Farm Creek Salt Marsh

A Louisiana Blue Heron (Ardea herodias) hunts in the shallows.

Farm Creek is a wonderful site for teaching students of all ages. It is a healthy, diverse salt marsh ecosystem in the disappearing natural Connecticut coastline. The Farm Creek Salt Marsh displays the normal salt marsh zonation that accompanies tidal wetlands that are inundated with the daily change in marine tides. The tidal creek and mud flats which are exposed at low tides are rich with the common mud snail (Illynassa obsoleta). One of my classes once counted over 400 snails in one square meter of a mud flat in Farm Creek. Eastern Oysters (Crassostrea virginica) and Soft Shell Clams (Mya arenaria), both very important commercial mollusks, are also found bordering the tidal creek and in the mud flat. Most of the species of mollusks are juveniles because the tidal marsh serves as a very important nursery for many invertebrate and vertebrate species.

In Connecticut the low marsh is an area that borders the mud flat and is defined by the marine grass (Spartina alterniflora). This zone is very important for two species of mussel, the ribbed mussel (Gukesmia desmia), and the economically important Blue mussel (Mytilus edulis).  This zone is also dominated by the fiddler crab (Uca pugnax).

All of these serve as very important food sources for many of the vertebrates such as fish and birds that inhabit the coastlines of Connecticut.

The high marsh is the area just above the high tide mark and only occasionally gets inundated with salt water. This area is extremely diverse in vegetation including salt hay (Spartina patens) and many other species of marine plants and grasses such as Saltwort (Saliconia), Seaside Goldenrod (Solidago sempervirens), Sea Lavender (Limonium nashii) and Spike Grass (Distichilis spicata). One of my marine biology classes found the Purple Marsh Crab (Sesarma sp.), Coffee Bean Snails (Melampus bidentatus) and another species of fiddler crab (Uca sp.) living in the high marsh zone.

The interesting thing about all of the marine plants and grasses is that while many of them are consumed by several organisms as they are growing in the marsh, more of the nutrients are consumed as they die seasonally and form a very rich nutrient food source known as detritus. Many of the invertebrate animals that inhabit Long Island Sound including many important commercial shellfish feed directly on detritus or indirectly on the organisms that feed on this rich source of organic matter. Salt marshes are some of the most productive ecosystems on the planet. “The amount of organic matter that they produce is unrivaled by any other natural soil and difficult to equal, even in intensive agriculture using commercial fertilizers”.¹

Most food webs have the largest number of organisms at the base of the web. Long Island Sound actually supports an inverted food web, with fewer producers than the huge numbers of consumers in that estuary. The reason for this is the effluent of organic matter from Connecticut’s salt marshes. If they continue to be destroyed the food web of Long Island Sound will collapse!

Probably the most interesting group of organisms that my students have enjoyed observing is the diverse species of birds, most of which
use the ecosystem as a food source and safe haven from the surrounding human population. It has been estimated that 385 or so species
of birds have been seen in the State of Connecticut. More than half of these species can be found in Connecticut tidal marshes. Our coastal marshes are a part of the Atlantic flyway that hundreds of species of birds use because of the abundant food and shelter provided by this ecosystem. There are also several species that utilize the salt marsh as their breeding ground. Many of these species include members of
the Heron family including: Black-crowned Night Herons (Nycticorax nycticorax), Louisiana Blue Herons (Ardea herodias), Green Herons (Butorides striatus), and Snowy Egrets (Egretta thula). Nearby Chimon Island in Norwalk is home to more than 1,000 breeding pairs of
Heron species! The Osprey (Pandion haliaetus) also claims the tidal marsh as its home. This endangered fishing hawk was at the brink of extinction during the 1950’s and is making a slow, but successful return to our Connecticut shores.

During the last 50 years Connecticut’s tidal marshes have been disappearing at an average rate of about 1% per year.² Close to sixty
percent of Connecticut’s coastal marshes have been destroyed since they were first monitored in 1914. Once a tidal marsh is destroyed, it
is gone forever and the very resource that supports Long Island Sound will be missing!

Footnotes

1. Connecticut Arboretum Connecticut College 1985
2. Ibid.

Bibliography

Birds of Connecticut Salt Marshes, The Connecticut Arboretum
Tidal Marsh Invertebrates of Connecticut, The Connecticut Arboretum
Connecticut Coastal Marshes, The Connecticut Arboretum