Figure 1. — Map ol capture locality. Nuinbers 

 indicate the capture sites for the ttiree harnessed 

 animals. 



ging methods that do not require kill- 

 ing are now required. These methods 

 seem to fall into two categories; (1) 

 those involving the capture of whales, 

 placement of harnesses and equipment 

 on them, tracking along the whale's 

 route, and subsequent release and re- 

 covery of data packages; and (2) those 

 involving placement of data or tele- 

 metering packages on whales without 

 capture, followed by tracking. 



The first method will allow data 

 collection from a few animals, while 

 the latter will presumably allow less 

 complete data collection from more 

 animals and from those species that 

 cannot be captured. The tests de- 

 scribed here are of the first sort; that 

 is. they involve capture and harness- 

 ing. The experiments of Evans (this 

 number of Marine Fisheries Review) 

 with Gigi are also of this sort, though 

 surgical attachment rather than har- 

 nessing was used. 



We chose our subject, the California 

 gray whale, because large numbers 

 of suckling calves are available in 

 their Mexican breeding lagoon during 

 January and February of each year 

 and because the calm working condi- 

 tions in the lagoon would assist these 

 preliminary tests. We expect that the 



majority of results obtained on this 

 relatively well-known animal will be 

 applicable to more oceanic species. 

 Our tests were restricted to capture, 

 harnessing, and very short term track- 

 ing, since we expected that our results 

 would require harness redesign prior 

 to long-term tracking. This proved to 

 be the case. 



We attempted to capture suckling 

 animals only because of the obvious 

 dangers and seamanship problems pre- 

 sented by adult whales. The rationale 

 supporting this choice is that a suck- 

 ling calf, harnessed and instrumented, 

 should keep station with its mother 

 and. hence, give a true migratory 

 route. 



To our knowledge five baby gray 

 whale captures or handlings have 

 been reported. Eberhardt and Norris 

 ( 1964) report working with a stranded 

 baby gray whale in Scammon's Lagoon. 

 Robert Eisner (pers. comm.) detailed 

 a capture of a baby gray whale in 

 Scammon's Lagoon from a small cata- 

 maran by use of a superficial harpoon 

 followed by netting. David Kenney 

 (pers. comm.) directed the capture of 

 Eisner's animal and the capture and 

 transportation of Gigi. the gray whale 

 calf caught in Scammon's Lagoon and 

 held for 12 months in Sea World. 

 The latter whale was captured with a 

 tail noose from a small fishing vessel 

 equipped with a bow plank. The ship 

 was reportedly damaged slightly by 

 the mother when the baby was brought 

 alongside. Theodore Walker (Cous- 

 teau. 1972) is shown manipulating a 

 stranded baby gray whale in circum- 

 stances much like those discussed by 

 Eberhardt and Norris (1964). Spencer 

 (1973) reported on the drug-assisted 

 capture of adult whales in Scammon's 

 Lagoon. 



THE STUDY SITE 



We chose northern Magdalena 

 Bay. Baja California Sur. Mexico, 

 near Boca de Soledad for our work 

 because of an abundance of whales 

 living in a system of shallow bays and 

 rather narrow channels and because 



Kenneth S. Norris and Roger L. 

 Gentry are associated with the 

 Coastal Marine Laboratory, Uni- 

 versity of California, Santa 

 Cruz,' Santa Cruz, CA 95064. 



the Mexican government has recently 

 declared the better known Scammon's 

 Lagoon (Laguna Ojo de Liebre) a 

 whale reserve. Headquarters were es- 

 tablished in the small government 

 cannery town of Lopez Mateos. which 

 fronts on the main lagoon channel 8 

 km southeast of Boca de Soledad 

 (Figure 1). 



In this region the channel is about 

 800 m wide and averages 1 1 m deep 

 in mid-channel. To the west a low 

 ridge of dunes separates the lagoon 

 from the sea. The shore along the 

 dunes drops precipitously into deep 

 water. The eastern bank is typically 

 bordered with dense mangrove thick- 

 ets often cut by shallow bays and 

 channels. The shore along the man- 

 grove coast usually shelves gradually 

 over a broad tidal flat to the main 

 channel. This difference in bottom con- 

 tour proved crucial to capture and 

 harnessing. 



While whales were found through- 

 out the deeper parts of the channel, 

 one concentration occurred just in- 

 side Boca de Soledad and another oc- 

 curred at a broad expanse of water just 

 north of Colina Coyote (see Figure 1). 

 It was here, or somewhat closer to 

 Lopez Mateos. that our captures took 

 place. Our counts showed approximate- 

 ly 86 whales in residence in the entire 

 channel system. Most were mothers 

 and young, but a few males were pres- 

 ent, as indicated by copulations ob- 

 served inside the channel. 



WHALE CAPTURE 

 AND HARNESSING 



Capture of suckling gray whales 

 proved to be rather simple, once the 

 basic techniques were established. Four 

 whales were netted in 3 days (27-29 

 January 1973). One was released be- 

 cause it was clearly too large for our 



59 



