Nitrogen fixation salinity

Marino, M., Chan, F., Howarth, R. W., Pace, M., and Likens, G. E. (2006). Ecological constraints on planktonic nitrogen fixation in saline estuaries. 1. Nutrient and trophic controls. Mar. Ecol. Prog. Ser. 309, 25-39. 

Figure 9 Comparison of the correlation of natural a C with silicate (A) and potential alkalinity (PALK = [alkalinity+ nitrate] x 35/salinity) (B) using the GEOSECS global data. Samples from high southern latitudes are excluded from the silicate relation. The presence of tritium was used to surmise the presence of bomb-A C. The somewhat anomalous high PALK values from the Indian Ocean are from upwelling-high productivity zones and may be influenced by nitrogen fixation and/or particle flux.

In most cases, fixation may be carried out at room temperature. Duration of formalin fixation depends on the nature and the size of the specimen, and may vary from 15 min to 24 h. Longer fixation may be associated with a partial loss of the antigenicity of the component of interest. After formalin fixation, tissue samples are washed in three changes of the buffered saline (PBS) from 15 min to 2 h, but not longer than 24 hours on the whole, since the formaldehyde fixation is partially reversible. After washing in PBS, specimens may be either snap-frozen in liquid nitrogen for subsequent cryosectioning, or dehydrated and embedded in paraffin or synthetic resin. 

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