Water Residence Time

2005 ◽  
Author(s):  
Kevin J. McGuire
Keyword(s):  
Residence Time ◽  
Water Residence Time

scholarly journals Mapping and Assessing Commercial Fisheries Services in the Lithuanian Part of the Curonian Lagoon

Fishes ◽  
2022 ◽  
Vol 7 (1) ◽  
pp. 19
Author(s):  
Edgaras Ivanauskas ◽  
Andrius Skersonas ◽  
Vaidotas Andrašūnas ◽  
Soukaina Elyaagoubi ◽  
Artūras Razinkovas-Baziukas
Keyword(s):  
Spatial Distribution ◽  
Residence Time ◽  
Fish Species ◽  
Circulation Model ◽  
Curonian Lagoon ◽  
Water Residence Time ◽  
Total Catch ◽  
Catch Per Unit Effort ◽  
Commercial Fish ◽  
The Impact

The spatial distribution of biomass of main commercial fish species was mapped to estimate the supply of a provisioning fishery service in the Curonian lagoon. Catch per unit effort (CPUE) was used as a proxy to estimate the efficiency of commercial fishing and, subsequently, the potential biomass of fishes. The relationship between distinctive characteristics of the fishing areas and corresponding commercial catches and CPUE was analyzed using multivariate analysis. The total catch values and CPUE used in the analyses were derived from the official commercial fishery records. RDE analysis was used to assess the variation of both catch and CPUE of commercial fish species, while the percentages of bottom sediment type coverage, average depth, annual salinity, and water residence time in each of the fishing squares were used as explanatory variables. This distance e-based redundancy analysis allowed for the use of non-Euclidean dissimilarity indices. Fisheries data spatial distribution map indicated the lack of coherence between the spatial patterns of commercial catches and CPUE distribution in the northern part of the lagoon. Highest CPUE values were estimated in the central-eastern part of the lagoon as compared to the western part of the lagoon where CPUE values were substantially lower. Both total catch and CPUE appeared not to be related to the type of bottom habitats statistically while being spatially correlated in-between. However, the impact of salinity and water residence time calculated using the 3D hydraulic circulation model on the distribution of both CPUE and commercial catches was statistically significant.

scholarly journals Coexisting ecosystem states in a tropical coastal lagoon under progressive eutrophication in the northern Cuban keys

2018 ◽  
Vol 82 (3) ◽  
pp. 139 ◽  
Author(s):  
Roberto González-De Zayas ◽  
Martin Merino-Ibarra ◽  
Patricia M. Valdespino-Castillo ◽  
Yunier Olivera ◽  
Sergio F. Castillo-Sandoval
Keyword(s):  
Residence Time ◽  
Coastal Lagoon ◽  
Spatial And Temporal Variability ◽  
Positive Trend ◽  
Water Residence Time ◽  
Effective Management ◽  
Management Options ◽  
Trophic Index ◽  
Tropical Coastal Lagoon ◽  
Mollusc Assemblages

Through a nested suite of methods here we contrast the coexistence of different ecosystem states in a tropical coastal lagoon, the Laguna Larga, with increasing eutrophication stress between 2007 and 2009. Water temperature averaged 27.4°C in the lagoon and showed a slight positive trend during the study period. Salinity averaged 35.0±6.2, exhibiting high spatial and temporal variability, and also a slight positive trend in time. In contrast, dissolved oxygen showed a substantial decreasing trend (–0.83 ml L–1 y–1; –13.3% y–1) over the period, while nutrients increased dramatically, particularly total phosphorus (2.6 µM y–1), in both cases sustaining the progression of eutrophication in the lagoon during the three years we sampled. The Karydis nutrient load-based trophic index showed that the lagoon has a spatial pattern of increasing eutrophication from the sea and the outer sector (oligotrophic-mesotrophic) to the central (mesotrophic) and the inner sector (mesotrophic-eutrophic). Two ecosystem states were found within the lagoon. In the outer oligotrophic sector, the dominant primary producers were macroalgae, seagrasses and benthic diatoms, while mollusc assemblages were highly diverse. In the inner and central sectors (where trophic status increased toward the inner lagoon) a phytoplankton-dominated ecosystem was found where mollusc assemblages are less diverse. In spite of the progression of eutrophication in the lagoon, these two different ecosystems coexisted and remained unchanged during the study period. Apparently, the effect of water residence time, which increases dramatically toward the inner lagoon, dominated over that of nutrient loadings, which is relatively more homogeneously distributed along the lagoon. Therefore, we consider that actions that reduce the water residence time are likely the most effective management options for this and other similarly choked lagoons.

scholarly journals Calanoid copepod zooplankton density is positively associated with water residence time across the continental United States

PLoS ONE ◽  
2019 ◽  
Vol 14 (1) ◽  
pp. e0209567 ◽  
Author(s):  
Jonathan P. Doubek ◽  
Cayelan C. Carey ◽  
Michael Lavender ◽  
Amanda K. Winegardner ◽  
Marieke Beaulieu ◽  
...  
Keyword(s):  
United States ◽  
Residence Time ◽  
Calanoid Copepod ◽  
Water Residence Time ◽  
Zooplankton Density

scholarly journals Nitrate sources and dynamics in the salinized rivers and estuaries – a <i>δ</i><sup>15</sup>N- and <i>δ</i><sup>18</sup>O-NO<sub>3</sub><sup>–</sup> isotope approach

2014 ◽  
Vol 11 (3) ◽  
pp. 4563-4589 ◽  
Author(s):  
D. Xue ◽  
P. Boeckx ◽  
Z. Wang
Keyword(s):  
Residence Time ◽  
Water Exchange ◽  
Aerobic Denitrification ◽  
Bohai Bay ◽  
Water Residence Time ◽  
Nitrate Sources ◽  
Attenuation Function ◽  
N Source ◽  
Three Rivers

Abstract. To trace NO3– sources and assess NO3– dynamics in the salinized rivers and estuaries, three rivers (HH River, CB River and JY River) and two estuaries (HH Estuary and CJ Estuary) along the Bohai Bay (China) have been selected to determine DIN and δ15N and δ18O-NO3–. Upstream of the HH River NO3– was removed 30.9 ± 22.1% by aerobic denitrification, resulting from effects of the floodgate: limiting water exchange with downstream and prolonging water residence time to remove NO3–. Downstream of the HH River NO3– was removed 2.5 ± 13.3% by NO3– turnover processes. Conversely, NO3– was increased 36.6 ± 25.2% by external N source addition in the CB River and 34.6 ± 35.1% by in-stream nitrification in the JY River, respectively. The HH and CY Estuaries behaved mostly conservative excluding the sewage input in the CJ Estuary. Hydrodynamics in estuaries have been changed by the ongoing reclamation projects, aggravating the estuaries losing the attenuation function of NO3–.

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