COPEPOD-PROTIST INTERACTIONS ALONG ENVIRONMENTAL GRADIENTS WITHIN THE GULF OF MEXICO DURING SUMMER AND FALL OF 2021

Copepods are important consumers of primary producers and primary consumers within the marine ecosystem. Most copepods operate as omnivorous suspension feeders that ingest varying protists, small metazoans, and detritus. In turn, these crustaceans provide an important food source for higher trophic levels, facilitating transfer of energy to a variety of consumers including fish, shellfish, seabirds, and mammals. Assessing natural copepod diets can be a complex task due to their ability to feed on a wide variety of prey. Copepods may also select for prey or adjust their feeding strategies in response to a changing prey environment. This study characterizes copepod-protist trophic interactions in mesotrophic nearshore and in oligotrophic offshore waters from shipboard incubations conducted on the Gulf of Mexico Ecosystems and Carbon Cruise (GOMECC-4) in September-October 2021. The goal of this study was to contribute to our understanding of protist-copepod dynamics in the Gulf of Mexico and explore potential trends in copepod grazing related to environmental gradients. Particle analysis for prey abundance and biovolume calculations was conducted using fluid imaging microscopy (FlowCam). Carbon-based copepod ingestion rates and estimates of copepod community grazing are further discussed in relation to prey carbon stocks and prey community structure. Dissolved oxygen was the most significant driver in explaining variability in the prey community across environmental gradients, with trophic index being a major factor in impacting copepod ingestion rates.

Presentation Preference: Poster

Primary Presenter: Will McClure, North Carolina State University (wtmcclur@ncsu.edu)

Authors:

Will McClure, North Carolina State University  (wtmcclur@ncsu.edu)

Miranda Hart, North Carolina State University  (msirby@ncsu.edu)

Beth Stauffer, University of Louisiana at Lafayette  (beth.stauffer@louisiana.edu)

Leticia Barbero, NOAA Atlantic Oceanographic and Meteorological Laboratory  (leticia.barbero@noaa.gov)

Astrid Schnetzer, North Carolina State University  (aschnet@ncsu.edu)