Project: How does intensity and frequency of environmental variability affect phytoplankton growth?

Acronym/Short Name:Enviro variability and phytoplankton growth
Project Duration:2015-12 -2018-11
Geolocation:laboratory experiment

Description

NSF Award Abstract:
Microscopic plants called phytoplankton are key members of global oceanic ecosystems, since their photosynthesis supports the majority of the marine food chain and produces about as much oxygen as land plants. Because of this, oceanographers have often carried out experiments examining how factors such as temperature and carbon dioxide levels may affect phytoplankton growth. Most previous experiments have used constant levels of temperature and carbon dioxide, but it is clear from looking at measurements from real ocean ecosystems that these two factors often vary greatly over timescales of days to weeks. Using field and laboratory experiments along with computer modeling, this project will test how the growth of several major groups of phytoplankton differs under constant conditions of temperature and carbon dioxide, compared to conditions in which these factors fluctuate in intensity and frequency. This research will give marine scientists a better picture of how phytoplankton may respond to a varying natural environment today and in the future, and therefore help us to understand how ocean food webs function to support critical living resources such as fisheries. The project will train graduate and undergraduate students and a postdoctoral researcher, and the lead scientists will be involved in an ocean science education program for largely minority high school students from a downtown Los Angeles school district.

The goal of this project is to use laboratory culture and natural community experiments to understand how realistically fluctuating temperature and pCO2 conditions may affect globally important phytoplankton groups in ways that differ from the artificial constant exposures used in previous work. Culture experiments will test how the intensity and frequency of short-term thermal and carbonate fluctuations affects the growth responses of diazotrophic and picoplanktonic cyanobacteria, coccolithophores, and diatoms under both current and projected future environmental conditions. These lab results will be supported and extended by parallel experiments using mixed natural assemblages from the California upwelling regime, allowing us to test these same questions using phytoplankton communities that experience large seasonal shifts between highly dynamic thermal and carbonate system conditions during the spring upwelling season, and relatively much more static conditions during fall stratification events. These results will be synthesized using a new generation of numerical models that employ novel approaches to incorporating realistic environmental variations to allow more accurate predictions of phytoplankton responses to a dynamic environment in today's marine ecosystems, and in the future changing ocean.


DatasetLatest Version DateCurrent State
Model code for the EpiGen model used in Walworth et al. 2020 and example output2021-10-12Final no updates expected
Model output of phytoplankton community composition variability as a function of intensity and duration of environmental disturbance at the Hawaii Ocean Time-series (HOT) location and nearby regions between 2003 and 20142021-06-29Final no updates expected
Changes in seasonal phytoplankton community composition as a response to temperature at the San Pedro Ocean Time-series.2021-06-01Preliminary and in progress
Intracellular elemental quotas under low and high temperatures for E. huxleyi in constant and fluctuating thermal environments2019-11-26Final no updates expected
Growth rates for Emiliania huxleyi thermal response curve across 12 temperatures from 8.5-28.6C2019-11-26Final no updates expected
Elemental stoichiometry for Emiliania huxleyi across a range of 12 temperatures from 8.5-28.6C2019-11-26Final no updates expected
Growth rates under low and high temperatures for Emiliania huxleyi in constant and fluctuating thermal environments2019-11-26Final no updates expected
Trichodesmium thermal curve from October to November 20182019-02-26Final no updates expected
specific growth rates of Trichodesmium GBR strain based on in vivo fluorescence for a thermal variation experiment from 2016-20182019-02-12Final no updates expected
Nitrogen and carbon fixation rates and POC and PON from thermal variation experiment of Trichodesmium GBR strain from 2016-20182019-02-05Final no updates expected

People

Principal Investigator: Feixue Fu
University of Southern California (USC-WIES)

Co-Principal Investigator: David A. Hutchins
University of Southern California (USC-WIES)

Co-Principal Investigator: Naomi M. Levine
University of Southern California (USC)

Contact: Feixue Fu
University of Southern California (USC-WIES)


Data Management Plan

DMP_Fu_Hutchins_Levine_OCE1538525.pdf (36.68 KB)
02/09/2025