In 2017, the East Bay Municipal Utility District (EBMUD)
reported that a modern record of more than 19,900 fall-run Chinook salmon had returned to spawn in the lower Mokelumne. The 2018 fall salmon returns were also impressive, with a total return of 17,474 fish. When one considers that in 2009, fewer than 400 fish returned to the Mokelumne, it’s clear that tremendous progress has been made in recent years.
In a March press release , Jose Setka, EBMUD Manager of Fisheries and Wildlife, said, “The best news is the amount of natural spawning we are seeing. This year the in-river spawning population of 10,194 salmon resulted in a record 2,432 redds or nests. To date, the number of naturally produced juveniles that have left the river is more than 2.8 million. The strategies we are implementing are working, and the Mokelumne River is a welcoming home where salmon can survive and thrive.”
The press release also noted that while the Mokelumne is among the smallest Delta tributaries, in 2018, Mokelumne salmon “comprised approximately 43 percent of the commercial and 33 percent of the recreational catch off the coast of California.”
We applaud EBMUD’s efforts to ensure a sustainable fishery on the Mokelumne. We also appreciate the agency’s cooperation and support in the Foothill Conservancy-led effort to explore whether fall-run Chinook salmon can be restored to the Mokelumne upstream of Pardee Reservoir. We reported the results of a related habitat study in our late fall 2017 newsletter, and finally were able to release the study results this winter.
The study shows that 13.7 miles of Mokelumne River above Pardee have the potential to support both spawning and rearing of chinook salmon. The next step in exploring this potential will be a pilot project, likely reintroducing a small number of salmon upstream of Pardee Reservoir.
“East Bay MUD and the California Department of Fish and Wildlife have done a great job of increasing the salmon population in the lower Mokelumne River through the operation of the Mokelumne River Fish Hatchery,” said Foothill Conservancy Vice-President Pete Bell. “For more than eight years in a row, the number of salmon returning to the hatchery exceeded its capacity. Those ‘excess’ fish could be available for direct reintroduction into the upper watershed without reducing the hatchery production. This new study shows that we may be able to return some of the returning salmon to their historic spawning habitat in the upper Mokelumne for the first time since Woodbridge and Pardee dams were built early in the last century.”
“This is an important step in the ongoing effort to restore the Mokelumne salmon fishery,” said Chris Shutes, a consultant for Foothill Conservancy. “Now that we have this data, we can start to design a pilot reintroduction project.”
The study also points out that the reintroduction of salmon to historical habitats on the Mokelumne may have significant cultural, economic and ecological benefits. Spawning salmon also attract people for viewing, which could bring economic benefits from ecotourism. In addition, the scientists point out that reintroducing salmon to the watershed could provide positive ecosystem-level impacts by restoring marine nutrients to the river and watershed and food for scavenging wildlife.
The Upper Mokelumne Salmon Restoration Team has been working diligently to develop the science and engage multiple stakeholders and agencies to help move this process from planning to implementation, according to Michelle Workman, Supervising Fisheries Biologist for East Bay Municipal Utility District. “We look forward to continuing this valuable collaboration for the benefit of the Mokelumne River fishery and for the enjoyment of a renewed public trust resource in the river above Pardee Reservoir.”
The salmon habitat study was funded by grants from the Lower Mokelumne River Partnership and the Firedoll Foundation. You can find a copy online .
For more information, contact Chris Shutes at 510-421-2405 or Michelle Workman at 209-263-6368.