Ecological functions of tidal marsh for estuarine and migratory fishes in Suisun Marsh

Start/End: March, 2016 to March, 2018

Tidal marshes are productive ecosystems that provide food and refuge to juvenile fish, increasing survival to adulthood. Their importance to juvenile rearing in the San Francisco Estuary is poorly understood as a result of widespread wetland reclamation. 35 years of data collected by the UC Davis Suisun Marsh Fish Study suggest that the largest remaining tidal marsh, the Rush Ranch National Research Reserve in Suisun Marsh, supports higher-than-average densities of juvenile estuarine and migratory fishes. This targeted study explicitly tests the nursery-role concept to guide tidal marsh restoration projects aimed to enhance native fish populations.

This project will explore the ecological functions of tidal marsh in the San Francisco Estuary as a nursery habitat to juvenile fishes. Specifically, researchers will:

  • Identify marsh characteristics associated with higher density, biomass and growth of juvenile fishes;
  • Characterize the time juvenile fishes spend in vegetated intertidal habitats and to relate their movement patterns to abiotic factors;
  • Test whether microhabitat or hydrology (i.e., access to the marsh surface) influences foraging patterns for juvenile fishes.

Results will be synthesized to develop a conceptual model on tidal marsh nursery functions for juvenile estuarine and migratory fishes in Suisun Marsh.