The California Department of Fish and Wildlife will host the fourth installment of its speaker series with a presentation on Aquatic Invasive Species in the American River at 7 p.m. Aug. 5 at the Nimbus Hatchery Visitor Center, 2001 Nimbus Road, in Rancho Cordova.

Preregistration is not required.

The presentation is part of a program highlighting California Invasive Species Action Week Aug. 2-10. Among other activities being offered that week are field tours to check invasive crayfish traps and opportunities to help remove invasive plants on the American River Parkway near the hatchery.

For more information on the speaker series, go to www.facebook.com/NimbusHatchery. For more information on invasive species week, go to dfg.ca.gov/invasives.