Natural trace elemental markers for adult red rock lobsters Jasus edwardsii vary among replicate distinct water masses

Abstract

In order to determine the potential utility of trace elemental natural tags to resolve fine-scale stock structure and residency patterns in adult crustaceans, we investigated whether concentrations of trace elements in exoskeleton could be used to resolve capture sites of red rock lobsters Jasus edwardsii. Using inductively coupled plasma mass spectrometry, we measured ratios of Li, Mg, Mn, Ba and Sr to Ca in samples of exoskeleton from 4 pairs of inner fjord and outer coast sites in Fiordland on New Zealand's southwest coast. Water column salinity structure was characterised at these 8 sites from a 12 yr series of conductivity, temperature and depth casts. Information on capture site, sex, carapace length and moult stage was used in an information theoretic framework to assess the degree to which capture site could be statistically discriminated using trace element signatures of exoskeleton. Using a permutational multivariate analysis of variance, we found significant differences in trace elemental signatures of exoskeleton at the scale of 10 to 20 km for 2 of the 4 fjords. In these same 2 fjords, we found persistent differences in water column salinity structure between sites. A multivariate permutational assignment test (canonical analysis of principal coordinates) successfully reclassified individuals from all 4 pairs of sites better than chance. These results indicate that trace elements can effectively be used to discriminate capture sites of adult rock lobsters between regions with different water mass characteristics. Within these limits, trace elements of exoskeleton may prove effective as natural tags to provide valuable information on fine-scale stock structure and residency patterns for rock lobsters. KEY WORDS: Trace elements · Jasus edwardsii · Metapopulation · Natural tag · FjordResale or republication not permitted without written consent of the publisher

Temporal, spatial, and interspecific variation in geochemical signatures within fish otoliths, bivalve larval shells, and crustacean larvae

“…In larval molluscs, a signature is found in either the analogous statolith (Zacherl 2005) or larval shell (Becker et al 2005(Becker et al , 2007. In crustaceans, a similar, spatially variable signature has been found in whole embryos (Carson et al 2008), whole larvae (DiBacco & Levin 2000), or adult exoskeleton (Jack et al 2011). Most studies have used these signatures in 'snapshot' fashion, where a short-term, static atlas of chemical variability is used to identify the origins of a recent set of recruits (but see Becker et al 2005, Cook 2011, Fodrie et al 2011 for notable exceptions).…”

Harvest locations of goose barnacles can be successfully discriminated using trace elemental signatures

“…Mg, Sr and P were the most abundant elements ( Fig. 2 ), as commonly recorded for calcified structures 4 7 18 34 . This is most likely because these elements are common and relatively abundant in seawater 35 .…”

“…Despite limited knowledge of the drivers of site-specific differences in calcified structures, TES have been used to track natal origins and dispersal of marine fish and invertebrate larvae 6 7 8 9 , detect migratory pathways 10 , classify habitats 11 , identify nursery areas 12 and discriminate between wild and farmed fish 13 . Additionally, this methodology has been successfully employed to delineate geographically distinct stocks of fishes 14 15 , bivalves 16 17 and crustaceans 18 .…”

Trace metal accumulation in decapods and its use in monitoring the marine environment

“…for several studies (Fukushima et al, 2001;Maharajan et al, 2011;Maharajan et al, 2012;Loflen et al, 2018). Jasus edwardsii has not been the subject of many trace element studies, although trace element markers have been used in population structure research (Jack et al, 2011). Uptake of pathogenic toxins into the hepatopancreas has been studied, but what little work has been done on heavy metal uptake has focused on muscle tissue, as Jasus edwardsii is a critical commercial species (Fabris et al, 2006;McLeod et al, 2018).…”

“…The chitosan used for research is usually derived from shrimp exoskeletons, however as the key factor is that they are chitin, it is expected that many crustacean species could be a source. Jasus edwardsii exoskeletons are primarily made of a chitin-protein matrix (Jack et al, 2011). Since the aim of this research is to investigate uptake of trace elements into living animals, it is important to find out whether passive absorption of metals into moulted exoskeletons takes place.…”