Spring has arrived, even if it doesn't feel like it. Increased stream flow and warmer water are triggers for migrating fish that it is time to mate. When they feel the urge, they come back to their home rivers to lay and fertilize their eggs. Right on cue, a river herring was seen on Buckeye Brook in Warwick near the first day of spring. The numbers of river herring returning to Narragansett Bay are extremely low when compared with recent history, as I discussed in my last blog post. While we try to reverse the trend, volunteer fish counts are an important way to keep an accurate estimate of the population size of local fish runs.
Groups of volunteers will be out again this spring to count herring at several locations around Rhode Island. Volunteers spend 10 minutes at a site counting the number of fish that pass upstream. The three largest runs that are monitored by RI DEM are Gilbert Stuart Mill in North Kingstown, Nonquit Pond in Tiverton, and Buckeye Brook in Warwick. At Gilbert Stuart and Nonquit, electronic counters at fish ladders assist DEM in addition to visual counts. Buckeye Brook is one of the few places in the Narragansett Bay watershed where migrating fish are unimpeded by a dam and can swim freely to their spawning area in Warwick Pond. At Buckeye Brook, fish are counted by volunteers at a culvert utilizing a white board that is placed on the stream bed to help see the swimming fish. Last year's count revealed that an estimated 45,244 fish returned to the river, while in 2012, the count was closer to 90,000.
A newly completed fishway project at Kenyon Mill will allow fish access to the entire reach of the Pawcatuck River up to Worden's Pond, and the removal of the Pawtuxet Falls Dam in 2010 has opened up the first seven miles of the Pawcatuck River in Warwick and Cranston. While the volunteers are out mostly counting river herring, several other species migrate to our rivers in the spring including American shad, sea lamprey, white perch, and American eel, which arrive in their juvenile stage to live their adult lives in fresh water.
A video monitoring system will be in use again this year on the Mill River in Taunton to help the Massachusetts Division of Marine Fisheries study recovery of that system. Many species of fish were seen last year including those that migrate within the river, like yellow perch and brook trout. With so many restoration success stories, this is a perfect time to learn more about the sometimes mysterious life cycles of these important fish species.