Oral Presentation Society for Freshwater Science 2026 Annual Meeting

The assessment of riverine wetland conditions, macroinvertebrate assemblages, and physical habitat conditions of streams on Santa Rosa Island, Channel Islands National Park. (134591)

Daniel Pickard 1 , Parsa Saffarinia 2
  1. Aquatic Bioassessment Lab (ABL) - Chico, Chico, CA, United States
  2. Biological Sciences, CSU Chico, Chico, CA, United States

Santa Rosa Island is an 82 sq. mi. island approximately 26 mi. off the southern California coast, located within Channel Islands National Park.  Thirty long term monitoring sites were assessed during two sampling events for riparian wetland health with CRAM (California Rapid Assessment Method). Bioassessment (including physical habitat assessment) was done on ten of these sites.  CRAM scores averaged 76 (range 60-91), with nine (14%) sites scoring impaired for overall CRAM score.  Thirty-two (50%) sites scored impaired for the BIO/PHYS CRAM submetrics.  California Stream Condition Index (CSCI) scores averaged 0.73 (range 0.58-0.95) and showed impairment at 17 (77%) sites.  Physical habitat metrics indicated grazing impacts.  All but one site showed impairment for specific conductivity.  NMDS analyses revealed a grouping of communities by watershed suggesting that community structure is driven by local watershed conditions rather than island-wide effects.