The annual count of blue back river herring at Buckeye Brook is down exponentially this year, according to the Buckeye Brook Coalition.
In an interview Monday, Coalition vice president Paul Earnshaw said in previous seasons the number of fish were “phenomenal.”
“This led us to believe we’d have another good year.”
But that didn’t happen this year, and there’s no clear reason why.
Throughout the six-week season there have been an estimated 15,333 fish counted. This is down 82 percent from the 2013 count of around 90,000. In 2014, 47,000 fish were counted, down another almost 45 percent, showing a steady decline. Volunteers count the river herring as the fish cross a white panel in the streambed. The data collected is then evaluated using an equation to determine the total number of herring to pass through Buckeye Brook.
“I’m disappointed, to say the least,” Earnshaw said.
Earnshaw said about 30 volunteers conducted several counts a day over a six-week period at the Warwick Avenue Bridge. Volunteers found that the highest count during a 10-minute period was 15 to 16 fish. “In previous seasons we’d count 500 fish in 10 minutes,” said Earnshaw.
River herring hatch in freshwater and mature in marine waters. After three to four years spent maturing in marine water, the fish will return to fresh water in the spring to spawn.
So, what’s causing the decline in Buckeye Brook?
Phil Edwards, a freshwater and anadromous fisheries biologist with the Rhode Island Department of Environmental Management, said that it is difficult to pinpoint one factor causing the decline. He suggested it could be a combination of environmental factors that cause the herring count to fluctuate.
“Although there was a decrease in the last couple years at Buckeye Brook, we’ve seen an overall improvement statewide since the 2006 river herring closure in Rhode Island marine and freshwaters, with the exception of 2015, which did, in fact, see a statewide decrease. It will be interesting to see how the trends progress over the next several years.”
Exact numbers for the statewide decline were not available. Numbers for the greater New England region have yet to be released.
Earnshaw believes several factors could be causing the negative outcome at Buckeye Brook. The abnormally harsh winter and unseasonably cold March temperatures, and the possibility of a predatory species could be to blame, but Earnshaw suspects offshore over-fishing is a large source of the problem. Fishing is banned in the brook.
According to Earnshaw, offshore fishing management has been skewed in addressing over-fishing. There is no cap on at-sea by-catches of river herring by trawlers, even if the catch is unintentional.
“The river herring are caught up in the nets and then discarded and there’s no accountability,” says Earnshaw.
Despite low numbers and offshore fishing issues, Earnshaw remains hopeful that the replacement of the culvert on Lakeshore Drive, which is part of the Rhode Island Airport Corporation effort to restore wetlands lost by the extension of the crosswind runway safety area, will help restore the ecosystem of the surrounding area and improve fish passage in the coming years.