River herring population on the rise
SouthCoasttoday.com
By Ariel Wittenberg
awittenberg@s-t.com
August 20, 2014 12:00 AM
RIVER HERRING
River Herring are small, silvery fish that grow to be six to 12 inches long
• The term “river herring” encompasses two separate fish species — alewives and blueback herring — which are very similar to each other.
• Millions of river herring migrate each spring to coastal rivers and streams from the Atlantic Ocean.
• Dams are one of the biggest problems facing river herring because they cannot travel through them to spawning grounds.
• In 2006, Massachusetts decided to ban catching river herring in an effort to help the fish bounce back.
ACUSHNET — Things are looking up for Buzzards Bay’s herring population. Way up, in fact.
This summer more than 10,000 herring swam up the Acushnet River, a 68 percent increase from the previous year. In the Mattapoisett River, the gains have been even greater with a 156 percent increase in river herring. On the Agawam River in Wareham, river herring numbers have more than doubled since 2011 with 49,000 fish swimming up the river in 2014.
These increases are just the latest, largest spikes in a more steady increase in river herring that has been occurring in Massachusetts river herring populations since 2011.
“This is great news all around,” said Paul Diodati of the Division of Marine Fisheries.
He said that river herring, which spend most of the year in the ocean but swim up-river to spawn in ponds and lakes, act as a “foundation” for many different habitats and ecosystems in fresh and saltwater alike.
“At different stages of their life, you have different feeding opportunities to other fish. For that reason alone they are a pretty important species,” Diodati said. “When herring are teeming in the system, it is an indication that the system overall is doing well.”
The herring population had actually been in decline through the early 2000s, dropping 90 percent in the past 90 years.
So why are herring making a comeback now? Diodati says it’s hard to tell.
“Trying to figure out why is like trying to figure out where they went in the first place. It’s complicated,” he said.
Among the theories is that a state ban on fishing river herring implemented in 2006 is finally yielding results.
After hatching, river herring take three to five years to mature before they begin spawning themselves. That means that these most recent spikes in herring population could be the second generation of fish that were spared by the 2006 regulation.
“Usually you have these sort of lags between when you take action and when you see a really small increase,” said Rachel Jakuba of the Buzzards Bay Coalition.
In the Acushnet River, her organization also took measures to help river herring migrate to spawning grounds by removing three dams in 2002, 2007 and 2008 that were blocking herring’s path to spawning grounds.
“It would make sense that now we have this critical mass of herring getting up to spawn,” she said.
The one river in the region that is not seeing such record increases in herring migration is the Nemasket, where the number of herring dropped from roughly 840,000 to less than 600,000 this year.
Diodati said the state is not sure why that river did not see the same increases as others, but hoped that it was a fluke.
“We are seeing some positive signs, but not everywhere,” he said.
Follow Ariel Wittenberg on Twitter @awittenberg_SCT
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