De Anda-Montanez et al. 2023 - Trace and macro elements in Baja California red crab

De Anda-Montanez and colleagues measured Cd, Cu, Fe, Mn, Ni, Pb, Zn, Ca, Mg, and P in whole adult red crab from the Pacific coast of the Baja California Peninsula, Mexico. The paper is routeable as shellfish/seafood occurrence evidence on a dry-weight whole-organism basis, with the important limitation that the source sampled wild red crab used or proposed for feed/flour and potential consumption rather than finished retail shellfish portions. Cadmium was the highest toxic-metal concern, while Pb was not detected in any cruise or zone group.

Key numbers

All concentration values below are dry-weight mean +/- SE with the source-reported range in parentheses. Trace metals are ug/g dry weight; Ca, Mg, and P are mg/g dry weight. Pb was reported as below the 0.07 ug/g quantification limit in every sampled group.

Element concentrations by cruise

Table 2 groups samples by research cruise: C1 (October-November 2004, El Nino; n=29), C2 (March 2005, neutral conditions; n=119), and C3 (November-December 2006, El Nino; n=131).

Element concentrations by coastal zone

Table 3 groups samples by collection zone along the Baja California Peninsula: south (Todos Santos-Bahia Magdalena; n=142), center (Gulf of Ulloa; n=81), and north (Punta Abreojos-Bahia Sebastian Vizcaino; n=56).

Intake and risk framing

For its screening health-risk calculation, the paper converted dry concentrations to a fresh-weight intake estimate using 73.8-79.4% moisture, assumed red-crab consumption of 41 g/day per person and 70 kg body weight, and compared estimated intake with source-selected RDI or RfD values. The printed screening table reports Cd at 1.33e-03 mg/day and 1.90% of the RfD; Cu at 6.31e-03 mg/day and 0.70% of the RDI; Fe at 1.90e-02 mg/day and 0.24% of the RDI; Mn at 7.86e-04 mg/day and 0.03% of the RDI; Ni at 2.96e-04 mg/day and 0.03% of the RDI; and Zn at 9.59e-03 mg/day and 0.09% of the RDI. For macro elements, the paper estimates Ca, Mg, and P contributions of roughly 1.03%, 0.37%, and 0.20% of the cited RDI values, respectively. The authors conclude that Cd, Pb, and Ni in the sampled red crab do not pose health risks under this assumed intake scenario.

Methods (brief)

The authors collected whole adult red crabs during three cruises off the west coast of Baja California Peninsula from 2004 to 2006. Specimens were measured, separated by sex and zone, dried at 70 C for 72 hours, and analyzed whole because red-crab flour and feed uses include the entire organism. Samples were microwave-digested (Mars 5x, CEM, Matthews, NC, USA) with concentrated nitric acid and 30% hydrogen peroxide in Teflon vials. Ca, Cd, Cu, Fe, Mg, Mn, Ni, Pb, and Zn were quantified by air-acetylene-flame atomic absorption spectrophotometry (GBS Scientific AVANTA, Dandenong, Australia), while P was measured by the molybdovanadate method. Quality control used standardized reference materials TORT-2, DORM-2, and DORM-4 (National Research Council of Canada, Ottawa) analyzed alongside samples, plus spiked blanks. Reported recovery ranged from 93% to 116%; LOQ values were 0.02 ug/g for Cd and Cu, 1.35 ug/g for Fe, 0.07 ug/g for Mn, 0.05 ug/g for Ni, 0.07 ug/g for Pb, 0.06 ug/g for Zn, 0.10 ug/g for Ca, and 0.08 ug/g for Mg. All concentrations are reported in dry weight. Cruise- and zone-grouped comparisons used two-way ANOVA with Bonferroni post hoc tests, supplemented by discriminant and factor analyses run in STATISTICA 13.5.0.17.

Implications

Certification: This source should be treated as Mexico-market/marine-ecosystem shellfish evidence on a whole-organism dry-weight basis, not as a direct US-market finished shellfish benchmark. It is most useful for Cd, Ni, Cu, Zn, Fe, Mn, and Pb nondetect context in crustacean shellfish and for documenting the basis conversion needed before any comparison with wet-weight regulatory limits or product-row pools.

Courses: Useful example of why basis and organism fraction matter. Whole red crab dry weight captures shell, viscera, and edible tissue together; it is therefore not directly comparable with papers that analyze only edible muscle or report as-consumed wet weight.

App: Route as shellfish and broader seafood context, with the Mexico Pacific coast, whole-organism matrix, dry-weight basis, and Pb censoring preserved. Do not use the source-reported RDI/RfD screen as a substitute for concentration evidence.

Wiki pages this source may touch

• shellfish
• seafood
• shellfish
• seafood
• cadmium
• copper
• iron
• manganese
• nickel
• lead
• zinc
• magnesium

Verification notes

The PDF has author attribution and DOI 10.3390/ani13050822; no DOI conflict was observed. The source reports total element concentrations only; it does not speciate arsenic, chromium, or mercury (none of which were among the measured analytes). Pb is censored as below the 0.07 ug/g quantification limit in every reported group. Values on this page come from the PDF tables rather than the abstract. The table values are dry-weight whole-organism results; any wet-weight comparison would require an explicit conversion using the paper’s moisture range (73.8-79.4%) and an audit trail.

2026-06-02 merge-enhance: added instrument vendor and model identifiers (Mars 5x CEM microwave, GBS Scientific AVANTA AAS), reference material identifiers (TORT-2, DORM-2, DORM-4 from NRCC), and statistical-method summary, per the scientific-method vendor/material exception to the brand firewall. No numerical values changed.

Page history

The five most recent substantive edits to this page. The full version history lives in git; when DOI minting comes online (see schema docs), each entry below will also link to a version-pinned DataCite DOI.