First reports of trace element bioaccumulation in the Antarctic deep-sea squid Psychroteuthis glacialis

Abstract

Trophic interactions in the Antarctic Ocean are likely to be affected by changing environmental conditions. Some of these impacts can be observed, and predicted, by monitoring trace element concentrations in the tissues of animals at certain trophic levels. The ‘glacial’ squid (Psychroteuthis glacialis) is an ideal indicator species for measuring trace element bioaccumulation in the Ross Sea because it plays a central role in local marine food webs. Trace elements (Al, As, Cd, Co, Cu, Fe, Hg, Ni, Mn, Pb, U, V, and Zn) were measured in mantle and digestive gland tissues of 57 P. glacialis specimens, including juvenile and mature individuals. Significant differences in Al, As, Cd, Cu, Fe, Mn, V, and Zn concentrations were observed across life stages, with juveniles generally having the highest concentrations. As the bioaccumulation of most trace elements is influenced by diet, our results suggest different feeding patterns between juvenile and mature P. glacialis. In turn, it is likely that the life stage of P. glacialis individuals consumed by predators will determine trace element exposure higher up the trophic web. Overall, this Antarctic squid appears to be influenced by the trace element cycling in the Ross Sea and contains lower concentrations of trace elements than have been observed in squids in warmer waters.