NO A A PROFESSIONAL PAPER 11 



Table 10-1. — Synopsis of primary produclnily and related measurements in New York Bight, August-September 1976 



Euphotic integral hourly production 



Percentage of total production 



Nanno- 

 to net- 

 plankton 

 produc- Incu- Dura- 



' DOM, photoassimilated carbon released as dissolved organic matter by phytoplankton 



- POM, particulate organic matter (netplankton -i- nannoplankton) produced during photosynthesis. 



' PAR. pholosynthetically active radiation (400-700 nm). 



■• Daily integral productivity = total euphotic integral hourly production x duration of experiment x (100/% daily PAR) 



' Efficiency = f(g C/m-Zd '"'''^ '^ l"'"^ "' ) / (Einstein/m-/d— ^^^ —)]■ 100, After PlatI 1971. 



■' ' ^ g C Einstein 



* MPZ, mean photic zone. 



' Doublings per day = daily productivity: euphotic chlorophyll-a ratio / 30, Assuming 30:1 carbon/Chla (Eppley 1968). 



" After Bannister 1974. 



Barlow et al. (1963) measured an average rate of 272 ml 

 0,/mVh during the summer in the heavily fertilized eu- 

 trophic Forge River estuary. Sirois (1974) measured 72 

 and 53 ml/O^/mVh in July and September, respectively, 

 in the surface water of the lower Hudson River above the 

 major influence of New York metropolitan area, about 

 15 km north of station 69. Farther north in the Hudson 

 River, Sirois reported lower rates (44 and 24 ml O./mVh 

 in July and September, respectively). During June 1977, 

 a "normal" summer, total plankton respiration rates 

 measured in the previously affected low D.O. area were 

 about 2 g C/m'/d oxidized and were several times higher 

 than the rates of integral aerobic respiration measured 

 there during August-September 1976. 



Above the pycnocline, during August-September 1976, 

 oxygen consumption rates were generally highest and de- 

 creased with depth from the surface (figs. 10-4 and 10-9, 

 station 34). Aerobic respiration in the water column above 



the pycnocline in the low D.O. area was much less, relative 

 to adjacent stations, even though oxygen was near satu- 

 ration and therefore not limiting (figs. 10-4 and 10-10; 

 fig. 10-9B, station 213). 



Below the pycnocline, total plankton aerobic respiration 

 rates were frequently near zero except at stations adjacent 

 to the oxygen-depleted area (figs. 10-4 and 10-9B, station 

 200) and in the estuary (Thomas et al., in press). Below 

 the pycnocline in the anoxic area no measurable aerobic 

 respiration occurred (figs. 10-4 and 10-9B, station 213). 

 However, the highest concentrations of phosphate and 

 silicate were measured in the anoxic area just below the 

 pycnocline, suggesting that anaerobic metabolism may 

 have played a major role in the regeneration of nutrients 

 from particulate and dissolved organic matter or that a 

 residual buildup from previous aerobic metabolism was 

 solubilized under low D.O. conditions or that water of 

 higher nutrient concentration was advected into that area. 



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