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Alley Pond Park

Salt Marshes in New York City Parks - Alley Pond Park

This text is part of Parks’ Historical Signs Project and can be found posted within the park.

Salt marshes play a critical role in the support of human life, acting as natural filtration systems by trapping pollutants that would otherwise contaminate our bays and oceans. Salt marshes have the ability to absorb fertilizers, improve water quality, and reduce erosion. They are also among the richest wildlife habitats.

Alley Pond Park, the second-largest park in Queens, lies on a glacier-formed moraine – a ridge of sand and rock that formed 15,000 years ago. The glacier, which dropped the boulders that sit on the hillsides of the park’s southern end, also left buried chunks of ice that melted and formed the ponds dispersed throughout the Alley, the 150-acre strip of wetlands in the north end of the park. Freshwater drains into the Alley from the hills and bubbles up from natural springs, mixing with the salt water from Little Neck Bay. As a result, the park is host to freshwater and saltwater wetlands, tidal flats, meadows, and forests, making for a diverse ecosystem and supporting abundant bird life

When the last of the glaciers melted 7,000 years ago, the oceans rose to their present levels. Sediments washed from the land were deposited offshore in narrow sandy strips, forming long islands parallel to the shoreline. These barrier beaches received the pounding surf on their ocean side, but had calm, protected bays behind their landward shores. While the waters were calm enough for vegetation to take root, the presence of saltwater made survival difficult. One species, however, saltmarsh cordgrass (Spartina alterniflora), was able to colonize the flat expanses of sand and silt, which were covered twice a day by the ocean’s tides. Today, the grass is still found along the Atlantic coast.

As this specialized grass spreads, its stems trap floating debris. Sediments and particles of decaying matter slowly build up, forming nutrient-rich mud. This mud, called detritus, supports life on the marsh. It is the basis of a complex food web in which energy is passed from one organism to another. The fiddler crab (Uca) and ribbed mussel (Geukensia demissa) have developed a mutually beneficial relationship with the saltmarsh cordgrass. While the crabs and mussels benefit from feeding on decaying matter trapped within cordgrass roots, cordgrass gains from the fiddler’s burrowing, which aerates the soil, and the mussel’s excretion, which provides necessary nitrogen.

At the end of each season, the cordgrass dies, creating a spongy peat. Each year’s peat layer raises the surface of the marsh, enabling it to colonize new territory. A variety of plants with less salt tolerance can colonize the peat, as it is out of the range of most of the high tides. This causes the formation of two separate plant communities, the intertidal marsh and the salt meadow. A third type of salt marsh community is the mudflat. Each of these communities has its own distinctive vegetation, insects, fish, birds, and mammals that have adapted to survive in a saltwater environment. The creek at the center of the Alley is lined by common reed (Phragmites australis) and further north by fertile salt marsh. Visitors to the marshes of Alley Pond Park can often see herons and egrets. Occasionally, a muskrat (Ondatra zibethica) can be spotted on the way to its secluded lodge among the reeds. While salt marshes do not have a very wide variety of species, the volume of life present is remarkable.

Since industrialization, human activity has destroyed many marshes. Where marshes are disturbed, reeds often grow in place of cordgrass. Since reeds do not decompose into as nutritious a substance as cordgrass, a reed marsh does not contribute as much to coastal ecosystems as a cordgrass marsh. In the last 200 years, humans have also filled over 80 percent of the city’s original salt marshes for construction. While recent conservation efforts have improved the condition of marshes, this valuable ecosystem continues to disappear from the City at an alarming rate.

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