One technical fishway and two innovative nature-like fishways were installed at three dams on the Acushnet River in Acushnet, Massachusetts to facilitate migration of river herring and juvenile American eels （elvers...One technical fishway and two innovative nature-like fishways were installed at three dams on the Acushnet River in Acushnet, Massachusetts to facilitate migration of river herring and juvenile American eels （elvers）. Pre-construction and post-construction monitoring of river herring and elver populations used census counting and abundance estimation, respectively. Numbers of adult river herring returning to the upstream spawning grounds during the pre-construction phase were very low; elver counts declined during the pre-construction period and served as baseline levels to determine the effectiveness of the new fishways. Post-construction monitoring of river herring and elvers indicated an increasing trend of spawning adult river herring returning to the spawning grounds, with the total count in the fourth year of post-construction representing an increase of 1,140% over baseline, pre-construction conditions. Results also show increased elver recruitment into the river as well as increased proportions of elvers accessing habitat in the upper watershed that was mostly inaccessible prior to fishway installation. The new fishways at the three dams on the river have improved diadromous fish passage, thereby increasing the probability of restoring healthy populations of river herring and American eels to the Acushnet River system.展开更多
文摘One technical fishway and two innovative nature-like fishways were installed at three dams on the Acushnet River in Acushnet, Massachusetts to facilitate migration of river herring and juvenile American eels （elvers）. Pre-construction and post-construction monitoring of river herring and elver populations used census counting and abundance estimation, respectively. Numbers of adult river herring returning to the upstream spawning grounds during the pre-construction phase were very low; elver counts declined during the pre-construction period and served as baseline levels to determine the effectiveness of the new fishways. Post-construction monitoring of river herring and elvers indicated an increasing trend of spawning adult river herring returning to the spawning grounds, with the total count in the fourth year of post-construction representing an increase of 1,140% over baseline, pre-construction conditions. Results also show increased elver recruitment into the river as well as increased proportions of elvers accessing habitat in the upper watershed that was mostly inaccessible prior to fishway installation. The new fishways at the three dams on the river have improved diadromous fish passage, thereby increasing the probability of restoring healthy populations of river herring and American eels to the Acushnet River system.
