Shellfish at Work! A Budd Inlet nutrient bioextraction project

Eutrophication is a problem throughout Puget Sound and specifically in  Budd Inlet it has led to problems including low DO.  Bioextraction is a method of removing nitrogen through harvesting shellfish and seaweed.  Mussel harvesting is a method of “recycling” these excess nutrients.  PSI has been investigating this method for use in Puget Sound.  In 2011 a pilot project in Quartermaster harbor was found to have success.  A project in Budd inlet was subsequently launched in 2013.  Monthly data was collected at three  sites.  By mid July 2013 a good mussel set was found on the sampling straps.  TESC was involved in composting the mussels that had grown on the setting straps.  4500 pounds were composted by TESC.  New composting collaborations with WDOC-Cedar Creek composting has begun.  Compost testing resulted in high calcium content, and grew vegetables successfully.  Results indicate that 8000 lbs. of mussels = A removal of 80 Lbs. of nitrogen, or 0.66  lbs. per day.  In order to remove 100 lbs. of nitrogen per day, 16,810 straps would need to be installed (compared to the pilot study of 120 straps).  This would equal the size of 2 West Bay Marinas.  In addition to the quantitative data and feasibility of this mediation process, this project served as a great way to educate the public through youth community involvement about nutrient systems and what they can do on a daily basis to help improve water quality.