II. An Experiment in Marine Fish Cultivation: II. Some Physical and Chemical Conditions in a Fertilized Sea-loch (Loch Craiglin, Argyll)

Author(s):  
A. P. Orr

The dependence of plant production in the sea on the presence of nutrient salts, especially nitrate and phosphate, and on illumination has been repeatedly demonstrated. The object of the present work was to find primarily whether, and to what degree, plant and animal production could be increased by adding fertilizers to an enclosed body of sea water under otherwise natural conditions.

2016 ◽  
Vol 4 (2) ◽  
Author(s):  
Indri S Manembu ◽  
Edwin L.A Ngangi

This research aimed to gather data and information as well as to evaluate the waters condition and water quality suitable for ornamental coral aquaculture, so the characteristic of Arakan waters for ornamental coral aquaculture could be examined.  The research applied Explorative Descriptive method with Purposive Sampling.  Research stations were established at 20 points representing the overall ecosystem of Arakan waters.  Data collected  consisted of physical conditions (bottom substrate, flow rate, turbidity, water depth, salinity, temperature, TSS) and  chemical conditions (pH, DO, nitrate, phosphate). Data were analyzed using Matching Method by matching the data obtained from sea water standard quality table for marine biota in accordance to Kep.Men. LH No. 51/2004 and data from Hutabarat and Evans (1984).  Based on physical and chemical conditions, Arakan waters was suitable for ornamental coral aquaculture or categorized as suitable. However, water temperature at the time of measurement was not proper,  thus monitoring of this parameter for longer period was required. Keywords: Arakan Village, ornamental coral, water quality, waters condition,  matching                      method


NeoBiota ◽  
2019 ◽  
Vol 44 ◽  
pp. 57-73 ◽  
Author(s):  
Alberto Romero-Blanco ◽  
Álvaro Alonso

The New Zealand mudsnail (NZMS) Potamopyrgusantipodarum (Gray, 1843) (Tateidae, Mollusca) is a successful invasive species able to alter the functioning of the invaded ecosystems. However, to arrive and establish in new aquatic ecosystems, this snail must survive to the overland translocation through aerial exposure and must tolerate the new physical and chemical conditions of the recipient ecosystem. In this study, we simulated different conditions for the NZMS invasion by combining two air exposure treatments (0 and 20 h) with different physical and chemical conditions of the rehydration water (low and normal water temperatures and normal and high water conductivities). Mortality, behavior and neonate production were compared across treatments. Air exposure caused a high percentage of mortality but survivors tolerated the subsequent abiotic conditions. Low temperatures and high conductivities altered the behavior of adult snails, increasing significantly their reaction time (i.e. time to start normal movement). This may have negative consequences for the survival of this species under natural conditions. Finally, these conditions did not affect significantly the production of neonates. These results supported that the surviving NZMS to a brief period of air exposure possess the ability to acclimate to contrasting abiotic conditions with a potential establishment of new populations and that survivors can reproduce in different abiotic conditions after an air exposure period.


1993 ◽  
Vol 265 (2) ◽  
pp. H543-H552 ◽  
Author(s):  
Y. Yuan ◽  
W. M. Chilian ◽  
H. J. Granger ◽  
D. C. Zawieja

This study reports measurements of albumin permeability in isolated coronary venules. The isolated microvessel technique allows the quantification of transmural exchange of macromolecules under tightly controlled physical and chemical conditions. Transvenular exchange of albumin was studied in isolated coronary venules during alterations in filtration rate caused by changes in intravascular pressure. The apparent permeability coefficient of albumin (Pa) at an intraluminal pressure of 11 cmH2O was 3.92 +/- 0.43 x 10(-6) cm/s. Elevating intraluminal pressure to 16 and 21 cmH2O increased Pa to 5.13 +/- 0.57 x 10(-6) and 6.78 +/- 0.66 x 10(-6) cm/s, respectively. Calculation of the true diffusive permeability coefficient of albumin (Pd) at zero filtration rate was 1.54 x 10(-6) cm/s. The product of hydraulic conductance (Lp) and (1 - sigma), where sigma is the solute reflection coefficient, was 3.25 x 10(-7) cm.s-1 x cmH2O-1. At a net filtration pressure of 4-5 cmH2O, diffusion accounts for > 60% of total albumin transport across the venular wall. Transmural albumin flux is very sensitive to filtration rate, rising 6.7% for each cmH2O elevation of net filtration pressure. At 11 cmH2O net filtration pressure, convection accounts for nearly 70% of net albumin extravasation from the venular lumen. We suggest that the isolated coronary venule is a suitable preparation for the study of solute exchange in the heart.


Life ◽  
2021 ◽  
Vol 11 (6) ◽  
pp. 539
Author(s):  
Benton C. Clark ◽  
Vera M. Kolb ◽  
Andrew Steele ◽  
Christopher H. House ◽  
Nina L. Lanza ◽  
...  

Although the habitability of early Mars is now well established, its suitability for conditions favorable to an independent origin of life (OoL) has been less certain. With continued exploration, evidence has mounted for a widespread diversity of physical and chemical conditions on Mars that mimic those variously hypothesized as settings in which life first arose on Earth. Mars has also provided water, energy sources, CHNOPS elements, critical catalytic transition metal elements, as well as B, Mg, Ca, Na and K, all of which are elements associated with life as we know it. With its highly favorable sulfur abundance and land/ocean ratio, early wet Mars remains a prime candidate for its own OoL, in many respects superior to Earth. The relatively well-preserved ancient surface of planet Mars helps inform the range of possible analogous conditions during the now-obliterated history of early Earth. Continued exploration of Mars also contributes to the understanding of the opportunities for settings enabling an OoL on exoplanets. Favoring geochemical sediment samples for eventual return to Earth will enhance assessments of the likelihood of a Martian OoL.


Author(s):  
Magdalena Golonko ◽  
Marcin Wysokiński ◽  
Arkadiusz Gromada

The main purpose of the article was to assess the regionalization of agricultural production in the world and the changes occurring in this aspect. The article presents the concentration level of agricultural production in the world by continent. The source of materials was data from FAOSTAT. The research period covered the years 2004 - 2016. In the analyzed period, the value of gross agricultural production doubled. Various trends were observed within the period studied. In the years 2004-2010, in all regions of the world, there was an increase in gross production of agriculture, while in the period 2010-2016 only in two – North America and Asia. It was noted that there was a high concentration of agricultural production, mainly concentrated in Asia and Europe. In the analyzed period, there was a relative increase in the share of agricultural production in Asia and South America as compared to other regions. Individual groups of agricultural products, such as cereals and animal production, were also analyzed. In both cases, concentration was different. The pace of concentration in animal production was higher than in plant production.


2008 ◽  
Vol 16 (4) ◽  
pp. 301 ◽  
Author(s):  
R. UUSITALO ◽  
E. TURTOLA ◽  
J. GRÖNROOS

Soil test phosphorus (P) concentration has a major influence on the dissolved P concentration in runoff from agricultural soils. Thus, trends in soil test P partly determine the development of pollution potential of agricultural activities. We reviewed the changes of soil test P and P balances in Finnish agriculture, and assessed the current setting of P loss potential after two Agri-Environmental Programs. Phosphorus balance of the Finnish agriculture has decreased from +35 kg ha–1 of the 1980’s to about +8 kg P ha–1 today. As a consequence, the 50-yr upward trend in soil test P concentrations has probably levelled out in the late 1990’s, as suggested by sampling of about 1600 fields and by a modelling exercise. For the majority of our agricultural soils, soil test P concentrations are currently at a level at which annual P fertilization is unlikely to give measurable yield responses. Soils that benefit from annual P applications are more often found in farms specialized in cereal production, whereas farms specialized in non-cereal plant production and animal production have higher soil test P concentrations. An imbalance in P cycling between plant (feed) and animal production is obvious, and regional imbalances are a result of concentration of animal farms in some parts of the country. A major concern in future will be the fate of manure P in those regions where animal production intensity is further increasing.;


Author(s):  
Fitri Andriyani

Binuangeun Mangrove Ecosystem is located in the south western Java Island, in the area of ​​Lebak Regency, Banten Province. Mangrove ecosystems are ecosystems that located at the Coastal areas which are a habitat for a variety of marine animals which are associated with it, mostly fish, because of its complex or a very effective root structure which can provide a place for fish to be able to live, take shelter, develop, breed and also look for food. This research was conducted to determine the physical and chemical condition and the variety of fishes which found in the Binuangeu, Banten Mangrove Ecosystem. This research method uses literature study. Physical and chemical conditions of the Binuangeun Mangrove Ecosystem, Banten have degrees of temperature ranging from 28.20 - 32.20; acidity range between 7.00 - 8.09; turbidity ranges from 22.50 - 76.00 NTU; water current ranged from 0.079 to 0.189; phosphate content ranges from 0.02 - 0.008; salinity ranges from 30-35 PSU; and dissolved oxygen content ranges from 5.67 - 8.70. The types of fish found in the Binuangeun Mangrove Ecosystem, Banten are 45 species from 22 Family. The most abundant and relatively high species of existence is the Gobiidae with 10 species.   Keywords: Banten, Binuangeun, Ecosystems, Fish, Mangroves


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