| Summary: | Cephalopods are known for their high bioaccumulation capacity of trace elements, particularly for Cd and Hg. With growing interests for alternative marine protein sources, due to overfishing and climate change, the importance of cephalopods for human consumption is increasing, which in turn creates additional pressures on already stressed trophic systems. Arrow squid (Nototodarus gouldi and N. sloanii) play a pivotal role in New Zealand’s food web: both as prey for a plethora of marine mammals, seabirds and fish species and as one of New Zealand’s main fishery targets for human consumption. The greater-hooked squid (Moroteuthopsis ingens) are also abundant and ecologically important, but have been less well studied as they have highly ammoniacal tissues and are not commercially fished. Due to their commercial and/or ecological importance, and the opportunity to compare squids of muscular body composition with those that are highly ammoniacal, these three species were selected as focus organisms. New Zealand waters are active regions, shaped by geothermal and volcanic activities, which are natural sources for trace elements. Concentration data for trace elements in Southern Hemisphere cephalopods are currently sparse, and this study aims to fill the existing knowledge gaps. In order to investigate the role of squids in the transfer of trace elements within New Zealand’s waters, a series of four complementary studies were undertaken. First, trace element concentrations (As, Cd, Co, Cr, Cu, Fe, Hg, Ni, Mn, Pb, U, V, and Zn) were assessed in different tissue types of Nototodarus sloanii from the Chatham Rise to analyse the bioaccumulation in edible muscular tissues and other organs. Arrow squid are an important vector of particularly Cd to top predators which was revealed by high concentrations in the digestive gland tissue. Next, the total body burden of the squids was calculated and toxicological and dietary consequences for predators (including humans) were assessed. Mean observed concentrations in the muscular ...
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