Phosphate Pacific Ocean

Fig. 10-20 Observed depth profiles of (a) phosphate, (b) dissolved inorganic carbon (TC), (c) alkalinity (TA), and (d) oxygen for the Atlantic, the Indian, and the Pacific Oceans as indicated. Data are from GEOSECS stations within 5° of the Equator in each ocean. (Modified from Baes et al. (1985).)...

Fig. 14-6 Profiles of potential temperature and phosphate at 21 29 N, 122 15 W in the Pacific Ocean and a schematic representation of the oceanic processes controlling the P distribution. The dominant processes shown are (1) upwelling of nutrient-rich waters, (2) biological productivity and the sinking of biogenic particles, (3) regeneration of P by the decomposition of organic matter within the water column and surface sediments, (4) decomposition of particles below the main thermocline, (5) slow exchange between surface and deep waters, and (6) incorporation of P into the bottom sediments.

Nitrate versus phosphate concentrations at 2500 m in the (a) Atlantic, (b) Indian, and (c) Pacific Oceans. Dissolved oxygen versus phosphate concentrations at 2500 m in the (d) Atlantic, (e) Indian, and (f) Pacific Oceans. The slopes of these lines represent the proportions by which these constituent concentrations are altered by the remineralization of POM in the deep sea. These data are replotted from Figure 10.1. Source From Conkright, M. E., et al. (2002). World Ocean Atlas 2001, Volume 4 Nutrients, NOAA Atlas NESDIS 52,... 

In the Pacific Ocean, most of the waters at 2500 m have a prefiormed phosphate concentration intermediate between NADW and AABW. Because preformed phosphate is a conservative tracer, it can be used to estimate the proportions of NADW and AABW present in the deep zones of the ocean basins. The average deep-water preformed phosphate concentration is 1.4 (jlM. This concentration would result from an equal-volume admixture of NADW and AABW. This conservative mixing estimate is based on the assumption that the preformed phosphate concentrations of the end-member water masses have remained constant over time scales at least as long as the mixing time of the ocean. 

Longitudinal cross section of preformed phosphate concentrations ( ji,M) in the (a) Atlantic and (b) Pacific Oceans. Constructed from WOCE-JGOFS data, cruises A20, A17, and PI8. Source. From Ito, T. and M. J. Follows (2005). Journal of Marine Research 63, 813-839. 

Correlation plots for the North Pacific Ocean concentration data from Figure 11.14 (a) zinc versus nitrate, phosphate, and silica, (b) cadmium versus nitrate, phosphate, and silica, (c) copper versus nitrate, phosphate, and silica, and (d) nickel versus nitrate, phosphate, and silica. 

Pytkowicz, R. M., and Kester, D. R. Relative calcium phosphate saturation in two regions of the North Pacific ocean. Limnol. Oceanogr. 12, 714-718 (1967). 

Figure 11 The depth distribution of nitrate ( ), phosphate f and silicate (A) in the North Pacific Ocean (Data from Bruland, 19802 )...

Moutin, T., Karl, D. M., Duhamel, S., Rimtnelin, P., Raitnbault, P., Van Mooy, B. A. S., and Claustre, H. (2008). Phosphate availahihty and the ultimate control of new nitrogen input by nitrogen fixation in the tropical Pacific Ocean. Biogeosciences 5, 95—109. 

Ocean, due to extremely low dissolved inorganic phosphate levels (Wu et al, 2000). Karl et al. (1997) found that diazotrophy increased in the subtropical North Pacific Ocean over seven years of time series observations in parallel with a decrease in soluble reactive P levels, suggesting a shift from N limitation towards P limitation. At some locations in the Baltic Sea, phosphorus additions show a significant impact on N2 fixation by cyanobacterial communities dominated by Nodularia, Aphanizome-non, and Anabaem (Fig. 38.12A). The level of observed stimulation of N2 fixation by P addition alone was equal to the simulation by P addition combined with Fe (Moisander et al., 2003). 

Perry M. J. and Eppley R. W. (1981) Phosphate uptake by phytoplankton in the central North Pacific Ocean. Deep-Sea Res. 28, 39-49. 

Both Die and Ax increase from surface waters to the deep Atlantic, Antarctic and Pacific Oceans as one follows the route of the ocean conveyor helt (Fig. 1.12). Along this transect pH changes from about 8.2 in surface waters to 7.8 in the deep Pacific Ocean, and CO3 decreases from nearly 250 geq kg to less than a third of this value, 75 geq kg. The reason for this change has to do with the ratio of the change in Aj and DIG in the waters and is discussed in the final section of this chapter. Notice that the contribution of the nutrients Si and P to the total alkalinity is only between 0 and 5 geq kg or at most 0.2% of the total alkalinity. Although Si concentrations are much greater than those of P, the two nutrients have nearly equal contributions to the alkalinity (Table 4.4) because the pK values for two phosphate reactions are closer to the pH of seawater than is the pK for sfiicate (see Table 4.1). 

Extracellular phosphatase activity has been detected in the oligotrophic Pacific Ocean (Perry, 1972), in the Sargasso Sea (Rivkin and Swift, 1979), in coastal waters (Taft et al., 1977) and in lakes (Berman, 1970). Under conditions where ample dissolved phosphate is present for growth or intracellular concentration of the storage polyphosphate is high, synthesis of these enzymes is impaired. Because enzyme synthesis and activity is induced in response to... 

Sepia. Cuttle-Fish bone. Calcareous substance found under the skin or the back of Sepia officinalis L., Cephalopoda. Habit. Mediterranean Sea, Atlantic and Pacific Oceans. Constit. Calcium carbonate and phosphate, gluten. 

Murray RW, Leinen M, Isem AR (1993) Biogenic flux of A1 in the central equatorial Pacific Ocean Evidence for increased productivity during glacial periods. Paleoceanogr 8 651-670 Murray RW, Knowlton C, Leinen M, Mix AC, Polski CH (2000) Export production and carbonate dissolution in the central equatorial Pacific Ocean over the past 1 Ma. Paleoceanogr 15 570-592 Nancollas GH, Amjad Z, Koutsoukas P (1979) Calcium phosphates-speciation, solubility, and kinetic considerations. Am Chem Soc Symp Ser 93 475-497... 

Efficient stripping of phosphate from surface waters by photosynthesis combined with build-up at depth due to respiration of biogenic particles results in the classic oceanic dissolved nutrient profile. The progressive accumulation of respiration-derived phosphate at depth along the deep-water circulation trajectory results in higher phosphate concentrations in Pacific Ocean deep waters at the end of the trajectory than in the North Atlantic where deep water originates (Figure 1). 

Fig. 10-1. Typical vertical distributions of silicate, phosphate, and nitrate in the North Atlantic (A), Indian Ocean (I) and the Central Pacific Ocean (P) based cm GEOSECS data 1977A78.

Fig. 22. Profiles from the water (unfiltered) column in the western North Pacific Ocean. Comparison of Nd, salinity and the nutrients, phosphate and silica from Sta. 271-1 at 24 N with Sta. 39-1 at 47°N. Data from Piepgras and Jacobsen (1992), Nitrate closely follows the distribution of phosphate.

Over 20% of the world s open ocean surface waters are replete in light and major nutrients (nitrate, phosphate, and silicate), yet chlorophyll and productivity values remain low. These so-called "high-nitrate low-chlorophyll" or HNLC regimes (Chisholm and Morel, 1991) include the sub-arctic North Pacific (Martin and Fitzwater, 1988 Martin et al, 1989 Miller et al, 1991), the equatorial Pacific (Murray et al, 1994 Fitzwater et al, 1996) and the southern Ocean (Martin et al.,... 

Perry, M. J. (1976). Phosphate utilization by an oceanic diatom in phosphorus-limited chemostat culture and in the oligotrophic waters of the central North Pacific. Limnol. Oceanogr. 21,88-107. 

Vertical distributions of (a) oxygen, (b) dissolved silicon (silicate is the primary chemical species), (c) nitrate, and (d) phosphate at selected latitudes within the Atlantic (20 to 30°W), Indian (91 to 95°W), and Pacific (135 to 158°W) oceans. These are WOCE data obtained from Java Ocean Atlas. 

The O2 content of the surface waters is lower at mid-latitudes because of higher temperatures, which lead to lower gas solubility. As shown in Figure 10.1a, the ther-mocline is characterized by a concentration minimum that increases in intensity from the Atlantic to the North Pacific. Note that the O2 minimum is less pronounced in the vertical profile from 45°S as compared to 9°N in the Atlantic Ocean because of close proximity to the site of AABW formation. Mid-water phosphate and nitrate maxima... 

Agricultural phosphates can also be obtained from steelmaking slags (Section 17.7) and from guano, the droppings of seabirds, accumulated over millennia on certain South Pacific islands such as Ocean Island and Nauru. The latter source has been heavily exploited and is now almost exhausted, bringing a catastrophic decline in the fortunes of the islands inhabitants. 

Fig. 9. Dissolved inorganic carbon, salinity, phosphate, nitrate, and temperature in surface ocean waters, during the 1982-83 El Nino, at the same longitude as in Fig. 7. Note that the high values for CO2 and nutrients south from the equator have disappeared while the water temperature has become warmer as warm waters from the Western Pacific flooded over the region. Measurements by C. D. Keeling, R. F. Weiss and others.

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