Living On The Margins

I've been thinking about Riparian Zones, those margins between one type of ecosystem and another; the zone where the two interact. Often one thinks of this zone as being alongside a river or creek. But what about the shoreline, the intertidal zone? It is where I and many others live.
We live at the margin, in between one ecosystem and another. It is a special place: I dare say sacred.
What happens when one ecosystem becomes unbalanced? How do we all suffer?
I, we, live on the margins.