Thursday May 28, 2026
Maven’s Notebook —
About a decade ago, researchers at the University of California, Davis made a surprising discovery while teaching a class in Suisun Marsh, the largest contiguous brackish wetland on the west coast of North America. While most of the Bay-Delta is a food desert for fish, the marsh offers a smorgasbord of zooplankton, the tiny creatures that fish eat.
“They said, ‘There’s crazy amounts of plankton in here, what’s up with that?” says Kyle Phillips, a UC Davis Center for Watershed Sciences researcher.
Phillips found that the answer lies in the wetlands managed by duck clubs in Suisun Marsh. Duck clubs account for about half of the 115,000-acre marsh, which also includes tidal wetlands, bays and sloughs. Managed wetlands are diked, shallow ponds with mechanisms that control water flows to and from neighboring waterways.
A new study Phillips led shows that when these managed wetlands are flooded for migrating waterfowl, they produce far more zooplankton than nearby tidal wetlands. This fish food peaks in the winter, which is perfect timing for baby Chinook salmon migrating towards the ocean.