Spatial and Temporal Patterns in Ocean Bycatch of River Herring: Developing More Effective Monitoring and Management Strategies

Many river herring runs have declined along the North American Atlantic coast to a degree such that a collapse of the coast-wide stock is feared to be underway. NOAA Fisheries has declared both species (alewife, Alosa pseudoharengus, and blueback herring, Alosa aestivalis) as “Species of Concern” and the Atlantic States Marine Fisheries Commission has passed a default closure of directed river herring fisheries effective in 2012. River herring undertake extensive migrations during which they encounter numerous impacts in riverine, estuarine, and oceanic habitat. All of these impacts need to be monitored, managed, and ultimately mitigated in a comprehensive restoration strategy.

Declines in many river herring runs, despite restoration and management efforts in rivers, suggest that impacts during their ocean phase might be a factor. Bycatch in ocean fisheries is known to occur, but has received little attention to date. In this research, the times and areas that river herring bycatch has occurred in the directed Atlantic herring (Clupea harengus) fishery are examined and compared with expected river herring distributions from seasonal bottom trawl survey. Additionally, possible management regulatory measures being developed by the New England Fishery Management Council to address river herring bycatch in the Atlantic herring fishery will be reviewed.