Spatio-temporal variability of trace elements fingerprints in cockle (Cerastoderma edule) shells and its relevance for tracing geographic origin

Abstract

Understanding spatio-temporal variability of trace elements fingerprints (TEF) in bivalve shells is paramount to determine the discrimination power of this analytical approach and secure traceability along supply chains. Spatio-temporal variability of TEF was assessed in cockle (Cerastoderma edule) shells using inductively coupled plasma-mass spectrometry (ICP-MS). Four elemental ratios (Mg/Ca, Mn/Ca, Sr/Ca and Ba/Ca) were measured from the shells of specimens originating from eight different ecosystems along the Portuguese coast, as well as from four different areas, within one of them, over two consecutive years (2013 and 2014). TEF varied significantly in the shells of bivalves originating from the eight ecosystems surveyed in the present study. Linear discriminant function analyses assigned sampled cockles to each of the eight ecosystems with an average accuracy of 90%. Elemental ratios also displayed significant differences between the two consecutive years in the four areas monitored in the same ecosystem. Overall, while TEF displayed by cockle shells can be successfully used to trace their geographic origin, a periodical verification of TEF (>6 months and <1 year) is required to control for temporal variability whenever comparing specimens originating from the same area collected more than six months apart.

The broad shell colour variation in common cockle (Cerastoderma edule) from Northeast Atlantic relies on a major QTL revealed by GWAS using a new high-density genetic map

“…We used the common cockle genetic map to ascertain the genetic component underlying the broad diversity observed for colour pattern on the wild populations of this species in the Northeast Atlantic. Ricardo et al (2017, 2022) showed an important variation in shell ion composition in common cockle, apparently related to environmental factors, that made possible to trace back the geographic origin of specimens, but they did not associate this variation with colour. Most phenotypes observed in wild populations in our study could be identified in the families produced at hatchery, although their intensity was somewhat faded, likely due to environmental factors operating across the lifespan of the adult specimens collected.…”

Inorganic Elements in Mytilus galloprovincialis Shells: Geographic Traceability by Multivariate Analysis of ICP-MS Data

“…Recently, some studies have also focused on shell inorganic composition, because it provides a stable, long-term, site-specific marker of elements, which is strongly influenced by the environment. This specific fingerprint may be useful for geographical-origin traceability [ 17 , 18 , 22 , 23 ].…”

“…The shell chemical composition is strongly influenced by external variables, such as water temperature, salinity, pH, dissolved oxygen, sea currents, and coastal pollution, which can influence the growth rate, the calcium carbonate crystallization, and the possible inclusion of trace elements in the shell structure. The shell can be an excellent reservoir for the accumulation of foreign inorganic chemical species, allowing even long-term environmental changes to be recorded [ 2 , 17 , 18 ].…”

Combining genotypic and phenotypic variation in a geospatial framework to identify sources of mussels in northern New Zealand

“…Understanding the spatio-temporal stability of geochemical tags is vital if such tags are to be informative. Some species, such as the cockle, Cerastoderma edule , demonstrate significant temporal variability in geochemical tags among years 51 , whereas other species show seasonal stability in geochemical tags e.g., the hardshell clam, Mercenaria mercenaria 52 . Analysing geochemical tags in mussels collected from Ahipara on a monthly timeframe (January, February, March, 2015) revealed that mussels could be assigned back to their site of origin (Ahipara) with a high degree of confidence (0.995–1.000), both in the context of the other five sites and also in terms of the month of collection (i.e., spatially and temporally).…”