Pubblicazione scientifica

Evaluation of a large-scale flow manipulation to the upper San Francisco Estuary: Response of habitat conditions for an endangered native fish

FILONE TECNOLOGICO	TEMA
economia circolare e sostenibilità

RIASSUNTO

While flow is known to be a major driver of estuarine ecosystems, targeted flow manipulations are rare because tidal systems are extremely variable in space and time, and because the necessary infrastructure is rarely available. In summer 2018 we used a unique water control structure in the San Francisco Estuary (SFE) to direct a managed flow pulse into Suisun Marsh, one of the largest contiguous tidal marshes on the west coast of the United States. The action was designed to increase habitat suitability for the endangered Delta Smelt Hypomesus transpacificus, a small osmerid fish endemic to the upper SFE. The approach was to operate the Suisun Marsh Salinity Control Gates (SMSCG) in conjunction with increased Sacramento River tributary inflow to direct an estimated 160 x 106 m3 pulse of low salinity water into Suisun Marsh during August, a critical time period for juvenile Delta Smelt rearing. Three-dimensional modeling showed that directing additional low salinity water into Suisun Marsh (“Flow Action”) substantially increased the area of low salinity habitat for Delta Smelt that persisted beyond the period of SMSCG operations. Field monitoring showed that turbidity and chlorophyll were at higher levels in Suisun Marsh, representing better habitat conditions, than the upstream Sacramento River region throughout the study period. The Flow Action had no substantial effects on zooplankton abundance, nor did Suisun Marsh show enhanced levels of these prey species in comparison to the Sacramento River. Fish monitoring data suggested that small numbers of Delta Smelt colonized Suisun Marsh from the Sacramento River during the 2018 Flow Action. Comparison of the salinity effects of the Flow Action to historical catch data for Suisun Marsh further supported our hypothesis that the Flow Action would have some benefit for this rare species. Our study provides insight into both the potential use of targeted flow manipulations to support endangered fishes such as Delta Smelt, and into the general response of estuarine habitat to flow management.

DATA

Data di pubblicazione: 01/10/2020

AUTORI

SOMMER TED
HARTMAN ROSEMARY
KOLLER MICHAL
KOOHAFKAN MICHAEL
CONRAD J LOUISE
MACWILLIAMS MICHAEL
BEVER AARON
BURDI CHRISTINA
HENNESSY APRIL
BEAKES MICHAEL

ENTE DI AFFERENZA

CALIFORNIA DEPT WATER RESOURCES SACRAMENTO CALIFORNIA USA
DELTA SCIENCE PROGRAM SACRAMENTO CALIFORNIA USA
ANCHOR QEA LLC SAN FRANCISCO CALIFORNIA USA
CALIFORNIA DEPT FISH & WILDLIFE STOCKTON CALIFORNIA USA
US BUREAU OF RECLAMATION SACRAMENTO CALIFORNIA USA
CTR INVESTIGACION CIENTIFICA Y DE EDUCACION SUPERIOR DE ENSENADA DIVISION DE FISICA APLICADA MEXICO

RIVISTA

PLoS ONE, 15(10), e0234673

IMPACT FACTOR

2,870

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