Trophic Relationships within the Seabird Community of Southeast Florida

Grant Winners

Deans

Abstract

The development of the ecological models used for fisheries and wildlife management require input values for the main components of the ecosystem. While such ecological values exist for plankton, a broad suite of fishes, and even marine mammals and sea turtles, the trophic position of seabirds in coastal ecologies is poorly known, in part because of the logistical difficulty obtaining samples. We propose applying state-of-the-art analytical techniques (compound specific stable isotope analysis and fatty acid profiling) to assess the feeding ecology of a suite of seabird species common to southeast Florida, including brown pelicans and common gulls Larus spp. We will use biological samples obtained through collaborations with local wildlife and bird rescue agencies throughout southwestern and southeastern Florida, including the Florida Keys. We aim to assess the relative role of marine-derived nutrients that is supporting the avian component of the marine food web, specifically targeting pelicans, gulls, and other seabirds opportunistically. The relative importance of both the pelagic and shore-based foraging characteristics could be apparent though the combined use of stable isotope analyses (trophic positioning) and fatty acid profiling (specific onshore versus offshore prey guilds). These seabird data will provide key missing information to numerous food web modeling efforts underway within NOAA.