Salmon Return Numbers: August – September 2024

Through SYRCL’s participation in the River Management Team (RMT), our staff receives monthly updates on the number of Chinook and steelhead adults utilizing the fish ladders at Daguerre Point Dam. This information is collected using VAKI River Watcher camera systems installed in the North and South ladders, which snap a photo every time a fish swims past it. 

It is important to recognize that passage numbers at the fish ladders are just one piece of the puzzle that helps us understand the population of adult salmon returning to spawn in the lower Yuba River. Data from redd and carcass surveys are also collected and plugged into models that will produce a more accurate population estimate of adults that make it to all stretches of the lower Yuba River. Further complicating the VAKI reporting data this season is that the system on the south ladder has been functional for less than 15% of the time since the beginning of the reporting period in March. On average, about 3% of the fish that make it past Daguerre Point Dam use the south ladder.   

Taking A Look At The Numbers  

Chinook salmon numbers are off to a pretty good start between the beginning of “salmon season” in March, through the end of September with about twice as many Chinook passing through the ladders compared to last year. We can assume that the majority of these individuals are actually spring-run, which are the threatened strain of Central Valley Chinook, due to their migration timing in the summer months. It is possible that the passage number is even higher given the frequency with which the south ladder’s camera system wasn’t working. 

As water temperatures cool, we hope to see a busy October, welcoming fall-run Chinook back to the Yuba River and up the fish ladders. Those fish are traveling upstream and many of them are choosing to utilize the recently completed spawning gravel project at Rose Bar. Our first survey was conducted just two weeks after construction equipment was pulled out of the water, and a total of 5 fresh redds were counted and measured in brand new habitat. For comparison, in the two years of pre-project monitoring we only saw 2 redds total. Since the initial surveys in September, our staff and partners have observed new redds nearly every time the site has been visited.

Formal October redd surveys will occur this week, so stay tuned for new numbers! 

What Is The RMT?  

The RMT is a group of agency and non-profit representatives that work together to better understand and promote research on the Lower Yuba River. Members of the RMT include SYRCL, Yuba Water Agency, US Fish and Wildlife Service, State Water Resources Control Board, Dept of Water Resources, Pacific States Marine Fisheries Commission, CA Dept Fish and Wildlife, National Marine Fisheries Service, HDR (a private engineering firm), and the US Army Corps of Engineers. The RMT helps fund restoration, monitoring, and make science-informed decisions for the Lower Yuba River.     

The RMT funds Pacific States Marine Fisheries Commission to provide the fish count updates, among many other monitoring tasks on the Lower Yuba River. They do so through the use of VAKI River Watcher camera systems. These cameras are located in the fish ladders at Daguerre Point Dam and take a picture of each fish (or otter) that swims past them. Specialized software then identifies what species the fish is, and biologists later confirm it. This process gives us a count, reported monthly during the RMT meeting, of the number and species of fish traveling up the Yuba.