Development and application of new amino acid isotope proxies to reconstruct California phytoplankton community composition change with shifting climate

Project Number
Project Date Range
Funding Agency
National Oceanic and Atmospheric Administration (NOAA)
Focus Area(s)
Healthy Coastal Ecosystems

In coastal California, climate variability and change regulate the composition of marine phytoplankton communities. Climate variation affects whole-ecosystem structure and productivity, as well as the risk of dangerous and costly harmful algal blooms. Despite the need for knowledge about likely effects of changing climate on coastal ecosystem productivity and health, understanding is limited by the relatively short duration of recent ecological monitoring efforts. 

To answer questions that pre-date manually taken records, the research team is turning to paleoclimate records. Reconstructions of past ecological change provide critical insight into climate-driven ecosystem dynamics before the mid-20th century. Currently few suitable proxies exist for reconstructions of phytoplankton community composition in coastal environments. 

This work will address two primary research questions about past change in phytoplankton communities: 

  1. What were the effects of a past warming and drought event on algal community composition and bloom incidence in Monterey Bay, and what are the implications for future change?
  2. How do decadal modes of climate variability like the Pacific Decadal Oscillation influence phytoplankton community composition on the central California margin?

The primary objectives of the project are to adapt and validate an innovative new isotope ecology method (i.e., carbon isotopes of essential amino acids “fingerprinting”) for quantifying phytoplankton community changes in coastal marine environments. After method development and validation, the team will apply the isotope fingerprinting method to deep sea coral skeleton and sedimentary paleoarchives to gain new insight into the influence of past climate change on phytoplankton community composition and algal bloom occurrence in central California. 

Principal Investigators
Genevieve Pugsley
University of California, Santa Cruz (UCSC)
Co-principal Investigators
Matthew McCarthy
University of California, Santa Cruz (UCSC)

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