FISHERY BULLETIN: VOL. 72, NO. 1 



Table 1. — Locations and duration of stay (h) of individual tautog during their daily movements as determined by ultra- 

 sonic tracking. 



Tautog 

 no. 



Day 



Night 



1 TL (cm) 

 Age'/sex 



Release (dote/time) 

 Track duration (h) 

 Mean temperature 



2 TL (cm) 

 Age/sex 



Release (date/time) 

 Track duration (h) 

 Mean temperature 



3 TL (cm) 

 Age/sex 



Release (date/time) 

 Track duration (h) 

 Mean temperature 



4 TL (cm) 

 Age/sex 



Release (dote/time) 

 Track duration (h) 

 Mean temperature 



5 TL (cm) 

 Age/sex 



Release (date/time) 

 Track duration (h)  

 Mean temperature 



6 TL (cm) 

 Age/sex 



Release (date/time) 

 Track duration (h) 

 Mean temperature 



7 TL (cm) 

 Age/sex 



Release (date/time) 

 Track duration (h) 

 Mean temperature 



45 



12/9 



7-25-72/1310 



67.5 



19.2°C 



42 



10/9 



8- 1 -72/0940 



68.3 



21.2°C 



42 



10/9 



8-8-72/1215 



66.5 



20.4°C 



43 



916 



9-15-71/0830 

 47.5 

 22.0°C 



38 



7/9 



9-27-71/1400 



41.5 



18.1°C 



47 



11/d 



8-16-71/1830 

 41.5 

 21.7°C 



20 



3/9 



10-4-72/0930 



34.0 



16.8°C 



A3'( 5.0)- Al( 2.2) A4( 9.8) A4( 2.6) Al(11.4) Al(lO.O) Al(14.1) 

 A3(10.2) 

 A4( 1.9) 



Al( 0.8) A4(11.5) A3( 3.1) A4( 0.5) Al( 9.6) Al( 9.8) Al( 9.6) 

 A4( 0.4) A5( 2.3) A4( 9.2) 

 C ( 8.4) A5( 1.8) 



Al( 3.0) A4( 0.9) A5( 6.2) A5(0.3) Al(11.3) Al(11.6) Al(10.8) 

 A4( 3.0) A9(10.3) A9( 7.0) 



Al( 1.0) A3( 2.5) A4( 0.5) 



A4( 5.7) A5( 0.8) 



A6( 0.6) A6( 4.5) 



A7( 2.3) A7( 0.8) 



Al( 0.3) A5( 2.7) A5( 1.0) 



A4( 0.2) A6( 1.4) 



A7( 4.0) 



A8( 0.1) 



Al( 1.4) A2(10.9) F ( 4.1) 



A5( 0,3) 



Al( 9.4) Al(12.5) 



Al(12,8) Al(15.6) 



Al(16.6) Al(15.1) 



Al(10.3) G (12.2) 



Al(11.5) Al( 0.6) 



The transmitter emitted pulsed signals at 70 

 kHz (kilohertz). Those used for small fish (20- 

 25 cm) measured 30 x 9 mm (manufactured by 

 Chipman Instruments''). Larger transmitters, 

 65 X 14 mm (SR-69B, Smith-Root Inc.) were 

 used for the remaining fish (38-50 cm). 



The pharyngeal mill apparatus of the fish 

 precluded internal insertion of the transmitter. 

 This necessitated external attachment through 

 the dorsal musculature, with nylon monofila- 

 ment line just below the midpoint of the dorsal 

 fin. On each side of the body, rubber disks (25- 

 mm diameter) were used to prevent the flesh 

 from tearing. Tags were made neutrally buoy- 

 ant by the addition of a styrofoam collar coated 

 with silicone sealant. Following attachment of 

 the transmitter, fish were held in a 50-liter 



•' Reference to trade names in this publication docs not 

 imply endorsement of commercial products by the Na- 

 tional Marine Fisheries Service. 



tank for 15 to 30 min to insure that the fish 

 were responsive and that the transmitter was 

 operating normally. 



Fish were released within the basin and 

 tracked from a 5.2-m skiff. The signal was moni- 

 tored with hydrophone and sonic receiver 

 (Model SR-70-H and TA-60 respectively, Smith- 

 Root Inc.) in a manner similar to that described 

 by McCleave and Horrall (1970). 



The location of each fish was recorded in 

 relation to local landmarks. We considered a 

 fish active whenever a change in transmitter 

 signal was detected. Direct underwater obser- 

 vations confirmed that we were able to detect 

 abrui)t changes in the fish's orientation and 

 straight line movement over 1 m. The data were 

 subse(iuently condensed to indicate the i)res- 

 ence of a fish for a i)eriod of time at a specific 

 location (Table 1). 



For each track, we recorded current velocity, 



28 



