River Herring Catch in the Gulf of Maine: Spatial and Temporal Trends in Catch from the Maine-New Hampshire Inshore Trawl Survey.

Peters, Rebecca, Briony Donahue, Maine Department of Marine Resources, Boothbay Harbor, ME

River herring is an important part of the freshwater and marine ecosystem in the Gulf of Maine, serving as food for larger fish, birds, and marine mammals. Most research has been on the freshwater phase of river herring, however, understanding the marine phase of river herring is important to understanding their role in the marine ecosystem. There is little published research describing spatial and temporal trends in abundance and biomass of river herring in the nearshore marine environment, especially in the Gulf of Maine. With the development of a biannual fishery-independent survey, the Maine-New Hampshire Inshore Trawl Survey (ME-NH Survey), there is now data available to examine trends in the inshore Gulf of Maine. This survey was established twenty-two years ago by the Maine DMR in collaboration with commercial fishers and New Hampshire Fish and Game to study the nearshore waters of Maine and New Hampshire that are inaccessible to federal surveys. Alewife are caught in the survey in similar numbers in the spring and fall, while blueback herring are more present in the spring surveys. In the spring smaller sizes, 5-15cm, of alewives are more common than other sizes, while in the fall more 15-20cm alewives are caught. Spatial trends show that river herring distribution changes based on size and season. Data on river herring from the ME-NH survey can be used in future studies to increase understanding of river herring and its role in the nearshore marine ecosystem in the Gulf of Maine.