Edmonds-Marsh

The organism I saw on our trip to the marsh was what I believed was a great heron. I was only able to see a few animals during the visit however it was interesting to see all the bird species. The heron was toward the back of the mash in the brown grasses and simply looked like it was hanging out cleaning its feathers. From what I understand herons are a predatory species, so in a way, I suppose its main role is population control. As for what I learned before the trip I actually had no idea what marshes were used for in nature I have a protected wetland near my house up north and the trip helped me understand the importance a little more.(the wetland is narbeck near Boeing)

My question is what is the most important species that is in marshes for our area.