Spatial and Temporal Variability of Trace and Macro Elements in the Red Crab Pleuroncodes planipes in the Pacific Coast of the Baja California Peninsula, Mexico

SIMPLE SUMMARY: The content of trace and macro elements may vary between fishery products. Although several trace and macro elements are essential for life, they can adversely affect health at concentrations above the requirements of a species. The present study evaluated differences in cadmium, calcium, copper, manganese, magnesium, nickel, lead, and zinc levels in red crabs between years with and without El Niño conditions. We also evaluated whether the composition of these elements varies between sites along the coast of the Baja California Peninsula and the potential risk to human health if red crab is consumed as food. Cruises showed significant differences in the content of trace and macro elements, mainly associated with environmental variables that influence the vertical distribution of the red crab from 51 m to 500 m. Red crab provides less than 2% of the nutrient requirements of calcium, copper, manganese, magnesium, and zinc in the human diet; in addition, the contribution of cadmium, lead, and nickel recorded in this study poses no risks to human health. ABSTRACT: The red crab, Pleuroncodes planipes, is a decapod crustacean abundant off the Pacific coast of the Baja California Peninsula. This species is caught and used in preparing animal feed, such as flour, particularly for aquaculture. Levels of calcium (Ca), cadmium (Cd), copper (Cu), iron (Fe), lead (Pb), magnesium (Mg), manganese (Mn), nickel (Ni), phosphorus (P), and zinc (Zn) were measured in red crabs collected from three geographic zones during three cruises in different seasons. Significant differences were found in the levels of Ca, Cd, Cu, Fe, Mg, Ni, P, and Zn between the two El Niño years (cruises C1 and C3, based on a threshold of ±0.5 °C for the Oceanic Niño Index). The highest concentrations of most elements were observed in the south of the Baja California Peninsula, a highly productive area influenced by upwelling events. Our findings suggest that while environmental temperature plays a central role in the benthic or pelagic distribution of red crabs, their content and variability of trace and macro elements appear to be associated with the presence of oceanic conditions, such as upwelling and potential changes in the composition of their diet associated with the depth in which these crustaceans are collected.