Despite an unusually high Delta outflow last year, the California Department of Fish and Wildlife’s annual fall smelt survey found only two fish. The outcome was disappointing to say the least. It’s time for a wake-up call.
The lackluster results of the Fall Midwater Trawl (FMWT) Survey should be a red flag.
Red flag #1: A separate survey taken in December, where researchers took samples closer to the surface, turned up three times the number of smelt as the FMWT survey. It may be time to reexamine the effectiveness of this survey and the survey methods beings used.
Red flag #2: Delta management strategies have clearly failed to produce results. How much longer will we continue to rely on flow-only measures before addressing non-flow stressors?
As we documented last year, more flow has not helped any of the endangered fish populations in the Delta. As the chart below shows, minimum flow requirements have not improved smelt population levels. Wet years also do not seem to correlate to population increases when you compare the FMWT survey results to recent wet years including 2005, 2011 and 2017.
Regulators must do more.
There are a host of other stressors that need to be addressed in the Delta, including non-native predators and habitat loss. Instead, state agencies like the State Water Resources Control Board continue to focus almost solely on increasing flow. Proposed policies like the Water Quality Plan update, that would increase unimpaired flows by historic proportions, are not the answer.
After the latest smelt survey results, the lowest on record, it should be clear to decision makers that current management strategies are not working. It’s time to take a serious look at the scientific methods being used in the Delta and focus on habitat and other stressors, such as predation that plague the Delta. Time is running out.