I read with disappointment Bruce Maiman’s op-ed (“Another fish tale mucks up debate over the Stan,” Page D3, April 26). His investigation into the “muck” on the release of 27,000 acre-feet of water from New Melones Reservoir to benefit 29 steelhead trout on the Stanislaus River did little to clear up these muddied waters.
So just the facts in response.
If Maiman had asked the fish experts he talked to, “What is the scientific basis for the pulse-flow releases, and by scientific basis we mean, what are the peer-reviewed and published journals or papers that support the premise that spring pulse flows will make or encourage resident trout to become steelhead?”
The answer is none.
Sign Up and Save
Get six months of free digital access to The Modesto Bee
Shocking for anyone in the business of science to do something not supported by science.
The Oakdale and South San Joaquin irrigation districts produce all the scientific data used by federal and state agencies regarding fisheries on the river. Based on actual monitoring data, the number of O. mykiss adults (trout greater than 16 inches) migrating upstream through the weir over the last seven years has ranged from 2 to 17, and averaged six. If you include 30 hatchery fish with adipose fins clipped and eight classified as unknown, the seven-year average is 12, not 29. In fact, without close evaluation of the scales, it’s unknown how many of the O. mykiss are actually steelhead.
In business management, it’s your “yield” compared to your “inputs” that determines success. When a farmer plants a field of tomatoes, he harvests those tomatoes and trucks them to the cannery for processing. He is paid based on the weight of tomatoes on those trucks. What’s left in the field is immaterial to the check he’ll receive from the cannery. Those lost tomatoes are considered a management loss.
Fisheries management, apparently, operates on a different paradigm. The 27,000 acre-feet (8.8 billion gallons) is apparently sent down the river to flush out “several hundred to 1,000 fish to the ocean.” The fishery people say this is the benefit, and that is good.
However, we in business see the return on investment for 27,000 acre-feet (input) as being done to yield annually about 29 returning steelhead trout. In a business analysis, it takes nearly a 1,000 acre-feet (326 million gallons) to produce one returning steelhead trout. That’s enough water for 1,000 Valley families for an entire year in order to “produce” one fish.
These pulse flows were not used for broader multiple environmental benefits, as Maiman claims. The Bureau of Reclamation’s notice indicates specifically that these pulse flows were to move fish, nothing more.
Maiman’s use of a “university expert” to casually dismiss predation as a primary reason for fewer fish is in direct conflict with the National Marine Fisheries Service’s 2009 “Recovery Plan” for the Central Valley steelhead populations. In that document, NMFS identifies predation as a “very high stressor” to steelhead recovery. If you want to know about successful predator suppression programs, Google “Predator Suppression-Columbia River Basin.”
Knell is general manager of the Oakdale Irrigation District.