scholarly journals Spawning Drivers and Frequency of Endangered Atlantic Sturgeon in the York River System

2020 ◽  
Vol 149 (4) ◽  
pp. 474-485
Author(s):  
Christian H. Hager ◽  
J. Carter Watterson ◽  
Jason E. Kahn
2014 ◽  
Vol 143 (5) ◽  
pp. 1217-1219 ◽  
Author(s):  
Christian Hager ◽  
Jason Kahn ◽  
Carter Watterson ◽  
Jay Russo ◽  
Kyle Hartman

2009 ◽  
Vol 10057 ◽  
pp. 99-110 ◽  
Author(s):  
Amanda Hewitt ◽  
Julia Ellis ◽  
Mary C. Fabrizio
Keyword(s):  

2012 ◽  
Vol 11 (3) ◽  
pp. 375-386 ◽  
Author(s):  
Patrick E. McGrath ◽  
Eric J. Hilton ◽  
John A. Musick
Keyword(s):  

1972 ◽  
Vol 1 (13) ◽  
pp. 126
Author(s):  
A.Y. Kuo ◽  
C.S. Fang

A long term time-dependent mathematical model has been developed for predicting the salinity distributions in the upper York River System, including the tidal portions of the Mattaponi and Pamunkey Rivers. The method of calculating the longitudinal dispersion coefficient is discussed in detail. The study area and field project are described. The downstream boundary condition was found from a scheme combining a semi-explicit technique and linear extrapolation. The mass-balance equation, averaged over a tidal cycle and solved numerically by the implicit finite difference scheme, provided a reasonable solution and afforded economy in computer time. Field data were compared with the corresponding model results, indicating the general accuracy of the methodology.


Author(s):  
Nathan Brown ◽  
Brian Louie ◽  
Frank Guerrero ◽  
Terry Foreman ◽  
Sorab Panday ◽  
...  
Keyword(s):  

2020 ◽  
Vol 20 (3) ◽  
pp. 325-332
Author(s):  
Le Nhu Da ◽  
Le Thi Phuong Quynh ◽  
Phung Thi Xuan Binh ◽  
Duong Thi Thuy ◽  
Trinh Hoai Thu ◽  
...  

Recently, the Asian rivers have faced the strong reduction of riverine total suspended solids (TSS) flux due to numerous dam/reservoir impoundment. The Red river system is a typical example of the Southeast Asian rivers that has been strongly impacted by reservoir impoundment in both China and Vietnam, especially in the recent period. It is known that the reduction in total suspended solids may lead to the decrease of some associated elements, including nutrients (N, P, Si) which may affect coastal ecosystems. In this paper, we establish the empirical relationship between total suspended solids and total phosphorus concentrations in water environment of the Red river in its downstream section from Hanoi city to the Ba Lat estuary based on the sampling campaigns conducted in the dry and wet seasons in 2017, 2018 and 2019. The results show a clear relationship with significant coefficient between total suspended solids and total phosphorus in the downstream Red river. It is expressed by a simple equation y = 0.0226x0.3867 where x and y stand for total suspended solids and total phosphorus concentrations (mg/l) respectively with the r2 value of 0.757. This equation enables a reasonable prediction of total phosphorus concentrations of the downstream Red river when the observed data of total suspended solids concentrations are available. Thus, this work opens up the way for further studies on the calculation of the total phosphorus over longer timescales using daily available total suspended solids values.


Author(s):  
A. V. Trapeznikov ◽  
V. N. Trapeznikova ◽  
A. V. Korzhavin ◽  
V. N. Nikolkin ◽  
A. P. Plataev

Relevance. In connection with the development of nuclear energy, many aquatic ecosystems have been exposed to radioactive substances. Fish, as an element of biota, is capable to accumulate radionuclides. However, fish is a traditional food. The control of the technogenic radionuclides accumulation level in the ichthyofauna is an important link in ensuring human security.Intention. To analyze the long-term data on the content of long-lived technogenic radionuclides 90Sr and 137Cs in the ichthyofauna of the Ob-Irtysh river system for the period from 2004 to 2016 and Beloyarsky pond for the period from 1977 to 2018.Methodology. Fish as a food product was assessed according to two criteria: a) permissible levels of specific activity of radionuclides (SanPiN 2.3.2.1078-01); b) using the indicator of conformity B and the uncertainty of its definition В (GOST 32161-2013 and GOST 32163-2013).Results and Discussion. Fish of all species that live in the river Tetcha, is not suitable for food use according to the criteria of SanPiN 2.3.2.1078-01, GOST 32161-2013 and GOST 32163-2013. The fish of the Ob-Irtysh river system, the habitat of which is located outside the Tetcha, meets the requirements for fish products. In the period from 1977 to 1989 in the Beloyarsk pond the accumulations of technogenic radionuclides in fish in quantities exceeding sanitary and hygienic standards were possible. Currently, the fish of the Beloyarsky pond fully complies with the sanitary and hygienic requirements for the radiation factor and is safe for human consumption.Conclusion. In the ponds exposed to the atomic energy enterprises, it is necessary to continuously monitor the content of long-lived technogenic radionuclides in fish and assess their amount in accordance with the requirements of SanPiN 2.3.2.1078-01 and using the conformity indicator В and the uncertainty of its determination В. 


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