both. Thus, the trap is, ina sense, anartificially 

 introduced part of the environment. Making a 

 trap an acceptable part of the environment is 

 essential to profitable fishing. Although un- 

 baited traps catch those lobsters that are 

 merely seeking concealment, baited traps are 

 decidedly more effective. During the survey a 

 wide variety of baits were successfully used-- 

 live and crushed conchs, small bottomfishes, 

 shark, black skipjack, live lobsters, and bits of 

 white china. The only preference indicated by 

 the lobsters was for the cut bait to be fresh. 



Conversely, the only bait, which was com- 

 pletely ignored by not only lobsters but also 

 by fish and crabs that entered the traps, 

 was a species of puffer, Sphaeroides annulatus . 

 Halstead and Russell (1956) described two 

 toxic substances, isolated from a related 

 species found in Japanese waters, which when 

 ingested by humans can cause illness within 

 30 minutes and possible coma and death within 

 1 to 24 hours. 



Seasoning the traps, that is, allowing them 

 to become coated with accumulations of slime, 

 barnacles, and other natural growths, appears 

 to make them more acceptable to lobsters. In 

 explorations covering a wide area, it is not 

 always possible to provide seasoned traps, be- 

 cause transport of traps onthedeckofa vessel 

 for a relatively long period kills the growths 

 and negates the seasoning effect to some 

 degree. 



During one 13-day interval between cruises, 

 however, wood traps were stored in the tidal 

 waters of a cove on Parida Island. They re- 

 mained completely submerged and became 

 covered with an accumulation of growths, silt, 

 and mud. When the traps were retrieved and 

 the fishing resumed at the beginning of the 

 next cruise, the catch rate was found to in- 

 crease daily to the sixth day of fishing before 

 leveling off, indicating a beneficial effect. Of 

 some interest was a series of postlarval 

 lobsters, presumably P. gracilis, which were 

 found clinging to the above-mentioned, stored 

 traps when they were retrieved. 



To determine the effect of duration of setting, 

 traps were hauled at intervals of 1 to 8 days. 

 The results indicate that catch rates are 

 slightly higher for traps fishing 2 to 3 days 

 than for those hauled daily or left 4 or more 

 days. These data were substantiated by Robin- 

 son and Dimitrou (1963) "...catch per trap- 

 day or gear use efficiency, decreases as the 

 time the traps are allowed to fish increases." 



SIMULATED COMMERCIAL FISHING- 

 SECOND YEAR 



The early termination of the project and lack 

 of sufficient personnel limited the work during 

 the second year to only one of the three areas 

 previously selected for investigation. This was 

 the Gulf of Panama area, where two cruises 



( Pelican cruises 15 and 16) were made in the 

 northwestern part of the Gulf of Panama be- 

 fore the termination date. On cruise 15 the 

 lobster traps, which were used almost ex- 

 clusively, produced 1,066 lobsters weighing 

 1,458 pounds. On cruise 16 the primary effort 

 devoted to trawling produced 2,843 lobsters 

 weighing 2,758 pounds. 



On cruise 15, 4 bushels of bay scallops 

 (Aequipecten circularis ) were caught while 

 trawling for lobster bait. A brief mention of 

 the commercial potential of the scallops was 

 included in Pelican 15 cruise report. Within 2 

 months a new fishery for scallops was de- 

 veloping, which employed 400 people and 15 

 vessels. 



Incidental catches of marketable red snapper 

 (Lutjanus guttatus ), up to 65 pounds per drag, 

 were taken in the trawl along with the lobsters 

 and miscellaneous bottomfish. 



Three private lobster trapping operations 

 were in various stages of development when 

 the project ended. One company completed the 

 conversion of a 33-foot diesel powered boat 

 (fig. 17). Another company had almost com- 

 pleted construction of a lobster pound (fig. 18), 

 and was starting to set out traps. The third 

 had recently acquired a 44-foot boat to be 

 modified for lobstering. 



There were two species of lobsters taken 

 in the trawls: spiny lobsters (P. gracilis ) and 

 sand lobsters (E. princeps). The total catch of 

 2,843 lobsters caught during cruise 16 in 

 trawls and traps consisted of 1,803 sand and 

 1,035 spiny lobsters. 



A tabulation of the sex ratio of 877 trawl- 

 caught and 302 trap-caught spiny lobsters was 

 made for comparative purposes (fig. 19). The 

 trap-caught ratio was 62 males: 38 females. 

 The trawl-caught ratio was 32 males: 68 fe- 

 males. 



Traps were fished in September, and trawls 

 used in December. Because the depth, tem- 

 perature, and salinity of the waters fished were 

 similar in both cases, this seasonal difference 

 is. not considered significant. The only apparent 

 variable that might account for the differences 

 in the observed sex ratio was that the trawls 

 were fished from 2 to 5 miles offshore whereas 

 traps were used from 50 yards to 1 mile from 

 either land or exposed rock formations. 



Pelican cruise 15 produced 1,066 lobsters 

 weighing 1,458 pounds. Pelican cruise 16 

 produced 2,843 lobsters weighing 2,758 pounds. 

 Two factors accounted for this difference in 

 number-weight ratio. First, trapping for 

 lobsters produces a higher percentage of 

 large male spiny lobsters (average weight 24 

 ounces). Second, trawling for lobsters, in ad- 

 dition to producing a higher percentage of the 

 smaller female spiny lobsters (average weight 

 17 ounces), also results in about 60 percent of 

 the catch being made up of sand lobsters whose 

 weight (combined male and female) was 12 

 ounces. 



15 



