I spent Wednesday in Sacramento, listening to federal and state fish biologists and water managers talk about the Delta smelt--an endangered fish sometimes described as a "minnow"--what they're learning about species, and how to keep it from being pulled into the pumping facilities that send water to the great farms and cities to the south. I am a sucker for terminology and argot, and the session was full of it. A few key terms and some that just sort of tickled me:
Entrainment. That's the process whereby currents created by the state and federal pumps capture smelt (and juvenile salmon and other species) and slowly draw the fish toward them.
Turbidity. Simply put, cloudiness of water. It's a hot topic in smelt circles. A consultant for one of the big San Joaquin Valley water contractors repeatedly expressed the thought that since smelt are believed to prefer turbid (cloudy) water, reduced turbidity in the area near the pumps--meaning clearer water--is probably responsible for the decline or absence of the fish there.
YOY. Year of young; fish born during the current year.
WOMT. (Pronounced "whomped.") Water Operators Management Team.
CHTR losses.Fish mortality caused by "capture, handling, transport, and release." CHTR happens when fish are entrained, drawn toward the pumps, and "salvaged" at a "fish facility" adjacent to one of the pumping plants. Depending on the species, they're then trucked someplace in the western reaches of the Delta to be released.
PEI. Potential Entrainment Index. A statistic method for forecasting times and circumstances when smelt may be sucked toward the pumps.
X2. From a paper on the delta smelt habitat: "the distance in kilometers from the Golden Gate to the position of the 2 percent salinity isohaline." (From elsewhere: "Isohalines are lines (or contours) that join points of equal salinity in an aquatic system.")
And I could go on. But as a non-scientist, non-engineer, layperson, here's what struck me in the discussions: How much uncertainty exists about the smelt--where it is, how it gets from one place to another, its spawning behavior. Of course, this mattered less when the Delta was full of smelt, and it was probably studied much less intensively than it is now. Now that the fish may be going extinct, it's harder to study and get answers that may help preserve it.
I checked my impression about the uncertainty with a biologist at the meeting. They said, "That's the elephant in the room--the uncertainty. When scientists meet with each other, they're more open about it. In a public setting, they tend not to want to get into that."
