MERCURY CONTENT OF OREGON GROUNDFISH* 



E. A. Childs and J. N. Gaffke- 



ABSTRACT 



The mercury content of Oregon groundfish was determined. The mercury content of rex 

 sole, Glyptocephalus zcichinis: Dover sole, Microstomiis pacificus: petrale sole, Eopsetta 

 jordani: English sole, Parophrys vetiilus; sand sole, Psettichthys melanosiictus; starry flounder 

 Plaiicluhys stclluius: canary rockfish, Selnistes pinniacr; flag rockfish, Sebasles ruhrivincius; 

 yellowtail rockfish, Schasies flavidu.s: rougheye rockfish, Schasies aleiitianus; sablefish, 

 Anoplopoiiui fiiiihria: lingcod, Ophiodon cl()ni;ailus: Pacific hake, Mcrliiccius prodmiiis: and 

 arrowtooth flounder, Aiheicsthes stomias: was significantly lower than 0.50 ppm mercury. 

 All spiny dogfish, Squalus acanthias, samples contained >0.50 ppm. No highly significant 

 relationship in those species appropriately examined between (a) catch location, (b) time of 

 catch, (c) weight and length of fish, or (d) sex and mercury content was observed. 



Although the possibility of seafood organisms 

 containing large amounts of mercury has been 

 of recent concern, no systematic survey of a 

 major American marine fishery has been pub- 

 lished. A number of freshwater studies in the 

 United States (Willford, 1971), Canada (Uthe 

 and Bligh, 1971; Bligh, 1972), England (Taylor, 

 1971), and Sweden (Ackefors, 1971). and ma- 

 rine studies in Canada (Zitko et al., 1971) and 

 Sweden (Ackefors, 1971) are found in the litera- 

 ture. The present study was undertaken to 

 determine the extent of mercury contamination 

 of commercially important groundfish in the 

 Oregon fishery, with data being obtained which 

 would allow evaluation of the effect of species, 

 location of catch, size of fish, time of catch, and 

 sex on mercury content. 



Wash. 



Oreg. 



Calif. 



MATERIALS AND METHODS 



Fish were obtained from each of the three 

 major fishing areas off the Oregon Coast (Figure 

 1). Specimens were immediately dissected, 

 packed in evacuated film, and held at -40 °C 

 until mercury analyses were performed. Five- 

 gram samples of the epaxial musculature on 



' Technical Paper No. 3422, Oregon State University 

 Agricultural Experiment Station. 



- Seafoods Laboratory, Department of Food Science 

 and Technology, Oregon State University, Astoria, OR 

 97103. 



100 mi. 



Figure l. — Commercial fishing areas along Oregon coast 

 from which samples for mercury analysis were obtained. 

 N. - Northern coast C. - Central coast S. - Southern coast. 



both the right and left sides were taken for 

 analysis, and thoroughly ground and mixed. 

 The digestion apparatus consisted of a 250-ml 

 flat-bottom distilling flask connected to a 45-cm 

 cold-water condenser. The homogeneous samples 

 were digested for 10 min in 20 ml of 1:1 (v/v) 

 concentrated sulfuric and nitric acid, with 5-10 



Manuscript accepted December 1972. 

 FISHERY BULLETIN: VOL. 71, NO. .V 1973. 



713 



