Aspen’s Aquatic Biologists Have Been Busy!
Aspen Environmental Group’s aquatic biologists have been very busy completing fieldwork and volunteering. The team completed spring site evaluation at three potential translocation sites for the federally threatened Santa Ana sucker (Catostomus santaanae) in the San Bernardino National Forest. These assessments included fish surveys, benthic macro-invertebrate sampling, algae, and diatom sampling, and several physical habitat measurements. The team used methods from the Santa Ana Sucker Translocation Plan to complete the assessments. The methods in the Santa Ana Sucker Translocation Plan were based on methods from the Surface Water Ambient Monitoring Program (SWAMP).
Last fall, Aspen’s aquatics team volunteered to assist the San Bernardino Valley Municipal Water District, U.S. Geological Service (USGS), Angeles National Forest, California Department of Fish and Wildlife Service, and other agencies to survey for native fish on the upper San Gabriel River within the Angeles National Forest. The purpose of the surveys was to better understand habitat requirements for native species. The Aspen team used the opportunity to collect data on the dietary preferences of Santa Ana sucker and Santa Ana speckled dace (Rhinichthys osculus). USGS biologists also collected genetic material from the native fish to better understand the genetic diversity of these species throughout their range.
The team also continues to work with the U.S. Army Corps of Engineers and Recon on a mitigation project to improve the habitat for Santa Ana sucker in the Santa Ana River, near downtown Riverside. River rocks were placed in the river channel to improve the habitat by increasing the surface area for diatoms and algae to grow on, scouring out the sand to create a deeper pool and run habitats, and providing protection from predatory birds and mammals. This will be ongoing for the next several years and our team will be continuing to monitor this work to see how the fish respond to the improved habitat.