performance of each previous type. None of the tags deployed completely. Tests on 

 carcasses after the field season revealed that we had been misled by tests in the lab on 

 "detached" sheets of blubber. High resolution 8 mm video shot at a high shutter-speed 

 was used to record the action and revealed the problem when played back at slow speed. 

 The video showed that the high energy sutures actually lifted the blubber into a "wrinicle" 

 before penetrating, which resulted in an attachment we could not achieve on a live 

 animal. This action occurred so fast that it was invisible to the naked eye and went 

 undetected in our earlier, normal speed video records of pre-tleld laboratory tests. 



The single, limited success in 1989 was an adult male (PTT #843, NEA #1446) 

 known as "Van Halen," which was tracked for 22 days. We believe this success was due 

 in part to the modified attachment of the tag. One animal ("Admiral," NEA #1027) 

 tagged in 1989 was observed in 1990 with a small, straight white scar. No other 1989 

 tagged animals have been resighted. 



1990 



We had little problem applying tags in 1990. Eight tags were applied in the first 

 three days of the field season (see Figure 9). We used VHP signals to identify tagged 

 individuals at a distance, and our New England Aquarium colleagues used callosity 

 patterns and scars (Crone and Kraus, 1990) to confirm these identifications at close 

 range. When we saw tagged animals, but did not hear a VHP signal, we made close 

 approaches to document tag problems. The 6 mm stainless steel attachments were bent 

 on at least two transmitters (by as much as 40 degrees) within two days. We do not 

 know if the physical damage was caused by rubbing on other whales or on the bottom. 

 However, as a result, a Delrin endcap was broken out of both cylinders, seawater entered 

 the transmitter, and the batteries were shorted out. We confirmed endcap failures on 

 two of the first eight animals we tagged. We used a modified design with attachments 

 fastened to the cylinder itself to tag PTT #823 (NEA #1421). The modified tag 

 transmitted for 43 days, matching the best of the eight original tags. 



At the range most whales were tagged, the power of the crossbow appeared 

 adequate. Some tags may not have deployed completely. It was difficult to tell because 

 the resilience of the blubber may have allowed the tag to "bounce" back when the barbs 

 opened. Deployment may not have been complete if the tag had a poor angle of 

 application. It would be necessary to test tags on fresh, dead specimens to answer some 

 of these questions. 



Of the nine whales we tagged in 1990, we received data from seven and resighted 

 five (Table 2). Only two had any swelling and both of these had obvious attachment 

 problems. One whale (PTT #834, NEA #1248) was observed 8 days after tagging 

 without its tag, but had one tyne still in the skin. The other (PTT #827, NEA #1941) 

 was observed 6 days after tagging with one endcap pulled from the housing and the tag 

 still attached by the other tyne. Both animals had swelling 1 cm - 2 cm high for a 5 cm 

 radius around the attachments. The three other whales were resighted from 6 to 59 days 



22 



