As we creep closer to the official start of winter, it is apparent that fall is on its way out. The last of the leaves are down and are covered with a variable crust of ice and snow. Looking across the water, the deciduous trees faintly stand out against the evergreens as lacy skeletons, delicate against fall’s dramatic skies.

These changes are easily visible and familiar on land, but are perhaps less familiar along the shore. The shift in color happens in our native salt grasses just as it does to the trees. Those verdant greens shift to muted tans and the tans shift to auburn red.

The beauty and utility of salt marshes was celebrated beginning with early settlers. Early European settlers harvested saltmeadow hay by making cuts or dykes in the marsh to redirect incoming water and allow the grasses to dry. The hay was then used to feed cattle and other livestock. Artists painted pastoral pictures of the “staddles” of drying hay amidst the cowlick patterned surrounding marsh. You can still see these cuts at Morse Mountain Preserve and Reid State Park.

But as the coast became more populous and there was pressure to develop the land, people began to think of marshes as wastelands rather than resources. In the period following World War II when coastal construction and recreation increased dramatically, marshes were seen as stinky waste spaces that were ditched to redirect water for navigation, drained to create buildable shoreline, and even used as dumping grounds for trash disposal. They were thought to be breeding grounds for harmful insects and diseases and people wanted to fill them up or drain them out.

Sadly, many of New England’s marshes were lost to development and it is rare to find a pristine marsh in Maine. Nearly all have been filled or ditched at some point. But, in recent decades people have begun to fully understand their value and efforts have been made to protect and restore them. A salt marsh may just look like a big blur of grasses, but it is actually a whole suite of plants that together form an amazing ecological community — golden saltmeadow hay, rugged cordgrass, black grass with its dark rounded seed clusters, sharp edged spike grass, delicate Sea lavender and Seaside goldenrod, and bright red glasswort that tastes like pickles.

The unusual thing about all of these species is that they are plants and plants don’t usually grow in salt water. Most marine “plants” we think of are actually algae. This includes all the seaweeds and other slippery stuff on the rocks. But, marsh grasses are true plants with vascular systems to circulate fluids and roots to connect them to their habitat. These two features make them incredible filters and habitat builders.

A salt marsh can filter out sediment and any pollutants it may carry by slowing the water flow down so that the particles settle to the bottom, leaving the remaining water cleaner and clearer. And, they can absorb excess nutrients that can cause algal blooms including those harmful to our shellfish. They also improve the water by adding vital oxygen to the water through photosynthesis.

Then comes the mucky part — and what we see at this time of year. As each year’s growth dies, the leftover plant material decays and is broken down into a nutrient-filled spongy mat that is poised to give rise to the next generation of salt grasses come spring. This builds up into a dense peat barrier along the shore that can prevent erosion by waves and currents and slow down shoreside input from heavy rainfall or snowmelt. This decaying peat can be a bit stinky and not the prettiest — perhaps why marshes were underappreciated for a stretch.

As far as habitat, if you are birder, you have likely been out to places like Wharton Point to see the amazing array of both shorebirds and songbirds. Flitting sparrows find food among the seeds and flowers of the marsh grasses and herons and terns forage in their shallow waters for tiny fish and other morsels. They are a wonderful place to see damsel and dragonflies as well.

And, if you look under the water, you’ll find an array of juvenile finfish, shellfish and marine worms. The grasses provide important protection from predators and are a critical nursery area for many of Maine’s most valuable commercial species.

So, take a moment in the last remaining days of fall to see the last colors of the marshes and all of the coastal life they support, including ours.

Susan Olcott lives in Brunswick, with her husband and 7-year-old twin girls. She earned her M.S. in zoology studying the lobster fishery in New England. She then designed education programs for the Scripps Institute of Oceanography and taught biology to military personnel in Sardinia, Italy before returning to Maine to work on ocean planning for The Ocean Conservancy. She is now a freelance writer and currently writes about coastal issues for the Harpswell Anchor and The Working Waterfront and about local foods for the Brunswick Topsham Land Trust and Zest Magazine. In addition, she helps local schools pursue educational grants and writes children’s book reviews for the Horn Book’s family reading blog as well as for her own blog: susanolcott.wordpress.com.