MFR PAPER 1045 



Respiration and Metabolism in 

 Two Baleen Whale Calves 



F.RIC A. WAHRENBROCK, GARY F. MARUSCHAK, 

 ROBERT ELSNER, and DAVID W. KENNEY 



ABSTRACT 



Eric A. Wahrenbrock and Gary 

 F. Maruschak are members of 

 the staff of the Anesthesia Labo- 

 ratory of the School of Medicine, 

 University of California, San 

 Diego. La Jolla, CA 92037. 

 Robert Eisner is a member of 

 the staff of the Physiological 

 Research Laboratory of Scripps 

 Institution of Oceanography. 

 L'niversitv of California. San 

 Diego, P^O. Box 109. La Jolla, 

 CA 92037. David W. Kenney 

 was formerly a member of the 

 staff of Sea World. Inc.. San 

 Diego. Calif.; his present address 

 is 14220 Poway Rd.. Poway, 

 CA 92064. 



W-V perfonucd rcspiiiilnry unci mcuiholic sliulics on two female gray whale 

 calves. Allhongh one died 2 inonlhs after capture, the other thrived during a 

 year'.f captivity, pennitting serial observations while growing, and weiglied in 

 e.Kcess of 6.350 kg when released. They appeared to he of normal size and 

 weight compared to whtdes in the wild. Relative increases in body length and 

 weight, lung volume, minute ventilation, and metabolic rale were similar to 

 those in terrestrial mammals, as was the growth efficiency. Lung volume and 

 metabolic rate could be predicted with only partial success from the relation- 

 ships of those variables to body weight proposed by Tenney and Kleiber, per- 

 haps due to intniuturity in the whales. 



Compared to terrestrial mammals, tite ratio of tidal volume to resting lung 

 volume in the wliule was large, while the ratio of wasted ventilation to tidal 

 volume was small. We measured respiratory excursions of arterial Oi and CO2 

 tensions of 36 and 16 mm Hg, respectively, consonant with the relationships 

 between respiratory rate, lung volume, tidal volume, and metabolic rate. 



INTRODUCTION 



Although the physiology of toothed 

 whales. particularU porpoises, has 

 been studied at some length (Irving. 

 Scholander, and Grinnell. 1941: Olsen. 

 Eisner. Hale, and Kenney, 1969; 

 Olsen. Hale, and Eisner. 1969; Scho- 

 lander. 1940), the study of living 

 baleen whales has been particularly 

 elusive. The size and dietary habits 

 of these large mammals present for- 

 midable obstacles to their maintenance 

 in captivity, and these obstacles are 

 compounded by ignorance of the 

 whales' growth rate, dietary require- 

 ments, metabolism, and hematologic 

 and cardiorespiratory physiology. 



However, these and other aspects 

 of the biology of baleen whales are, 

 in many respects, unique among mam- 

 mals: research would therefore be 



doubly rewarding. This line of rea- 

 soning led to the capture and study 

 of the two animals reported herein, 

 and to this workshop. 



We were naturally inclined toward 

 studies of especial personal interest, 

 and recognize their limited scope 

 and serious omissions (cardiac out- 

 put, for example). We are here re- 

 porting observations on growth, res- 

 piratory function, and metabolic 

 rate: additional reports of detailed 

 nutritional, metabolic, biochemical 

 and hemotologic studies; inert and 

 anesthetic gas uptake; and respira- 

 tory mechanics will follow. 



METHODS 



The first gray whale calf (Gigi 1) 

 was captured in Scammon's Lagoon, 

 Baja California, Mexico in February 



1965 and brought to San Diego, 

 where a number of respiratory and 

 metabolic studies were performed. 

 Although the whale at first seemed 

 to thrive, it died of an uncontrollable 

 infection about 2 months after it 

 was captured. 



The second calf. Gigi II, was cap- 

 tured in March 1971, again in Scam- 

 mon's Lagoon, and was again kept 

 in (increasingly larger) pools at an 

 oceanarium in San Diego. Gigi 11 

 thrived indeed: gained in size, was 

 weaned, was studied intensively, and 

 was reluctantly (but inevitably) re- 

 leased almost exactly a year after 

 her capture. 



Two of the authors were members 

 of each of the expeditions (DWK. and 

 RE on the first, and DWK and EAW 

 on the second) and one of us (DWK) 

 was responsible for the medical care 

 of both animals while in captivity. 



For most of the studies reported 

 here, the water level in the tank was 

 lowered so as to nearly immobilize 

 the whale, leaving about 12 inches 

 of dorsal body surface above the wa- 

 ter level, and the blowhole barely 

 awash. A few of the studies were per- 

 formed with the whale completely 

 stranded on the bottom of the empty 

 tank. 



The respiratory pattern in whales 

 and other marine mammals consists 

 of an expiration followed by an im- 

 mediate inspiration, followed by an 

 interrespiratory pause during which 



