|
For the Love of Herring: Local History & Care
Background
In his 1921 A Report Upon the Alewife Fisheries of Massachusetts, Dr. David Belding noted that the run from the Herring River estuary to Herring and Higgins Ponds was “established by the Freeman family by digging a ditch to Herring Pond, and subsequently, about 1700, (giving) it to the town of Wellfleet”. He also reported that in 1893 the spawning area was greatly increased by creating a connection (“The Sluiceway”) between Higgins and 90-acre Gull Pond. However, there is evidence that these connections, and the presence of herring throughout the north Wellfleet kettle ponds, could be much older. Modern sampling and analysis of plankton remains in Herring, Higgins and Gull Pond sediment suggests that river herring were present at certain time intervals thousands of years before European settlement; presumably the channels between ponds were originally dug by Native Americans, who used herring for both food and fertilizer.
European settlers were quick to exploit the river-herring resource during the 18th and 19th century, when the Wellfleet run was one of the largest in the state. By the 1890s, town annual reports noted that as many as 250,000 adult fish were being harvested – and likely over-harvested according to Belding - as the run was in sharp decline by the turn of the 20th century.
The most serious blow to Wellfleet’s fish run was the 1908 construction of a dike at Chequessett Neck. The dike’s purpose was to reduce mosquito breeding by dewatering the 1100-acre salt marsh, and thereby promote the budding tourism industry. After the dike was built the fish run went into more severe decline, at that time attributed by Dr. Belding (1921) to overharvest, the dike’s restriction of river flow and the growth of wild rice, blocking upstream reaches. Today we know that diking and wetland drainage caused much broader system-wide damage, including acidified and oxygen-depleted surface water, which seriously harms migratory fish even today.
Recent work by UMass-Amherst fisheries biologists determined, by following hundreds of PIT- tagged herring from the river mouth to their spawning ponds, just how restrictive the Chequessett Neck dike and upstream culverts are to migratory fish: about half of those spawners that approach the dike each spring never pass through. Held back by artificially fierce currents that course through the dike’s narrow sluiceways, these fish linger just seaward of the dike where they are easy prey for larger predatory fish. Recent annual sample censuses of the spring herring run, conducted by Friends of Herring River for Mass. Division of Marine Fisheries, have produced estimates of the total (unharvested) run at only 10,000-60,000 individuals, only about a fifth of just those fish that were harvested in the 1890s before the river was diked.
A Brighter Future
All that is about to change for the better with the start of the Herring River Restoration Project. The principal infrastructure component is the ongoing construction and planned incremental opening of the new Chequessett Neck Bridge, in place of the dike. The bridge, with a maximum opening width of 165 feet, will replace the 18-foot-wide opening of the old dike. Modeling has shown that this greatly increased width, approaching that of the natural river channel, reduces tidal currents to velocities easily negotiated by returning river herring. It’s expected that herring passage under Chequessett Neck Road should at least double, with many more fish reaching the kettle ponds to spawn. At the same time, the return of tides and seawater should greatly improve water quality, promoting migratory fish survival. More broadly, the re-establishment of salt marsh habitats across hundreds of acres of wetlands upstream of Chequessett Neck Road will benefit a multitude of native estuarine animals, including other fish, crustaceans, shellfish, turtles, birds and mammals.
Above Chequessett Neck, the Herring River Restoration Project features additional improvements to tidal flow and fish passage, with the removal of the High Toss Bridge causeway and a much-enlarged culvert on the mainstream at Bound Brook Island. Farther upstream, the Seashore and the Friends have plans and are seeking funding to greatly enlarge the river crossings at Old Kings Highway and Schoolhouse Hill Road (aka “Patience Brook”), just seaward of the spawning ponds. This should reduce herring predation by snapping turtles that currently lurk in the narrow and deteriorating culverts under these old roads.
All of these improvements to physical fish passage and water quality will contribute to the recovery of a fish run that once was, and could again be, a significant component of the Cape Cod Bay and broader Gulf of Maine ecosystem.
Steps in Bridge Construction
The incremental re-opening of the estuary can’t begin until the new bridge is completed. During bridge construction, flow and fish passage will be maintained, per environmental permits, by removing dike components and replacing them with new sluiceways and bridge spans sequentially, rather than all at once. Then, after all new bridge and tide-gate components have been completed and their operations tested, incremental increases in gate openings and tidal exchange will begin.
Continued monitoring
Besides the continuation of a broad range of physical and ecological monitoring by the National Park Service and cooperators, Friends of Herring River will continue the annual herring sample census at the Olds Kings Highway count site. We hypothesize a substantial increase in the river herring population as impediments to fish passage are removed and estuarine habitat, especially estuarine water quality, is gradually restored. There are of course other factors responsible for the serious Atlantic coast-wide decline of river herring populations over the last few decades, a decline that has caused Massachusetts to prohibit their harvest since 2006. Perhaps most damaging to the adult population is by-catch during trawling for Atlantic Herring (Clupea harengus); however, the restoration of migratory, spawning and nursery habitat by projects like the Herring River restoration may contribute substantially to recruitment and coast-wide recovery.
Author: John W. Portnoy, Ph.D.
April 2023
| 
