Is there any link between sea-water inflitration into groundwater and nitrate? I recently read a pop-science article about sea-water infilitration into (sweet) groundwater. One specific instance mentioned was the gaza strip: Exzessive well building and drawing of groundwater lowers the groundwater level, this leads to sea water infiltration. Then the article states the the nitrate content in the groundwater is higher, leading to blue baby sysndrome.

Now, I assume that an elevated nitrate content in the groundwater is due to fertilizer runoff, damaged sewer systems or similiar and unrelated to the saltwater problem, the author of the article simply mixed those problems up. But I'm not sure, hence this question: Is there any causal link between sea-water inflitration and groundwater nitrate?  

An answer not specific to Gaza would be ok as I want to understand possible mechanisms.
While the context and specifics would likely vary from site to site, the situation along the Gaza strip may be due to contamination of the Mediterranean Sea.  I am unsure of natural levels of Nitrate in ocean water, but I know that it is possible to contaminate water, independent of it's salinity.

Nitrate, like other water-soluble ions, ultimately is transported from the land to the oceans via the hydrologic cycle.  Waste from marine organisms also likely contributes nitrate.  This paper talks on the content of nitrate in ocean water. For more information on the various major constituents of sea water, check out this site.

There has been reported incidence of sewage draining into the Mediterranean, which would explain nitrate contamination in conjunction with sea-water intrusion.