Harwich Conservation Trust

“It all started two years ago when I was removing invasive purple loosestrife from Bank Street Bogs,” said Ben Wright, Assistant Director for the Harwich Conservation Trust.

“As I dug out one of the plants, I found an eel in its root ball.”

That discovery sparked some quiet research that led to the Massachusetts Division of Fisheries and Wildlife installing an eel ramp this spring over an impassable cranberry flume in the heart of Harwich.

Since its purchase of the land in 2001, HCT had been struggling to come up with a workable management plan for the 60-acre Bank Street Bogs. Eyed for wildlife protection and passive recreational use, the bogs also had an agricultural option. But the vagaries of the cranberry market and the high cost of restoration did not lead the Trust to settle on a farming future.

“We needed to know what was in the bogs, before we could proceed.”

A botanical survey completed by Dr. Robert Zaremba in 2007 showed an abundant variety of native plants returning to the area. Over 270 species were identified, two of them rare state-listed plants. A state-listed insect, the water willow stem borer moth, was also found residing in the bogs.

“We still didn’t know what was in the water, and whether there was a fisheries component,” said Wright.

The Bank Street Bogs is a connecting waterway between Saquatucket Harbor on Nantucket Sound to the freshwater Grass Pond, located just south of Harwich Center.

HCT contacted the Natural Resources Conservation Service (NRCS) which is administered through the US Department of Agriculture (USDA), and were referred to Steve Hurley of the Massachusetts Division of Fisheries and Wildlife.

“Steve came by last summer and found 4-spined stickleback, mummichog, and American eel in the bogs. So we knew we had eels. And further research showed that the bogs had historically been a herring run.”

Eels and herring have opposite life cycles. Eels spend their adult lives in freshwater ponds, then move out to the open ocean’s Sargasso Sea to spawn. Herring spawn in ponds, and spend their adult lives in the ocean. Both species need an open passage in the spring and fall to complete these cycles. A tidal gate(now gone) near Hoyt Road kept the herring out of the bogs and older cranberry culverts with flume boards had closed off the eels from Grass Pond.

Both species are important links in aquatic food chains and have been in decline in recent years. Massachusetts has been closed to the taking of herring for the past three years. Because of declining commercial harvests, eels were recommended for review for Endangered Species Act protection in 2004, but this was not granted. The legal size for commercial eel harvest in Massachusetts is 6 inches. Recreational anglers have a limit of a possession of 50 eels. Though the eel fishery is not big here, it is prominent in Asia and Europe.

The Trust decided to manage the bogs for eels and submitted a plan to the Wildlife Habitat Incentive Program (WHIP) administered through NRCS. In March of this year, WHIP granted the Trust a $77,811 re-imbursement over ten years for its conservation efforts.

“Here’s where we got lucky. Brad Chase, an aquatic biologist with the Massachusetts Division of Marine Fisheries, had just moved to Harwich.”

Considered an eel specialist, Chase had been involved with placing the state’s first aluminum eel ramp in Saugus, and was eager to experiment with the smaller bog complex. Phil Brady of the Division of Marine Fisheries and Harwich Harbormaster Tom Leach added their expertise. Permission was obtained from two private property owners for access to the flume.

“We knew we had eels in the bogs, but we didn’t know if they would move all the way up Cold Brook (also known locally as Carding Machine Brook) into Grass Pond. Because we weren’t sure this would work we opted for a cheaper wooden ramp, built by a carpenter with the Division of Marine Fisheries.”

The shallow but long ramp was lined with a plastic fiber material and screened against overhead predators. Pond water was pumped down the sluice and to the bottom of the ramp. Eels are attracted to the smell of the fresh water and can wriggle up the plastic mesh. At the end of this ramp, they would fall into a bucket of water.

“The ramp was set on May 16, and the next morning when we checked it, we had 78 eels in the bucket.”

The bucket was checked each morning by HCT staff and volunteers and the eels were counted and age-classed before being released into the pond. Small translucent glass eels, measuring 2-3 inches are the young of the year. One-year olds are slightly larger and thicker, with more pigment. Eels 4-6 inches are 2-4 years old.

“We had our peak day the end of May with 1184 eels counted. The run had actually begun in April, so we were fortunate to get the ramp set this year. We counted over 6,000 eels. The numbers gradually tapered off in June. We will pull the ramp soon.”

HCT was also fortunate to have retired electrical engineer Rich Cooper help with the pump system, as the batteries were not sufficient to keep the pump going. A private residence loaned electrical power. Cooper is still working out the kinks in a solar-powered pump system.

HCT plans for a more permanent aluminum ramp are not definite, but in line with their WHIP project, the Trust hopes to replace five large rusting flumes in the bog system with more eco-friendly models that have a natural substrate on the bottom. They will continue invasive plant management, mow for an early successional habitat, and keep the water levels appropriate for the state-listed plants and insects.

If there are adult eels in Grass Pond, they will have a chance to migrate out this fall, when neighboring cranberry farmer, John Sennott, will open the flume to flood his bogs. Sennott shares water rights with HCT and has been very supportive of their conservation efforts.

Ben Wright will also be moving on this fall. After a two-year stint with AmeriCorps Cape Cod and three years with Harwich Conservation Trust, he will be attending Clark University in Worcester to pursue a Masters in Environmental Science and Policy. A host of creatures, including box turtles, wood frogs and salamanders in the 36 vernal pools Wright has certified with volunteers in Harwich, and now eels, will have him to thank for saving their places to live.