San Gabriel River Regional Monitoring Program

Fish Tissue Contaminant Concentrations

The monitoring design for Question 5 is focused on assessing if the consumption of recreationally caught fish in the San Gabriel River Watershed are safe to eat. Since 2006, a total of 54 composites of fish tissues have been collected from eleven species, at eight different recreational fishing locations.

State of California Office of Environmental Health Hazard Assessment

Fish Consumption Guidelines
The OEHHA Advisory Tissue Levels (ATLs) were developed with the recognition that there are unique health benefits associated with fish consumption and that the advisory processshould be expanded beyond a simple riskparadigm in order to best promote the overallhealth of the fish consumer. ATLs protect consumers from being exposed to more than the average daily reference dose for non-carcinogensor to a life time cancer risk level of1 in 10,000 for fishermen who consume an 8 ounce fish fillet containing a given amount of aspecific contaminant.
These samples were analyzed for arsenic, selenium, total DDT, and total PCB, and concentrations were compared to OEHHA consumption thresholds.

Mercury was by far the most common fish tissue contaminant to exceed at least one of the OEHHA consumption guidelines across multiple species. Concentrations in largemouth bass were greatest, especially at the Santa Fe Dam Recreation Area Lake. Both tilapia and redear sunfish had low concentrations of mercury at all of the waterbodies.

PCB concentrations exceeded OEHHA guidelines less frequently and only in common carp, striped mullet, and largemouth bass.

Neither selenium nor DDT concentrations exceeded OEHHA standards in any fish over the time period.

The authors of the State of California's OEHHA fish consumption guidelines stress that the health benefits of eating fish must be taken into consideration. For much more information regarding the risks of eating fish, go to: