Talk about a wild ride.

Every year, millions of fish make a strange and harrowing detour through the Skinner Fish Facility, part of the State Water Project’s facilities in the Delta.

In my last post, I wrote about my visit to the Banks Pumping Plant, whose giant pumps slurp water from the Delta to help quench California’s thirst. As the volumes of water are sucked up, both resident and migrating fish come along for the ride. The Skinner Facility, in operation since 1968, was built to protect fish from being killed at the pumps–an effort that sadly is not as successful as one would hope (more on that below).

I was amazed to learn there is a whole art and science to fish screens, which range from physical barriers–called positive barriers–like perforated plates or wire mesh, to behavioral barriers like sound, light, or other stimuli aimed at keeping fish away. Well-designed screens minimize both entrainment (fish being pulled into the pump or diversion) and impingement (fish being trapped or injured against the screen itself due to water velocity).

Both physical and behavioral barriers are used at the Skinner Facility. Fish being pulled toward the pumps first encounter a trash rack that diverts many bigger fish, along with floating debris. Next, fish encounter a large, v-shaped array of metal louvers. The louvers create turbulence that functions as a behavioral signal, encouraging the fish to swim away into bypass pipes that function, as our tour guide put it, like “a big vacuum system.”

From the bypass pipes fish travel to another set of louvers and pipes, concentrating them into a smaller volume of water, and then into holding tanks in a nearby warehouse. Giant, suspended cone-shaped buckets are used to periodically sample the fish, which are identified, counted, and measured. Some 90 species turn up in the facility, including Chinook salmon, steelhead, white sturgeon, and delta smelt. (I asked our guide if delta smelt really do smell like cucumbers. He confirmed it. In fact, when a school of smelt comes through–an event that has become rare–the warehouse smells “like a salad.”) When enough fish have been collected, they are loaded into trucks and driven back to the Delta.

Here’s the rub. Many fish caught in the pull of the pumps are lost to predation before even reaching the screening facility. Then, the facility does not effectively screen fish smaller than about 1.5 inches, meaning that littler, less powerful species and juveniles are still vulnerable to the pumps. For the fish that make it to the holding tanks, the process is such a trauma–with big and little fish squashed together in the tanks, buckets, and trucks–it’s no surprise there are casualties; in fact, the delicate delta smelt often do not survive. And even for fish that make it through the entire process and out the other end, there’s a final, fatal hurdle: the trunks routinely dump salvaged fish at the same locations, where more predators have learned to cluster for a free lunch.

Scientists agree that the loss of fish at the huge state pumps–and other pumps and intake pipes throughout the Delta–is a major contributor to plummeting populations. How much water we use makes a difference: The higher the export rates, the more fish are entrained. There also is broad consensus that more state-of-the-art fish screening facilities are needed. That could come with a hefty price tag. But with our fish disappearing, can we afford not to invest in their survival?

First things first: If you swim in the bay, no need to worry about sharks. None of the experts we spoke to could remember a single instance of someone getting bitten. And you can rest easy about Great Whites too; they don’t seem to have a taste for Bay waters. For more on this, see the Aquarium’s Chris Spaulding’s blog post.

The San Francisco Bay is much more of a mystery to scientists than I, at least, had realized. Why? It’s simply too hard to peer into. There’s no point in scuba diving. The bay is thick with sediment, much of it a legacy of gold mining explosions in the Delta. So if you want to know what’s swimming around in those murky waters, you have to go fishing.

At first glance, this struck me as both laborious and tough on the animals – catch and release may spare lives, but not without putting a lot of stress on whatever’s on the other end of the line. But when you think about how heavily we humans use the bay – sewage leaks, oil spills, urban runoff, coastal development — it becomes clear we have to take a closer look at how its inhabitants are faring. Sharks are at the top of the food chain, which means they’re a great indicator of how everything underneath them is doing.

Of course, tagging is only worth the effort if you catch enough animals to have meaningful data – which means this project requires tenacity on the part of Aquarium researchers. For updates (as well as info on what to do if you catch a tagged shark) check out the Aquarium’s website. Also, here’s the radio piece we did on the same project.

Watch the “Cool Critters: Sharks of the Bay” TV Story online, as well as find additional links and resources. Also don’t miss our behind-the-scenes photos for this story.

Amy Standen is a Reporter for QUEST and Radio News at KQED-FM.

This year the federal Endangered Species Act (ESA) will celebrate its 35th anniversary. Under the ESA over 1,350 species are listed in the United States as threatened or endangered, including over 300 in California. This includes a number of “celebrities” of the conservation world such as the humpback whale and California condor, but also dozens of much more low profile species. Around our offices, we have a particular soft spot for the California freshwater shrimp (Syncaris pacifica), the impetus for our Students and Teachers Restoring a Watershed (STRAW) Project).

The California freshwater shrimp is 10-legged crustacean in the family Atyidae.

Found only in a handful of Bay Area creeks, the shrimp is a detritus feeder that prefers glides (calm, slow-flowing sections of streams) with undercut banks, exposed roots, and overhanging vegetation. Adult females produce relatively few eggs-about 50-120-that stick to the mother’s pleopods during winter incubation. The young measure about 6 millimeters and are released in late spring or early summer. They grow rapidly, reaching up to 2.5 inches as adults and ranging in color from translucent to rusty red.

The species’ closest cousin, the Pasadena freshwater shrimp (Syncaris pasadenae), went extinct in the 1930s, leaving the California freshwater shrimp as the only representative of its genus. The California freshwater shrimp was listed under the ESA in 1988. Recently the U.S. Fish & Wildlife Service issued its 5-year review of the shrimp’s status. The report concludes that the species is not ready for delisting, as it still faces many of the same threats as 20 years ago: loss of habit due to agricultural activities and development, water pollution, water diversions-even the construction of recreational summer dams for swimming and fishing.

But there is also good news in the report. At the time it was listed, the shrimp was known from 17 streams; it now has been found in 23. In one of these, the number of shrimp surveyed increased from 1,878 in 1991 to 4,407 in 2000. Many of the streams in which the shrimp is found have watershed management plans in place. And the report also acknowledged the ongoing work of STRAW to restore more than 50,000 linear feet of stream bank, creating new habitat for the shrimp-not to mention other native species.

When Congress passed and Richard Nixon signed the ESA in 1973, a little freshwater shrimp was not at the forefront of their minds. But there is an inspiring sense of democracy in the ESA as written: It empowers citizens to petition or sue the government to protect species. And it doesn’t discriminate between the big, showy species and the small and obscure-but equally unique and imperiled-ones.

According to the US Fish & Wildlife Service, since 1973 the ESA has protected 99% of listed species from extinction. National Endangered Species Day is coming up May 16. Find out about ways to help celebrate.

Ann Dickinson is Communications Manager for The Bay Institute (www.bay.org), a nonprofit research, education, and advocacy organization dedicated to protecting and restoring San Francisco Bay and its watershed, “from the Sierra to the sea.”

photo courtesy of the San Francisco Public Utilities CommissionWe’d had “aging infrastructure” on our story lists for some time when we first heard about the sewage spills in Mill Valley. When news came in that not just one, but two sewage spills had poured five million gallons of partially treated wastewater into Richardson Bay, we decided to move that story to the top of the list.

Those spills got a lot of coverage, including by KQED, so our question was a little broader. Were those spills an anomaly? (Answer: No, they were big, but not unusual.) And how does this happen in as eco-conscious a place as the Bay Area? What would it take to stop it?

The two Mill Valley spills seem to have resulted from a few different problems: overwhelmed capacity, failed alarms, operator error, and probably other factors, too. But the underlying cause is the same, and it’s true of many sewage systems in the Bay Area: These systems — the pipes, the digesters, the pumps – are reaching the end of their useful lives. (Some of the older clay pipes were built in the 1850s!) Few cities are jumping to do the necessary upgrades, and who can blame them? What’s less sexy than an expensive, disruptive construction project that takes place mostly underground, out of sight?

Still, as we say in the piece, we’ve done it before. Those who lived in the Bay Area before the 1970s may remember the stench of raw sewage drifting up through the car window as they crossed the Bay. Thanks to the Clean Water Act of 1972, the Bay is vastly cleaner than it used to be and there are far less spills.

So what will it take to get cities to pony up the cash this time around? Baykeeper is taking the issue to the courts – you can read more about their Sick of Sewage campaign here: http://www.baykeeper.org/

You may listen to the “Sewage Happens” Radio report online, as well as find additional links and resources.

Amy Standen is a Reporter for QUEST and Radio News at KQED-FM.