Introduction Newell Creek Reservoir Data Organization and Algal Bloom Analysis December 11, 2012 City of Santa Cruz Water Department Presented by CSUMB ENVS 660 Class: Scott Blanco, Brittani Bohlke, Cherie Crawford, Christina David, Thomas DeLay, Shane Keefauver, Gwen Miller, Polly Perkins, Rochelle Petruccelli, Kirk Post, John Silveus Instructor: Fred Watson

Goal The goal of this study was to digitize and organize all available data provided by the City of Santa Cruz Water Department for the Newell Creek Reservoir watershed, and to use the data for analysis of phytoplankton dynamics.

Overview I.Background John Silveus II.Public Database Rochelle Petruccelli & Shane Keefauver III.Hydrology Thomas Delay & Kirk Post IV.Algal Summary Cherie Crawford & Gwen Miller V.Algal Dynamics – Methods, Results, Discussion Christina David & Scott Blanco VI.Conclusions Brittani Bohlke VII.Questions

Background Newell Creek Reservoir is a critical water source for the City of Santa Cruz. Loch Lomond is a popular recreation area, with 50,000 visitors a year.

Background During summer months, periodic freshwater algal blooms have been observed. Blooms can impact water quality, water treatment efficiency, fish populations, and the beneficial recreational use of the reservoir.

Public Database Newell Creek Reservoir watershed data ranges from , of which were in hardcopy form and required digitization. Data included: Water Quality Plankton Precipitation Flow Reservoir Elevation Wildlife

Data Availability Figure

Public Database Excerpt from public database website Under Construction !

Hydrology Summary

Phytoplankton Summary Total phytoplankton count and chlorophyll concentration with algaecide applications at Site 2 of the Newell Creek Reservoir. Digitized phytoplankton data were plotted ( ) from Site 2.

List of all plankton taxa that have occurred from bact0200/anabae03.htm

Phytoplankton count for Site 2 at Newell Creek Reservoir at the surface of the reservoir, an elevation of 550 ft, and 530 ft.

Plankton Dynamics Newell Creek Reservoir has experienced recurrent phytoplankton blooms which have been monitored and treated to stem high densities and associated water quality issues. Erin Stanfield

Environmental factors considered here that can affect bloom density, timing and composition: Temperature Conductivity Dissolved oxygen (DO) pH Precipitation and flow Turbidity and light availability Limited data available: Nutrients Plankton Dynamics

The main phytoplankton of interest for management at Newell Creek Reservoir is cyanobacteria (“blue- green algae”): Cyanobacteria taxa of interest: Anabaena spp. Aphanizomenon spp. Lyngbya spp.

Plankton Dynamics Top functional groups were ranked based on the minimum NU count treated for a bloom during the study period. Final groupings: Cyanobacteria, Diatoms, & Green Algae

Plankton Dynamics - Methods 1. Time series graphs and select scatter plots of NU plankton counts v. environmental parameters for: Anabaena, Aphanizomenon, and Lyngbya ( ) Cyanobacteria, diatoms, and green algae ( ) Close-up of Anabaena in 2010 (wet year)

Plankton Dynamics - Methods 2. Spearman Rank Correlation tests, NU plankton count v. environmental parameter for these datasets: Diatom (surface) Green Algae (surface) Cyanobacteria (surface, 550 ft, 530 ft) Cyanobacteria “bloom season” subset (surface)

Plankton Dynamics - Results Precipitation Intensity of bloom may be tied to intensity of nutrient flows delivered by precipitation and surface water flow, however the relationship may not be linear

Plankton Dynamics - Results Peak discharge and peak cyanobacterial density Peak discharge in the preceding water year corresponds with peak cyanobacteria densities (need to assess more years)

Plankton Dynamics - Results Temperature No discernible patterns or correlations between temperature and bloom intensity at ten year time scale

Plankton Dynamics - Results Interspecific interactions Anabaena appears to be the dominant taxa, occurring in every bloom year, seemingly outcompeting Aphanizomenon. However in the 2011 bloom season, Aphanizomenon reached high densities, possibly being release from competition with Anabaena following algaecide treatment

Plankton Dynamics - Results Phytoplankton and environmental interactions Occurrence of diatoms in the cooler spring “clear-water phase” preceding warmer water cyanobacteria blooms.

Plankton Dynamics - Results Phytoplankton and environmental interactions Diatoms occur during higher flow and precipitation periods that precede cyanobacteria dominated low flow and precipitation periods

Plankton Dynamics - Results 2010 Anabaena bloom analysis

Plankton Dynamics - Results 2010 Anabaena bloom analysis (continued)

Plankton Dynamics - Results Spearman Rank Correlation Tests resulted in many significant p-values, most of the correlations (rhos) were weak (<0.25)

Plankton Dynamics - Results Spearman Rank Correlation Cyanobacteria versus pH, Secchi depth, and turbidity yielded moderate to strong ( moderate & >0.5 strong) correlations These correlations were largely assumed to be caused BY the blooms, not vice versa

Summary of Results Precipitation Flow Nutrients Temperature Algaecide Treatment Cyanobacteria Bloom -Interspecies interactions (+/-) -Role of turbidity/light availability (+) +/-+/- Inferences on cause of algal blooms:

Discussion Future Analysis Recommendations Create subset of green algae for bloom periods Disconnect between bloom data and environmental parameter changes (precipitation, temperature) – time lag Degree days instead of temperature data

Discussion Data Collection and Processing Recommendations Collect turbidity and nutrient load data from Newell Creek inflows Collect regular nutrient samples from current reservoir sampling sites Consider augmenting NUs with additional biomass- related lab metrics

Discussion Recommendations for Future Projects Analyze temperature for genera-specific bloom predictions Further examination of taxa between depths In situ environmental probe

Conclusions Organized and documented existing data Demonstrated one approach to begin comprehensively visualizing and analyzing data Provided basis for future analyses A few inferences were made - not able to clearly identify causes of blooms Nutrient data are needed

Acknowledgements The CSUMB Advanced Watershed Science and Policy Class of 2012 would like to recognize the following for their contributions to our efforts: SCWD - Chris Berry, Terry Tompkins, Hugh Dalton, Ryan Basset, Ezekiel Bean CSUMB - Erin Stanfield and Fred Watson for their endless patience

Questions? Erin Stanfield