The temperature regimes in each of these exposure periods were different (Fig. 3). Aug-Feb began 

 when ambient water temperatures were warmest (> 20 "C) and ended when water temperatures were 

 coldest ( < 2 °C). Feb-Aug began when water temperatures were coldest ( < 2 °C) and ended when water 

 temperatures were warmest ( > 20 °C). Nov-May occurred during the coldest months (average = 5.8 "C) 

 of the year and May- Nov occurred during the warmest months (average = 17.2 °C). Seawater temperatures 

 in this report were based on data collected from 1978-1986 and the monthly averages were based on the 

 interval from the 15th of one month to the 15th of the next. 



After collection, panels were either placed in flowing, filtered seawater and processed inmiediately or 

 frozen and processed at a later time. Primary cover, as a percentage, was estimated for each organism 

 that occupied more than 1% of the panel surface, e.g., barnacles, bryozoans, tunicates and some algae. 

 In addition, primary cover was estimated for other classifications such as freespace, mud and the dead tests 

 of fouling species, to complete the description of total primary cover for each panel. Numerical abundance 

 was determined for barnacles and mussels by counting the individuals on each panel. If the number of 

 individuals per panel exceeded 100, six subsamples of 1 x 1 inch were randomly selected, three from the 

 upper half and three from the lower half of the panel. 



The abundance of woodborers was determined after the panel had been scraped of fouling species. 

 All individuals of the genera Limnoria and Chelura were counted when densities were less than 100 

 individuals per panel; otherwise, the subsampling scheme previously described for barnacles and mussels 

 was used. Subsampling was always conducted evenly between the top half and the bottom half so that 

 approximately 100 individuals were collected from each panel. After assessing the limnorid and chelurid 

 abundances, panels were frozen and subsequently radiographed using a 250 kV X-ray tube 

 (80 kV, 5 mA, for 1.2 min). The radiographs were used to visually estimate the number of shipworms. 

 Teredo navalis and T. bartschi, and the percentage of wood lost per panel. The percentage of wood lost 

 was expressed as the average "wood-loss" assigned to the the entire panel 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. To determine the species of shipworms collected, shipworms were randomly removed from 

 the panels until all or at least 100 individuals were identified from each site. Shipworms < 5 mm in 

 length were classified only as juvenile teredinids because their pallets were too small and underdeveloped 

 for making accurate identifications. 



