![Sample our Earth Sciences journals, sign in here to start your access, latest two full volumes FREE to you for 14 days]({"type":"image" , "src" : "/sda/5930/TOC-Subject-Sample-2021-Earth-Sciences.jpg"})
ABSTRACT
Brittle stars (Ophiura spp.) and other benthic macrofauna were collected in a prospective mariculture area in the North Sea to determine if these taxa could be used as indicator species to track nutrients released from future offshore aquaculture sites. We analysed natural carbon and nitrogen stable isotopic signatures in tissues from macrofauna and compared these to six feed ingredients and four experimental diets made thereof, as well as to a commercial feed with and without lipid and carbonate removal. Our data suggest practicability of using isotopic signatures of Ophiura spp. to track aquaculture-derived organic material if plant-based fish diet ingredients and commercial feed were used for fish farming in the German Exclusive Economic Zone. Diets with high fish meal content would not be detected in Ophiura spp. using isotopic measures due to the similarity with the marine background. Our data provide valuable baseline information for studies on the impact of offshore aquaculture on the marine environment.
Acknowledgements
The authors thank Dr M. Kloppmann (Thünen Institute of Sea Fisheries, Hamburg) for providing samples of benthic macrofauna and Dr F. Meyberg, B. Alpers and G.-M. Velasquez (University of Hamburg) for their help with sample preparation and Dr A. Giesemann and her team at the Stable Isotope Laboratory of the Thünen Institute of Climate-Smart Agriculture (Braunschweig) for conducting the stable isotope measurements. They also thank the anonymous reviewers for comments on an earlier manuscript version.
Disclosure statement
No potential conflict of interest was reported by the authors.
