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RRWSS to Sponsor Austin Creek Analog Study

09-Mar-2013

The Russian River Wild Steelhead Society will sponsor a nutrient study in Austin Creek as proposed by Bob Coey of the National Oceanic and Atmospheric Association (NOAA).  The study will monitor the effectiveness of introducing AquaDine Salmon Analog pellets into selected tributaries of Austin Creek in an effort to supplement the food web with additional Marine Dissolved Nutrients (MDN's).  It will involve the addition of  "Salmalogs" into tributaries in amounts based on recent fish counts for those tributaries.  These pellets are engineered to melt in as little as 7 days or as long as 7 weeks, providing some control as to how the MDN's are introduced into the food web.  Similar studies in Oregon and Washington show increased Salmonid returns to streams treated with analogs as the increased nutrient levels provide food for young fry, invertebrates and other organisms within the ecosystem.   In conjunction with habitat restoration, this short-term supplementation of the food web has shown marked increases in the return of spawning salmonids as more young fish survive the early in-stream rearing stages.

When spawning runs were larger, significant numbers of salmon made their way to upstream spawning grounds.  After spawning, these fish would die and their carcasses would decompose, providing valuable nutrients for the aquatic and terrestrial environment.  Since salmon put on most of their weight in the ocean before returning to their freshwater spawning grounds, these nutrients are referred to as Marine Dissolved Nutrients (MDN's).  Of course there are other nutrients found naturally in the freshwater spawning grounds, but it has been found that the addition of MDN's to the food web actually results in higher returns of salmonids to the spawning tributaries.  With the increase of nutrients in the system, more of the young fish survive the early stages of freshwater development.  As Salmonid runs have declined, there are now fewer carcasses in the tributaries and less nutrients in the food web.  As we identify rehabilitation needs, it should be noted that improving habitat independent of similar improvements in food web nutrients could significantly limit the effectiveness of any tributary restoration program.

There have been programs that manually place salmon carcasses into spawning tributaries, but obtaining, storing and handling these carcasses creates significant logistic and health problems.  The "Salmalogs" pellets alleviate the storage and health concerns of handling actual decomposing carcasses.  The pellets are 84% salmon carcass and 16% "porcine" binding agent, a common binder for aquatic uses.  They are distributed by weight into target tributaries based on the observable spawning fish returns for those areas.  The analogs melt at controlled rates, which limits the need to re-apply pellets after the initial distribution.  Analogs are considered a short-term addition to the food web and it is hoped that after two or three years, the percentage of returning salmon to the spawning grounds will increase and begin to naturally provide decaying carcasses to the system.The Russian River Wild Steelhead Society will assist Bob Coey and NOAA in the distribution of the Salmalogs in selected tributaries of Austin Creek.  NOAA will then monitor fish counts, water chemistry, nutrient levels and all effects of the analog pellets within each tributary and downstream.  Returning spawning adults will also be monitored to determine any increase or decrease over time.   This program monitoring will take place over a number of years to determine the potential effectiveness of an analog program in the Austin Creek watershed.  There is successful precedent for this program and similar analog programs have proven successful in spawning streams in both Oregon and Washington, especially when augmented with habitat restoration programs.