Year 1 field sampling wraps up for developing intermittent stream bioindicators

SCCWRP and its partners have completed Year 1 of field sampling for a study investigating the feasibility of using terrestrial arthropods, riparian insects and bryophytes (e.g., mosses) to assess the biological condition of streams that run dry for much of the year.

Field researchers this summer collected data from 39 stream sites across the San Diego area representing a range of conditions and environmental settings. The goal is to develop a regional Southern California scoring tool for intermittent and ephemeral streams, similar to the California Stream Condition Index scoring tool that is used in perennial streams statewide.

Although intermittent streams make up about 60% of all streams in Southern California, there is no scoring tool calibrated for intermittent streams at the drier end of the hydrologic spectrum.

Researchers hope that terrestrial arthropods, which include insects and crustaceans, can serve as sentinel indicators of how intermittent streams are impacted by agricultural and urban runoff. Bryophytes like mosses and liverworts, meanwhile, have been shown to be highly sensitive to changes in water quality and siltation.

Researchers anticipate sharing initial data and analyses in spring 2017; more field work also is planned in the spring.