River Herring Spawning Stock Survey
This three year survey began in the spring of 1999 and continued through the spring of 2001 to look at how river herring use the Hudson River and its tributaries, including the Mohawk River. River herring include both alewife and blueback herring.
Recent concerns of fishers indicate that changes "appear" to be occurring in the herring stocks. To document current status, NYS Department of Environmental Conservation biologists developed this program with funding through the Hudson River Estuary Program.
River Herring Life History
- Alewife arrive in the Hudson in late March - early April when the water temperatures reach 40F, bluebacks arrive later as the water warms.
- Alewives primarily spawn in the Hudson and tributaries below the Federal Dam at Troy. Bluebacks, spawn in similar areas as the alewife, but have increased their use of the Mohawk River for spawning.
- Males spawn for the first time at age 3, age 4 for females. The oldest herring caught in the Hudson was only 7 years old. In other rivers herring get as old as 14.
- After spawning, herring return to the ocean. Some fish will return in subsequent years to spawn again.
Objectives:
Objectives are to: monitor the spawning populations of blueback herring and alewife in the Hudson River Estuary, the Mohawk River and tributaries. Specific items examined are size, age, sex ratio and mortality rates; and comparisons of the life history characteristics of alewife and blueback spawning populations found in each of the three areas.
Methods:
The contractor, Normandeau Associates, Inc., used many different methods to sample fish. These include gill nets, cast nets, scap and dip nets, and jigging.
The first year of the project was intended to catch and tag as many fish early in the spawning run as they could. It was hoped that returns of tags would show how quickly and where the herring moved throughout the Hudson and its tributaries. The first year, 1999, over 9000 herring were tagged. In 2000, approximately 2400 fish were tagged and in 2001 they only tagged fish in the Mohawk River (about 260 herring).
River herring were tagged with a small yellow, uniquely numbered tag. Tag returns can be called into a TOLL FREE number : 1-800-448-8322. A person returning a tag will be given a REWARD after answering a few questions about when and where they caught the fish. WATCH OUT FOR TAGS!
Highlights:
Normandeau Associates, Inc. is credited with developing new criteria for aging herring.
Reports:
The report from this project is not available on-line because it is very large. If you want a copy of the report please email us (address located in right hand column).
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