Another report about the Delta seems to collaborate existing ones that a loss of fish, wildlife and plant species continues, to be expected with the huge increase in human habitat.
It will always be a balancing act to protect enough of the natural world to keep it viable and flourishing versus human needs.
An excerpt.
Bay, delta habitats suffer big declines Most of 39 species studied have lost half of original populations
David Perlman, Chronicle Science EditorFriday, November 3, 2006
For more than a thousand years the waters of San Francisco Bay and the rivers that feed the delta have been losing critical species of fish, wildlife and plants, and the loss rate is steadily increasing today, say marine biologists.
Records from the bay's history, combined with findings by archaeologists, reveal a "disturbing trend of species depletion and collapse, and a decline in habitats," said Heike Lotze, a specialist in historical ecology at Dalhousie University in Halifax, Nova Scotia.
Lotze and her colleagues studied long-term trends in 39 species of marine mammals, birds, fish, shellfish, plankton and plants around the bay, the Sacramento-San Joaquin River Delta and the rivers that feed the delta, tracing their population trends back for 1,000 years.
They found that more than 90 percent of the original water-dwelling species in those waters have lost at least half their populations, and a third of those populations collapsed close to extinction before their numbers partially recovered in more recent times.
"This has been going on for centuries," Lotze said in a telephone interview, "and the problem has become increasingly critical in the past 150 years -- since the Gold Rush sent huge quantities of silt down the rivers and into the delta."
