Spawning adult salmon on the Stanislaus River – the linchpin of what irrigation districts within the Northern San Joaquin Valley describe as a massive water grab proposal by the state – have increased by a factor of five since 2007 when work started on the 3,500-page State Water Control Board plan.
Research data shows spawning numbers in 2015 were the 12th highest since 1950. How that is tied into hatchery practices, predators, and water temperatures and how they collaborate with surviving juvenile fish forms the foundation of the South San Joaquin Irrigation District’s – and that of its Stanislaus River partner the Oakdale Irrigation District – scientific argument against the state plan.
The state plan calls for commandeering 360,000-acre feet of water between February and June each year to bump up the unimpaired flows on the Stanislaus, Merced, and Tuolumne rivers to 40 percent. The state contends that will lead to a maximum of 200 more fish on each of the three rivers on an annual basis.
In exchange roughly 240,000 acres of farmland will be permanently fallowed under drought conditions that exist today. As a result, 2,000 to 3,000 jobs tied directly to agriculture would vanish, and annual losses to the economies of San Joaquin, Stanislaus and Merced counties will hit $260 million.
The plan that will deliver those consequences if it is implemented is the subject of a public input meeting this Friday, Dec. 16, at 9 a.m. at the Stockton Civic Auditorium.
“We (the SSJID and OID) are saying the state needs to look at the data and consider other solutions that will actually work,” said SSJID General Manager Peter Rietkerk.
Those solutions center on hatchery management, better timing and more restrained water release strategies, and restoring habitat.
State hasn’t done fish research on Stanislaus
FISHBIO – a fisheries research, monitoring and conservation firm employing scientist engineers and technicians with offices in Oakdale, Chico, and Santa Cruz – has been conducting extensive monitoring and research of young rainbow trout on the Stanislaus River that have the potential to become steelhead when they migrate to the ocean since 2009. OID also invested $1.1 million in habitat improvements at Honolulu Bar in 2012 while funding the research along with SSJID. The state hasn’t done fish research or undertaken spawning area restoration efforts on the Stanislaus.
The scientists have collected data they contend discredits the prevailing strategy of state and federal agencies to release more water from Melones Reservoir earlier in the year on the assumption “more flow equals more fish.” The government water managers have not provided research data to back up their working theory that has resulted in tens of thousands of acre feet of water being released resulting in no measurable impact on rainbow trout population. The early releases, particularly in the current drought, have had detrimental impacts on urban, farm and even environmental uses of stored water.
Between 2009 and 2014 FISHBIO estimated there were about 20,200 rainbow trout in peak years in the Stanislaus River. During that time the numbers never dipped below 14,000 fish. This abundance is due in part to high-quality habitat, particularly in Goodwin Canyon east of Knights Ferry, where fast-moving water, boulders and other features offer a diversity of hiding places and food for the fish. However, in 2015 the number of trout counted per river mile dwindled in the canyon by about 80 percent.
The reason for the drop in numbers was traced by FISHBIO data and research to the timing of releases from New Melones as well as predators.
FISHBIO noted the average daily water temperature in the Stanislaus River reached 69 degrees Fahrenheit at Knights Ferry in August 2015, which is higher than any summer water temperature recorded since 1998. These warm temperatures were related to the exceedingly low water level in New Melones Reservoir (upstream of Tulloch and Goodwin dams), which was then at 12 percent of capacity. Trout and salmon prefer cooler water. So to protect these fish, FISHBIO scientists say the reservoir should ideally be managed to maintain a reserve of deeper, cold water. However, by summer 2015, the level of the reservoir had dropped too low for the water to remain cool, so the water released from New Melones was warm during that summer. This likely had serious consequences both for trout living in the river and for eggs they laid during the winter.
FISHBIO notes that “with the exception of extremely high flows that were released for flood control in 2011, water temperature has played a much bigger role than river flow in determining rainbow trout abundance – so much so that rainbow trout have declined even though flows have been relatively high in recent years, because water released from the reservoir has been too warm.”
Salmon were born on other rivers
Meanwhile fish populations are on the upswing this year on the Stanislaus despite the drought.
Rietkerk noted that research has found that most of the fish did not originate from the Stanislaus River but rather nearby rivers underscoring the argument the fish will find their way to rivers that are managed properly without the need of a massive uptick in releases.
That goes against the theory many hold that the basic salmon lifecycle comprises of traveling from river to ocean and back to the same river. FISHBIO scientists believe that almost all of these returning fish were not actually born on the Stanislaus River, but instead came from hatcheries either on the Merced River or in the Sacramento River basin.
The state plan that’s the subject of Friday’s hearing mandates that more water be left in reservoirs year round as cold water pools for fish. It calls for New Melones Reservoir that has a 2.4 million acre foot capacity to go no lower than 700,000 acre feet of water at any given time. New Melones on Friday was at 535,561 acre feet of water. That means had the state plan be in effect, water releases to SSJID and OID likely would have stopped in June this year to avoid the reservoir from dropping as low as it has.
The state also wants a permanent cold water pool of 800,000 acre feet at Don Pedro (39 percent of capacity) and 300,000 acre feet at McClure Lake (29 percent of capacity).
Districts urge other methods to help fish
Rietkerk said the state is sidestepping the issue of non-native fish that are aggressive predators of native fish such as the steelhead.
The SSJID general manager points to how increasing the limit and lowering the size of non-native predators that fishermen catch has helped endangered salmon and steelhead on the Columbia River in the Pacific Northwest to enjoy higher survival rates.
The bag limits of non-native predators such as bass, walleye, and catfish were removed and the size of the allowable catch decreased first by the Washington Fish and Wildlife Commission in 2015. Earlier this year the Oregon Department of Fish and Wildlife followed suit to coordinate with Washington’s efforts to protect endangered salmon and steelhead.
The SSJID and OID support a petition currently before the Department of Fish and Game Commission to implement the same tools in California to help the federally protected salmon and steelhead.
The requested fishing regulation changes are as follows:
* BLACK BASS: Decrease the size limit from 12 inches to 8 inches while increasing the daily bag limit from 5 fish to 10 fish.
* STRIPED BASS: Decrease the size limit from 18 inches to 12 inches while increasing the daily bag limit from 2 fish to 6 fish.
The Coalition for a Sustainable Delta notes the predation of the endangered native salmon, steelhead and smelt by non-native species is “well documented” and is a major contributing factoring to their dwindling numbers. They cite a 2011 DFG report that concluded “studies of striped bass feeding habits indicate they consume an enormous volume of fish, overlap in their geographic range with the listed species (the endangered Delta smelt, Chinook salmon, and Central Valley steelhead), and have historically consumed listed species, at times in very substantial quantities.”
Studies by FISHBIO biologists on the Stanislaus River reaffirm the DFG’s conclusion about the impact non-native fish are having on endangered fish species.
Experts for the coalition have noted water policies involving the Delta put in place in 2003 set the stage for the steady decline of threatened species in the Delta. Since then state regulators have narrowly focused on increased flows and water pumping restrictions while essentially ignoring predation.