TOWN BROOK: Herring running further upstream 8-4-15

TOWN BROOK: Herring running further upstream

During this year's run, which lasted 69 days, a combination of hand counting by volunteers and camera counts recorded 173,567 herring heading west in Town Brook.

Wicked Local Plymouth
By Frank Mand
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Posted Aug. 4, 2015 at 10:00 AM

PLYMOUTH – The yearly herring counts for Town Brook are in and the trend is up – further upstream and higher numbers overall.
During this year's run, which lasted 69 days, a combination of hand counting by volunteers and camera counts recorded 173,567 herring heading west in Town Brook.
That's a nearly 40,000 increase over 2014's total, and 66,000 more than was recorded in 2013.
Is that enough?
Looking back to 2010, before the completion of many of the expensive projects intended to make fish passage easier, the count was 195,091.
Now that several dams and other impediments have been removed and the herring can make it all the way upstream to their spawning grounds, should the numbers be higher?
David Gould, director of the town's Department of Marine and Environmental Affairs, says it's not that simple.
"Lots of factors come into play," Gould told the Old Colony, "including the out-migration success of that particular young-of-the-year class, ocean conditions, impacts of commercial fishing activities over those four years, water quality impacts and predation levels."
And it's not simply a case of herring heading up stream, spawning, and the young fish returning the next year.
"Typically, it's four years before a herring will return from the ocean to the stream to spawn," Gould explained.
That means that we might not see the results from this year's spawning until 2019.
"DMEA and our project partners are quite happy with the numbers this year," Gould said, adding that they now expect to see continued growth in the run.
"It's important to remember that even with all of the work done on Town Brook it's only the last two years that two of the dams have been removed and that this season was the first that unimpeded access existed from Newfield Street to Billington Sea," Gould said. "That's not sufficient time to impact the size of the run – it's just the beginning.
"In addition, the Water Street bridge rock ramp was only installed this past winter, so it's only been in place for one season. In the next three to five years we hope to see the run size increase."
Gould produced two charts, one detailing the last few years, and the other comparing herring runs along the Massachusetts.
"In regards to other stream populations Town Brook is quite good," Gould pointed out using the comparative chart. "You can see the population run size for Town Brook versus some of the larger coastal streams, including Kingston's Jones River.

The chart lists 11 rivers and brooks and their counts beginning in 1997 and continuing through 2011.
· The Parker River on the North Shore recorded just under 7,000 herring in 1997, a high count of 15,000 in 2003, and 3,624 in 2011.
· The Ipswich River had no count in 1997, a high count of 2,726 in 2002, and 663 in 2011.
· Stony Brook in Brewster on Cape Cod had no count in 1997, a high count of 48,099 in 2010, and 37,091 in 2011.
· Also on the Cape, the Marston Mills River had no count in 1997, a high count of 43,948 in 2008, but just 494 in 2011.
· The Jones River had no count in 1997, a high of 4,512 in 2010 and 3,597 in 2011.
· Plymouth's Town Brook had no count in 1997, a high of 195,091 in 2010, and 142,633 in 2011.
Gould also points out that the town has not yet finished working on Town Brook.
"Among the other projects we are working on is the final engineering and permitting for the removal of the Holmes Dam/Newfield Street bridge replacement project," Gould said. "This will leave just Jenney Pond Dam on the Brook and again will improve fish passage and water quality.
"We also want to get started on permitting a dredge of Jenney Pond, as it's been close to 50 years since that pond was dredged and the accumulated sediment, nutrients and poor water quality is clearly evident.
"We also will seek grant funds to undertake a feasibility study to look into enhance passage at Jenney Grist Mill. This would not include dam removal but perhaps a stone step pool system. The new fishway installed in 2007 works well but still cannot pass all the fish that pile up there in the spring."
It's not simply a numbers game. River herring played an important part in the history of Plymouth and remain sacred to the Wampanoag. They are also an important part in the coastal food chain, scientists say, and are considered to be a keystone species: If the herring are healthy health it's likely that the coastal ecosystem is as well.
Follow Frank Mand on Twitter @frankmandOCM