Evaluation of the Surf Zone as a Nursery Habitat for Juvenile Fishes in San Diego

Brennen Field and Steven Searcy, University of San Diego, Environmental and Ocean Sciences, San Diego, CA, United States
Relatively little attention has been paid to the role of the ocean surf zone as a nursery habitat for marine coastal fishes. The large amounts of drift algae and sea grass may provide an ideal place for small fishes to forage and avoid predators. Despite the potential of surf zones as a nursery habitat, they have historically been understudied due to difficulty in sampling in this high-energy environment. We conducted a minimum of three replicate 1-m beam trawl tows weekly at Mission Beach, San Diego from June-September 2019. Juvenile and late stage larval fishes were identified and wave height, water temperature, and volume of drift material for each tow was recorded. At least two species of early juvenile fishes were found: California corbina (Menticirrhus undulatus) and Yellowfin croaker (Umbrina roncador). Abundance peaked in the late summer and was associated with warmer water and lower wave heights. Understanding the nursery role of the surf zone is critical as these areas have high levels of recreational use and are commonly disturbed by activities such as dredging and beach nourishment.