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On a recent end-of-summer day, researchers with the state Department of Fish and Game were aboard the vessel as part of a wide-ranging scientific effort to determine why California's delta is dying. Over the past three years, scientists have recorded a collapse in four key fish species and are scrambling to determine whether the decline is due to one culprit or many.
The declining fish populations is considered a harbinger of the health of the Sacramento-San Joaquin River Delta, which drains 61,000 square miles, or 42 percent of California's land area, and collects and filters water used by 26 million Californians. "It's just really dramatic. We looked at that and said, 'Wow, this isn't good,"' said biologist Chuck Armor of the California Department of Fish and Game, one of the scientists aboard the Scrutiny. Armor manages the ecological program that is trying to decipher the many clues about the delta's health. His job is to help identify the problems for six federal and three state agencies that all have a stake in the estuary's health. A scientific report is due in December.
Some of the answers may be as obvious as water hyacinth, one of the exotic weeds that would clog the channel were it not for herbicides sprayed onto the water. The water hyacinth is one of more than 200 foreign species that have invaded the delta, including a toxic blue-green algae, a spiny zooplankton that may be replacing more beneficial species, and tiny clams that filter the water and compete with fish for food.
Visible over the levees that line the ship canal are fields where farmers are using new pesticides that are safer for humans but may be more harmful for fish. Beside those fields are new subdivisions where runoff from lawns and parking lots adds to what longtime delta environmentalist Bill Jennings calls "a chemical sea." "We are at a critical threshold," said Jennings, who until recently headed the Deltakeeper environmental watchdog organization. "We are going to make decisions within the next year that are either going to fix the delta, or we are going to use it essentially as a way station to transport water to Southern California."
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