MARINE PROTECTIVE ELEMENTS AGAINST MARINE BORERS.

Abstract : Wood coupons, 3 in. x 4 in. x 3/4 in. of all sapwood Southern Yellow Pine and all heartwood Douglas Fir comprising 27 systems of various marine protective treatments are being exposed at Boston, Massachusetts and Wrightsville Beach, North Carolina. Samples in replicates of three are removed from each treatment system at 6 month intervals, examined for marine borer attack, and the outer 1/8 in. of the faces and edges analyzed for the amount of preservative retained after exposure. After 6 months and 12 months exposure no attack was evident in the samples removed from Boston Harbor. At Wrightsville Beach, Limnoria tunnels were present in 12 systems, of which only 4 contained actual organisms. There was little difference in the average treatment retentions after 6 months and 12 months exposure. Samples removed from Wrightsville Beach after 18 months exposure showed light Limnoria activity in 9 systems. (Author)