Pelagic cnidarians and ctenophores in low dissolved oxygen environments: A review

2001 ◽  
pp. 77-100 ◽  
Author(s):  
Jennifer E. Purcell ◽  
Denise L. Breitburg ◽  
Mary Beth Decker ◽  
William M. Graham ◽  
Marsh J. Youngbluth ◽  
...  
Keyword(s):  
Dissolved Oxygen ◽  
Low Dissolved Oxygen

A study of water quality in an urban river and potential improvement using a prototype instream aerator

1989 ◽  
Vol 16 (3) ◽  
pp. 308-316 ◽  
Author(s):  
C. A. Town ◽  
D. S. Mavinic ◽  
B. Moore
Keyword(s):  
Water Quality ◽  
Dissolved Oxygen ◽  
Data Base ◽  
Chlorophyll A ◽  
Late Summer ◽  
Urban River ◽  
Agricultural Activity ◽  
Fish Kills ◽  
Low Dissolved Oxygen ◽  
Oxygen Levels

Urban encroachment and intensive agricultural activity within the Serpentine–Nicomekl watershed (near Vancouver, B.C.) have caused a series of fish (salmon) kills on the Serpentine River since 1980. Low dissolved oxygen was responsible for these kills. This field project investigated some of the dynamic chemical and biological relationships within the river, as well as the use of an instream aerator as a temporary, in situ, water quality improvement measure. Weekly sampling for a 6-month period during the latter half of 1985 established a solid data base for deriving and interpreting meaningful interrelationships. A strong correlation between chlorophyll a and dissolved oxygen levels before the algae die-off supported the hypothesis that algae blooms dying in the fall could create a serious oxygen demand. Because of these environmental conditions, the river is unable to sustain healthy dissolved oxygen levels during this period. As such, a prototype, 460 m artificial aeration line was designed, installed, and monitored to evaluate its potential for alleviating low dissolved oxygen conditions and improving overall water quality during the critical fall period.The instream aerator ran continuously for over 2 months, starting in September 1985. Despite better-than-expected weather conditions (i.e., cool, wet weather) and relatively high dissolved oxygen levels during the fall of 1985, the data base appeared to support the use of this prototype aeration unit as a means of "upgrading" a stretch of an urban river subject to periodic, low dissolved oxygen levels. As a result, a 2-year follow-up study and river monitoring was initiated. In both 1986 and 1987, late summer and early fall river conditions resulted in the potential for serious salmon kills, due to higher-than-normal river temperatures and very low dissolved oxygen. In both instances, the instream aerator prevented such fish kills in a key stretch of the river. Expansion of the system to include other critical stretches of the Serpentine and other urban river systems, near Vancouver, is being considered. Key words: algae, aerator, chlorophyll a, eutrophic, fish kills, instream aeration, river improvement, urban river.

Effects of Low Dissolved Oxygen Events on the Macrobenthos of the Lower Chesapeake Bay

Estuaries ◽  
1992 ◽  
Vol 15 (3) ◽  
pp. 384 ◽  
Author(s):  
Daniel M. Dauer ◽  
Anthony J. Rodi ◽  
J. Ananda Ranasinghe
Keyword(s):  
Dissolved Oxygen ◽  
Chesapeake Bay ◽  
Low Dissolved Oxygen

Lethal Low Dissolved Oxygen Concentrations for Postlarvae and Early Juvenile Penaeus setiferus at Different Salinities and pH

1998 ◽  
Vol 29 (2) ◽  
pp. 221-229 ◽  
Author(s):  
Evenor Martínez ◽  
Miguel Aguilar ◽  
Limber Trejo ◽  
Isaac Hernández ◽  
Eugenio Díaz-Iglesia ◽  
...  
Keyword(s):  
Dissolved Oxygen ◽  
Early Juvenile ◽  
Low Dissolved Oxygen ◽  
Penaeus Setiferus ◽  
Oxygen Concentrations

Study of the COD Release in the Sediment of Tang He Reservoir

2012 ◽  
Vol 610-613 ◽  
pp. 1134-1138
Author(s):  
Zhi Ping Li ◽  
Xin Yi Li ◽  
Ya Jing Li
Keyword(s):  
Dissolved Oxygen ◽  
Organic Pollutants ◽  
Simulation Experiment ◽  
Scientific Basis ◽  
Comprehensive Treatment ◽  
Low Dissolved Oxygen

The character of COD release in the sediment of Tang He Reservoir was studied under the condition of different concentrations, temperatures, pHs, disturbances, and dissolved oxygen through indoor simulation experiment. It was concluded that sediment could adsorb more organic pollutants when the river was at a higher concentration; whether the temperature was raised or lowered, the COD emission all increased, so the maintenance of temperature could inhibit the release of COD in water; the water stable at the pH of 8; disturbance significantly increased the released quantity of COD; low dissolved oxygen could promote release of COD. The study can provide scientific basis for comprehensive treatment of Tang He Reservoir.

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