DSB Related Journals, Newspaper Articles, ETC...

[Yellotang]

type in phosphate and sediments I get over 750 documents.

[Yellotang]

Here is one on trace metals and denitrification.

Addition of trace metals increases denitrification rate in closed marine systems
Normand Labbéa, Serge Parentm4.cor*m4.cor*, mailto:sparent@ville.montreal.qc.camailto:sparent@ville.montreal.qc.ca, b and Richard Villemura

a INRS-Institut Armand-Frappier, 531 boul. des Prairies, Laval, Canada H7V 1B7
b Biodôme de Montréal, 4777 Ave Pierre-De Coubertin, Montreal, QC, Canada H1V 1B3

Abstract
We investigated the effect of trace metals (Fe, Mn, Cu, Zn and Mo) on the denitrification unit at the Montreal Biodome. Two dosages of the five trace metals were tested on a denitrifying bacterial population which was extracted from the denitrification unit and cultured in 250 mL chemostats with artificial seawater. The low dosage showed a 20% increase in the denitrification rate whereas the high dosage had a more pronounced effect with a 250% increase. No increase in bacterial growth was observed, suggesting that the trace metals had an effect on the denitrification activity. When the trace metals were tested separately, only iron had a significant effect similar to the increase in the denitrification rate observed when the five trace metals were added. The combination of Fe and Mn caused a small but significant increase compared to the five trace metals. We then tested the effect of adding Fe, Mn and Cu to the denitrification unit at the Montreal Biodome. A high dosage of these trace metals showed a 250% increase in the denitrification rate, which went from 200 to 700 g NOx-N/d. Our results showed that the addition of trace metals is crucial for denitrification activities.

[Bomber]

Metals are a good thing. specially iron dosing. LOL

Read 1, 3, 4, 5, 16, 17and 19 looks like a winner, and so do 27 and 28. Get 30 and 31 for Randy. LOL

I'll check back with you tomorrow. Looks like your hands a full.

[photobarry]

Well it looks like someone is doing their research!

[Yellotang]

As I search through other documents, not the ones I have posted, I am coming across so many that talk about vertical flux of organic nutrients, direct relations to algae growth. Shallow waters all over the world are having problems with sedimentational burping (if you will) of Phosphates and chlorophyll.

Did you realize that DSB's can actually hold onto or "SINK" more phosphates at higher levels of salinity?

[Yellotang]

And once that salinity changes at all the DSB's release phosphates back into the water column?

[Yellotang]

According to this article, UV lights play a large part in DOC to remineralization. The organisms that grow by light can absorb or eat the DOC's and turn them into minerals. But only when under increased levels of organisms is this possible. Something we don't want in our aqauria.

Journal of Photochemistry and Photobiology B: Biology
Volume 46, Issues 1-3 , October 1998, Pages 53-68
Effects on aquatic ecosystems
D. -P. Hädera, *, H. D. Kumarb, R. C. Smithc and R. C. Worrestd

a Institut für Botanik und Pharmazeutische Biologie der Universität Erlangen-Nürnburg, Staudstraße 5 D-91058 Erlangen Germany
b Center of Advanced Study in Botany, Banaras Hindu University, 214, Saketnagar Colony, PO Box 5014 Varanasi 221005 India
c Institute for Computational Earth System Science (ICESS) and Department of Geography, University of California Santa Barbara, CA 93106 USA
d CIESIN, Columbia University, 1747 Pennsylvania Avenue, NW, Suite 200 Washington, DC 20006 USA

Regarding the effects of UV-B radiation on aquatic ecosystems, recent scientific and public interest has focused on marine primary producers and on the aquatic web, which has resulted in a multitude of studies indicating mostly detrimental effects of UV-B radiation on aquatic organisms. The interest has expanded to include ecologically significant groups and major biomass producers using mesocosm studies, emphasizing species interactions. This paper assesses the effects of UV-B radiation on dissolved organic matter, decomposers, primary and secondary producers, and briefly summarizes recent studies in freshwater and marine systems.

Dissolved organic carbon (DOC) and particulate organic carbon (POC) are degradation products of living organisms. These substances are of importance in the cycling of carbon in aquatic ecosystems. UV-B radiation has been found to break down high-molecular-weight substances and make them available to bacterial degradation. In addition, DOC is responsible for short-wavelength absorption in the water column. Especially in coastal areas and freshwater ecosystems, penetration of solar radiation is limited by high concentrations of dissolved and particulate matter. On the other hand, climate warming and acidification result in faster degradation of these substances and thus enhance the penetration of UV radiation into the water column.

Several research groups have investigated light penetration into the water column. Past studies on UV penetration into the water column were based on temporally and spatially scattered measurements. The process of spectral attenuation of radiant energy in natural waters is well understood and straightforward to model. Less known is the spatial and temporal variability of in-water optical properties influencing UV attenuation and there are few long-term observations. In Europe, this deficiency of measurements is being corrected by a project involving the development of a monitoring system (ELDONET) for solar radiation using three-channel dosimeters (UV-A, UV-B, PAR) that are being installed from Abisko (North Sweden, 68°N, 19°E) to Tenerife (Canary Islands, 27°N, 17°W). Some of the instruments have been installed in the water column (North Sea, Baltic Sea, Kattegat, East and Western Mediterranean, North Atlantic), establishing the first network of underwater dosimeters for continuous monitoring.

Bacteria play a vital role in mineralization of organic matter and provide a trophic link to higher organisms. New techniques have substantially changed our perception of the role of bacteria in aquatic ecosystems over the recent past and bacterioplankton productivity is far greater than previously thought, having high division and turnover rates. It has been shown that bacterioplankton play a central role in the carbon flux in aquatic ecosystems by taking up DOC and remineralizing the carbon. Bacterioplankton are more prone to UV-B stress than larger eukaryotic organisms and, based on one study, produce about double the amount of cyclobutane dimers. Recently, the mechanism of nitrogen fixation by cyanobacteria has been shown to be affected by UV-B stress. Wetlands constitute important ecosystems both in the tropics and at temperate latitudes. In these areas, cyanobacteria form major constituents in microbial mats. The organisms optimize their position in the community by vertical migration in the mat, which is controlled by both visible and UV-B radiation. Cyanobacteria are also important in tropical and sub-tropical rice paddy fields, where they contribute significantly to the availability of nitrogen. Solar UV radiation affects growth, development and several physiological responses of these organisms.

On a global basis, phytoplankton are the most important biomass producers in aquatic ecosystems. The organisms populate the top layers of the oceans and freshwater habitats where they receive sufficient solar radiation for photosynthetic processes. New research strengthens previous evidence that solar UV affects growth and reproduction, photosynthetic energy-harvesting enzymes and other cellular proteins, as well as photosynthetic pigment contents. The uptake of ammonium and nitrate is affected by solar radiation in phytoplankton, as well as in macroalgae. Damage to phytoplankton at the molecular, cellular, population and community levels has been demonstrated. In contrast, at the ecosystem level there are few convincing data with respect to the effects of ozone-related UV-B increases and considerable uncertainty remains. Following UV-B irradiation, shifts in phytoplankton community structure have been demonstrated, which may have consequences for the food web.

Macroalgae and seagrasses are important biomass producers in aquatic ecosystems (but considerably smaller than phytoplankton). In contrast to phytoplankton, most of these organisms are sessile and can thus not avoid exposure to solar radiation at their growth site. Recent investigations showed a pronounced sensitivity to solar UV-B radiation, and effects have been found throughout the top 10-15 m of the water column. Photoinhibition can be quantified by oxygen exchange or by PAM (pulse amplitude modulated) fluorescence. Surface-adapted macroalgae, such as several brown and green algae, show a maximum of oxygen production at or close to the surface; whereas algae adapted to lower irradiances usually thrive best when exposed deeper in the water column. Mechanisms of protection and repair are being investigated.

UV effects on aquatic animals are of increased interest. Evidence for UV effects has been demonstrated in zooplankton activity. Other UV-B-sensitive aquatic organisms include sea urchins, corals and amphibians. Solar UV radiation has been known to affect corals directly. In addition, photosynthesis in their symbiotic algae is impaired, resulting in reduced organic carbon supply. Amphibian populations are in serious decline in many areas of the world, and scientists are seeking explanations for this phenomenon. Most amphibian population declines are probably due to habitat destruction or habitat alteration. Some declines are probably the result of natural population fluctuations. Other explanations for the population declines and reductions in range include disease, pollution, atmospheric changes and introduced competitors and predators. UV-B radiation is one agent that may act in conjunction with other stresses to affect amphibian populations adversely.

The succession of algal communities is controlled by a complex array of external conditions, stress factors and interspecies influences. Freshwater ecosystems have a high turnover and the success of an individual species is difficult to predict, but the development of general patterns of community structure follows defined routes. There is a strong predictive relationship between DOC concentration and the depth to which UV radiation penetrates in lakes. Since DOC varies widely, freshwater systems display a wide range of sensitivity to UV penetration. In these systems, increased solar UV-B radiation is an additional stress factor that may change species composition and biomass productivity.

The Arctic aquatic ecosystem is one of the most productive ecosystems on earth and is a source of fish and crustaceans for human consumption. Both endemic and migratory species breed and reproduce in this ocean in spring and early summer, at a time when recorded increases in UV-B radiation are maximal. Productivity in the Arctic ocean has been reported to be higher and more heterogeneous than in the Antarctic ocean. In the Bering Sea, the sea-edge communities contribute about 40-50% of the total productivity. Because of the shallow water and the prominent stratification of the water layer, the phytoplankton are more exposed and affected by solar UV-B radiation. In addition, many economically important fish (e.g., herring, pollock, cod and salmon) spawn in shallow waters where they are exposed to increased solar UV-B radiation. Many of the eggs and early larval stages are found at or near the surface. Consequently, reduced productivity of fish and other marine crops is possible but has not been demonstrated.

There is increased consensus, covering a wide range of aquatic ecosystems, that environmental UV-B, independent of ozone-related increases, is an important ecological stress that influences the growth, survival and distribution of phytoplankton. Polar ecosystems, where ozone-related UV-B increases are the greatest and which are globally significant ecosystems, are of particular concern. However, these ecosystems are characterized by large spatial and temporal variability, which makes it difficult to separate out UV-B-specific effects on single species or whole phytoplankton communities. There is clear evidence for short-term effects. In one study a 4-23% photoinhibition of photosystem II activity was measured under the ozone hole. However, extrapolation of short-term effects to long-term ecological consequences requires various complex effects to be accounted for and quantitative evaluation remains uncertain.

[Yellotang]

Aquacultural Engineering
Volume 27, Issue 3 , March 2003, Pages 159-176

Water quality and nutrient budget in closed shrimp (Penaeus monodon)
Dhirendra Prasad Thakurm4.cor*m4.cor*, mailto:dpthakur@hotmail.commailto:dpthakur@hotmail.com, a, b and C. Kwei Lina

Nutrient budget revealed that shrimp could assimilate only 23–31% nitrogen and 10–13% phosphorus of the total inputs. The major source of nutrient input was feed, shrimp feed accounted for 76–92% nitrogen and 70–91% phosphorus of the total inputs. The major sinks of nutrients were in the sediment, which accounted for 14–53% nitrogen and 39–67% phosphorus of the total inputs.

[Yellotang]

Water Research
Volume 36, Issue 4 , February 2002, Pages 1007-1017

Phosphorus Budget as a water quality management tool for Closed aquatic mesocosms

Awesome Article in how the St. Lawrence Mesocosm at the Montreal Biodome have dealt with nitrates and phosphate reductions. It seems that they have tried for the last ten years to try to remedy the amounts of phosphates and nitrates in their setup. After close controlled experiments and nutrient removal they have developed what they feel as the only reliable reduction process and that’s using Large mechanical filters and cleaning them regularly and sucking out the detritus with an underwater vacuum cleaner.

[Bomber]

Originally posted by photobarry
Well it looks like someone is doing their research!

Well I'll be damned! I was right all along.

[photobarry]

Now lets not get ahead of ourselves!

Originally posted by Bomber
Well I'll be damned! I was right all along.

[Bomber]

Not a chance. Phosphate burping is my speciality

LOL

[Yellotang]

This is just leading up to a new article that needs to be run in the ReefKeeping mag.

Every article I am coming across keeps stressing the issue that in nature as well as closed systems that Phosphates are returning back to the water column and needs to be addressed either by large amounts of macro - micor algaes or by sucking the stuff out.

Bomber, I no longer question anything you have stated about DSB's.

[Bomber]

Originally posted by Yellotang
Did you realize that DSB's can actually hold onto or "SINK" more phosphates at higher levels of salinity?

Originally posted by Yellotang
And once that salinity changes at all the DSB's release phosphates back into the water column?

YT
You just saved me some leg work. I need that paper. Can you get me the address?

[Yellotang]

Yes looking for it now.
Came across this.

Advances in Environmental Research
Volume 6, Issue 2 , March 2002, Pages 135-142
Field measurements of SOD and sedimenthit2hit2 nutrient hit1hit1fluxe****3hit3 in a land-locked embayment in Hong Kong
K. W. Chaum4.cor*m4.cor*, mailto:cekwchau@inet.polyu.edu.hkmailto:cekwchau@inet.polyu.edu.hk

Department of Civil and Structural Engineering, The Hong Kong Polytechnic University, Hunghom, Kowloon, Hong Kong

It is logical that sediments in eutrophic water may contain enormous amounts of phosphorus existing in both organic and inorganic forms. Under aerobic conditions, a thin aerobic layer with a thickness of a few millimetres covering the sediments exists, which has been determined to be one of the factors contributing to the assimilation capacity of phosphorus. (Promeroy et al., 1965) When the condition changes to anaerobic, the ferric compounds are reduced and the sorption capacity substantially decreases. A free exchange of dissolved substances between the sediments and the overlying water takes place. Under such conditions, phosphorus will be gradually released into the overlying water.
Compared with phosphorus, the process of nitrogen release from sediments is more complicated since it involves the inter-conversion of a larger number of nitrogen species. It was noticed that ammonia nitrogen was, among others, the key form of nitrogen released from the sediment, which agreed well with results reported by Boynton et al. (1980). The release of a high concentration of ammonia nitrogen from the sediment is the result of the decomposition of organic nitrogen, which previously accumulated continuously in the sediment. The concentration of nitrate-nitrite nitrogen was found to be low since it can be released from or absorbed into the sediment, depending on the concentration gradient across the interface between sediment and water. When the external nutrient loadings or sources were gradually decreased and removed from Tolo Harbour, sediment previously enriched with nitrogen could still release sufficient nitrogen quantities to support the growth of plankton and hence improvement of water quality could not be achieved immediately.
It is also noted that the sediment release rate measurements are of the same order as those computed independently from a diagenesis model (Lee and Feleke, 1999).

[Yellotang]

Here is one of them, but not the one I was looking at earlier.
http://dx.doi.org/10.1016/S0043-1354(98)00286-3

[Yellotang]

If you need me to continue to search for it let me know. I'm getting ready to leave work soon.

[Bomber]

Originally posted by Yellotang
Here is one of them, but not the one I was looking at earlier.
http://dx.doi.org/10.1016/S0043-1354(98)00286-3

That's one, see if you can find any more on this. Of all things I've had people looking for this and you found it. Try to find the one you looked at before. Was it Nakamura?

I need those real bad for something else.

I mean I really need them. no kidding

[Bomber]

Originally posted by rshimek
If you say so, but I think the only problem is that you are working under a couple of false assumptions, and misconceptions about ecosystem energy and material dynamics. These interfere with your understanding of the system.

Originally posted by rshimek
How do I now I am right? Well, these sand beds, when maintained (as by your own admission you were too disinterested to do) work. They are good analogues of natural systems, and are supported by a vast of scientific literature (and a list of some of those you could read, for starters) is given on my web site and linked to from this forum and other sites.

Read....

Originally posted by rshimek
Oh yea, one more thing that I forgot to ask earlier in the thread, do you know of any papers that have been written about DSB's as filters for reef tanks, other than those written recently for the hobby?

No. Nobody discusses "reef" tanks other than hobbyists. Probably the only ones would be Adey's books on microcosms, but I don't think he considers them in much detail.

[Bomber]

Here I found you one too.

http://www2.fimr.fi/en/itamerikanta/bsds/1709.html

>>This near bottom water has a low oxygen content, which increases the dissolution of phosphates from the sediment into the water mass itself.<<

Referring to the anoxic area, same as a DSB.

>>As the oxygen content decreases, phosphates bound in sediment start to dissolve back into the water. If this kind of a stagnation phase lasts a long time, considerable amounts of phosphates will accumulate in deep near bottom water.<<

The anaerobic areas. So much for binding to CaCO3 (calcium carbonate sand).

>>These only require phosphate dissolved in water, since they absorb the nitrogen they need directly from the atmosphere.<<

The final product.

[Yellotang]

Serious.

Yes I will look, and I am sure it was Nakamura. If memory serves me right, he was writing about the vertical flux of nitrates, phosphates and at what levels and depths. The sedimentation would actually change the amounts of phosphates that they could retain based upon temperature and salinity levels. This article had actual charts showing the levels.

I can not access the same stuff until Tuesday. I will dive back in and try to trace my steps.

I didn't realize how much stuff was written about ocean sediments and nutrients. And I didn't come across even one article that even suggested that the oceans floor could process nutrients into benign elements.

[Bomber]

That's the one! I hate to do this to you cause I know it's ten times harder to go back and find something, but please find that one. There's a smoking gun in there.

And I didn't come across even one article that even suggested that the oceans floor could process nutrients into benign elements.

That's because it don't.

[Bomber]

YT, how's your day so far? Do you have time for this.

I hope.

[Habib]

Jerel:

Which Nakamura? There are many with that name.

FWIW:

Nakamura Y. (1994). Effect of flow velocity on phosphate release from sediment. Water Science and Technology, vol.30, 10, pp.263-272.

[Habib]

Not knowing waht you want the following might be useful or not.



Water Science & Technology Vol 42 No 3-4 pp 265–272 © IWA Publishing 2000

Non-steady variations of SOD and phosphate release rate due to changes in the quality of the overlying water
T Inoue*, Y Nakamura** and Y Adachi***
* Department of Maritime Systems Engineering, Kyushu University, 6-10-1 Hakozaki, Higashi-ku, Fukuoka 812-8581, Japan
** Port and Harbour Research Institute, Ministry of Transport, 3-1-1 Nagase, Yokosuka, 239-0826, Japan
*** Department of Maritime Systems Engineering, Kyushu University, 6-10-1 Hakozaki, Higashi-ku, Fukuoka 812-8581, Japan



--------------------------------------------------------------------------------
ABSTRACT
A dynamic model, which predicts non-steady variations in the sediment oxygen demand (SOD) and phosphate release rate, has been designed. This theoretical model consists of three diffusion equations with biochemical reactions for dissolved oxygen (DO), phosphate and ferrous iron. According to this model, step changes in the DO concentration and flow velocity produce drastic changes in the SOD and phosphate release rate within 10 minutes. The vigorous response of the SOD and phosphate release rate is caused by the difference in the time scale of diffusion in the water boundary layer and that of the biochemical reactions in the sediment. Secondly, a negative phosphate transfer from water to sediment can even occur under aerobic conditions. This is caused by the decrease in phosphate concentration in the aerobic layer due to adsorption.