Accumulation of current‐use and organochlorine pesticides in crab embryos from northern California, USA

Abstract

Invertebrates have long been used as resident sentinels for assessing ecosystem health and productivity. The shore crabs, Hemigrapsus oregonensis and Pachygrapsus crassipes, are abundant in estuaries and beaches throughout northern California, USA and have been used as indicators of habitat conditions in several salt marshes. The overall objectives of the present study were to conduct a lab-based study to test the accumulation of current-use pesticides, validate the analytical method and to analyze field-collected crabs for a suite of 74 current-use and legacy pesticides. A simple laboratory uptake study was designed to determine if embryos could bioconcentrate the herbicide molinate over a 7-d period. At the end of the experiment, embryos were removed from the crabs and analyzed by gas chromatography/mass spectrometry. Although relatively hydrophilic (log K(OW) of 2.9), molinate did accumulate with an estimated bioconcentration factor (log BCF) of approximately 2.5. Following method validation, embryos were collected from two different Northern California salt marshes and analyzed. In field-collected embryos 18 current-use and eight organochlorine pesticides were detected including synthetic pyrethroids and organophosphate insecticides, as well as DDT and its degradates. Lipid-normalized concentrations of the pesticides detected in the field-collected crab embryos ranged from 0.1 to 4 ppm. Pesticide concentrations and profiles in crab embryos were site specific and could be correlated to differences in land-use practices. These preliminary results indicate that embryos are an effective sink for organic contaminants in the environment and have the potential to be good indicators of ecosystem health, especially when contaminant body burden analyses are paired with reproductive impairment assays.

Irrigation-induced pollution of organochlorine pesticides and polychlorinated biphenyls in paddy field ecosystem of Liaohe River Plain, China

“…However, the average lipid-basis concentration of ∑DDT in loaches (418.89 ng g −1 ) was higher by 2.2 times than that in mitten-handed crabs (137.70 ng g −1 ). Compared with published data, the total DDT concentrations in mitten-handed crabs from this study were comparable to those (mean, 12.8 ng g −1 ww) in sea crabs (Scylla serrata and Ovalipes punctatus) collected from South China [25], but were less than those in river crabs (526−821 ng g −1 lw) collected from Qiangtang River of China [26], and also less than those in most of sand crabs (43-13000 ng g −1 lw) along the California coast [20,27,28]. Moreover, the total DDT contents in loaches determined in this study were found to be less than those (125−127 ng g −1 ww) in rice field eel (Monopterus albus) obtained from Hong Kong markets [29].…”

“…Mitten-handed crab and loach both have the habit to dig deep burrows in the mud, and thus they have the higher potential to accumulate the hydrophobic organic pollutants from the mud. Several studies indicated the site specific bioaccumulation of organochlorine pesticides and PCBs in crab, and suggested crab embryo as a good indicator of ecosystem health [19,20]. Therefore, a great concern should be paid to the health risk of consuming mitten-handed crab and loach cultivated in rice field.…”

Interannual variability in an atlas of trace element signatures for determining population connectivity

“…For example, Bodega Harbor is a tidally flushed estuary that experiences negligible freshwater runoff during summer and fall but substantial runoff events during winter and spring. In particularly rainy winters, Petrolisthes cinctipes in Bodega Harbor is exposed to greater volumes of freshwater runoff as well as increased concentrations of pollutants, such as fertilizers, pesticides, herbicides, and automobile fluids (Smalling et al 2010). Freshwater runoff and pollutants may strongly affect the trace element signature of water masses and embryos in Bodega Harbor in a wet year, such as 2006 (124.5 cm rainfall), whereas the signature would be more heavily influenced by the influx of seawater during a dry year, such as 2008 (72.4 cm rainfall; data collected by the Bodega Ocean Observing Node at 38°19.110' N, 123°04.294' W; http:// bml.…”

“…We created a site atlas for the porcelain crab Petrolisthes cinctipes because crabs are excellent candidates for trace-element studies. Embryos are brooded externally and incorporate trace elements from substrates as well as surrounding waters, resulting in distinctive signatures (Anderson et al 2006, Smalling et al 2010.…”

Trace element signatures in larval soft tissues reveal transport, but not population connectivity

“…This species is an excellent candidate for trace element studies because (1) embryos are brooded externally and take up trace elements from substrates as well as surrounding waters (Anderson et al 2006, Smalling et al 2010, resulting in distinctive signatures along the open coast of northern California, USA , and (2) larvae molt through only 2 larval stages before metamorphosing to postlarvae after approximately 42 d (Shanks & Eckert 2005). In this study, we (1) collected embryos from sites with distinctive trace element signatures and reared larvae in seawater from a common source in the laboratory; (2) extracted and analyzed soft tissues from each developmental stage; and (3) compared elemental signatures from the larval and postlarval stages to the embryos obtained from each site.…”