of the 17 GSAs. Estimate of trawling pressure showed a minor role in the organization of the assemblages for the spatial scale and years investigated (axis 2, 4.67%).

scholarly journals Volatility in coral cover erodes niche structure, but not diversity, in reef fish assemblages

2021 ◽  
Author(s):  
Cheng-Han Tsai ◽  
Hugh PA Sweatman ◽  
Löic M Thibaut ◽  
Sean R Connolly
Keyword(s):  
Coral Reefs ◽  
Reef Fish ◽  
Fish Assemblages ◽  
Environmental Gradients ◽  
Coral Cover ◽  
Species Abundance ◽  
Alpha Diversity ◽  
Deterministic Processes ◽  
Diversity Systems ◽  
Commonness And Rarity

Environmental fluctuations are becoming increasingly volatile in many ecosystems, highlighting the need to better understand how stochastic and deterministic processes shape patterns of commonness and rarity, particularly in high-diversity systems like coral reefs. Here, we analyse reef fish time-series across the Great Barrier Reef to show that approximately 75% of the variance in relative species abundance is attributable to deterministic, intrinsic species differences. Nevertheless, the relative importance of stochastic factors is markedly higher on reefs that have experienced stronger coral cover volatility. By contrast, alpha diversity and species composition are independent of coral cover volatility but depend on environmental gradients. Our findings imply that increased environmental volatility on coral reefs erodes assemblage's niche structure, an erosion that is not detectable from static measures of biodiversity.

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