SEASONAL LEVELS OF HEAVY METALS IN SOFT TISSUE AND MUSCLE OF THE PEN SHELL Atrina maura (SOWERBY, 1835) (BIVALVIA: PINNIDAE) FROM A FARM IN THE SOUTHEASTERN COAST OF THE GULF OF CALIFORNIA, MEXICO

Abstract

The pen shell (Atrina maura) is a filter-feeder bivalve that may accumulate metals in its body. The objective of this study was to determine seasonal concentrations of copper (Cu), chromium (Cr), cadmium (Cd), nickel (Ni), lead (Pb), arsenic (As), zinc (Zn), and mercury (Hg) in soft tissue and muscle of A. maura cultivated in a farm located in the southeastern coast of the Gulf of California from summer 2011 to summer 2012. Except for Cu, the higher metal concentrations were found during the dry season (winter 2011-spring 2012). The mean values in soft tissue fluctuated from 0.064 ± 0.01 µg/g (dry weight [dw]) for Hg to 485.66 ± 71.12 µg/g (dw) for Zn, while for muscle they varied from 0.058 ± 0.03 µg/g (dw) for Hg to 64.83 ± 4.90 µg/g (dw) for Zn. Concentrations of cadmium (18.15 µg/g in soft tissue and 1.82 µg/g in muscle, wet weight [ww]) and lead (2.31 µg/g in soft tissue, ww) exceeded the permissible limits (36.3, 3.64, and 2.31 times, respectively) recommended by the sanitary regulations of the official mexican standards. The results suggest that variation of metal levels in cultivated pen shell could be influenced by seasonality and anthropogenic activities such as agriculture and aquaculture developed around the culture zone. Continual monitoring of metals in farmed pen shell is recommended.Palabras clave: concentración de metales, variación estacional, bivalvos, cultivo, monitoreo RESUMEN El callo de hacha (Atrina maura) es un bivalvo filtrador que puede acumular metales en su cuerpo. El objetivo de este trabajo fue determinar las concentraciones estacionales de cobre (Cu), cromo (Cr), cadmio (Cd), níquel (Ni), plomo (Pb), arsénico (As), zinc (Zn) y mercurio (Hg) en tejido suave y músculo de A. maura proveniente de una granja del sureste del Golfo de California, del verano de 2011 al verano de 2012. Las concentraciones más altas de todos los metales, con excepción del Cu, se encontraron en la estación de secas (invierno 2011-primavera 2012). Los valores promedio (peso seco) en A.M. Góngora-Gómez et al. 58el tejido suave fluctuaron de 0.064 ± 0.01 µg/g para Hg a 485.66 ± 71.12 µg/g para Zn, mientras que en músculo variarion de 0.058 ± 0.03 µg/g para Hg a 64.83 ± 4.90 µg/g para Zn. Las concentraciones promedio en peso húmedo para cadmio (18.15 µg/g en tejido suave y 1.82 µg/g en músculo) y plomo (2.31 µg/g en tejido suave) excedieron los límites permitidos (36.3, 3.64 y 2.31 veces, respectivamente) por la regulación sanitaria de las Normas Oficiales Mexicanas. Los resultados sugieren que la variación de metales encontrada en el callo de hacha pudo estar influida por la estacionalidad y las actividades antropogénicas desarrolladas en los alrededores de la zona de cultivo, como agricultura y acuacultura. Se recomiendan monitoreos continuos de metales en callo de hacha cultivado.

TRACE METALS IN TWO WILD POPULATIONS OF THE SQUALID CALLISTA CLAM (Megapitaria squalida) IN THE SOUTHEASTERN GULF OF CALIFORNIA, MEXICO

“…For instance, Frías-Espericueta et al ( 2008) obtained higher Cu (21-73.2 µg/g dw) and Cd (1.8-7.2 µg/g dw) levels, but lower Pb (2.6-8.7 µg/g dw) burdens in a wild bank of the pleasure oyster (Crassostrea corteziensis) from the Altata bay. The Zn (1-1.66 µg/g dw), Cr (0.4-1 µg/g dw), Ni (0.33-2.3 µg/g dw), Pb (0.66-2 µg/g dw), and As (0.2-0.57 µg/g dw) concentrations reported by Góngora-Gómez et al (2018) in the muscle of the pen shell (Atrina maura) cultivated at a farm located between the two sample sites were lower than the levels we obtained for Zn (2.44-5.16 µg/g dw), Cr (3.51-9.76 µg/g dw), Ni (2.49-8.55 µg/g dw), Pb (6.68-14.45 µg/g dw), and As (0.4-1.82 µg/g dw). Muñoz-Sevilla et al ( 2017) registered variations of Cu (10.2-26.6 µg/g dw), Cd (0.8-3.8 µg/g dw), Pb (1.3-3.6 µg/g dw), Zn (57.2-219.4 µg/g dw), and Hg (0.02-0.11 µg/g dw) in Pacific oysters (C. gigas) cultivated near the Agiabampo bay.…”

“…To analyze the metal burdens, the clam soft tissue samples (1-1.5 g dw) were digested with 3 ml of 70 % NHO 3 and 0.5 ml of 30 % H 2 O 2 using a microwave digestor (Parr Physica Multiwave Six Place) at 300 W for 5 min, then at 600 W for 10 min, which proved to be satisfactory for an adequate digestion of samples. Digestions were performed and stored until metal analysis as described by Góngora-Gómez et al (2018).…”

“…Marine bivalves feed selectively, filtering large volumes of seawater through their gills (Silvester et al 2005) with which they trap suspended materials and sediments, phytoplankton, fecal pellets, detritus, and high molecular weight substances (Liu and Deng 2007) that are eventually ingested. Thus, metals associated with the aqueous phase, food, and sediments accumulate in the shells (Cravo et al 2002) and soft tissues of these organisms (Góngora-Gómez et al 2018).…”

A Study on the Distribution and Level of Cadmium in Scallop Bractechlamys vexillum (Reeve 1853) from the Visayan Sea, Philippines

“…Such seasonal fluctuations were largely correlated with seasonal changes in flesh weight during the development of gonatic tissues (Otchere 2003;Bustamante and Miramand 2005). A similar increase of cadmium levels during the dry season was observed by Góngora-Gómez et al (2018). Contrary to these results, Bjerregaard and Depledge (1994) concluded that cadmium uptake and bioaccumulation in crustaceans and mollusks are higher at low salinities during the rainy season.…”

Bioaccumulation of Trace Metals in Oyster (Crassostrea gasar) from the Milliardaires Bay (Ebrié Lagoon, Côte d’Ivoire)

“…The minimum and maximum Cd as μg/g detected in C. gasar tissue were 0.16 μg/g in ST2 (also ST4) and 6.08 μg/g in ST6. Some of Cd levels in bivalves reported in the literature were in the range of 0.6 to 1.25 mg/kg ww with an average value of 16.6 mg/kg ww in Boulay Island 15 , 0.6-1.03 μg/g ww in C. gasar from a lagoon in Togo 16 , 1.93-62.62 μg/g dw 27 , 23-33 dw 28 , 0.001-0.13 mg/g dw 11 . C. gasar inhabiting in NIGER Delta was thus more contaminated with Cd than those of the Milliardaires Bay.…”