Date of Award


Degree Name

MS in Environmental Sciences and Management


Natural Resources Management


College of Agriculture, Food, and Environmental Sciences


Christopher Surfleet

Advisor Department

Natural Resources Management

Advisor College

College of Agriculture, Food, and Environmental Sciences


Estuaries support abundant biodiversity but are threatened by anthropogenic influences making it a priority to effectively monitor water quality to identify if and when it becomes detrimental to aquatic life. The purpose of the study was to analyze water quality in local San Luis Obispo estuaries to measure baseline conditions to inform future studies and management and to identify if key water quality parameters such as dissolved oxygen or temperature result in stressful or lethal conditions for steelhead trout (Onchorynchus mykiss). An EXO1 multiparameter snode (probe) was used to measure dissolved oxygen (mg/l), temperature (in Celsius), conductivity (Us/cm), salinity (parts per thousand), and pH while grab samples were used for comparisons to the ESXO1 measurements and determine toxic ammonia, inorganic nitrogen, phosphorus and chlorophyll a concentrations. In addition to probe and grab sampling, the weather and frequency of bar breaching where recorded from three central California coast estuaries, the Villa Creek, Santa Rosa, and San Simeon, from December 2019 to July 2020. At each estuary sampling was concluded at three collection sites representing the front (near the ocean), middle, and back (near river) of the estuary. Notable results from the sampling show that in July dissolved oxygen conditions in Villa Creek estuary were measured at lethal levels for steelhead (0 mg/l) in the upper water layers in July, while in other estuaries the levels remained at tolerant level for steelhead (~ 7 mg/L). Temperature remained relatively stable with one exceptionally high reading in December at San Simeon estuary (over 35 degrees Celsius), but this may have been due to a measurement error.

Included in

Hydrology Commons