scholarly journals Load of Aeromonas salmonicida in Swamp Water and it's Effect on Tilapia (Oreochromis mossambicus)

1970 ◽  
Vol 15 ◽  
pp. 165-168 ◽  
Author(s):  
Habiba Khatun ◽  
Rowshatul Afza ◽  
M Iqbal Hossain ◽  
M Afzal Hussain ◽  
AR Khan ◽  
...  
Keyword(s):  
Organic Matter ◽  
Shallow Water ◽  
Aquatic Ecosystems ◽  
Oreochromis Mossambicus ◽  
Aeromonas Salmonicida ◽  
Water Bodies ◽  
Fish Culture ◽  
Unemployment Problem ◽  
Lentic Water

Swamps are one of those types of lentic water bodies, which form links between terrestrial and aquatic ecosystems. Dehadrai and Tripathi (1976) have characterized these water bodies as waterlogged, shallow water areas with a loose peaty bottom, rich in decaying organic matter retaining water either periodically or shrinking or drying summer months. There are numerous water bodies, including swamps, present in Bangladesh. But all of these water bodies are not used for scientific fish culture. To meet the increasing protein demand and to solve the unemployment problem in Bangladesh, swamps should be used for fish culture scientifically. This may also be helpful to destroy the habitat of many biological vectors such as mosquitoes. doi: 10.3329/jbs.v15i0.2158 J. bio-sci. 15: 165-168, 2007

scholarly journals Transferencia de oxígeno en agua anóxica utilizando un dispositivo de aireadores de rueda de paletas a bajas revoluciones

2021 ◽  
Vol 34 (2) ◽  
Author(s):  
Nicolás Rojas Arias ◽  
Cesar René Blanco Zúñiga ◽  
A.J.D. Vargas-Bolívar ◽  
W.T. Sáchica-Tenjo ◽  
V. R. Barrales-Guadarrama
Keyword(s):  
Shallow Water ◽  
Aquatic Ecosystems ◽  
Biological Species ◽  
Water Bodies ◽  
Natural Environments ◽  
Paddle Wheel ◽  
Adverse Impacts ◽  
Optimal Value ◽  
Do Concentration ◽  
Bodies Of Water

The reduction of dissolved oxygen (DO) in water is associated with the effect of climate change. The lack of oxygen in water bodies directly affects the biological species present in different shallow water bodies such as swamps and wetlands, as well as in aquaculture processes. An optimal value in the DO concentration favors the reproduction of these biological species present in both artificial and natural environments. For this, various equipment has been developed to favor the increase of DO in the water to acceptable values. However, some of these systems are expensive, energy inefficient, and noisy which generate adverse impacts in aquatic ecosystems due to perturbances in the water. This study measures the efficiency (KgO2·kWh-1) of introducing DO into the water using a paddle wheel aerator system at low RPMs destined for shallow bodies of water. Tests were performed on anoxic water samples using aerators with 6, 12, and 24 paddles at the laboratory level. By increasing the voltage (6, 9, and 12V), the RPMs applied to each device through a geared motor is also increased. The results show a higher DO transfer rate in the 1 and 5 mg of O2·L-1 range. The best configuration concerning energy consumption worked at low RPMs using the 6-paddle wheel aerator at 6V. This establishes that, in addition to the management of low revolutions, the use of a smaller number of wheels favors an increase in efficiency during the DO restoration process in shallow water bodies.

Gametogenesis and the reproductive cycle in the deep-sea anemone Paracalliactis stephensoni (Cnidaria: Actiniaria)

1990 ◽  
Vol 70 (1) ◽  
pp. 163-172 ◽  
Author(s):  
Michel Praet-Van
Keyword(s):  
Organic Matter ◽  
Shallow Water ◽  
Deep Sea ◽  
Phytoplankton Bloom ◽  
Sea Anemone ◽  
Bay Of Biscay ◽  
Sea Anemones ◽  
Spring Phytoplankton Bloom ◽  
Sea Floor ◽  
Ultrastructural Investigation

This ultrastructural investigation of gametogenesis in a deep-sea anemone of the Bay of Biscay trawled around 2000 m depth, contributes to the knowledge of biology and strategy of reproduction of deep-sea benthos.This sea anemone is dioecious. The sperm appears very similar to those of shallow water sea anemones of the genus, Calliactis. The ultrastructural investigation of oogenesis allows the characteristics of the stages of previtellogenesis and vitellogenesis to be defined. The latter begins with a period of lipogenesis correlated with the formation of a trophonema. Mature oocytes measure up to 180 (im in diameter. Study of spermatogenesis and oogenesis reveals that spawning occurs in April/May. In males, the main area of testicular cysts, full of sperm, reaches maximal development from March to May and, in females, the percentage of mature oocytes decreases from 33% in April to 1% in May.Spawning may be induced by the advent in the deep-sea of the products of the spring phytoplankton bloom. This period of spawning, during the increased deposition of organic matter to the deep-sea floor, may be an advantageous strategy for early development of Paracalliactis.

scholarly journals Paleoenvironment of the Lower–Middle Cambrian Evaporite Series in the Tarim Basin and Its Impact on the Organic Matter Enrichment of Shallow Water Source Rocks

Minerals ◽  
2021 ◽  
Vol 11 (7) ◽  
pp. 659
Author(s):  
Mingyang Wei ◽  
Zhidong Bao ◽  
Axel Munnecke ◽  
Wei Liu ◽  
G. William M. Harrison ◽  
...  
Keyword(s):  
Organic Matter ◽  
Shallow Water ◽  
Tarim Basin ◽  
Water Environment ◽  
Water Source ◽  
Major Elements ◽  
Source Rocks ◽  
Middle Cambrian ◽  
Sedimentary Environments ◽  
The Impact

Just as in deep-water sedimentary environments, productive source rocks can be developed in an evaporitic platform, where claystones are interbedded with evaporites and carbonates. However, the impact of the paleoenvironment on the organic matter enrichment of shallow water source rocks in an evaporite series has not been well explored. In this study, two wells in the central uplift of the Tarim Basin were systematically sampled and analyzed for a basic geochemical study, including major elements, trace elements, and total organic carbon (TOC), to understand the relationship between TOC and the paleoenvironmental parameters, such as paleosalinity, redox, paleoclimate, paleo-seawater depth, and paleoproductivity. The results show that the Lower–Middle Cambrian mainly developed in a fluctuating salinity, weak anoxic to anoxic, continuous dry and hot, and proper shallow water environment. The interfingering section of evaporites, carbonates, and claystones of the Awatag Fm. have higher paleoproductivity and higher enrichment of organic matter. Paleosalinity, redox, paleoclimate, paleo-seawater depth, and paleoproductivity jointly control the organic matter enrichment of shallow water source rocks in the evaporite series. The degree of enrichment of organic matter in shallow water source rocks first increases and then decreases with the increase in paleosalinity. All the samples with high content of organic matter come from the shallower environment of the Awatag Fm.

On methodological approaches to the improvement of surface water bodies and target indicators of the natural waters’ quality

2021 ◽  
Vol 27 (1) ◽  
pp. 6-14
Author(s):  
V. Zaslonovsky ◽  
◽  
N. Sharapov ◽  
M. Bosov ◽  
◽  
...  
Keyword(s):  
Water Quality ◽  
Surface Water ◽  
Natural Water ◽  
Aquatic Ecosystems ◽  
Natural Waters ◽  
Water Bodies ◽  
Surface Water Bodies ◽  
Methodological Approaches ◽  
Natural Water Bodies

The paper is devoted to the development of proposals concerning the improvement of surface water bodies and the appointment of target indicators of the natural waters’ quality. The paper considers a variety of problems of preserving, restoring and improving the quality of natural surface waters: from regional features of the formation of natural water composition, to differences in the requirements for the quality of water consumed. The object of the study is the qualitative indicators of the waters of natural water bodies, and the subject of the study is the methodological approaches to the normalization of these indicators. The purpose of the work is to identify the main shortcomings in the domestic system of rationing the quality of natural waters, and to form appropriate proposals. For this purpose, the following tasks were set and solved: to review the methodological approaches to assessing and rationing the quality of natural waters used in some foreign countries and in the Russian Federation, to identify the main causes and shortcomings; to make proposals for improving the current system of water quality rationing. The result of this work is the conclusions about the lack of impact of the strategy operating in Russia in the development of schemes of complex use and protection of water objects, standards of permissible impact on water bodies, the appointment of permissible discharge limits in terms of maintaining and improving the water quality of natural water bodies. The reasons that led to this are indicated. The necessity of taking into account, in addition to the physical and chemical composition, also hydrobiological parameters is shown. It is concluded that instead of fisheries management standards, environmental standards should serve as the basis for target indicators of water quality of natural water bodies, which determine the well-being of humans and the stable functioning of aquatic ecosystems, taking into account regional factors. Proposals were made to adjust the methodological approaches to the implementation of this strategy. According to the authors, these proposals will speed up the solution of the main objectives of the strategy – the ecological improvement of water bodies, the preservation of unique aquatic ecosystems and the environmentally safe development of territories that previously experienced relatively small anthropogenic impacts (Eastern Siberia and the Far East)

scholarly journals Heavy-metal pollution alters dissolved organic matter released by bloom-forming Microcystis aeruginosa

RSC Advances ◽  
2017 ◽  
Vol 7 (30) ◽  
pp. 18421-18427 ◽  
Author(s):  
Haiming Wu ◽  
Li Lin ◽  
Guangzhu Shen ◽  
Ming Li
Keyword(s):  
Heavy Metals ◽  
Heavy Metal ◽  
Organic Matter ◽  
Dissolved Organic Matter ◽  
Microcystis Aeruginosa ◽  
Metal Pollution ◽  
Heavy Metal Pollution ◽  
Aquatic Ecosystems ◽  
Eutrophic Lakes

The risk of heavy metals to aquatic ecosystems was paid much attention in recent years, however, the knowledge on effects of heavy metals on dissolved organic matter (DOM) released byMicrocystiswas quite poor, especially in eutrophic lakes.

Sign in / Sign up

Export Citation Format

Share Document