Samples of rainwater runoff collected in Monterey County will be studied to determine what pollutants were flushed into the Monterey Bay National Marine Sanctuary by the recent rain.

Volunteers working with the National Oceanic Atmospheric Administration on Saturday collected samples from 20 storm drains in Pajaro, Seaside, Monterey, Pacific Grove and Carmel.

The water samples will be analyzed by a laboratory for metals, nutrients, bacteria, urea and suspended sediment, according to NOAA.

Storm water runoff in coastal urban areas has been known to have toxic effects on marine life, causing reproductive failure, deformities and death, according to NOAA.

This is the ninth year runoff samples have been collected. Monitoring in previous years has revealed high concentrations of metals along with orthophosphate and bacteria.

"Monitoring helps us pick out problem areas to target for upstream source tracking of pollutants," said Anna Holden-Martz, coordinator of the Sanctuary Citizen Watershed Monitoring Network.

Holden-Martz said the network works with cities to find solutions and implement best management practices to curb urban pollution in storm water.