TIMBER STUDY 

 MATERIALS AND METHODS 



This study used five different types of wooden blocks or "timbers" which were exposed to the marine 

 envirormient at five sites for periods of one to five years. The timbers (6.4 x 10,8 x 30.5 cm) were cut 

 from planks (6.4 x 24 x 300 cm) commonly used for building docks. The five types of wood were: 

 untreated Red Oak and Douglas Fir, and three types of chemically treated Southern Yellow Pine. The 

 three chemical treatments were; 20 lbs per ft creosote, 0.6 lbs per ft chromated copper arsenate (CCA), 

 and 2.5 lbs per ft CCA. The timbers were deployed at four sites used for monitoring fouling and 

 wood-boring species: White Point (WP), Fox Island (FI), Effluent (EF) and Giants Neck (GN), and at 

 a fifth site (Fig. 1), located at the Niantic Bay Yacht Club, Black Point (NB). The timbers were fastened 

 with plastic cable ties to wire lobster pots (Fig. 11). Three pots per site were deployed on the bottom 

 with timbers arranged so that all untreated wood blocks were attached to the same pot. 



Three timbers of each type were collected at each site in November and new ones deployed. Four 

 replicate timbers of each type were placed at each site when this study began in March 1983, to be collected 

 in November 1985, 1986, 1987, and 1988. These timbers, deployed for long-term exposures, were not 

 replaced upon collection. 



Wood-loss was quantified by comparing the weights of replicate timbers that have not been placed 

 in seawater (blanks) with those that have been exposed. Every year, three blanks of each type of timber 

 were cut from the same planks used to make timbers for deployment. After collection, the exposed timbers 

 were processed according to the following procedure. First the percentage of surface area covered by each 

 fouling species was recorded, and then the timbers were scraped clean and frozen. Next, they were 

 radiographed using a 250 kV X-ray tube and the approximate percentage of wood lost was visually 

 estimated from the radiographs. Wood-loss was expressed as the average of that percentage assigned to 

 the top left, top right, bottom left and bottom right quadrants of each timber and was accomplished by 

 rating the general proportions of bright areas, caused by various densities of shipworm tubes and the dark 

 areas caused by various degrees of wood-loss. Finally, the timbers and the blanks were sectioned into one 

 inch lengths and dried in a solar oven until they reached a constant weight. The untreated timbers were 



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