Environmental Challenges for Extracting U from Seawater George T. Bonheyo, Ph.D. PNNL Sequim Marine Research Operations (360)

Challenges: Site selection and permitting Policy for Siting:  Cannot write an EIS without basic information (marine hydrokinetic power example)  Impact of design on benthic ecology – coral reefs are protected  Impact on migratory marine mammals, fish, shellfish  Entanglement of animals  Creation of artificial communities o Grazing, predation, and entry of metals into foodchain o Attracts sportfishing, diving  Leaching of sorbant chemistry  Durability and consequence of breakdown  Impact on current  Impact on other commercial Interests  Finfish and shellfish  Public input

Challenges: Site selection and permitting Policy for Siting:  Who controls near-shore environment site permits:  State  County – impact on local industry  NOAA  Coast Guard  EPA  Potentially ACE  DOE (per energy policies)  Dept of Interior – impact on marine sanctuaries and parks  >30 years to finally determine who controls ballast water policies (for now…)  Need for scaled field testing  Multi-season assessments

Biofouling: Marine biofouling: generally a 4-step process 1)Surfaces are rapidly coated (beginning in minutes, continuing for hours) with an organic conditioning film of amino acids, peptides, glycoproteins, humic material, lipids, nucleic acids, and other undefined macromolecules 2)During the second stage, single bacterial cells and diatoms begin to settle, adhere and colonize 3)During the third stage, microbial films and rough surfaces trap more particles and organisms, including spores of algae, marine fungi, and protozoa. Eventually larval stages of macrobiota settle 1)Finally, outgrowth of macrobiota occurs.

Successive chemistry in fouling Marine biofouling: Development of coating chemistry 1)Primary coating and ooze: proteins and peptides first then polysaccharides 1)Secondary compounds: colonizer-generated polysaccharide complexes, metabolites, nucleic acids 1)Messenger compounds- quorum sensing, recruiting 1)Macrobiotic adhesive compounds: proteins (e.g. Mcfp1) and carbohydrates

Biofouling: Potential Impacts of fouling:  Macrofouling- impact on drag and localized current (greater spacing needed- then larger field  Impact on efficiency of extraction (free water exchange on active surfaces)  Microenvironment alteration: potential acidification of surfaces (Cyanobacteria)  Grazing and entry into foodweb  Grazing or metabolic impact on organic ligands  Impact of fouling materials on recovery  Carbonates, silicates, and biomass impact on stripping  Contribution to algal blooms (red tide, coral diseases)  Creation of reef community – attracts predators and man

Antifouling: You cannot stop fouling, but you can delay it  Short duration exposures (<60 day) would be best  Molecular fouling occurs in minutes- may need to assess what would cause your system the most trouble and design out coating to slow the process  U-Extraction process should also include effort to remove foulants  The closer you are to the shore, the greater the problem (nutrient sources, sediments, biomass)  Estuarine areas – fouling within days to weeks