Restoring the Herring River

The Herring River Estuary. Photo by Christine Harris.

The Herring River Estuary. Photo by Christine Harris.

By Christine Harris

In 1908 the Herring River Estuary in Wellfleet, Massachusetts, a system supporting 1100 acres of salt marsh, was diked off, restricting normal tidal flow and eliminating all but 10 acres of the marsh. The reasoning behind the construction of the dike seems ludicrous in light of modern ecological understanding. Today an effort is being made to restore salt marshes throughout the country, including those of the Herring River Estuary.

At the turn of the twentieth century the quaint coastal town of Wellfleet, Massachusetts was becoming a popular resort area to which many wealthy city-dwellers flocked. One popular hotel, the Chequesset Inn, located near the mouth of the Herring River, attracted an elite clientele. Guests at the Chequesset, and other area establishments, enjoyed spending time relaxing by Wellfleet Harbor, but complained about the mosquitoes. At the time it was believed that the source of the mosquitoes was the Herring River, and it was thought that if the salt marshes of the estuary were eliminated, the mosquito population in the area would decrease significantly. Thus the Chequesset Neck Dike was constructed by the state in 1908, reducing the mouth of the river from a width of several hundred feet to six feet, and effectively cutting off tidal flow beyond the dike.

Cutting off tidal flow to the Herring River significantly affected the health of the ecosystem it supported. In place of native salt marsh plants the Herring River now hosts a number of invasive plant species, including a large amount of the invasive reed phragmites. Furthermore, without the flushing of the tides and the presence of saltwater minnows such as the mummichog, a type of killifish that feed on mosquito larva, the Herring River likely provides breeding grounds for more mosquitoes now than it did before it was diked off.

Once considered to provide little more than foul smells and insects, salt marshes are now recognized as biologically significant ecosystems on which many species, including humans, depend. Peat, the spongy layer of decomposing plant material which is the base of a salt marsh, has been recognized to provide a buffer from storm damage. When storm surges threaten coastlines, peat absorbs flood waters and reduces the height of these surges, protecting coastal communities from the impacts of severe flooding.

Salt marsh peat. Photo by Christine Harris.

Salt marsh peat. Photo by Christine Harris.

Another beneficial feature of salt marshes is their role as the nurseries of the ocean. Over two thirds of all commercially harvested seafood species, including shellfish, finfish, crabs, and lobsters, depend on the salt marsh for part of their life cycles. Salt marshes provide cover and camouflage for many of these harvestable species when they are young and most susceptible to predation, and provide a safe place for breeding and foraging. Salt marshes also have recreational value as popular places to fish, kayak, and contemplate the natural world.

With knowledge of the benefits which marshes provide, local communities, the state, the county and the Cape Cod National Seashore have taken on the task of restoring several previously degraded salt marsh systems on Cape Cod, including that of the Herring River. Most of these restoration projects focus on the use of gradual tidal restoration to reintroduce saltwater, along with the species of plants and animals it supports, over the course of many years.  The Herring River restoration project centers around the reconstruction of the Chequesset Neck Dike. The proposed structure would provide access to the public for fishing and boating and have a series of sluice gates that could allow for incremental tidal restoration across a width of 100 feet. Construction of the new dike is set to begin in 2016.

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Cultch is Clutch in Wellfleet Harbor

Wellfleet Harbor.  Photo by Christine Harris.

Wellfleet Harbor. Photo by Christine Harris.

By Christine Harris

For seafood aficionados the town of Wellfleet, Massachusetts is synonymous with one thing: oysters. These briny morsels have been a staple of the town’s economy since the 1700s and are known far and wide for their unique flavor. The decline, recovery, and cultivation of oysters in Wellfleet follows the ecological understanding of these animals and has led to an innovative recycling project in the town.

First called Oyster Bay by Samuel de Champlain when he explored the area in 1605, Wellfleet Harbor has been a hotbed of oyster harvest and cultivation for over 300 years and was likely harvested by the native Wampanoag people for centuries beforehand. However, by the beginning of the 1800s the oysters in Wellfleet Harbor were gone. The disappearance is likely due to a combination of overfishing and a lack of cultch in the harbor. Cultch is a term used to describe broken shells used by baby oysters or “spat” as a substrate on which to grow. The spat attach to cultch and grow and live affixed to that substrate.

Oyster. Photo by David Monniaux courtesy of Wikicommons.

Oyster. Photo by David Monniaux courtesy of Wikicommons.

During the 1700s the shells of oysters and clams that were harvested from the harbor were used to make shell lime for mortar for construction and thus not returned to the water. Without the return of shells to the harbor spat had no cultch on which to grow and over time the oysters disappeared. With little understanding of the life cycle of the oyster, many of the people of Wellfleet believed that God was punishing them for their sins by taking away their most valuable food and economic source.

With the loss of its native oysters, the people of Wellfleet began to bring in oysters from the Chesapeake Bay to grow in the waters of Wellfleet Harbor and later be sold in markets in Boston. Though the oysters may have originated elsewhere, the flavor of an oyster comes from the waters in which it lives, so these imported oysters still tasted like Wellfleet oysters. Today the cultivation of oysters in the harbor continues to thrive.

In celebration of the importance of the oyster to Wellfleet, an annual Oysterfest is held in October each year. The event has grown in recent years and in 2013 an estimated 25,000 people descended on the small town to indulge in a variety of oyster dishes, listen to live music, browse products from local artists, and have a good time. With so many people consuming oysters many shells are left behind. At the event in 2012 an estimated 100,000 oysters and 10,000 clams were consumed. Five tons of oyster shells were collected and recycled, amounting to 43 percent of the waste stream from the event. These shells, and others collected since, are now being used as cultch in Wellfleet Harbor and are providing habitat for future generations of shellfish.

It is estimated that in the three years since the shell-recycling program began enough habitat has been added to Wellfleet Harbor for 60 million new oysters which is 15 times the annual harvest rate. The oysters also improve the water quality in the harbor by filtering 3 billion gallons of water a day. In 2012 Shellfish Promotion and Tasting (SPAT), the organization behind Oysterfest, and the Town of Wellfleet won the Municipal Innovation Award at the annual Mass Recycle Awards.  This innovative program holds promise for the future of oysters in Wellfleet Harbor and beyond.