Local Students Explore Cold Brook Preserve

Spring Beckhorn engages local 5th graders.

“We survived!” one fifth grader exclaimed as she jumped up and down. Her class at Monomoy Regional Middle School was playing a game about the life cycle of the American eel, taught by Mass Audubon Wellfleet Bay Wildlife Sanctuary School Programs Coordinator Spring Beckhorn with curriculum in part created by 30-year veteran science teacher Valerie Bell. The students from Harwich and Chatham were learning about the Robert F. Smith Cold Brook Preserve owned by Harwich Conservation Trust (HCT) in the heart of Harwich Port.  HCT and Wellfleet Audubon are partnering to connect Monomoy students to local conservation land, water, and wildlife, thereby educating future generations about the importance of being sensitive stewards of Cape Cod’s natural heritage.

The game led students from eel larvae hatched in the Sargasso Sea to elvers to “glass” (nearly transparent) eels to adults; on the way learning that not every eel survives their early life stages since eel can be on the menu for shorebirds as well as marine fish including striped bass and bluefish. Beckhorn showed what makes a fish a fish with features such as gills and fins. She asked the students if, in fact, the serpentine eel is a fish, which it is.

Interestingly, the American eel (Anguilla rostrata) is a unique fish species on the Cape in that it migrates as a young elver from salt water through streams like Cold Brook to freshwater ponds for maturation into adulthood. The young of river herring and alewives go the other way, traveling from our ponds in the late summer downstream to the sea where they reach maturity after a few years before migrating back to the Cape to their spawning ponds each spring.

Water temperature affects what sex eels will become and when they return from fresh water as adults to the sea to spawn. Females may linger 30 years in local ponds. Males may return to the ocean sooner. Like most fish, their body temperature adapts to the temperature of the surrounding water.

Old dilapidated culverts are obstacles for eel migration.

One student guessed that eels may be endangered. Indeed American eel has been under consideration by the federal government for formal listing under the Endangered Species Act. Beckhorn showed the class a graph of eel populations over recent decades with peaks in the 1970s-80s and dramatic declines today, dropping by 90%. Showing the height and precipitous percentage decline of the eel population is just one of the ways the study of HCT’s Cold Brook Preserve aligns with teaching to state standards of Science, Technology, Engineering, Math also known as S.T.E.M. The downward trend on the graph also clearly conveys that the time for habitat preservation and species conservation is here and now.

Finishing the eel life cycle game, about seven thrilled student “eels” survived to adulthood to become fully mature “yellow eels” (called “yellow” because of the brownish-yellow bellies and sides). Some can grow over the years to as much as four feet long. The eels that the students were pretending to be are the ones which migrate as young elvers at just a few inches long from the Sargasso Sea up the East Coast into Harwich’s Saquatucket Harbor through HCT’s Robert F. Smith Cold Brook Preserve then under Bank Street and ultimately into Grassy Pond. 

Long before a field trip to HCT’s Cold Brook Preserve, the children were excited about visiting the site during the spring to see the actual eels. “It will be really fun to see how many eels go up the brook,” one said. Another said, “It’s fun to learn about eels because they’re not that common.” “It will be fun to help the eels,” another exclaimed.

During one science class held at the regional middle school in the weeks before the Cold Brook field trip, fifth graders had learned about some of the human induced consequences for the stream and wildlife amidst the landscape of long since retired cranberry bogs, right-angle ditches, and steep straight channels. One student said, “that erosion of sand along the way can mess up the stream,” and that erosion is only one of the human impacts on the watershed. Students also learned that dams, changes in water temperature, pesticides, pollution, and over-harvesting can also disrupt eel migration and the life cycles of other creatures dependent on natural ecosystems. 

Students search for macroinvertebrates sampled from Cold Brook and the bordering wetlands.

Understanding human impacts on the environment for good and for ill is another part of the state teaching framework, and a big part of why HCT has partnered with Wellfleet Audubon and Monomoy Middle School educators to teach children about restoring an ecosystem on their local Cold Brook Preserve turf, a place many have enjoyed visiting. On the spring field trip in addition to more eel musings, the students netted for macro invertebrates (insect larvae) the presence of which can indicate ecosystem health. The fifth graders also engaged in water quality sampling and compared the features of upland and wetland plant species.  Classroom teacher Kathleen Widegren explained that each student would create a slide show expressing what they learned throughout the school year about their Cold Brook experience.

“This kind of hands-on, outdoor education in their own Cape Cod backyard helps the students see and experience the connections between land, water, and wildlife. Over time the kids form a framework of knowledge and understanding from which to make future decisions as community leaders about how to protect and manage our natural resources,” said Michael Lach, HCT Executive Director. 

Cold Brook as with so much of our natural environment has undergone changes through time due to humans. Farming changed it from meandering stream and hummocky wetland replete with possible Atlantic white cedar trees to cranberry bogs in the 19th and 20th century. Agriculture changed the course and flow of Cold Brook, altered the flora and fauna in and around it, and over more than a century layered sand across the original wetlands, sometimes 2-3 feet thick in places. To repair and restore the sinuosity of Cold Brook and natural topography of the bordering wetlands, HCT is partnering with the State’s Division of Ecological Restoration, U.S. Fish & Wildlife Service, and the Town of Harwich to enhance wildlife habitat health and diversity, improve water quality, and beautify the visitor experience.

The partners have made progress in the planning stage of the Cold Brook Ecological Restoration Project. Eco-restoration design elements could include removing failing culverts, peeling back the over burden of sand that sits

Dilapidated flumes hinder water flow. HCT’s eco-restoration project seeks to improve water flow, wildlife habitat & walking trails. Photo by Bill Giokas

atop the original wetland surface, forming open water habitats, re-creating the curvature of Cold Brook, and enabling salt marsh migration in the southerly portion of the site as sea level rises.  The design phase will transition to the permit phase and then eventually restoration construction to implement design elements across the site in 2019 or 2020.

As the design process unfolds, the project partners still find room to take action when needed. For example, one big step forward was the removal of a downstream dam called the Wheeler Dike. It was discovered that the abandoned dam was about to collapse and potentially block stream flow. HCT and partners including the Town Highway Department organized an emergency response to clear the stream obstruction. “Town Highway staff were quick, efficient, and just in time before the spring eel migration,” said Lach.

“It’s not just about the land, it’s about the people who live here on the Cape,” Bell explained. “HCT wants donors to see where their money goes, not just to the physical restoration, but also to helping children understand the eco-restoration process.” As the children follow the restoration over time it will be fascinating to see what unfolds, grows, returns to life; swimming in the brook and flourishing in the lands it nourishes and to experience the biodiversity which a healthy ecosystem creates like the increase in interdependent plants and animals. This way the students become engaged citizens, involved with their own neighboring land and water. In a way the children help educate their parents, too.

Wellfleet Audubon’s Joel Wagner demonstrates the use of turbidity tubes to compare the clarity of drinking water with a sample of water from the stream. Excessive turbidity, or cloudiness, can affect the animals that live in a body of water.

“Through partnering with Harwich Conservation Trust, we were able to use the outdoors as a classroom to introduce students to land conservation in their own community and the concept of eco-restoration. Doing field work in special, ecologically important sites not only provides a hands-on educational experience. It also connects students with places that we hope they’ll appreciate and want to protect as they get older,” said Beckhorn.

“We’re excited to partner with Wellfleet Audubon & Monomoy teachers on this new educational venture that connects kids and their families to the natural world,” said Lach.

Story by Lee Roscoe, Photos courtesy of Wellfleet Audubon