Larval fish ingress to Delaware Bay

Delaware Bay is the second largest estuary on the east coast of the United States and supports vibrant commercial and recreational fisheries. The estuary serves as an important nursery habitat for the larval and juvenile stages of many fish species that are found along the coast. Because larval fish are largely planktonic in nature (hence the formal name, ichthyoplankton!), they depend on a suite of physical mechanisms to transport them from the spawning areas on the shelf into the estuary. These factors may interact with larval behavior (some can control their vertical position in the water column!), physiology, and estuarine morphology, thus the overall strategy that fish may utilize to ingress into estuaries is both species- and location-specific. 

The mechanisms of ingress of larval fish to Delaware Bay is still being studied. Most of this work depends heavily on routine ichthyoplankton sampling both inside and outside the mouth of the bay. Due to time and resource constraints, sampling is usually limited to a weekly or bi-weekly frequency. However, some physical mechanisms of ingress can act on shorter time scales, such as storms. Therefore, we sampled fall-ingressing larval fish daily over the course of a month to both (1) quantify the extent of daily variation and (2) better understand the physical mechanisms at play.

Publications:

  1. Schieler, B.M., Hale, E.A., and T.E. Targett (2014) Daily variation in ingress of fall-spawned larval fishes into Delaware Bay in relation to alongshore and along-estuary wind components. Estuarine, Coastal and Shelf Science 15: 141-147. Link.

Grants/Funding:

  1. Delaware Sea Grant Program, NOAA, U.S. Department of Commerce Grant # NA05OAR4171041 (Project R/ECO-3) to T. Targett and R. Garvine.
  2. Undergraduate Research Program and Department of Biological Sciences at the University of Delaware to B. Schieler.