Nutrient addition incubation experiments over an annual cycle in coastal Newport Beach, CA

Phytoplankton communities in coastal California are influenced by changing physical and chemical conditions throughout the year. To identify the conditions that limit phytoplankton growth in coastal Southern California over an annual cycle, 15 monthly nutrient addition incubation experiments were conducted off of Newport Beach from August 2017 through September 2018. Treatments included control (no addition), nitrate, ammonium, phosphate, silicate, and a simulated upwelling treatment that received all of the listed nutrients in combination.  Results showed that the availability of light and N were the two main growth limiting factors of the bulk phytoplankton community. The January, February, March, and April 2018 experiments are examples of relief from light limitation; whereas, the remaining experiments were all limited by N. In several of the N limited experiments, the effect of light limitation was sometimes apparent at low levels. These included experiments in August and Septe..., , # Nutrient addition incubation experiments over an annual cycle in coastal Newport Beach, CA

Dataset DOI: [10.5061/dryad.xpnvx0ktd](10.5061/dryad.xpnvx0ktd)

## Description of the data and file structure

### Files and variables

#### File: Incubation_chlorophyll.xlsx

**Description:** The file “incubation_chlorophyll.xlxs” gives concentrations in the unit microgram chlorophyll per liter.  Empty cells indicate missing data.

##### Variables

* chlorophyll a concentration

- Nutrient addition incubation experiments were conducted over an annual cycle. Seawater was collected from Newport Pier (33.60, 117.93oW °W) in 2017 on August 16, September 6, September 25, October 16, November 13, and December 13, and in 2018 on January 16, February 21, March 14, April 18, May 21, June 15, July 8, August 29, and September 26. All plasticware used in the experiments was acid-cleaned and triple rinsed with sample water before use. On each sampling date, a 20 L plastic carboy was filled with seawater c...,