Monitoring the Spread of Invasive Aquatic Snails



Stanislaus State graduate student Christina Robinson is studying the distribution and population dynamics of the New Zealand mud snail, a non-native species that has invaded the United States over the past few decades.

In 2012, the mud snail was discovered in Marin County’s Corte Madera Creek. By sampling streams in the vicinity, Robinson is comparing the current aquatic community composition to historical data to determine how far the snail has spread and its effects on other aquatic animals, as well as the snail population’s susceptibility to drought and floods.

A consortium of local water, watershed, and fish and wildlife authorities are collaborating to identify and manage aquatic invasive species in local streams. This consortium has teamed up with the university to initiate early detection surveys for invasive species in three streams that support endangered and threatened coho salmon and steelhead fish.

“An infestation could seriously alter the stream habitat and lead to the eradication of coho and steelhead,” says Greg Andrew, fisheries program manager for the Marin Municipal Water District. “The surveys by Christina Robinson and the Stanislaus State team are vital to controlling the spread of these invasive species and helping protect these streams as habitats for our native species.”