Science Stories: Adventures in Bay-Delta Data

  • May 17, 2021

One of life’s greatest joys is playing with data. However, not everyone has the time or experience needed to make fancy graphs. Fortunately, availability of on-line web applications that allow people with no data analysis experience to visualize status and trends of data across space and time has exploded in recent years.

Three fish look at a graph. One says 'I want to make graphs, but I can't type with fins'. Another says 'I don't even know where to get the data!'. The third says 'Don't worry, there are lots of apps that you can use to graph the data automatically.'
Figure 1. Fish love data, but they need a little help making their graphs.

One of the first data visualization tools was the mapping widgets on the CDFW website. These maps allow you to plot the catch for different fish species as different size bubbles, and have been available since the late 1990s:

But we needed better ways to display data from multiple surveys at once at the click of a button. The website Bay Delta Live was launched in 2007 as a home for Bay-Delta data and data visualizations. It includes summaries, graphs, and interactive visualizations for water quality, operations, fish monitoring, and special studies.

A similar website, SacPas, was built specifically for synthesizing, summarizing, and displaying data for salmonids in the Central Valley. It allows a user to visualize data on salmon abundance, temperature thresholds, river conditions, and hydrologic conditions. It also lets you play with a nifty Chinook Salmon population model and download all the underlying data.

Three fish look at a map. The tule perch says 'This app lets you see how much flow you need to get different amounts of salmon habitat.' The splittail says 'This is great! Where is ths splittail habitat app?'
Figure 2. FLowWest's Central Valley Instream Rearing Habitat Calculator shiny app

Custom-built websites like Bay Delta Live and SacPas are great, but they are built by web developers, not fisheries scientists. Now, thanks to user-friendly data display tools such as Tableau and the increase in coding literacy among environmental scientists, more and more people can create their own on-line data visualizations. This means the number of data visualizations apps has grown astronomically in the past few years, and many apps are custom-built for specific scientific questions.

The Delta Science Program now hosts a number of these visualizations built with the R package “shiny’

Three fish look at a map. The tule perch says 'This app lets you make maps of all the IEP fish sampling stations.' The striped bass says 'Oh, good, now I know all the places I should avoid.'
Figure 3. You can now map all the stations monitored by IEP's long-term surveys.

Other Shiny apps have launched recently on a variety of other platforms:

Three fish look at a graph of salmon survival. The Tule Perch says 'you can use the STARS model to look at survival probabilities'. The splittail says 'I'm glad I don't have to migrate through the Delta.'
Figure 4. CalFishTrack includes a Shiny App of their Survival Travel time And Routing Simulation (STARS).

USGS has developed several new dashboards for mapping water and water quality data:

With all these tools out there, it’s one big data playground! If you’re interested in making your own, it’s easy to get started with Shiny. Visit the Learn Shiny video tutorial!

Categories: General