Date of Award

Winter 1-21-2021

Document Type

Thesis: Open Access

Degree Name

MS Marine Science

Department

Environmental and Ocean Sciences

Committee Chair

Drew Talley

Committee Member

Christine Whitcraft

Committee Member

Sharon Herzka

Abstract

The California killifish, Fundulus parvipinnis Girard, is an ecologically important marsh resident. Fundulus parvipinnis is a low-level carnivore, displaying high-site fidelity and occurring in high densities across a range of environmental conditions. Despite the importance of F. parvipinnis to the ecosystem functions of the threatened coastal wetlands of southern California and the Baja California Peninsula, there are critical gaps in our knowledge of this species. In particular, information on their diet and food habits is lacking.

Understanding wetland food web linkages, interactions, and trophic transfer is essential for informing effective habitat management and contributes to our ability to evaluate the functional equivalence of restoration efforts. Within an adjacent created and natural salt marshes in Mission Bay, San Diego, California, F. parvipinnis exhibited significant ontogenetic, spatial, and temporal variation in isotopic values (ẟ13C and ẟ15N values) and gut contents. Adults exhibited higher ẟ15N values relative to juveniles and primarily consumed amphipoda, while juveniles consumed a wider range of prey at greater relative proportions, including bivalvia, copepoda, insecta, and polychaeta. Spatial and temporal factors also influenced prey consumption in juveniles and young adults. Despite differences in prey consumption, there was a high degree of overlap in isotopic niche across life stage, though juveniles did exhibit a wider niche space. Understanding the spatial, temporal, and ontogenetic variations in the trophic ecology of F. parvipinnis provides critical information for informing successful restoration and management efforts that meaningfully consider critical food web linkages and habitat heterogeneity.

Download

Share

COinS