The area was marked by fence anchors at each corner of a 20- square- foot 

 area. Erosion of the bottom destroyed the markers soon after establish- 

 ment, and the location of the bed was lost for 5 months. The bed was 

 rediscovered the summer of 1972, and only 34 clams were recovered by 

 September. A second subtidal bed of 95 clams was then reestablished on 

 19 December 1972, using larger fence anchors and smaller buoys to mark 

 the location. This bed was located 15 feet below MLLW to avoid losses 

 from wave action. However, only eight marked clams were recovered from 

 this bed on 22 February 1973, and no further recaptures were made. 



The most successful study site was established at the -1.0-foot tide 

 level in the intertidal zone in front of the Moss Landing Marine 

 Laboratories. The site was marked with a fence anchor and planted with 

 108 marked clams on 19 April 1972 and an additional 42 clams on 17 May 



1972. On 30 June 1972, 26 clams were recovered and remeasured. 



The intertidal bed was sampled several times after June 1972, and 

 growth data were obtained for five periods: 17 May to 30 June (44 days), 

 30 June to 9 August [40 days), 11 August to 28 September (48 days), 

 28 September to 26 October (28 days), and 26 October to 21 November 

 (26 days) . 



The bed was resampled on 21 December 1972, and 21 marked clams were 

 recovered, remeasured, and returned to the bed, with an additional 117 

 newly marked clams and 17 marked clams which had become too large for the 

 pails at the pier. A total of 165 clams was returned to the intertidal 

 bed. 



On 18 January 1973, the bed was sampled again, and only 25 clams 

 recovered. In the interval between the December and January sampling, 

 storms had increased the sand depth more than 1 foot in the intertidal 

 bed which probably accounted for the few recoveries. 



After more storms, the intertidal bed was sampled again on 15 February 



1973, and only six marked clams were recovered. However, conditions were 

 poor for sampling. An additional 37 marked clams were added to the bed. 



In March, no clams were recovered from the intertidal bed because of 

 unfavorable tides and weather. Extremely heavy wave action between 

 mid-February and mid-March changed the beach contours at Moss Landing 

 where the intertidal bed was located. The primary change was a 3-foot 

 decrease in sand depth, which probably caused the loss of many clams. 



On 10 April 1973, 27 clams were recovered, remeasured, and returned 

 with an additional 72 clams. On 8 May 1973, 45 clams were recovered and 

 remeasured, and returned with 90 newly marked clams. Seventy-nine clams 

 on 3 June 1973 and 40 clams on 3 July 1973, were recovered, remeasured, 

 and returned. 



Another method of obtaining growth data was to suspend a rack with 

 measured clams and sand in two 5-inch plastic tubes from the end of 



45 



