MERCURY IN FISH AND SHELLFISH OF THE NORTHEAST PACIFIC. 

 II. SABLEFISH, ANOPLOPOMA FIMBRIA 



Alice S. Hall, Fuad M. Teeny, and Erich J. Gauglitz, Jr.* 



ABSTRACT 



Sablefish, Anoplopoma fimbria, collected from several locations in Alaska, Washington, Oregon, and 

 California were analyzed for their mercury content. Mean mercury level in this species varied with the 

 geographical location of catch, showing a gradual increase in magnitude from north to south; the 

 average size of the specimens decreased in the same pattern, north to south. Of the 692 specimens 

 analyzed in this study, approximately 30% exceeded the U.S. Food and Drug Administration action 

 level of 0.50 ppm mercury. Significant relationships between the size of the fish and mercury content 

 were observed. 



Following the Canadian disclosure in March 1970 

 of high mercury levels in fish caught in Lake St. 

 Clair (Hearnden 1970), the National Marine 

 Fisheries Service (NMFS) initiated studies to 

 determine the distribution and level of mercury in 

 our marine resources. Since that time, the Pacific 

 Utilization Research Center, NMFS, has been 

 conducting extensive screening studies of fish and 

 shellfish of the northeast Pacific in order to evluate 

 the mercury problem as it relates to those species 

 taken by both commercial and sport fisheries. The 

 main objectives were to determine which species 

 contained mercury in excess of the Food and Drug 

 Administration (FDA) action level of 0.50 ppm 

 (Schmidt 1974) and the severity of the problem. 



During our preliminary screening of Pacific 

 species, we found that the edible muscle tissue of a 

 number of sablefish contained mercury in excess 

 of the FDA action level. This species ranges from 

 southern California to the Bering Sea (Clemens 

 and Wilby 1961:240). Domestic landings in 1971 

 were about 6 million pounds (2.7 x 10'' kg) 

 (Thompson 1971) but its high value as a smoked 

 product and the availability to the fishermen of 

 additional supplies of this species suggests that 

 landings will increase. 



This paper is the second in a series and reports 

 our findings on mercury in the edible muscle tissue 

 of sablefish, Anoplopoma fimbria (Pallas). The first 

 paper in the series is on the Pacific halibut, Hip- 

 poglossus stenolepis Schmidt (Hall et al. 1976). 



'Pacific Utilization Research Center, National Marine Fish- 

 eries Ser\'ice, NOAA, 2725 Montlake Boulevard East, Seattle, 

 WA 98112. 



EXPERIMENTAL PROCEDURE 

 AND METHODS 



Most of the sablefish used in this study were 

 obtained by NMFS personnel aboard National 

 Oceanic and Atmospheric Administration 

 (NOAA) research vessels. Some samples were 

 obtained from commercial lots through the coop- 

 eration of fish processors in order to cover the range 

 of this species. Samples were obtained from the 

 waters off Alaska, Washington, Oregon, and 

 California. Date and location of catch were 

 recorded for all specimens. 



Weights and lengths are reported for heads-off 

 eviscerated fish because this is the standard prac- 

 tice for landing sablefish. Round weights and 

 lengths were converted to the heads-off eviscerat- 

 ed values using conversion tables. Where possible, 

 sex was determined by physical examination when 

 the specimens were eviscerated. Age was deter- 

 mined from the otoliths which were removed at 

 the same time. 



Analytical samples consisted of the entire fillets 

 of each fish. The edible muscle tissue was ground in 

 a Hobart grinder'^ equipped with a stainless steel 

 plate perforated with holes Vs inch (3.2 mm) in 

 diameter. The comminuted flesh was mixed thor- 

 oughly; subsamples were removed, packaged, and 

 stored at -29°C until analysis. 



Total mercury was determined by either the 

 FDA method of Munns and Holland (1971) or 

 Malaiyandi and Barrette (1970) as modified by 



^Reference to trade names does not imply endorsement by the 

 National Marine Fisheries Service, NOAA. 



Manuscript accepted April 1976. 



FISHERY BULLETIN: VOL. 74, NO. 4, 1976. 



791 



