scholarly journals Nitrification Activity of the Sponge Chondrosia reniformis Under Elevated Concentrations of Ammonium

2021 ◽  
Vol 7 ◽  
Author(s):  
Philip Nemoy ◽  
Ehud Spanier ◽  
Dror L. Angel
Keyword(s):  
Oxygen Consumption ◽  
Dissolved Oxygen ◽  
Water Samples ◽  
Laboratory Experiments ◽  
Ammonium Uptake ◽  
Ambient Seawater ◽  
Nitrification Activity ◽  
Surrounding Seawater

This study examined the ability of a Mediterranean demosponge Chondrosia reniformis to oxidize exogenous ammonium, simulating N-rich conditions that occur near finfish farms. We hypothesized that as the concentration of ammonium increases in the surrounding seawater, nitrification mediated by microbes associated with C. reniformis will lead to enhancement of ammonium uptake, nitrate excretion and oxygen consumption by the sponge holobiont. To test this hypothesis, we conducted laboratory experiments with C. reniformis explants exposed to ammonium enrichments (300–6667 nM) and to ambient seawater (45–1511 nM ammonium). We analyzed inhaled (IN) and exhaled (EX) water samples for dissolved oxygen, ammonium, nitrates and retention of picoplankton cells. We observed ammonium uptake in nearly half the cases and excretion of nitrate in most experimental outcomes. Yet, the consumption of ammonium and oxygen, as well as the excretion of nitrate by C. reniformis were not related to the concentration of inhaled ammonium, which suggests that the nitrification activity of sponge-associated microbes is not necessarily related to the concentration of ammonium in the surrounding seawater. Further research is required to reveal the sources of nitrate released from sponges and the fate of this nitrate in natural and manipulated ecosystems.

scholarly journals Oxygen uptake during mineralization of photosynthesized carbon from phytoplankton of the Barra Bonita Reservoir: a mesocosm study

2008 ◽  
Vol 68 (1) ◽  
pp. 115-122 ◽  
Author(s):  
MB. Cunha-Santino ◽  
SP. Gouvêa ◽  
I. Bianchini Jr ◽  
AAH. Vieira
Keyword(s):  
Electrical Conductivity ◽  
Oxygen Consumption ◽  
Oxygen Uptake ◽  
Dissolved Oxygen ◽  
Water Samples ◽  
Microbial Respiration ◽  
Co2 Concentration ◽  
Ph Values ◽  
Organic Products ◽  
Aulacoseira Granulata

This study aimed to discuss and describe the oxygen consumption during aerobic mineralization of organic products (cells and excretion products) from five unialgal cultures: Cryptomonas sp., Microcystis aeruginosa, Anabaena spiroides, Thalassiosira sp. and Aulacoseira granulata. These species were isolated from Barra Bonita reservoir (22º 29’ S and 48º 34’ W) and cultivated in the laboratory. From each culture, two decomposition chambers were prepared; each chamber contained about 130 mg.L-1 of carbon from water samples of the reservoir. The chambers were aerated and incubated in the dark at 20.0 ºC. The concentration of dissolved oxygen, pH values and electrical conductivity of the solutions were determined during a period of 10 days. The results indicated increases in oxygen consumption for all the solutions studied and also for electrical conductivity. The pH values presented a decreasing tendency throughout the experiment. Oxygen consumption varied from 43 (Aulacoseira granulata chamber) to 345 mg O2 g-1 C (Anabaena spiroides chamber). Decrease in pH values was probably due to increase in CO2 concentration from microbial respiration. Increase in electrical conductivity might be due to the liberation of ions during decomposition. The results demonstrate the potentiality of the studied genera in influencing oxygen availability followed by a die-off event. It also indicates the possibility of changing of the electrical conductivity and pH values in the water column due the aerobic algae mineralization.

scholarly journals Methodological tests of a heterotrophy index for aquatic ecosystems

2003 ◽  
Vol 63 (3) ◽  
pp. 373-380 ◽  
Author(s):  
R. M. Antonio ◽  
I. Bianchini Jr.
Keyword(s):  
Oxygen Consumption ◽  
Dissolved Oxygen ◽  
Electric Conductivity ◽  
Water Samples ◽  
Aquatic Ecosystems ◽  
Carbonic Acid ◽  
Carbon Sources ◽  
Field Work ◽  
Glucose Content ◽  
Aerobic And Anaerobic

Experiments in glucose mineralization were carried out to investigate the effects caused by natural forcing functions on both the decomposition rates and heterotrophy capacity of aquatic ecosystems. In addition, the methodology used could show connections between mineralization rates measured in both laboratory and field work with those measured in aquatic ecosystems. Water samples from Infernão lagoon (21º35'S and 47º51'W) were collected, filtered, enriched with glucose, and incubated under aerobic and anaerobic conditions. The glucose concentration variation, dissolved oxygen (DO) consumption, pH, electric conductivity, and total CO2 amount in the water were determined for sixteen days. In the period with intense oxygen consumption there was also an evident glucose demand and the dissolved oxygen consumption rate was approximately the same as that for glucose mineralization. The process in the aerobic chambers was 2.2 times faster than that in the anaerobic chambers. An initial acidification of the water samples, probably due to microbial carbonic acid liberation, was noted. A rise in pH values was also observed at the end of the process. The electric conductivity was low for both aerobic and anaerobic chambers, indicating a probable ion uptake by microbial organisms due to the presence of carbon sources. The glucose content variations corresponded to both CO2 formation and dissolved oxygen consumption. It was estimated that 19.4% of the initial glucose content turned into CO2 and the remaining 80.6% into humic compounds and microbial biomass. This experiment showed that glucose can be used as a substrate indicating the heterotrophy of a given aquatic ecosystem.

Occurrence and Removal of Cryptosporidium spp. Oocysts and Giardia spp. Cysts in Kenyan Waste Stabilisation Ponds

1993 ◽  
Vol 27 (3-4) ◽  
pp. 97-104 ◽  
Author(s):  
A. M. Grimason ◽  
H. V. Smith ◽  
W. N. Thitai ◽  
P. G. Smith ◽  
M. H. Jackson ◽  
...  
Keyword(s):  
Waste Water ◽  
Water Samples ◽  
Laboratory Experiments ◽  
Municipal Waste ◽  
Retention Period ◽  
Waste Stabilisation Ponds ◽  
Cryptosporidium Spp ◽  
Physico Chemical ◽  
Microbiological Parameters ◽  
Final Effluent

This study was designed to determine tlie occurrence and removal of Cryptosporidium spp. oocysts and Giardia spp. cysts, in municipal waste-water by waste stabilisation ponds in tlie Republic of Kenya. Eleven waste stabilisation pond systems located in towns across Kenya were included. A total of 66 waste-water samples were examined for the presence of oocysts and cysts, comprising 11 raw waste-water and 55 pond effluent samples over a two month period. Cryptosporidium spp. oocysts were detected in 6 and Giardia spp. cysts in 9 of the designated pond systems analysed demonstrating their ubiquitous nature throughout Kenya. Oocyst levels detected in raw waste-water samples ranged from 12.5 - 72.97 oocysts/l and various pond effluents between 2.25 - 50 oocysts/l. Cyst levels detected in raw waste-water samples ranged from 212.5 to 6212.5 cysts/l and in various pond effluents from 3.125 to 230.7 cysts/l. No Cryptosporidium spp. oocysts were detected in the final effluent from any pond systems studied (11/11). Whereas no Giardia spp. cysts were detected in the final effluent from 10 of 11 waste stabilisation pond systems studied, one pond system was found to be consistently discharging cysts in the final effluent at concentrations ranging from 40 to 50 cysts/l. The minimum retention period for the removal of Cryptosporidium spp. oocysts and Giardia spp. cysts was 37.3 days. Laboratory experiments were performed to assess physico-chemical and microbiological parameters to express relationships between pond performance and protozoa removal.

Positioning changes of mayfly nymphs due to behavioral regulation of oxygen consumption

1980 ◽  
Vol 58 (4) ◽  
pp. 618-622 ◽  
Author(s):  
Michael J. Wiley ◽  
Steven L. Kohler
Keyword(s):  
Oxygen Consumption ◽  
Dissolved Oxygen ◽  
Oxygen Concentration ◽  
Field Conditions ◽  
Experimental Investigations ◽  
Behavioral Patterns ◽  
Behavioral Regulation ◽  
Dissolved Oxygen Concentration ◽  
Habitat Distribution ◽  
Renewal Rate

Experimental investigations in a small artificial stream showed that the positioning of mayfly nymphs (Ephemeroptera) on stones varied with dissolved oxygen concentration (DO). At low DO levels nymphs moved to current-exposed positions, presumably to increase the renewal rate of oxygen at respiratory exchange surfaces. The expected magnitude of positioning changes under field conditions was determined and suggests that behavioral regulation of oxygen consumption may commonly influence both habitat distribution and diel behavioral patterns. The implications of these results to drift studies are also discussed.

scholarly journals Rapid water parcel transport across the Kuroshio Extension in the lower thermocline from dissolved oxygen measurements by Seaglider

2020 ◽  
Author(s):  
Shigeki Hosoda ◽  
Ryuichiro Inoue ◽  
Masami Nonaka ◽  
Hideharu Sasaki ◽  
Yoshikazu Sasai ◽  
...  
Keyword(s):  
Oxygen Consumption ◽  
Dissolved Oxygen ◽  
Water Mass ◽  
Kuroshio Extension ◽  
Exchange Process ◽  
Surrounding Water ◽  
Small Water ◽  
Low Salinity ◽  
Mass Migration ◽  
The Kuroshio

Abstract Small water parcels with low salinity and high dissolved oxygen (DO) are observed in the main thermocline south of the Kuroshio Extension (KE). The Seaglider data, which was collected for four months beginning in late winter 2014 with fine spatial and temporal resolutions, identified small water parcels characterized by low salinity and high DO in the subsurface layer (26.0–27.0 σθ) with a few ten kilometers and a few ten meters in the horizontal and vertical scales, respectively. Water mass analyses revealed larger negative salinity anomalies (< − 0.05 PSS-78) and positive DO anomalies (> 15 µmol kg− 1) than those of the surrounding water. The characteristics are similar to those of water mass with low salinity and high DO in the subpolar Northwestern Pacific Ocean. Additionally, higher DO anomaly water parcels appear in the upper layer (< 26.7 σθ) while low salinity parcels appear in the lower layer (> 26.7 σθ). Oxygen consumption rates from the apparent oxygen utility suggest that the small water parcels consume less oxygen than the surrounding water, implying that they migrate in a shorter time across the KE after subduction and their characteristics may reflect the sea surface temperature, salinity, and DO in the subduction region. Similar small water parcels represented by high-resolution numerical simulations indicate that they pass through the KE in one month. The simulations support the oxygen consumption rate from the Seaglider observations. The existence of a faster process for water mass migration by meso- and submesoscale subduction processes across the KE affects the amount, subduction, and exchange process of water mass. Our study indicates a small water mass contributes to the exchange process across the KE rapidly, which had not been identified in previous studies. Consequently, detailed observations using multiple Seagliders should capture detailed spatial and temporal variability of the water mass exchange process.

scholarly journals KONSUMSI OKSIGEN BENIH IKAN KERAPU BEBEK (Cromileptes altivelis) UKURAN PANJANG 5-7 CM

2012 ◽  
Vol 2 (1) ◽  
pp. 1
Author(s):  
Yopi Novita ◽  
Budhi Hascaryo Iskandar ◽  
Bambang Murdiyanto ◽  
Budy Wiryawan ◽  
Hariyanto Hariyanto
Keyword(s):  
Oxygen Consumption ◽  
Dissolved Oxygen ◽  
Body Length ◽  
Oxygen Consumption Rate ◽  
Consumption Rate ◽  
Sea Water ◽  
Consumption Level ◽  
Water Measurement

Disolved oxygen plays an important role for fish living in its life environment. Information on the ammount of oxygen consumption of a fish in certain volume of water is needed in order to give balancing between the ammount of disolved oxygen and fish in it. The objective of this research is obtaining oxygen consumption level of a juvenile of humpback grouper (Cromileptes altivelis) of 5-7 cm body length. Oxygen consumption of fish was measured using a tube that equiped with DO tool (dissolved oxygent, DO), and the tube was filled by sea water. Measurement of oxygen con-sumption of juvenil was done by measuring the concentration of dissolved oxygen from sea water in the respirometer tube, began when fish had entered into the respirometer tube up to two hours observation. The result showed that oxygen consumption rate of a juvenile of humpback grouper (Cromileptes altivelis) of 5-7 cm length, is ranging between 0.816 and 1.734 mg/hour.

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