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#976
08/19/2004, 09:59 AM
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Honorable Golden Shellback "Lemon Curry????" |
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#977
08/19/2004, 11:30 AM
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Quote:
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-Barry "smart people win debates, stupid people win shouting matches" -skippy |
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#978
08/19/2004, 11:47 AM
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LOL...you know, I just reread a cyano/southdown thread over at the other place...and just realized that this is the same Frank that doesn't believe in bacteria....I'm running too.
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Honorable Golden Shellback "Lemon Curry????" |
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#979
08/19/2004, 11:49 AM
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I didn't know if you would get the connection. I'm glad you did! LOL
(Quick, edit your other post  )
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-Barry "smart people win debates, stupid people win shouting matches" -skippy |
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#983
08/19/2004, 08:48 PM
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#985
08/20/2004, 08:29 AM
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There are things in marine environments that "fix" nitrogen compounds. Cyano for instance, but there are other bacteria that will do that also. They take nitrogen literally out of thin air, and introduce it into the marine environment. As long as you realize that, you understand that nitrogen/nitrates can never be limiting.
Plants in particular, need two foods. Nitrogen and phosphorous. The only one of those two that can be limiting is P. So again, Bomber, you contend that nitrogen is never limiting to growth in the ocean? That iron is never limiting? There are tons of articles showing that nitrogen and iron can be limiting. FWIW, nitrogen fixation too can be limited, making the availability of nitrogen compounds limiting. Iron and phosphorus co-limit nitrogen fixation in the eastern tropical North Atlantic. Mills, Matthew M.; Ridame, Celine; Davey, Margaret; La Roche, Julie; Geider, Richard J. Marine Biogeochemistry, IFM-GEOMAR Leibniz-Institut fuer Meereswissenschaften, Kiel, Germany. Nature (London, United Kingdom) (2004), 429(6989), 292-294. Abstract The role of iron in enhancing phytoplankton productivity in high-nutrient, low-chlorophyll oceanic regions was demonstrated first through iron-addn. bioassay expts. and subsequently confirmed by large-scale iron fertilization expts. Iron supply has been hypothesized to limit nitrogen fixation and hence oceanic primary productivity on geol. timescales, providing an alternative to phosphorus as the ultimate limiting nutrient. Oceanog. observations have been interpreted both to confirm and refute this hypothesis, but direct exptl. evidence is lacking. We conducted expts. to test this hypothesis during the Meteor 55 cruise to the tropical North Atlantic Ocean. This region is rich in diazotrophs and strongly impacted by Saharan dust input. Here we show that community primary productivity was nitrogen-limited and that nitrogen fixation was co-limited by iron and phosphorus. Saharan dust addn. stimulated nitrogen fixation, presumably by supplying both iron and phosphorus. Our results support the hypothesis that aeolian mineral dust deposition promotes nitrogen fixation in the eastern tropical North Atlantic Ocean.
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Randy Holmes-Farley Last edited by Randy Holmes-Farley; 08/20/2004 at 08:47 AM. |
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#986
08/20/2004, 08:31 AM
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And some more:
Distribution features of main observational elements in Laizhou Bay in the summertime of 2000. Wan, Xiu-quan; Wu, De-xing; Bao, Xian-wen; Jiang, Hua. Institute of Physical Oceanography, Ocean University of China, Qingdao, Peop. Rep. China. Zhongguo Haiyang Daxue Xuebao, Ziran Kexueban (2004), 34(1), 7-12. Abstract Based on the investigation data in Laizhou Bay in the summertime of 2000, the distribution features of temp., salinity, dissolved oxygen, turbidity, chlorophyll, inorg. nitrogen, phosphate and silicate in the sea water are expounded. Also discussed is their relationship between each other. The results show that the salinity in Laizhou Bay has increased remarkably compared with the previous observational data. The high value zone of chlorophyll in the south of Laizhou Bay corresponds with the low value zone of dissolved oxygen and the thermal zone. The distribution of turbidity is mainly governed by the run-off of the Yellow River. It is also found that the inorg. nitrogen concn. is high in the west of Laizhou Bay and low in the east, and the discrepancy is very great. The limiting factor of phytoplankton growing in the east of Laizhou Bay is different from that in the west: the former being nitrogen whereas the latter being phosphor. Determination of the limiting nutrients for growth of nori laver and diatoms in Ariake Bay (Japan) by analyses of long-term variation in water quality. Kawaguchi, Osamu; Yamamoto, Tamiji; Matsuda, Osamu; Hashimoto, Toshiya. Grad. Sch. Biosphere Sci., Hiroshima Univ., Higashihiroshima, Japan. Umi no Kenkyu (2004), 13(2), 173-183. Abstract The limiting nutrients for growth of Nori laver and planktonic diatoms were analyzed from data on the long-term variation in water quality. By comparing the elemental ratio and half-satn. consts. for nitrogen uptake by Nori laver with the nutrient concns. and their ratios in situ, nitrogen was detd. to be the limiting factor for growth of Nori laver in the entire region of Ariake Bay. On the other hand, analyses showed that phosphorus has been limiting the growth of diatoms in the northern part, while nitrogen has been limiting the growth of diatoms in the southern part of Ariake Bay. Silicate was shown not to have been limiting for growth of diatoms in Ariake Bay. There was a decreasing trend in dissolved inorg. nitrogen (DIN) for four years after the construction of the Isahaya dike. This implies that the environmental perturbation of the dike in changing water quality in Ariake Bay has been advantageous for the growth of diatoms rather than for Nori. Nutrient dynamics in the Pomeranian Bay (Southern Baltic): impact of the Oder River outflow. Pastuszak, Marianna; Nagel, Klaus; Grelowski, Alfred; Mohrholz, Volker; Zalewski, Mariusz. Department of Fisheries Oceanography and Marine Ecology, Sea Fisheries Institute, Gdynia, Pol. Estuaries (2003), 26(5), 1238-1254. Abstract Pomeranian Bay is a coastal region fed by the Oder River, one of the seven largest Baltic rivers, whose waters flow through a large and complex estuarine system before entering the bay. Nutrients (NO3-, NO2-, NH4+, total N, PO43-, total P, dissolved Si), chlorophyll a concns., dissolved oxygen content, salinity, and temp. were measured in e Pomeranian Bay in nine seasonally distributed cruises during 1993-1997. Strong spatial and temporal patterns were obsd., and they were governed by: the seasonally variable riverine water-nutrient discharges, the seasonally variable uptake of nutrients and their cycling in the river estuary and the Bay, the character of water exchange between Pomeranian Bay and the Szczecin Lagoon, and the water flow patterns in the Bay that are dominated by wind-driven circulation. Easterly winds resulted in water and nutrient transport along the German coastline, while westerly winds confined the nutrient-rich riverine waters to the Polish coast and transported them eastward beyond the study area. Two water masses, coastal and open, characterized by different chem. and phys. parameters and chlorophyll a content, were found in the Bay independently of the season. The role of the Oder estuary in nutrient transformation, as well as the role of temp. in transformation processes, is stressed in the paper. The dissolved inorg. N:dissolved inorg. P:dissolved inorg. Si ratio indicated that phosphorus most probably played a limiting role in phytoplankton prodn. in the Bay in spring, while nitrogen did the same in summer. During the spring bloom, predominated by diatoms, the dissolved Si:dissolved inorg. N ratio dropped to 0.1 in the coastal waters and to 0.6 in the open bay waters, pointing to silicon limitation of diatom growth, similar to what is being obsd. in other Baltic regions.
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Randy Holmes-Farley |
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#987
08/20/2004, 08:40 AM
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And more:
Dissolved inorganic phosphorus, dissolved iron, and Trichodesmium in the oligotrophic South China Sea. Wu, Jingfeng; Chung, Shi-Wei; Wen, Liang-Saw; Liu, Kon-Kee; Chen, Yuh-ling Lee; Chen, Houng-Yung; Karl, David M. International Arctic Research Center, University of Alaska Fairbanks, Fairbanks, AK, USA. Global Biogeochemical Cycles (2003), 17(1), 8/1-8/10. Abstract Dissolved inorg. P (DIP) concns. in the oligotrophic surface waters of the South China Sea decrease from .apprx.20 nM in Mar. 2000 to .apprx.5 nM in July 2000, in response to seasonal water column stratification. These min. DIP concns. are one order of magnitude higher than those in the P-limited, iron-replete stratified surface waters of the western North Atlantic, suggesting that the ecosystem in the South China Sea may be limited by bioavailable N or some trace nutrient rather than DIP. Nutrient enrichment expts. using either nitrate, phosphate or both indicate that nitrogen limits the net growth of phytoplankton in the South China Sea, at least during Mar. and July 2000. The fixed N limitation may result from the excess phosphate (N:P<16) transported into the South China Sea from the North Pacific relative to microbial population needs, or from Fe control of N fixation. The Fe-limited N fixation hypothesis is supported by the observation of low population densities of Trichodesmium spp. (<48 ´ 103 trichomes/m3), the putative N2 fixing cyanobacterium, and with low concns. of dissolved Fe (.apprx.0.2-0.3 nM) in the South China Sea surface water. N fixation can be limited by available Fe even in regions with a high rate of atm. dust deposition such as in the South China Sea. Monitoring of eutrophication and nutrient limitation in the Izmir Bay (Turkey) before and after Wastewater Treatment Plant. Kontas, A.; Kucuksezgin, F.; Altay, O.; Uluturhan, E. Institute of Marine Sciences and Technology, Dokuz Eylul University, Izmir, Turk. Environment International (2004), 29(8), 1057-1062. Abstract The distribution of inorg. nutrients and phytoplankton chlorophyll-a was studied and N/P ratios were detd. in Izmir Bay during 1996-2001. The av. concns. showed ranges of 0.01-0.19 and 0.01-10 mM for phosphate-phosphorus; 0.11-1.8 and 0.13-27 mM for (nitrate + nitrite)-nitrogen, 0.30-4.1 and 0.50-39 mM for silicate and 0.02-4.3 and 0.10-26 mg/L for chlorophyll-a in the outer and middle-inner bays, resp. The results are compared with the values obtained from the relatively unpolluted waters of the Aegean Sea. The N/P ratio is significantly lower than the assimilatory optimal (N/P = 15:1) in conformity with Redfield's ratio N/P = 16:1. Nitrogen is the limiting element in the Izmir Bay. Phosphate, which originates from detergents, is an important source for eutrophication in the bay, esp. in the inner bay. In early 2000, a Wastewater Treatment Plant (WTP) began to treat domestic and industrial wastes. This plant treats the wastes .apprx.60% capacity between 2000 and 2001. The sampling periods cover before and after treatment plant. Although the capacity of wastewater plant is sufficient for removal of nitrogen from the wastes, it is inadequate for removal of phosphate. This is also in accordance with the decreasing N/P ratios obsd. during 2000-2001 (after WTP) in the middle-inner bays. Sulfate inhibition of molybdenum-dependent nitrogen fixation by planktonic cyanobacteria under seawater conditions: a non-reversible effect. Marino, Roxanne; Howarth, Robert W.; Chan, Francis; Cole, Jonathan J.; Likens, Gene E. Department of Ecology & Evolutionary Biology, Cornell University, Ithaca, NY, USA. Hydrobiologia (2003), 500 277-293. CODEN: HYDRB8 ISSN: 0018-8158. Journal written in English. CAN 140:240313 AN 2003:531414 CAPLUS Abstract The trace element molybdenum is a central component of several enzymes essential to bacterial nitrogen metab., including nitrogen fixation. Despite reasonably high dissolved concns. (for a trace metal) of molybdenum in seawater, evidence suggests that its biol. reactivity and availability are lower in seawater than in freshwater. We have previously argued that this difference is related to an inhibition in the uptake of molybdate (the thermodynamically stable form of molybdenum in oxic natural waters) by sulfate, a stereochem. similar ion. Low molybdenum availability may slow the growth rate of nitrogen-fixing cyanobacteria, and in combination with an ecol. control such as grazing by zooplankton, keep fixation rates very low in even strongly nitrogen-limited coastal marine ecosystems. Here we present results from a seawater mesocosm expt. where the molybdenum concn. was increased 10-fold under highly nitrogen-limited conditions. The obsd. effects on nitrogen-fixing cyanobacterial abundance and nitrogen-fixation inputs were much smaller than expected. A follow-up expt. with sulfate and molybdenum addns. to freshwater microcosms showed that sulfate (at seawater concns.) greatly reduced nitrogen fixation by cyanobacteria and that addns. of molybdenum to the levels present in the seawater mesocosm expt. only slightly reversed this effect. In light of these results, we re-evaluated our previous work on the uptake of radiolabeled molybdenum by lake plankton and by cultures of heterocystic cyanobacteria. Our new interpretation indicates that sulfate at saline estuarine levels (>8-10 mM) up to seawater (28 mM) concns. does inhibit molybdenum assimilation. However, the max. molybdenum uptake rate (Vmax) was a function of the sulfate concn., with lower Vmax values at higher sulfate levels. This indicates that this inhibition is not fully reversed at some satg. level of molybdenum, as assumed in a simple competitive inhibition model. A multi-enzyme, mixed kinetics model with two or more uptake enzyme systems activated in response to the environmental sulfate and molybdate conditions may better explain the repressive effect of sulfate on Mo-mediated processes such as nitrogen fixation. Autotrophy, nitrogen accumulation and nitrogen limitation in the Baltic Sea: a paradox or a buffer for eutrophication? Thomas, Helmuth; Pempkowiak, Janusz; Wulff, Fred; Nagel, Klaus. Royal Netherlands Institute for Sea Research (NIOZ), Texel, Neth. Geophysical Research Letters (2003), 30(21), OCE8/1-OCE8/4. Abstract The autotrophic Baltic Sea acts as a sink for atm. CO2; however it is also characterized by nitrogen limitation and nitrogen accumulation, the latter indicating heterotrophy. Phys. and biogeochem. processes generate this paradox, since the developments of the seasonal thermocline, the spring bloom and the riverine nitrogen inputs start during early spring. The Baltic Intermediate Water (BIW) is sepd. from the above surface layer, i.e., from the euphotic zone preventing a significant amt. of the former winter mixed layer nitrogen from being used by phytoplankton, which finally becomes nitrogen limited. The deepening of the mixed layer in autumn reintegrates the nitrogen constrained within the BIW into the surface layer. Nitrogen in turn accumulates over an annual time scale depending on the riverine nitrogen loads. The temporal nitrogen enclosure in the BIW buffers the potential impact of nutrient inputs on the Baltic Sea and its trophic state. Sulfate inhibition of molybdenum-dependent nitrogen fixation by planktonic cyanobacteria under seawater conditions: a non-reversible effect. Marino, Roxanne; Howarth, Robert W.; Chan, Francis; Cole, Jonathan J.; Likens, Gene E. Department of Ecology & Evolutionary Biology, Cornell University, Ithaca, NY, USA. Hydrobiologia (2003), 500 277-293. Abstract The trace element molybdenum is a central component of several enzymes essential to bacterial nitrogen metab., including nitrogen fixation. Despite reasonably high dissolved concns. (for a trace metal) of molybdenum in seawater, evidence suggests that its biol. reactivity and availability are lower in seawater than in freshwater. We have previously argued that this difference is related to an inhibition in the uptake of molybdate (the thermodynamically stable form of molybdenum in oxic natural waters) by sulfate, a stereochem. similar ion. Low molybdenum availability may slow the growth rate of nitrogen-fixing cyanobacteria, and in combination with an ecol. control such as grazing by zooplankton, keep fixation rates very low in even strongly nitrogen-limited coastal marine ecosystems. Here we present results from a seawater mesocosm expt. where the molybdenum concn. was increased 10-fold under highly nitrogen-limited conditions. The obsd. effects on nitrogen-fixing cyanobacterial abundance and nitrogen-fixation inputs were much smaller than expected. A follow-up expt. with sulfate and molybdenum addns. to freshwater microcosms showed that sulfate (at seawater concns.) greatly reduced nitrogen fixation by cyanobacteria and that addns. of molybdenum to the levels present in the seawater mesocosm expt. only slightly reversed this effect. In light of these results, we re-evaluated our previous work on the uptake of radiolabeled molybdenum by lake plankton and by cultures of heterocystic cyanobacteria. Our new interpretation indicates that sulfate at saline estuarine levels (>8-10 mM) up to seawater (28 mM) concns. does inhibit molybdenum assimilation. However, the max. molybdenum uptake rate (Vmax) was a function of the sulfate concn., with lower Vmax values at higher sulfate levels. This indicates that this inhibition is not fully reversed at some satg. level of molybdenum, as assumed in a simple competitive inhibition model. A multi-enzyme, mixed kinetics model with two or more uptake enzyme systems activated in response to the environmental sulfate and molybdate conditions may better explain the repressive effect of sulfate on Mo-mediated processes such as nitrogen fixation. Biogeochemical phosphate cycle as a key factor in the control of planktonic production and carbon export from the photic to the aphotic zone. Moutin, T. Fr. Oceanis (2002), Volume Date 2000, 26(4), 644-660. Abstract A review. Quantification of primary prodn. in the upper ocean and its fate are major objectives of present-day oceanog. Although nitrogen is still considered to be an essential factor controlling algal prodn., little is known about the availability and the role of phosphate as a limiting factor of org. prodn. In numerous oceanic environments, and particularly in the Mediterranean Sea, extremely low phosphate concns., in the <1nM range, have been shown to control both bacterial and algal prodn. The large dissolved org. carbon accumulation occurring in these situations may be seen as a direct consequence of this control. Thus, phosphate appears as a key factor controlling the food chain structure and carbon export from the photic to the aphotic zone.
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Randy Holmes-Farley |
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#988
08/20/2004, 08:47 AM
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More:
Biomonitoring of marine waters by the use of microalgal tests: results from the Campania coastal zone (South Tyrrhenian Sea). Torricelli, L.; Manzo, S.; Accornero, A.; Manfra, L. Environmental Department, ENEA-Research Center Portici, Portici, Italy. Fresenius Environmental Bulletin (2002), 11(9b), 691-696. Abstract Growth tests upon marine microalgae can provide important information about factors limiting algal growth, and bioavailability of nutrients, and can be used as indicators of the water trophic state and toxicity levels. This study was aimed at assessing the quality of the Regione Campania (Italy) coastal waters through algal bioassays with the marine chlorophyta, Dunaliella tertiolecta. Superficial waters were sampled monthly, from Oct. to Dec. 2000, in 22 stations along the Campania shoreline, with the objective to evaluate the environmental trophic state and likely chronic toxicity. Exptl. results showed eutrophication and high toxicity effects in the northern part of the study area, particularly, near the Garigliano, Volturno and Sarno rivers. The growth response of microalgae to nutrient addn. indicated phosphorus as limiting factor in the proximity to river mouths, probably as a result of the high nitrogen load carried by rivers, and nitrogen in all other stations. In our study microalgal test cultures have proven to be a sensitive chronic toxicity assay and a useful tool to evaluate the "health" of marine coastal waters by allowing their classification into quality categories. Nutrient content of the seagrass Thalassia testudinum reveals regional patterns of relative availability of nitrogen and phosphorus in the Florida Keys USA. Fourqurean, James W.; Zieman, Joseph C. Department of Biological Sciences and Southeast Environmental Research Center, Florida International University, Miami, FL, USA. Biogeochemistry (2002), 61(3), 229-245. COD Abstract From 1992 to 2000, 504 randomly chosen sites in the Florida Keys, Florida, were sampled to assess the elemental content of green leaves of the seagrass, Thalassia testudinum. C content was 29.4-43.3% (dry wt.), N from 0.88 to 3.96%, and P from 0.048 to 0.243%. N and P content were not correlated, suggesting the relative availability of N and P varied across the sampling region. Spatial pattern in C:N indicated a decrease in N availability from inshore water to the reef tract, 10 km offshore; in contrast, the C:P pattern indicated an increase in P availability from inshore water to the reef tract. The N:P spatial pattern was used to define a P-limited region of seagrass beds in Florida Bay and nearshore, and an N-limited region of seagrass beds offshore. The close juxtaposition of N- and P-limited regions allows the possibility that N loading from the suburban Florida Keys could affect the offshore, N-limited seagrass beds without impacting the more nearshore, P-limited seagrass beds. Distribution of N/P ratio and its limitation to growth of phytoplankton in Sanya Bay. Wang, Han-kui; Dong, Jun-de; Zhang, Si; Huang, Liang-min. South China Sea Inst. of Oceanol., Chinese Acad. of Sci., Canton, Peop. Rep. China. Redai Haiyang Xuebao (2002), 21(1), 33-39. Abstract According to the monthly data collected from Apr. 2000 to Apr. 2001, the distribution of N/P ratio and its limitation to the growth of phytoplankton in the Sanya Bay are discussed adopting the std. which was founded to assess the stoichiometric limitations of nutrients (Justic, et al., 1995). The changes of relative frequency reveal that the growth of phytoplankton in the Sanya Bay is governed by nitrogen in summer and autumn and by phosphate in winter and spring, whereas the possibility of limitation by silicate is very low. The results of phytoplankton culture in lab. by adding nutrients into original seawater is basically coincident with the results by analyzing the in situ investigation data. Nutrient management for coastal zones: A case study of the nitrogen load to the Stockholm Archipelago. Scharin, H. Beijer International Institute of Ecological Economics, Royal Swedish Academy of Sciences, Stockholm, Swed. Water Science and Technology (2002), 45(9, Diffuse/Non-point Pollution and Watershed Management), 309-315. Abstract This study investigates cost-effective solns. of decreasing the nutrient load to a coastal area, using a drainage basin approach. The study is applied to the Stockholm Archipelago, a coastal area of the Baltic Sea suffering from eutrophication caused by the load of nutrients entering the area. Nitrogen is the nutrient of concern in this study since it is the limiting nutrient of the Archipelago. The main sources of nitrogen are wastewater plants, agriculture, and atm. depositions. The final impact of a deposition depends on the buffering capabilities it is subject to on its trajectory from the source to the recipient. This is the reason for using a recipient oriented approach, in which the focus is to reduce the final impact of a deposition. The model integrates data over hydrol., land cover, land use, and economy in order to find the optimal allocation of measures. Results indicate that in order to achieve cost effectiveness, the major part of nitrogen load redn. to the Archipelago should be done at the wastewater plants and by constructing wetlands. The min. annual cost of reaching a 50% redn. of the load to the Archipelago was estd. to around 191 million Swedish crowns (around $ 19 million).
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Randy Holmes-Farley |
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#989
08/20/2004, 11:24 AM
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Even corals can be limited by nitrogen in the ocean:
Effect of ammonium enrichment on animal and algal biomass of the coral Pocillopora damicornis. Muller-Parker, G.; McCloskey, L. R.; Hoegh-Guldberg, O.; McAuley, P. J. Dep. Biol., Western Washington Univ., Bellingham, WA, USA. Pacific Science (1994), 48(3), 273-83. Abstract Algal and animal biomass parameters of colonies of the Pacific coral Pocillopora damicornis were measured as a function of time of exposure to elevated concns. of seawater ammonium (20 and 50 uM [(NH4)2SO4]) ranging from 2 to 8 wk. Areal concns. of zooxanthellae, chlorophyll, and protein increased with 20 uM ammonium addn. During the 8-wk period of exposure to 20 uM ammonium, the population d. of zooxanthellae increased from 3.5 to 7.5 ´ 105 cells/cm2, chlorophyll a content of zooxanthellae increased from 5.7 to 8.6 pg, and animal protein concn. doubled (from 0.74 to 1.38 mg/cm2). These data indicate that both the coral animal and the zooxanthellae respond to the addn. of exogenous dissolved inorg. nitrogen provided as 20 mM ammonium. Growth of the symbiotic assocn. in response to the addn. of 20 uM ammonium adds further evidence to support the argument that growth of tropical symbioses is limited by the availability of nitrogen. However, the coral response is likely to depend on the concn. of ammonium provided, because the biomass parameters of corals held at 50 uM ammonium did not change significantly with time of exposure to the added nutrient.
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Randy Holmes-Farley Last edited by Randy Holmes-Farley; 08/20/2004 at 01:35 PM. |
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#990
08/20/2004, 11:40 AM
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What is 20mM ammonium in ppm?
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-Barry "smart people win debates, stupid people win shouting matches" -skippy |
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#991
08/20/2004, 11:59 AM
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Sorry, the microsymbol became an m in the RC font. They should all be micromolar in that article. 1 uM = 1 micromole/L = 14 ug N/L.
So 20 uM = 0.28 ppm ammonia-N.
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Randy Holmes-Farley |
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#992
08/20/2004, 12:03 PM
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Thanks! I just wanted to point out that 20uM is a very small amount of additional nitrogen so that people don't start thinking that we need more N in our tanks. Also, it shows that it doesn't take a large increase in ammonium to make something else the limiting factor. (I'm thinking about the fish that probably sleep around the coral at night in nature and provide it with more than enough excess ammonium.)
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-Barry "smart people win debates, stupid people win shouting matches" -skippy |
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#993
08/20/2004, 12:43 PM
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That's open ocean. Try again. |
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#994
08/20/2004, 12:45 PM
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What does this have to do with coral reefs? This is eutrophic. |
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#995
08/20/2004, 12:49 PM
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Do you know what you're reading?? Quote:
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#996
08/20/2004, 12:51 PM
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#997
08/20/2004, 12:53 PM
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#998
08/20/2004, 01:37 PM
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You have stated repeatedly that nitrate cannot be limiting with no qualifications or caveats whatsoever. No possibility in an aquaruium anywhere.
Now you qualify that. OK, so if your claim is now that in natural systems phosphate is sometimes limiting, and nitrogen is sometimes limiting, I'm happy.
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Randy Holmes-Farley |
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#999
08/20/2004, 02:39 PM
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Movement of P from interstitial (pore) water High populations of sediment burrowing benthic organisms such as the midge larvae (Chironomous spp.) can accelerate the release of P from sediments If burrowing organisms can accelerate the release of P from sediments, then wouldn't they help reduce it's net accumulation in the first place? And, if he's always advocated high levels of burrowing organisms in the DSBs, then hasn't he always advocated a method that will help reduce P accumulation in the DSB?
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Mike Reefcentral Folding@Home team 37251 - Click my little red house to learn more and help medical science! |
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#1000
08/20/2004, 02:41 PM
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I probably went through one of my rambling all over the place to get there explanations and you went to sleep before I finally got there. Short answer, yes nitrate can be limiting. You just don't want that to happen in a reef tank.  (I'm getting better - or delusional) |
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Linear Mode
