notable features. It is not our intention to review 

 the instances of mercury poisoning, the legal as- 

 pects of the mercury guideline, nor the issue of 

 natural versus pollution-caused heavy metal con- 

 tamination. 



MATERIALS AND METHODS 



Of the 56 striped marlin sampled, 42 were caught 

 off southern California, while the remaining 14 were 

 from Hawaiian waters. All of the 37 blue marlin and 

 2 of the 3 swordfish were from Hawaiian waters. 

 One small (2.7 kg) swordfish was caught with long- 

 line gear in the central equatorial Pacific. The rec- 

 reational fishery provided all the California sam- 

 ples; data and tissues were collected either at the 

 weighing facilities of the Balboa Angling Club or 

 the Marlin Club of San Diego. The Hawaii samples 

 consisted offish caught by the commercial longline 

 fleet and by the troll sport fishery. The commercial 

 catch was sampled at the Honolulu fish auction, 

 while the sport catch was from fish caught during 

 the 1971 Hawaiian International Billfish Tourna- 

 ment held at Kailua-Kona, Hawaii. 



With the exception of the small swordfish which 

 was preserved in Formalin,^ all of the samples were 

 collected from fresh, unfrozen specimens. From Vi 

 to 1 pound (0.23 to 0.45 kg) of white muscle tissue 

 was excised from each fish. In the California 

 striped marlin samples, the tissue was removed 

 from the dorsal loin above the left pectoral fin. 

 Nearly all the Hawaii samples came from near the 

 caudal area because this portion is usually dis- 

 carded after a buyer has purchased the fish from the 

 auction market. In all cases the tissue sample was 

 cleaned of skin and bone, wrapped in inert 

 aluminum foil, labeled, and then frozen as soon as 

 possible. After the samples had been collected they 

 were packed in Dry Ice and shipped to the analyti- 

 cal laboratories by air. Liver tissue from 4 

 Hawaiian striped marlin and 26 blue marlin also 

 were collected for comparative analysis. 



The Hawaii samples were analyzed at a National 

 Marine Fisheries Service Laboratory while those 

 from California were done by a Department of Fish 

 and Game Laboratory. In 17 of the California 

 striped marlin sampled, muscle tissues were sent to 

 each of the analytical laboratories. 



Similar laboratory procedures were followed in 

 all cases; this consisting basically of the 

 semiautomatic, cold vapor, atomic absorption 

 technique (Uthe, Armstrong, and Stainton, 1970). 

 This technique requires a lengthy process of ho- 

 mogenizing, digesting, etc., prior to obtaining a 

 total mercury value fi"om the atomic absorption ap- 

 paratus. 



RESULTS 



Striped Marlin 



Our study covered a relatively wide size range for 

 this species; the smallest weighed 56 pounds (25.4 

 kg) and the largest 231.5 pounds (105.0 kg). Gener- 

 ally, the larger striped marlin were from southern 

 California while the smaller fish were from Hawaii. 

 Total mercury values averaged 0.8 ppm and ranged 

 from a low of 0.03 ppm in a 135-pound (61.2 kg) fish 

 to 2.1 ppm in a 231.5 pound (105.0 kg) fish, the 

 largest sampled (Fig. 1). Seventy percent or 42 fish 

 exceeded the FDA guideline of 0.5 ppm. A trend 

 line calculated for these data indicates a general in- 

 crease in total mercury with increasing size offish. 

 However, as Figure 1 indicates, the increase is er- 

 ratic and impossible to predict. While the largest 

 fish resulted in the highest mercury content, it is 

 well to note that the second largest, a 218 pounder 

 (99.0 kg), was tested at 0.29 ppm, a figure well 

 below the FDA guideline. 



^Reference to trade names does not imply endorsement by the 

 National Marine Fisheries Service. NOAA. 



Figure 1. — Relationship between total mercury (ppin) in 

 white muscle tissue and size offish of striped marlin from 

 southern California and Hawaiian waters. 



161 



