Richardson Bay, a protected embayment, shows a relatively uniform input of organic carbon over the last 100 years. In contrast, in San Pablo Bay there is an upcore increase in organic carbon corresponding to an increase in urbanization and industrialization around 1950.

The polycyclic aromatic hydrocarbon (PAH) profile in Richardson Bay shows an increase of PAHs around the turn of the century in response to increasing industrialization around the Bay Area. In San Pablo Bay the increase in PAHs parallels the increase of organic carbon.