APPENDIX A 

 TAGS ON WHALES, DOLPHINS, AND PORPOISES 



Field studies of cetaceans are very difficult. First, it is 

 extremely hard to be positive that an individual or a group of 

 animals is the same from one encounter to the next. This 

 means that it is nearly impossible to determine, for example, 

 whether herds of animals are resident in an area or only 

 seasonal visitors. Without information of this kind, 

 determinations vital to population management, such as sizes 

 of populations and natural ranges, are impossible to make. 



Secondly, as we frequently point out in this guide, 

 individual cetaceans are usually visible to a surface observer 

 only during the brief moments when they break the air- water 

 interface to breathe. The majority of their vital activities 

 (e.g., feeding, reproduction, communication, establishing 

 and maintaining position within the herd, and defending 

 against natural enemies) take place primarily below the 

 surface, well out of view to a surface observer. 



In recent years, in an attempt to overcome some of these 

 problems, scientists have been placing markers on various 

 species of cetaceans and monitoring their movements. The 

 following brief summary of major methods of tagging 

 cetaceans is provided to acquaint the reader with markers he 

 may expect to see in the western North Atlantic. 



Static Tags 



Since their development in the mid-1920's, numerous 

 Discovery marks (small stainless steel projectiles with 

 identifying information stamped on them) have been shot into 

 commercially valuable species by means of a shotgun. The 

 recovery of these marks from whales subsequently killed in 

 the whaling industry has provided valuable information on 

 the movement patterns and on basic aspects of the growth 

 and development of harvested species of whales. Discovery 

 marks are limited, however, because they are not visible in a 

 living animal. Reduction in whaling activities will bring about 

 a significant reduction in their use. 



More recent tagging developments relate to marks which 

 will be visible on a free-swimming animal. Large whales, for 

 instance, may be tagged with color-coded streamers, such as 

 that shown in Appendix Figure A2. The tags, which are 

 modified versions of the spaghetti tags first constructed for 

 use on fishes, consist of a small stainless steel head for 

 attachment to the blubber and a colorful streamer ( sometimes 

 stamped with information on agencies to which tags should 

 be returned) which is visible above the surface of the animal. 

 These tags may be applied by using either a pole applicator or 

 a crossbow and crossbow bolts. Both applicators are equipped 

 with a stop to limit the depth of penetration into the animal's 

 blubber. Extensive experimentation indicates that the tags 

 do not harm the animals and that their application is not 

 traumatic. With the continued reduction in whaling activity, 

 it is hoped that the use of such markers in the study of 

 movements of big whales will be increased. 



Because they often ride the bow wave of a moving vessel, 

 thereby making themselve accessible for tagging and 

 capture, small porpoises and dolphins have been tagged with 

 a greater variety of marks than large whales. In recent years, 

 at least three kinds of static tags, including spaghetti 



|i ^ ni, u| i H | lii i iH|, li| iiy ill l lrl| U lillljr ll| ll l |l ll |iil| iii| l n| iil| l i yin | u i| l li|l » ^ 



Appendix Figure Al. — Some of the basic kinds of tags used to mark 

 porpoises, dolpliins, and small whales. A, B, and C are nylon button tags, 

 which are placed in the dorsal fin of animals and may be clearly visible as 

 the animal surfaces to breathe. D is a vinyl spaghetti tag. {Photo by R. 

 Krenic, courtesy of Naval Undersea Center.) 



streamers, have been placed on small and medium-sized 

 cetaceans. 



Spaghetti tags, placed in the animal's blubber near the 

 base of the dorsal fin as it rides the bow wave, stream to 

 conform to the contour of the animal's body as it swims ( App. 

 Fig. A3). It is not possible to identify the numbers on the 

 spaghetti tag of a moving animal, although color codes may be 

 used to indicate different species, populations, or tagging 

 areas. 



Button tags and freeze brands are placed on captured 

 animals prior to their release. The button tags (App. Figs. 

 A4, A5) are placed in the dorsal fin and should be visible as the 

 animal surfaces to breathe or as it rides the bow wave. At 

 close range, the number, letter, or design may also be visible. 

 Freeze brands (App. Fig. A6) are placed on the back or dorsal 

 fin with a supercooled branding iron, apparently without pain 

 or discomfort to the animal, and provide a permanent mark 

 which leaves the tagged animal free of encumbrances. The 

 use of freeze brands shows promise and should come into 

 more extensive use. 



Other static tagging techniques currently under 

 investigation include the use of laser beams to apply small 



154 



