whether or not drag is a factor in tag longevity might be accomplished by an experiment 

 which used both "standard" size tags and "miniature" tags on the same species during the 

 same season, even if the smaller tags resulted in location data alone. Smaller size (and 

 possibly reduced weight) may also be achieved by "potting" (filling air spaces) transmitters 

 with suitable materials to reduce the need for heavy pressure housings. This has not been 

 done in the past because the dielectric of the potting material caused the sensitive RF 

 section of the transmitter to become detuned. Telonics has recently achieved potting of both 

 the digital and RF portions of their smallest transmitter. However, the "savings" in weight 

 may be negligible and additional structural strength beyond the potting material may be 

 needed for anchoring the attachments. Most of the recent weight savings in transmitters 

 have come from reduced battery requirements due to lower power output or reduced 

 transmission schedules. Additional savings in battery power can be achieved by even better 

 coordination of transmissions with the satellite passes. 



Because sensor data are prone to error from a variety of sources, we recommend the 

 sensor data include an error detection, if not error correction, code. There is also a need 

 for Service Argos to complete its promised work on this issue and reporting the details of 

 all messages, including the times of transmission for duplicate messages. 



Our data suggest that temperature plays a significant role in right whale movements 

 and their food gathering. Temperature monitoring should be one of the data priorities. We 

 recommend satellite sea surface temperatures and meteorological information be included 

 in future tracking budgets as they are key to interpreting some of the animal's behaviors and 

 movements. 



As our previous knowledge of whales has been collected largely from visual 

 observations of surface activity, and much of the animal's behavior occurs below the surface 

 and out of sight, we recommend additional sensor and microprocessor capabilities be 

 developed for pressure, temperature, acoustics and heart rate. Pressure sensors describe the 

 third dimension of the whale's World and demonstrated its usefulness for right whales in 

 1989. Dive depths deserve further attention. 



Physiological monitoring such as heart rate would also be desirable to appreciate the 

 animal's response to potentially adverse stimuli. Whales reduce their heart rate 

 (bradycardia) during diving. Most animals increase their heart rate in response to 

 frightening stimuli. Heart rate is presently monitored for seals with VHF tags by the Sea 

 Mammals Research Unit in the U.K. (M. Fedak, pers. comm.) and has been demonstrated 

 by T. Williams (pers. comm.) on bottlenose dolphins and by K. Brennan and J. Lien (pers. 

 comm.) on large whales with a wire lead system. Further monitoring of the animal's acoustic 

 environment could demonstrate tolerances and sensitivity to ship traffic and seismic events 

 while exploring the animal's own communications. 



This is the first large data set of its kind to be analyzed. As a result, we now know 

 a great deal more about the specific movements and round-the-clock dive patterns of right 

 whales than ever before. The amount of satellite-acquired information and additional data 



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