Modeling pesticide loadings into the Sacramento-San Joaquin Delta: potential impacts on weed biological control

Each year, millions of dollars are spent in the Delta to prevent invasive weeds from obstructing navigation, reducing water quality, displacing native species and harboring mosquitoes. Biological control of aquatic weeds by insects – a promising means of mitigating these weeds – is not performing as well as expected. One reason for this may be the high levels of pesticides or fertilizers in the Delta waters, which are largely influenced by runoff from upstream agriculturally intensive watersheds.