FLANAGAN and HENDRICKSON: FISHERY AND REPRODUCTIVE BIOLOGY OF TOTOABA 



River. All fishing was prohibited north of an 

 imaginary line extending from Bahi'a Ometepec 

 on the Baja California coast to the mouth of the 

 Rib Santa Clara on the Sonora coast. 



In addition to the standard commercial fishery, 

 the Seri Indians of the Bahi'a Kino and Punta 

 Chueca areas of Sonora were alleged to capture 

 totoaba in coastal waters during the fall and 

 winter, but we have been unable to confirm this by 

 personal observation. Further pressure was ex- 

 erted on the stocks by an enthusiastic sport 

 fishery, based largely on the Baja California side 

 of the northern gulf, which took unknown 

 numbers of breeding adults during the prime 

 season. In recent years when diminution of the 

 stocks caused the success rate to drop, sport fishing 

 virtually disappeared. At the peak of the sport 

 fishery, large numbers of immature fish resident 

 in the upper gulf waters were also reportedly 

 taken, usually unrecognized as totoaba. For a time, 

 a deepwater handline commercial fishery and 

 accompanying sport fishery continued out of San 

 Felipe during the summer after the adult fish had 

 left the spawning grounds, but this activity also 

 declined in recent years. Craig (1926), Chute 

 (1928), and Berdegue (1955) provided further 

 information on the history of the fishery and 

 contain most of the documented information on 

 the sport fishery. 



METHODS AND MATERIALS 



The junior author began field studies on the 

 species in 1970 with the primary objective of 

 gathering life history information for conserva- 

 tion purposes. The results reported here derive 

 primarily from data collected by the senior author 

 during three cruises aboard commercial fishing 

 vessels from Puerto Peiiasco in March and April 

 1972. Fishing patterns during these cruises in- 

 cluded most of the Gulf of California north of lat. 

 31°N; with few exceptions, the locations were 

 selected by the fishing captain. 



The data were gathered by direct observation of 

 catch and, in a few cases, by reports from fishers 

 on "companion" vessels (as many as five other 

 boats in the cooperating group, in one instance). 

 During 22-24 March 1972 we also collected data 

 from the panga fleet at Golfo de Santa Clara as the 

 catch was landed and cleaned at the port. In both 

 circumstances, our data consisted of information 

 on location, time and size of catch, number of 

 operational net hours, time and state of tide. 



sexual composition of the catch, and reproductive 

 state of the individual. 



All fish examined by us were breeding adults. 

 They were classified according to three mutually 

 exclusive categories of gonadal development: If 

 not running eggs or milt at the time of capture (or 

 within 24 h of capture in the case of several 

 individuals kept alive for a period of hours), they 

 were classified as "unripe"; if milt or hydrated 

 eggs ("applesauce" color and texture) could be 

 expressed with light pressure, they were classified 

 as "ripe"; females with flaccid ovaries and running 

 ripe males taken in the same catch with such 

 females were classified as "spent." 



Effort data are reported as the number of 

 operational net hours rather than total time 

 (man-hours or boat-hours) spent fishing because 

 many of the large boats "hunt" for schools suitable 

 for encircling with their nets during the day and 

 then set their gill nets in the usual manner to fish 

 overnight. We believe that recent daytime hunt- 

 ing for schools to encircle was practiced more in 

 memory of times past than as a practical matter of 

 probability. In approximately 50 days aboard such 

 vessels, we have never seen a school located, 

 although one heard of such catches each season. 

 The method persisted because, if successful, it can 

 yield very high tonnage. The larger, diesel- 

 powered trawlers with ice-filled holds frequently 

 stayed at sea for more than a week and commonly 

 traveled considerable distances back to their home 

 ports to land the catch. This is in marked contrast 

 to the methods of the fishers of Golfo de Santa 

 Clara, who fished primarily from pangas and who 

 customarily inspected their nets each day by 

 passing the net over the boat, leaving the weight- 

 ed ends in place. Such nets "fished" continually, 

 except for occasions when they were taken up to be 

 moved to alternate spots. Lacking storage and 

 refrigeration facilities, the pangas had to return 

 to port each day with their catch from one or two 

 gill nets. Catch in kilograms was recorded by a 

 Mexican government fisheries inspector for each 

 panga, each day. Although we attempted to cal- 

 culate catch per unit effort, we were unable to 

 resolve its heterogeneous nature. Here we present 

 only our analysis of effort from the panga fishery 

 of Golfo de Santa Clara. 



In late May and early June 1972, a number of 

 Sonora and Baja California sites around the pe- 

 rimeter of the extreme northern gulf were sur- 

 veyed for juvenile totoaba, using both commercial 

 trawl nets and beach seines. Many of these sites 



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