Trace elements in deep-water fish species from the Rockall Trough

Samples of three species of deep-water demersal fishes. Nezumia aequalis, L epidion eques and Raja fyllae were obtained from fish caught by bottom traw l at depths between 850 and 950 m on the continental slope of the Rockall T rough west of Scotland (58-59 degrees 30 'N) in March 1998. Muscle, liver a nd gill tissues were analysed for cadmium. copper, lead, zinc, and mercury by various atomic absorption techniques. In N. aequalis, median concentrati ons were in muscle tissue 0.004, 0.21, 0.005, 0.150 and 3.91 mg/kg wet weig ht, respectively, in liver 0.29, 1.92, 0.048, 0.075 and 16.18 mg/kg wet wei ght, respectively, and in gills 0.045. 0.87, 0.093. 0.058 and 29.88 mg/kg w et weight, respectively. In L. eques, median concentrations were in muscle tissue 0.005. 0.17, 0.002, 0.077 and 2.62 mg/kg wet weight, respectively, i n liver 0.268, 3.07, 0.033, 0.050 and 15.05 mg/kg wet weight. respectively, and in gills 0.040, 0.93, 0.039. 0.033 and 24.32 mg/kg wet weight, respect ively. In R. fyllae. median concentrations were in muscle tissue 0.012. 0.3 3, 0.027. 0.129 and 5.53 mg/kg wet weight, respectively, for liver 0.509, 1 .98, 0.026, 0.083 and 17.97 mg/kg wet weight, respectively, and in gills 0. 094, 0.47, 0.012, 0.101 and 12.89 mg/kg wet weight, respectively. Nickel an d chromium were not detectable in any of the samples analysed. In general, the concentrations are similar to those previously reported in other specie s from this area. Differences in accumulation patterns between species and elements are described using univariate and multivariate statistics (discri minant analysis). (C) 2001 Published by Elsevier Science B.V.