Elemental and spectral chemometric analyses of Octopus vulgaris beaks as reliable markers of capture location.

The high demand and economic relevance of cephalopods make them prone to food fraud, including related to harvest location. Therefore, there is a growing need to develop tools to unequivocally confirm their capture location. Cephalopod beaks are nonedible, making this material ideal for traceability studies as it can also be removed without a loss of commodity economic value. Within this context, common octopus (Octopus vulgaris) specimens were captured in five fishing areas along the Portuguese coast. Untargeted multi-elemental total X-ray fluorescence analysis of the octopus beaks revealed a high abundance of Ca, Cl, K, Na, S, and P, concomitant with the keratin and calcium phosphate nature of the material. We tested a suite of discrimination models on both elemental and spectral data, where the elements contributing most to discriminate capture location were typically associated with diet (As), human-related pressures (Zn, Se, and Mn), or geological features (P, S, Mn, and Zn). Among the six different chemometrics approaches used to classify individuals to their capture location according to their beaks' element concentration, classification trees attained a classification accuracy of 76.7%, whilst reducing the number of explanatory variables for sample classification and highlighting variable importance for group discrimination. However, using X-ray spectral features of the octopus beaks further improved classification accuracy, with the highest classification of 87.3% found with partial least-squares discriminant analysis. Ultimately, element and spectral analyses of nonedible structures such as octopus beaks can provide an important, complementary, and easily accessible means to support seafood provenance and traceability, whilst integrating anthropogenic and/or geological gradients.

Projecting Future Climate Change-Mediated Impacts in Three Paralytic Shellfish Toxins-Producing Dinoflagellate Species.

Toxin-producing microalgae present a significant environmental risk for ecosystems and human societies when they reach concentrations that affect other aquatic organisms or human health. Harmful algal blooms (HAB) have been linked to mass wildlife die-offs and human food poisoning episodes, and climate change has the potential to alter the frequency, magnitude, and geographical extent of such events. Thus, a framework of species distribution models (SDMs), employing MaxEnt modeling, was used to project changes in habitat suitability and distribution of three key paralytic shellfish toxin (PST)-producing dinoflagellate species (i.e., Alexandrium catenella, A. minutum, and Gymnodinium catenatum), up to 2050 and 2100, across four representative concentration pathway scenarios (RCP-2.6, 4.5, 6.0, and 8.5; CMIP5). Despite slightly different responses at the regional level, the global habitat suitability has decreased for all the species, leading to an overall contraction in their tropical and sub-tropical ranges, while considerable expansions are projected in higher latitudes, particularly in the Northern Hemisphere, suggesting poleward distributional shifts. Such trends were exacerbated with increasing RCP severity. Yet, further research is required, with a greater assemblage of environmental predictors and improved occurrence datasets, to gain a more holistic understanding of the potential impacts of climate change on PST-producing species.