INTERACTIONS BETWEEN NEW ZEALAND MUD SNAILS (Potamopyrgus antipodarum) AND TOXIC CYANOABACTERIA (Anabaena) IN BADUWA’T (MAD RIVER), HUMBOLDT COUNTY, CALIFORNIA

Author

Cecilia F. KennellyFollow

Graduation Date

Fall 2024

Document Type

Thesis

Program

Master of Science degree with a major in Natural Resources, option Fisheries

Committee Chair Name

Darren Ward

Committee Chair Affiliation

HSU Faculty or Staff

Second Committee Member Name

Rafael Cuevas Uribe

Second Committee Member Affiliation

HSU Faculty or Staff

Third Committee Member Name

Emily Jones

Third Committee Member Affiliation

HSU Faculty or Staff

Keywords

New Zealand mud snail, Cyanobacteria, Harmful algae blooms, Coastal California

Subject Categories

Fisheries

Abstract

Invasive species in freshwater systems are circulated around the globe, wreaking havoc on natural communities. The New Zealand mud snail (Potamopyrgus antipodarum) is a very successful aquatic invader that has established populations in freshwater streams, lakes, and rivers around the globe. The goal of this project was to evaluate the interactions of invasive New Zealand mud snails (NZMS) and toxic cyanobacteria Anabaena in the Mad River in Humboldt County, California. These two species of concern are found in similar habitats along the river, but their whether NZMS consume Anabaena or affect toxin production is unknown. First, I conducted field surveys and measured species abundances and various abiotic factors. Next, I used a Bayesian generalized linear model to determine if abiotic factors could predict hotspots of NZMS abundance and evaluate NZMS association with Anabaena. However, this model was not able to predict areas of high NZMS abundance, despite accounting for temperature, salinity, conductivity, substrate type, flow, depth, and algae coverage. The model did show that NZMS distribution was not associated with Anabaena. Finally, I conducted laboratory experiments with the goals of determining 1) if NZMS have a preference between Anabaena and other local algae (Cladophora and Spirogyra) and 2) if NZMS affect toxin release by Anbaena. My lab experiments showed that NZMS moved towards Anabaena more often than other algae, both when comparing each algae against a blank and when choosing between two types of algae. NZMS chose Anabaena 65% of the time when compared to a blank choice and about 50% of the time when offered different algae. I also found that Anabaena releases more microcystin in the presence of NZMS than when NZMS are absent. My findings suggest that current densities of NZMS are not high enough to affect Anabaena toxin concentrations in the Mad River. However, because NZMS do not avoid Anabaena and they can affect toxin concentrations when they cooccur, they should continue to be monitored.

Citation Style

Chicago

Recommended Citation

Kennelly, Cecilia F., "INTERACTIONS BETWEEN NEW ZEALAND MUD SNAILS (Potamopyrgus antipodarum) AND TOXIC CYANOABACTERIA (Anabaena) IN BADUWA’T (MAD RIVER), HUMBOLDT COUNTY, CALIFORNIA" (2024). Cal Poly Humboldt theses and projects. 809.
https://digitalcommons.humboldt.edu/etd/809