Atlantic Menhaden Spawning Locations Inferred from Long-Term Ichthyoplankton Data

Atlantic Menhaden Brevoortia tyrannus are a migratory, coastal-spawning species, which move seasonally along the North American Coast from Nova Scotia to Florida.  Despite a coast-wide reduction in juvenile production, Atlantic Menhaden supports one of the oldest and largest commercial fisheries on the US east coast. To better understand the underlying causes of this decline, improved knowledge of early history is essential. We used larval data collected from two large-scale Northeast Fisheries Science Center ichthyoplankton surveys during 1977-2013 that occurred from Nova Scotia, Canada to Cape Hatteras, NC to describe spatial and temporal patterns of larval size and abundance. We used a linear model to estimate spawning location by latitudinal region and depth.  Atlantic Menhaden spawning appears to primarily occur south of Virginia and North of the Delaware Bay, based on the distribution of newly hatched larvae.  Larger, older larvae, in contrast, were observed in the central Mid-Atlantic Bight. We observed temporal shifts in locations of spawning intensity over the course of the study period. This research, while providing information Atlantic Menhaden spawning location, can also serve to better inform larval transport models and, thus, further contribute to our understanding of Atlantic Menhaden recruitment dynamics.