how does the intertidal zone influence humans?
Since this is not my area of expertise, I searched Google under the key words "'intertidal zone' humans" to get these possible sources:
http://www.iopan.gda.pl/rbdo/mekodb/litus/human.html
(Broken Link Removed)
http://www.uwex.edu/ces/csreesvolmon/RelatedResearch/WABeachWatchersVolMon.htm
http://www.advancedaquarist.com/2006/11/lines
http://geography.about.com/od/physicalgeography/a/intertidal.htm
In the future, you can find the information you desire more quickly, if you use appropriate key words to do your own search.
I hope this helps. Thanks for asking.