Expansion of a Northern Snakehead Population in the Potomac River System

2007 ◽  
Vol 136 (6) ◽  
pp. 1633-1639 ◽  
Author(s):  
John Odenkirk ◽  
Steve Owens
Keyword(s):  
River System ◽  
Potomac River

Eels at the Edge: Science, Status, and Conservation Concerns

2009 ◽  
Keyword(s):  
Water Temperature ◽  
Stream Flow ◽  
River System ◽  
Lunar Phase ◽  
Upstream Migration ◽  
Potomac River ◽  
River Drainage ◽  
Thermal Refuge ◽  
American Eels ◽  
Atlantic Coastal

<em>Abstract.—</em>Yellow-phase American eels <em>Anguilla rostrata </em>migrate upstream extensively in Atlantic coastal river systems. However, few studies have focused on movements of large yellow American eels near dams in upper watersheds of Atlantic coastal rivers. We examined relationships between environmental variables (stream flow, water temperature, and lunar phase) and movements of radio-tagged yellow American eels (518–810 mm TL) near Millville hydroelectric dam in the lower Shenandoah River drainage of the upper watershed of the Potomac River system, West Virginia. Movements of yellow American eels differed seasonally. Water temperature and stream flow were associated with upstream migration during spring. Downstream movements during fall coincided with decreasing water temperatures and darker nights near the new moon. Eels overwintered in thermal refuge areas near tributary mouths. Localized irregular upstream and downstream movements during summer occurred near dusk and dawn and possibly reflected crepuscular foraging. Our study in the Potomac River drainage suggests the need for upstream eel passage at hydroelectric facilities when spring water temperatures exceed 15°C.

Proceedings of the First International Snakehead Symposium

2019 ◽  
Keyword(s):  
Yellow Perch ◽  
River System ◽  
Potomac River ◽  
Inland Fisheries ◽  
Channa Argus ◽  
Wet Weight ◽  
Virginia Department ◽  
Prey Items ◽  
Lentic Systems ◽  
Banded Killifish

<em>Abstract.</em>—The nonnative Northern Snakehead <em>Channa argus </em>was first documented in the Potomac River system in 2004. Since then, their range in Virginia has expanded to include other rivers and numerous lakes as a result of dispersal and illegal introductions. Most Northern Snakehead lake populations were discovered after 2012. Through 2017, nearly 4,000 Northern Snakehead were collected via Virginia Department of Game and Inland Fisheries (VDGIF) electrofishing surveys, resulting in a robust dataset. These collections provided an opportunity to investigate food habits of Northern Snakehead in both lotic and lentic systems which may assist with management and a better understanding of potential community effects. Incidence of identifiable prey items (<em>n </em>= 677) was evaluated since 2004, however wet weights (<em>n </em>= 370) were not recorded until 2014. A total of 30 prey types were identified from Northern Snakehead stomachs taken from rivers, whereas 7 prey types were identified from lakes. Banded Killifish, Bluegill, and crayfish were the most abundant prey types (in order) based on frequency of occurrence for Northern Snakehead collected from rivers; whereas Bluegill, frogs, and Yellow Perch were most common in Northern Snakehead collected from lakes. Most important food types (in order) based on % wet weight for Northern Snakehead collected from rivers were Bluegill, Gizzard Shad, and Banded Killifish; whereas Bluegill, Yellow Perch, and frogs contributed the most mass for Northern Snakehead from lakes.

Northern Snakeheads in the Tidal Potomac River System

2005 ◽  
Vol 134 (6) ◽  
pp. 1605-1609 ◽  
Author(s):  
John Odenkirk ◽  
Steve Owens
Keyword(s):  
River System ◽  
Potomac River

Managing Salinity in the Upper Santa Clara River System of California

2009 ◽  
Author(s):  
Nathan Brown ◽  
Brian Louie ◽  
Frank Guerrero ◽  
Terry Foreman ◽  
Sorab Panday ◽  
...  
Keyword(s):  
River System

Establishing an empirical equation for the relationship between total suspended solids and total phosphorus concentrations in the downstream Red river water

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 ◽  
...  
Keyword(s):  
Total Phosphorus ◽  
Suspended Solids ◽  
Empirical Relationship ◽  
Water Environment ◽  
Total Suspended Solids ◽  
River System ◽  
Red River ◽  
Reservoir Impoundment ◽  
Downstream Section ◽  
Reasonable Prediction

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.

Basic principles for assessing the safety of fish products from the ponds exposed to the influence of nuclear fuel cycle enterprises

2019 ◽  
pp. 106-114
Author(s):  
A. V. Trapeznikov ◽  
V. N. Trapeznikova ◽  
A. V. Korzhavin ◽  
V. N. Nikolkin ◽  
A. P. Plataev
Keyword(s):  
Fuel Cycle ◽  
Specific Activity ◽  
River System ◽  
Food Product ◽  
Human Consumption ◽  
Basic Principles ◽  
Fish Products ◽  
Permissible Levels ◽  
Irtysh River

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. 

Morphotectonic Analysis of Tanjung Bungo Area Based on Geological Structure Control, Central Sumatera Basin

2020 ◽  
Author(s):  
D., A., L., A. Putri
Keyword(s):  
Natural Resources ◽  
River Flow ◽  
Measurement Data ◽  
River System ◽  
Flow Patterns ◽  
Source Rocks ◽  
Aerial Photographs ◽  
Morphological Data ◽  
Tectonic Activity ◽  
Geological Structures

Tectonic activity in an area could result in various impacts such as changes in elevation, level of slope percentages, river flow patterns and systems, and the formation of geological structures both locally and regionally, which will form a new landscape. The tectonic activity also affects the stratigraphic sequences of the area. Therefore, it is necessary to study morphotectonic or landscape forms that are influenced by active tectonic activities, both those occur recently and in the past. These geological results help provide information of the potential of natural resources in and around Tanjung Bungo area. Morphological data are based on three main aspects including morphogenesis, morphometry, and morphography. The data are collected in two ways, the first is field survey by directly observing and taking field data such as measuring geological structures, rock positions, and outcrop profiles. The second way is to interpret them through Digital Elevation Model (DEM) and aerial photographs by analyzing river flow patterns and lineament analysis. The field measurement data are processed using WinTensor, Dips, and SedLog Software. The supporting data such as Topographic Maps, Morphological Elevation Maps, Slope Maps, Flow Pattern Maps, and Lineament Maps are based on DEM data and are processed using ArcGis Software 10.6.1 and PCI Geomatica. Morphotectonically, the Tanjung Bungo area is at a moderate to high-class level of tectonic activity taken place actively resulted in several joints, faults, and folds. The formation of geological structures has affected the morphological conditions of the area as seen from the development of steep slopes, structural flow patterns such as radial, rectangular, and dendritic, as well as illustrated by rough surface relief in Tanjung Bungo area. This area has the potential for oil and gas resources as indicated by the Telisa Formation, consisting of calcareous silts rich in planktonic and benthonic fossils, which may be source rocks and its contact with the Menggala Formation which is braided river system deposits that could be good reservoirs. Further research needs to be done since current research is only an interpretation of surface data. Current natural resources being exploited in Tanjung Bungo region are coals. The coals have thicknesses of 5-7 cm and are classified as bituminous coals.

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