Anadromous fish passing upstream through the Holyoke Fish lift are identified and counted during the spring and early summer migration season. Continuous counts are collected and can be found here during the anadromous fish passage season, April 1-June 30. Please note, weekly fish counts are subject to change as quality control checks are completed throughout the season. Also, see historical fish counts from the Fishway.
For updates on fish counts visit US Fish & Wildlife Service.
2025 Upstream Fish Passage Counts
| Species | Weekly Total 5/25-5/31 | Year to Date |
| American Shad | 108,132 | 271,023 |
| Blueback Herring | 5 | 141 |
| Gizzard Shad | 4 | 38 |
| Striped Bass | 26 | 47 |
| Sea Lamprey | 6,792 | 9,911 |