"An informed citizenry is the only true repository of the public will."

                                                                                                                          - Thomas Jefferson

San Franciscans sure are good at reusing Ziploc bags and tin foil, but could do a lot better when it comes to turning off the water when we brush our teeth.

Those are some of the findings of the second annual Nalgene   Least Wasteful Cities Study, ranking us the least wasteful city in the country for the second year in a row. Other cities that fared well were Seattle , New York , Portland and Boston , while Houston was at the bottom of the trash heap.

San Franciscans are tops when it comes to recycling, taking public transportation, using rain barrels, never driving our cars for trips that are less than a mile from home, participating in sustainability programs and, yes, reusing bags and foil.

But we lag far behind other cities in turning off the water while we're brushing our teeth and throwing out fewer than two bags of garbage weekly. The study found that 43 percent of San Franciscans are "extremely concerned" about the environment and 45 percent are "fairly concerned."

Asked to assign grades for environmentalism, San Franciscans gave themselves and City Hall a B. They gave their friends, their companies and their country a C.

San Francisco 's high rankings:

• 1st Recycling glass/metal/plastics on a regular basis
• 1st Taking public transportation
• 1st Using rain barrels
• 1st Never driving their car for trips that are less than one mile from home
• 1st Using reclosable bags and tinfoil  
• 1st Participating in their city’s sustainability/environmental programs
• 2nd Using reusable containers in place of disposable food storage items such as plastic  
• 2nd Limiting showers to five minutes
• 2nd Reusing wrapping paper and ribbons
• 2nd Hanging their clothes out to dry when possible
• 2nd Borrowing books from the library (or buying used) rather than buying them new
• 2nd Buying bulk food to avoid extra packaging
• 3rd Using reusable bottles in place of single-serve bottles of water/soda/other beverages
• 3rd Composting fruits and vegetable scraps
• 3rd Saving leftover food/meals to eat again

The Gulf of the Farallones National Marine Sanctuary is asking visitors to avoid the Bay Area's coastal cliffs and offshore rocks, where breeding season has started for thousands of seabirds and disturbances could disrupt their nests and threaten their eggs.

Cormorants and Common Murres are laying eggs there and preparing to rear their chicks; Western Gulls, Tufted Puffins and Pigeon Guillemots will soon follow, said Mary Jane Schramm of the sanctuary.

Many seabirds spend most of their lives at sea, but they come ashore when spring arrives to nest in dense breeding colonies that can number in the thousands, Schramm said.

Boaters, fishermen, wildlife enthusiasts and pilots of small aircraft should avoid coming close as disturbances can cause them to abandon their eggs or neglect their chicks, she said.

Some of the major nesting colonies of seabirds in the Bay Area are Bodega Head, Tomales Point, Point Reyes and Point Bonita in Marin County ; Land's End and Seal Rocks in San Francisco , and San Pedro Rock and Devil's Slide in San Mateo County .