Celebration of success – upgraded shellfish beds in Henderson Inlet

In the last talk of the day Linda Hofstad from Thurston County told a story of success in the effort to improve water quality and upgrade shellfish beds in Henderson Inlet.   After 26 years of over 650 acres of shellfish beds degraded in Henderson Inlet the situation is now turning around and shellfish beds are now being upgraded.  She identified some primary keys to their success:

  • an organized process that addressed local people’s concerns and developed a plan with priority actions.
  • a risk based organized approach to inspection of septic systems – a major target of the effort to address water qualtiy
  • incentives and assistance provided to local homeowners with septic systems including rebates, low interest loans, grants and workshops to help landowners address problem septic systems.

The result of this focused cooperative effort has been the upgrading of shellfish beds in Henderson Inlet.

Large scale analysis of a restoration strategy for South Sound nearshore

A large scale analysis of landform types and restoration opportunities identified 2 major river deltas (Nisqually and Deschutes) ,  144 coastal inlets, 179 barrier embayments, and 288 beaches in the South Puget Sound.   Paul Cereghino from NOAA explained that these different types of nearshore habitat were then examined looking at both degradation of the habitat and the potential of the habitat.   A cluster analysis was used to group the sites into different restoration opportunities and a color coded map with recommendations was created.  

One of the unique opportunities in the South Sound that Paul identified is that the South Sound has the shortest beaches in Puget Sound.  This provides an interesting opportunity to engage local communities who can focus on their local beach.

Western South Sound Coastal Cutthroat stock assessment suggests population is stable

Larry Phillips from the Washington Department of Fish and Wildlife explained how very little work has been done to assess the status of coastal cutthroat in South Puget Sound.   Some work has been done in the past few years to establish potential index areas to monitor spawning cutthroat population numbers and to track cutthroat movements using acoustic tags and receivers.  

Results of this work have identified Skookum Creek as a high density population of cutthroat.  Other potential index areas or important spawning locations include Kennedy Creek, Little Creek, Goldsborough Creek and Mill Creek.   The acoustic tagging results have suggested that the cutthroat seem to be staying in South Puget Sound and not migrating out into other parts of Puget Sound.

Chinook survival tied to offshore growth from May to July

An analysis of Chinook survival in Puget Sound and growth patterns in juvenile fish are indicating that the growth period between May to July when the Chinook are primarily feeding offshore is highly correlated with adult survival rates.    Dave Beauchamp from the University of Washington explained that a study looking at feeding rates, food availability, water temperatures and competition found that the adult survival rate was highly correlated with July body weights and there was no correlation with weights in September.  The primary diet items for that critical growth and feeding time were crab larvae and adult and terrestrial insects.

Freezing and salinity used to control invasive mudsnails in Capitol Lake

The invasive New Zealand mud snail was discovered by a birdwatcher/shell enthusiast  in Capitol Lake in October of 2009.  There has been an intensive effort to control the mudsnail since it’s discovery.   Mudsnails outcompete native gastropods by outfeeding them and they don’t serve as an alternative food source for fish.  They have been spreading west from the Great Lakes where it is believed they were introduced through the release of European ship’s ballast water.

Wendy Brown from the Invasive Species Council warned the audience that these mudsnails have also been spread by unsuspected restoration biologists by moving them from one stream restoration site to another.  She also told the story of one biologist who found over 120 mudsnails hidden in the mud on his boots. 

Two primary methods have been attempted in Capitol Lake to try to control the invasion – freezing and increased salinity levels.   The freezing was found to be very effective – killing 98 percent of the snails.  The saltwater flush from opening the tidegate in the lake caused increased salinities above 20 for 7 to 8 hours.  This was much less effective than the freezing – only 12 percent mortality.  

Next steps will be to continue to experiment with freezing conditions this winter, weather permitting, and to do some follow up small scale trials of salt concentrations.

Ocean acidification could have local impacts on South Sound shellfish populations

Shellfish growers in Oregon and Washington are finding that their shellfish production is being negatively impacted by increasing ocean acidity caused by increased atmospheric carbon dioxide.  Betsy Peabody explained how the shellfish are not able to grow their shells when the ocean water acid levels are too high.  

There is a study of natural shellfish populations in Puget Sound to see if there is a similar impact on their populations as what is being experienced in the hatcheries.  At Big Cove in Totten Inlet and Dabob Bay in Hood Canal it was found that high periods of spatfall coincided with low CO2 conditions in the water in both 2009 and 2010.   There is not enough evidence yet to demonstrate a definite effect from acidification on natural shellfish populations, but it is recommended that monitoring continue to look for an impact.

Climate change will impact Nisqually River flow and sediment

A climate change analysis conducted by the University of Washington that used the results of 20 different climate models projected that by 2080 there would be a 75 percent loss of snowpack in the upper Nisqually watershed.   Alan Hamlet from the University of Washington explained that by the 2040’s the models also predicted a 20 percent higher chance of a 100 year flood event than historical conditions. 

The hydrologic patterns in the watershed due to climate change are  predicted to be a shift towards more runoff in the winter and the loss of flow in the summer months due to reduced summer precipitation and the loss of the snowpack.

Low Impact Development pilot project demonstrates success

Stormwater in a pilot low impact development (LID) project in Pierce County near Hylebos Creek is successfully being infiltrated and filtered of contaminants despite some problems with construction of the LID elements and poor soils at the site.

Curtis Hinman from the Washington State University Puyallup Research and Extension Center explained how an 8 acre development with 35 homes was constructed in 2002 as a pilot project to evaluate the potential of low impact development techniques to mimic native hydrologic function and protect the nearby Hylebos stream.   The project was built using bioretention swales or raingardens along all the roadways, previous concrete along the road shoulders, compost amended soils around the homes, and a compost amended sloped dispersion area for any remaining stormwater runoff.

Curtis explained that there were problems with the project because the builder did not have much guidance on how to build the raingardens, the largest raingarden ended up being lined because of sewer concerns, and the site had poor soils for infiltration.   Despite these challenges when post development stormwater was evaluated the results showed that the site was exceeding the goals for stormwater reduction and infiltration.   The LID features in the development combined with the compost amended slope removed 96 percent of the stormwater on site.   In addition a water quality analysis showed that metal contaminants in the water were at non detectable levels and were much less than metal levels in stormwater runoff in typical residential developments.

Nitrogen loading and wastewater treatment in Thurston county

The Budd Inlet Treatment Plant in Olympia operated by LOTT discharges the equivalent of 17 Olympic size swimming pools of water a day into Puget Sound, according to Laurie Pierce of the LOTT Clean Water Alliance.  It’s nitrogen contribution to the Sound is equal to that of the Deschutes river watershed.   In 1992 an upgrade to the plant significantly reduced nitrogen levels in the plant’s discharge.  Without that improvement the wastewater from the Thurston County area would be having a much greater impact on nitrogen levels in the South Sound.  

The new focus for reduction of nitrogen loading and impacts of wastewater on Budd Inlet and the South Sound is the movement towards decentralized treatment facilities that are focused on where the growth is happening in Thurston County – Lacey/Hawks Prairie, Tumwater, and Chambers Prairie.   At each of these decentralized locations the goal is to reclaim water for reuse and for recharge of the aquifer instead of discharging to Puget Sound.  LOTT is also working with the Squaxin Tribe and others to identify and implement projects to address non point sources of nitrogen to the Deschutes River to help reduce the overal nitrogen contribution to Budd Inlet and the South Sound.

Improvements in forestry road construction practices help reduce stream sediment

A long term study of turbidity trends in the Upper Deschutes watershed in Thurston County by Weyerhauser have indicated that improvements in forestry road construction practices have made a significant difference in reducing sediment in the Deschutes river and its tributaries.   Maryanne Reiter explained that the analysis of data from 1974 to 2004 suggested that even when adjusting for flow levels there is a clear correlation with reduced turbidity in the river and better road construction practices that have reduced sediment runoff.