scholarly journals Influence of nutrient enrichment on temporal and spatial dynamics of dissolved oxygen within northern temperate estuaries

2021 ◽  
Vol 193 (12) ◽  
Author(s):  
MRS Coffin ◽  
KM Knysh ◽  
SD Roloson ◽  
CC Pater ◽  
E Theriaul ◽  
...  
Keyword(s):  
Dissolved Oxygen ◽  
Agricultural Land ◽  
Practical Implication ◽  
Chlorophyll Concentration ◽  
Spatial Dynamics ◽  
Spatial Relationship ◽  
Local Conditions ◽  
Depth Profiles ◽  
Primary Hypothesis ◽  
Oxygen Monitoring

AbstractIn temperate estuaries of the southern Gulf of St. Lawrence, intermittent seasonal anoxia coupled with phytoplankton blooms is a regular occurrence in watersheds dominated by agricultural land use. To examine the spatial relationship between dissolved oxygen and phytoplankton throughout the estuary to assist in designing monitoring programs, oxygen depth profiles and chlorophyll measurements were taken bi-weekly from May to December in 18 estuaries. In five of those estuaries, dissolved oxygen data loggers were set to measure oxygen at hourly intervals and at multiple locations within the estuary the subsequent year. The primary hypothesis was that dissolved oxygen in the upper estuary (first 10% of estuary area) is predictive of dissolved oxygen mid-estuary (50% of estuary area). The second hypothesis was that hypoxia/superoxia in the estuary is influenced by temperature and tidal flushing. Oxygen depth profiles conducted in the first year of study provided preliminary support that dissolved oxygen in the upper estuary was related to dissolved oxygen throughout the estuary. However, dissolved oxygen from loggers deployed at 10% and 50% of estuary area did not show as strong a correlation as expected (less than half the variance explained). The strength of the correlation declined towards the end of summer. Spatial decoupling of oxygen within the estuary suggested influence of local conditions. Chlorophyll concentration seemed also to be dependent on local conditions as it appeared to be coupled with the presence of sustained anoxia in the upper estuary with blooms typically occurring within 7 to 14 days of anoxia. The practical implication for oxygen monitoring is that one location within the most severely impacted part of the estuary is not sufficient to fully evaluate the severity of eutrophication effects.

scholarly journals Agriculture and land use in the North of Russia: Case study of Karelia and Yakutia

2020 ◽  
Vol 12 (1) ◽  
pp. 1497-1511
Author(s):  
Alexey Naumov ◽  
Varvara Akimova ◽  
Daria Sidorova ◽  
Mikhail Topnikov
Keyword(s):  
Land Use ◽  
Agricultural Development ◽  
Agricultural Land ◽  
Geographical Location ◽  
Special Role ◽  
Sources Of Information ◽  
Local Conditions ◽  
Climate Conditions ◽  
The North ◽  
The Republic

AbstractDespite harsh climate, agriculture on the northern margins of Russia still remains the backbone of food security. Historically, in both regions studied in this article – the Republic of Karelia and the Republic of Sakha (Yakutia) – agricultural activities as dairy farming and even cropping were well adapted to local conditions including traditional activities such as horse breeding typical for Yakutia. Using three different sources of information – official statistics, expert interviews, and field observations – allowed us to draw a conclusion that there are both similarities and differences in agricultural development and land use of these two studied regions. The differences arise from agro-climate conditions, settlement history, specialization, and spatial pattern of economy. In both regions, farming is concentrated within the areas with most suitable natural conditions. Yet, even there, agricultural land use is shrinking, especially in Karelia. Both regions are prone to being affected by seasonality, but vary in the degree of its influence. Geographical location plays special role, and weaknesses caused by remoteness to some extent become advantage as in Yakutia. Proximity effect is controversial. In Karelia, impact of neighboring Finland is insignificant compared with the nearby second Russian city – Saint Petersburg.

scholarly journals Active Potentiometry for Dissolved Oxygen Monitoring with Platinum Electrodes

Sensors ◽  
2018 ◽  
Vol 18 (8) ◽  
pp. 2404 ◽  
Author(s):  
Peter Zimmermann ◽  
Andreas Weltin ◽  
Gerald Urban ◽  
Jochen Kieninger
Keyword(s):  
Transfer Function ◽  
Dissolved Oxygen ◽  
Oxygen Concentration ◽  
Potentiometric Sensors ◽  
Platinum Electrodes ◽  
Forming Mechanism ◽  
Long Term Stability ◽  
Measurement Results ◽  
Oxygen Monitoring ◽  
Dissolved Oxygen Monitoring

Potentiometric oxygen monitoring using platinum as the electrode material was enabled by the combination of conventional potentiometry with active prepolarization protocols, what we call active potentiometry. The obtained logarithmic transfer function is well-suited for the measurement of dissolved oxygen in biomedical applications, as the physiological oxygen concentration typically varies over several decades. We describe the application of active potentiometry in phosphate buffered salt solution at different pH and ion strength. Sensitivity was in the range of 60 mV/dec oxygen concentration; the transfer function deviated from logarithmic behavior for smaller oxygen concentration and higher ion strength of the electrolyte. Long-term stability was demonstrated for 60 h. Based on these measurement results and additional cyclic voltammetry investigations a model is discussed to explain the potential forming mechanism. The described method of active potentiometry is applicable to many different potentiometric sensors possibly enhancing sensitivity or selectivity for a specific parameter.

scholarly journals Ecological status of surface water of the river Stokhid basin

2017 ◽  
Keyword(s):  
Water Quality ◽  
Surface Water ◽  
Agricultural Land ◽  
Spatial Dynamics ◽  
Ecological Status ◽  
Surface Water Quality ◽  
Treated Wastewater ◽  
Clean Water ◽  
Environmental Indices ◽  
The Village

Purpose. The analysis of the surface water quality of the Stokhid river, the definition of the class and the category of water quality. Methods. Comparative geographic, analytical, generalization and systematization. Results. Inner annual dynamics of the components of the hydro chemical conditions of surface water composition is closely linked with river runoff, the formation of which occurs due to loss of precipitation and nutrition of groundwater. Based on the analysis of monitoring observations, carried out by the State Environmental Inspectorate in the Volyn region for the period from 2007 to 2017, it has been determined the multi-year time and spatial dynamics of the average annual values of integrated environmental indices by the average values. They are following: in the village Malinovka IEaver. = 2,2 and in Lyubeshiv village IE aver. = 2,4. The water of river Stokhid belongs to the second class of quality ("good", "pure"), to the second category ("very good", "very pure") and subcategories 2 (3) ("very good", " clean" water with a tendency to approach the category of "good", "fairly clean") respectively. Dynamics of average annual values of integral ecological indexes for the worst values in village Malinovka IEworst = 2,6 and in the village Lyubeshiv IEworst = 2,8 was characterized by water of the second class ("good", "pure"), third category ("good", "fairly clean"), subcategory 2-3 (water transitions in quality from "very good", "pure" to "good", "fairly clean") and subcategory 3 (2) ("good", "fairly clean" water with a bias to "very good", "clean"). Conclusions. In general, it should be noticed, that when calculating the values of integral ecological indexes, the value of the indexes of trophic and sapro-biological indicators are the worst. Compounds of Nitrogen was among the substances that determined the water quality as "very poor" and "very dirty". Increased levels of Nitrogen compounds in the Stokhid river is mainly due to the intake of insufficiently treated wastewater, surface runoff from agricultural land and the decomposition of non-living organic matter in the spring.

scholarly journals Growth of rainbow trout (oncorhynchus mykiss) in the conditions of Tashkent province, Uzbekistan

2021 ◽  
Vol 258 ◽  
pp. 04040
Author(s):  
SH Sulaymonov ◽  
G Abdullaev ◽  
S Saidumarov
Keyword(s):  
Water Quality ◽  
Rainbow Trout ◽  
Dissolved Oxygen ◽  
Oncorhynchus Mykiss ◽  
Water Temperature ◽  
Fish Farming ◽  
Local Conditions ◽  
Rainbow Trout Oncorhynchus Mykiss ◽  
Fish Productivity ◽  
Feed Coefficient

Rainbow trout is a new fish farming object for Uzbekistan, the adaptability of which (first of all, growth) to local conditions should be carefully studied. We analyzed the growth of rainbow trout in the conditions of flowing pools and cages in the foothill zone of Tashkent province of Uzbekistan. From March to October, the water temperature in the Khojikent reservoir varied from 4.9 to 13.1 °C, the amount of dissolved oxygen was 8.4 to 11.5 mg/l, and the pH was 7.40 to 7.67. In the flowing basin, the temperature was 15-18 °C, pH 7.2-7.5, the amount of dissolved oxygen 6.1-11.2 mg/l. The conditions of the foothill zones of Uzbekistan in terms of water quality are favorable for the development of trout breeding. During the season, fish in cages increased from 250 g to 623 g, in pools from 25 g to 390 g on average. The waste was 1.7%. The actual fish productivity of the basin is 39 kg/m3, the cage is 30 kg/m3 and the feed coefficient in the basin is 1.2, in the cages - 1.09.

scholarly journals Embedded Wireless Dissolved Oxygen Monitoring Based on Internet of Things Platform

2021 ◽  
pp. 363-368
Author(s):  
Wasana Boonsong ◽  
Keyword(s):  
Internet Of Things ◽  
Dissolved Oxygen ◽  
Water Temperature ◽  
Monitoring System ◽  
Pearson Correlation ◽  
The Social ◽  
Iot Platforms ◽  
Oxygen Monitoring ◽  
Dissolved Oxygen Monitoring ◽  
The Relationship

Recently, Internet of Things (IoT) applications are distributing into many areas, such as industry and agriculture. This article presents the embedded wireless Dissolved Oxygen (DO) monitoring system based on IoT platforms. The module contains two types of data sensing, which are water temperature and DO sensors. Both devices are embedded with a wireless IoT module using NodeMCU-ESP8266, an integration WiFi-Microcontroller on a single board. The proposed IoT-DO monitoring system detects information data from the aquaculture pond environment. Namely, the parameters studied are water temperature and DO values. The cloud internet network collects and stores the experimental data and link to the users. The relationship between both parameters is analyzed using Statistical Package for the Social Sciences based Pearson correlation coefficient theory. The findings found that the water temperature and DO values are negatively related, with a statistically significant .05. Water temperature is the principal affection to other parameters of water. In this work, the DO value is studied to relate the water temperature. It was found that when the water temperature increases, the DO decreases accordingly and vice versa.

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