Event Title
Seasonal changes in trophic interactions in the plankton community in the Strait of Georgia
Streaming Media
Presentation Abstract
As the base of the food web, plankton are key in energy transfer and influence the biomass and composition of organisms higher up in the food web. However, the diversity of plankton species, as well as their trophic processes and interactions are often over-simplified in food web models. Throughout a year, the plankton community varies greatly, further increasing the complexity of trophic flows. Here, we have used Ecopath to model the plankton food web in the Strait of Georgia in three seasons. The plankton community is represented in the models by ten mesozooplankton groups, two mixotrophic microzooplankton groups, one phytoplankton group, a heterotrophic bacteria group, and one detrital group. In the spring, diatoms dominate the plankton biomass in the Strait of Georgia, leading to high primary productivity and fueling the growth of many zooplankton. In summer, primary production is limited by nutrients, diatom biomass declines and mixotrophic flagellates become more dominant. Zooplankton biomass, dominated by large crustaceans such as copepods, amphipods, and euphausiids, peaks and their diets shift to become more omnivorous, and the microbial loop becomes a more important energy source. In winter, plankton biomass and productivity are low, and the microbial loop again becomes an important energy source for the system. The changes in planktonic food web structure throughout a year could have important implications higher up the food web, and these models could help inform estimates of the food availability for fish.
Session Title
Poster Session 2: The Salish Sea Food Web and Cycles of Life
Conference Track
SSE14: Posters
Conference Name
Salish Sea Ecosystem Conference (2022 : Online)
Document Type
Event
SSEC Identifier
SSE-posters-207
Start Date
26-4-2022 4:30 PM
End Date
26-4-2022 5:00 PM
Rights
Copying of this document in whole or in part is allowable only for scholarly purposes. It is understood, however, that any copying or publication of this document for commercial purposes, or for financial gain, shall not be allowed without the author's written permission.
Type
Text
Language
English
Seasonal changes in trophic interactions in the plankton community in the Strait of Georgia
As the base of the food web, plankton are key in energy transfer and influence the biomass and composition of organisms higher up in the food web. However, the diversity of plankton species, as well as their trophic processes and interactions are often over-simplified in food web models. Throughout a year, the plankton community varies greatly, further increasing the complexity of trophic flows. Here, we have used Ecopath to model the plankton food web in the Strait of Georgia in three seasons. The plankton community is represented in the models by ten mesozooplankton groups, two mixotrophic microzooplankton groups, one phytoplankton group, a heterotrophic bacteria group, and one detrital group. In the spring, diatoms dominate the plankton biomass in the Strait of Georgia, leading to high primary productivity and fueling the growth of many zooplankton. In summer, primary production is limited by nutrients, diatom biomass declines and mixotrophic flagellates become more dominant. Zooplankton biomass, dominated by large crustaceans such as copepods, amphipods, and euphausiids, peaks and their diets shift to become more omnivorous, and the microbial loop becomes a more important energy source. In winter, plankton biomass and productivity are low, and the microbial loop again becomes an important energy source for the system. The changes in planktonic food web structure throughout a year could have important implications higher up the food web, and these models could help inform estimates of the food availability for fish.
