Assessing Water Conditions in Dreissenid Mussel Spread

Susan Le, Adul Samon, William Zambito

Overview

  • Objective: Assess water conditions in the spread of Dreissenid mussels
  • Selected States: AZ, NV, UT, NM, OK, OR, WY, CA
  • Key Conditions: pH, Calcium

Introduction

  • For our final project we wanted to focus on the correlation between pH, calcium, and the presence of veligers.

  • Are there any trends? Is there an sweet spot for pH and calcium levels that allow them to thrive the best?

  • We hoped to answer these questions as we cleaned and prepped the data for visualization.

Selected States

  • Number of Waterbodies :
AZ CA NM NV OK OR UT WY
1886 1580 900 243 296 557 3537 863

Prior Research

  • Prior research has shown that veligers spread from human activity. Meaning that as people move from place to place, they carry mussel babies (veligers) with them.

  • This allows them to thrive in other locations, causing the spread from the east to the west in the states.

  • Veligers thrive with a pH of about 7.5 to 9.3. This study shows that lower pH leads to increased mortality (Claudi et al., 2012)

  • When calcium levels are below 20g/l, unlikely the zebra mussels will spread and establish a colony (Cohen, 2004)

Our Data Sets

waterbody_name state SampleDate pH VeligerCount huc6 latitude longitude WaterYear VeligerDetect avg_class_ph avg_VeligerCount avgCalcium total_waterbodies detected_veliger occupancy_rate
LAKE MEAD AZ-NV 2012-10-10 7 312 150100 36.2898 -114.3880 2013 1 7.44 1035.08 33.89 60 45 0.75
LAKE MEAD AZ-NV 2012-11-14 7 719 150100 36.2898 -114.3880 2013 1 7.44 1035.08 33.89 60 45 0.75
LAKE MEAD AZ-NV 2012-11-27 7 107 150100 36.0467 -114.2733 2013 1 7.44 1035.08 33.89 60 45 0.75
LAKE MEAD AZ-NV 2012-11-27 7 826 150100 36.1002 -114.1168 2013 1 7.44 1035.08 33.89 60 45 0.75
LAKE MEAD AZ-NV 2012-12-11 7 0 150100 36.2898 -114.3880 2013 0 7.44 1035.08 33.89 60 45 0.75

  • Occupancy Rate: Calculated by taking the percentage of samples out of the total amount of samples with the presence of at least one veliger.

  • Water Quality Portal

Disclaimer:

  • Some of the data can be inaccurate. There are instances of samples containing the veligers being spilled, skewing the numbers.

  • Keep in mind that human error plays a factor. The data scientists who count these veligers have to do it by hand, and they are counting up hundreds if not thousands of little babies.

  • The data entries are also sometimes missing a decimal, so sometimes pH, although ranging from 1-12, were found to be up to 635 for example.

Condition: pH

Condition: pH

Condition: Calcium

Condition: Calcium

Shiny App

https://william-zambito.shinyapps.io/ShinyApp/

Conclusions:

  • Veligers were detected from a pH of 5 to around 8.5. However, veliger count was highest with a pH of around 6-8.

  • In regards to calcium levels, veligers were found from calcium levels of 20 to 170, but veligers were detected the most in environments with calcium levels of 75 or higher.

  • Based on these observations, it seems that these may be the optimal conditions for veligers to thrive

Sources:

  • Water Quality Portal:

    • Search parameters: WQP_data <- readWQPdata( huc = i, # enter the HUC number here siteType = “Lake, Reservoir, Impoundment”,
      startDateLo = “10-01-2012”, startDateHi = “12-31-2020”, characteristicName = “pH”)

  • Bureau of Reclamation

  • Claudi, Renata & Graves, Albert & Taraborelli, Ana & Prescott, Robert & Mastitsky, Sergey. (2012). Impact of pH on survival and settlement of dreissenid mussels. Aquatic Invasions. 7. 21-28. 10.3391/ai.2012.7.1.003.

  • Cohen, Andrew. (2004). Calcium Requirements and the Spread of Zebra Mussels.

  • Professor Winder’s research