The striped bass population in San Francisco Bay has been plummeting since the 1970s and now scientists know why: fish moms are passing down damaging pollutants in the water to their young, according to a new study published today in the Proceedings of the National Academy of Sciences. Researchers say the findings may pave the way for stiff new regulations on the chemical culprits.

Striped bass and other fish have been dying in droves off the coast of San Francisco for decades; pollution from industry and agricultural runoff has long been blamed.

Now a team of scientists from the University of California, Davis, and the University of California, San Diego, have fingered the killer contaminants. They found that wild female fish from the Sacramento River produced eggs containing a host of pollutants at levels high enough to cause biological harm. The list includes chemicals called PBDEs (flame retardants), PCBs (a known carcinogen banned in the 1979), and a slew of pesticides. They even found DDT, the infamous pesticide linked to cancer that was banned in 1972 after being indicted in Rachel Carson's Silent Spring). 

The scientists performed chemical analyses that showed that baby fish were inheriting these contaminants from their moms and that the pollutants were causing problems such as smaller brains and livers. The authors say that these problems probably lead many baby fish to an early death in the wild.

And it's not just a striped bass problem. These types of pollutants may accumulate in all kinds of fish and fowl, according to the report. Something to mull next time you're downing that surf and turf.

(Image of striped bass larva courtesy David Ostrach)