CalCOFI Data Visualization Tool

This app is an exploratory tool to visualize seawater characteristics off the coast of California from the CalCOFI dataset. The interactive graphics provide a tool to explore the variation of the following properties over space and time: dissolved oxygen concentration, temperature, salinity, and chlorophyll presence.

The visualizations use data collected by the California Cooperative Oceanic Fisheries Investigations (CalCOFI), an ocean observing and monitoring program. Data is collected through seawater sampling at numerous discrete depths (between 0 - 500+ meters) at locations (sampling stations) that are arranged along parallel transect lines that extend perpendicular off the coast of Central and Southern California. CalCOFI samples these stations quarterly — in Winter, Spring, Summer, and Fall of each year — and has been doing so for over 73 years (since 1949). 2 We have displayed dissolved oxygen concentration less than or equal to 1.4 ml/l, called hypoxia, off the California coast.1 In deeper depths, within the twilight and abyssal zones (the areas with low to no light, begins around 200 m depth), low dissolved oxygen concentrations are normal, but at shallower depths within the photic (sunlit) zone, above 200 meters, low dissolved oxygen concentrations have negative effects on the chemical and biological processes within the ocean.3 During the Spring and Winter a phenomenon called upwelling brings these deep, oxygen poor, cold waters to the surface. However, increasing temperatures and other effects from climate change are causing increased hypoxia at the surface during the Summer and Fall when low oxygen concentration is unexpected to the local environment and oceanic systems.1 These visualizations display these increasing hypoxic zones throughout the California coast.

Click on the "Spatial Trends" tab to see how dissolved oxygen concentration, temperature, salinity, and chlorophyll concentration varies with depth and distance from shore.

Click on the temporal tab to see how dissolved oxygen concentration, temperature, salinity, and chlorophyll varies over time.

For explanations on how to interpret the graphs, the information button in the bottom left corner of the screen provides detailed instructions on how to effectively navigate through each tab.

About the Fellows

Mallika Gupta, Teresa Gonzales, Dante Coletta, Prerana Kottapalli worked on this project since Winter quarter in the capacity of fellows with CCDSP. They worked under the supervision and guidance of Trevor Ruiz and Erin Satterthwaitehe for Winter '22 and Spring '22 Quarters.

  1. Chan, F., J.A. Barth, K.J. Kroeker, J. Lubchenco, and
    B.A. Menge. 2019. The dynamics and impact of ocean
    acidification and hypoxia: Insights from sustained
    investigations in the Northern California Current
    Large Marine Ecosystem. Oceanography 32(3):62–71,
  2. Satterthwaite, E.V., Semmens, B., Bowlin, N., Coates, J., Goericke, R., Swalethorp, R., Thompson, A. Brady, B. & CalCOFI personnel.
    2021. Long-term marine ecosystem observations to support sustainability & resilience in the California Current System: California Cooperative Oceanic
    Fisheries Investigations (CalCOFI) 2017 - 2021.
  3. DeVries, T. (2022). Distribution of DIC and Alkalinity in the Ocean [PowerPoints Slides].

Contact Us:

© 2022 CCDSP@UCSB. Back to top


Select Parameters

Data compiled for CalCOFI by CCDSP Fellows


Data compiled for CalCOFI by CCDSP Fellows