A14-2.05 Marine Borers 



1, Terqdlnidae. Kiere was relatively little evidence of the 

 activity of Teredinldae , including Tteredo navalis and T, sp., at any 

 of these locations except during 19W^ Th© details of the occurrence 

 of thbse borers at each location is summarized belov. 



a. Barge Pier . Only 5 minute pits occurred in 2 of the 

 control panels submerged from August 8 to October 6, 19^7. ^redinidae 

 were recorded in 5 of the 51 test panels, but none at all were noticed 

 until the latter part of 19^6. The largest number found in any of the 

 test panels was 67 In one panel submerged from April 25 to December 10, 

 19U7. The maximum length recorded was 90 mm in 2 paiiels, each submerged 

 for 6 months. The breeding season at this location appears to be relatively 

 brief, apparently lasting from August to early October. Tbsre was no attack 

 in 19^5> only a single specimen was recorded late in 19^6, and the attack 



in 19^7 rated only moderate. 



b. Wharf No. 2 .. Uiere were only 2 minute pits in the control 

 panel submerged from September 5 "to October 6, 19^7. Teredinldae occurred 

 only in the last 5 test panels, which had been submerged from November k, 

 19h6 to December 10, 19^7. ^e largest number in any test panel was 6h in 

 one panel submerged from December I5, 19^6 to September 5^ 19^7. ^e maximum 

 length recorded was 65 mm, this specimen appearing in a panel submerged 9 

 months. The breeding season at this location seems to be extremely brief, 

 probably lasting only from August to early October. There was no attack in 

 1914.5 or 19*»-6, and that of 19^7 rated only moderate. 



c. Wharf No. 5 . Only 2 minute pits occurred in the control 

 panel submerged from September 5 to October 6, 19^7. Teredinldae occurred 

 on]^ in the last 3 test pajiels, which had been submerged from February 



26 to December 10, 19^7. The maximum length recorded was 60 mm in this 

 same panel after being submerged for 7^ months. The breeding season at 

 this location Is extremely brief, apparently being limited to September 

 and early October, Biere was no attack in 19^5 or 19^6, and that In 19^7 

 rated very slight. 



The slight to relatively light Teredo attacks at these locations 

 are unquestionably caused by the low salinity conditions which prevail 

 dvirlng a large part of the year and which are unfavorable for the develop- 

 ment of borers. It is interesting to note, in this connection, that the 

 attack at Wharf No. 2 was lighter than that at the Barge Pier, and that 

 the attack at Wharf No. 3 was lighter than that at Wharf No. 2. 



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