The final day of the symposium focused on the physical environment that underpins the complex riparian and aquatic river ecosystem. We learned that while the Trinity River is actually used as an example for successful implementation of a functional flows approach to streamflow management, we are still missing some key components of a functional flow hydrograph that are essential to optimizing the physical and ecological processes of the river.

Contrary to the prevailing folk wisdom in salmonid streams that all fine sediment in salmonid streams is bad, it was revealed that having too little fine sediment can impede the movement of larger gravels, and that having river flows match tributary flows is important to moving fine sediment in a way that is healthy for the river, rather than harmful. There were insights about what we know about how gravel routes through the upper river and what that means for our approach to sediment augmentation. A uniquely interdisciplinary presentation focused on how flow management influences where riparian plants grow, spurring conversation about how varying base flows could promote willow growth across different active channel widths, which could provide roughness and improve sediment sorting and storage. The takeaways really came down to this; we can’t have healthy fish and other wildlife populations without process, and we have learned a lot about how to improve those processes.

The panel discussion at the day’s conclusion was moderated by SAB member John Buffington, Ph.D.. The questions from the audience were stimulating and the panelists conversation informative. The discussion can be viewed in its entirety by clicking the YouTube link below.

Presentation videos are being edited to include presenter slides – we will be uploading them to the 2024 Science Symposium page as they become available. For a list of power point presentations, please click here.

Day two of the 2024 Trinity River Restoration Program Science Symposium was intended to explore the function of the Trinity River and other lotic (rapidly moving fresh water) systems. With an emphasis on creating a common understanding that can be applied to management in the future. Much has been learned in the relatively young field of river restoration over the last few decades, and leveraging that learning is critical to successful restoration in our watershed and others.

The day started with new TRRP Science Advisory Board member and world renowned researcher, John Hayes, Ph.D.. Dr. Hayes presented on his work with salmonids in New Zealand to describe their flow requirements through numerical modeling of drifting macroinvertebrates and drift foraging behavior. These innovations have changed the way managers think about the effects of flow management on salmonid populations. 

We had additional talks on temperature and thermal diversity from Eli Asarian (Riverbend Sciences) Klamath Basin water temperature expert along with Todd Buxton, Ph.D. (TRRP) a physical scientist and an accomplished fisheries researcher. We heard from regional reptile and amphibian expert, Don Ashton (McBain and associates) about the decades of research on the Trinity River and the impacts that flow management have had on these important indicator species of ecosystem health.

Finally, we heard from Seth Naman, currently with NOAA Fisheries and long time Klamath Basin Fisheries researcher, and Derek Rupert, currently with Reclamation and former USFWS Fisheries Biologist on the Trinity River, about 2 proposed methods to manage flow releases year-round on the Trinity River and Clear Creek respectively. These proposed methods rely on seasonal and annual patterns of run-off to restore the functionality of the river to that which the species evolved with to ensure reproductive success and productivity.

Together this suite of talks described our current understanding of how cold-blooded species feed and behaviorally regulate their body temperature in regulated and unregulated rivers. As well as the known and suspected impacts of flow and temperature management and proposed methods to reduce impacts and improved function of the environments we seek to restore.

The panel discussion at the day’s conclusion was moderated by SAB member and Fisheries Researcher from Canada, Andy Paul, Ph.D.. The conversation was stimulating and informative and can be viewed in its entirety by clicking the YouTube link below. The direct communication between SAB members, scientists within the Program, managers, and the public is critical to moving management forward together to benefit the resource for all.

Presentation videos are being edited to include presenter slides – we will be uploading them to the 2024 Science Symposium page as they become available. For a list of power point presentations, please click here.

The first day of the 2024 Trinity River Restoration Program Science Symposium was a great start to the week. Science Advisory Board members Kurt Fausch, Ph.D. and Andrew Paul, Ph.D. (link to bios) started the day by sharing their sage wisdom from decades of scientific practice and learning.

Next, Dr. Paul rounded out the morning with a lesson on study design and a cautionary tale on how good intentions can sometimes lead us astray, while sound, well formulated sampling designs can buffer against unintended missteps.

The rest of the afternoon was dedicated to a short list of the challenges that juvenile salmonids face in their journey to the ocean and back. Chad Martel of the Hoopa Valley Tribal Fisheries Program described a multiagency, multiyear study of juvenile outmigration survival from Lewiston Dam to the Klamath River Estuary, where survival has so far shown to be higher than most area biologists expected.

Dr. Nicholas Som from US Geological Survey and Cal-Poly Humboldt taught us about the fish parasite Ceratanova shasta, the history of learning in the Klamath basin, and successes in translating scientific discovery into water management implementation.

Finally, renowned ocean fish ecologist Nate Mantua, Ph.D. from the National Oceanic and Atmospheric Administration provided a glimpse of insight into the complex world of Pacific Ocean circulation patterns, tropical teleconnections, coastal upwelling, food web dynamics and the perils and opportunities that face young salmon as they survive, die, grow and mature to return to the Klamath river and complete their lifecycle.

The evening was rounded out with a panel discussion held at the Lewiston Hotel, Restaurant and Dance Hall which was moderated by Science Advisory Board member John Hayes from the Cawthron Institute in New Zealand. The 90-minute discussion provided insightful questions and educational dialogue between attendees and panelists and we thank everyone who was able to participate.  

Presentation videos are being edited to include presenter slides – we will be uploading them to the 2024 Science Symposium page as they become available. For a list of power point presentations, please click here.