Relevance of intracellular partitioning of metals in prey to differential metal bioaccumulation among populations of mummichogs (Fundulus heteroclitus)

Abstract

Intracellular partitioning of trace metals is critical to metal tolerance in aquatic organisms and may also influence metal trophic transfer in ecosystems. In this study, we tested the relevance of metal (Cd, Cu, Pb, and Zn) intracellular partitioning in prey as an indicator of metal trophic availability to benthic forage fish, mummichogs (Fundulus heteroclitus), in chronically metal-polluted salt marshes in New York, USA. Two common prey of mummichogs in the study area, Palaemonetes pugio and Nereis acuminata, generally stored increasingly higher proportions of non-essential metals (particularly Pb) in insoluble (less trophically available) cellular components, as the whole body burdens increased. In contrast, intracellular partitioning of essential metals (Cu and Zn) in invertebrate prey varied relatively little among sites. Differential Cd and Pb intracellular partitioning patterns within P. pugio among sites were significantly associated with Cd and Pb whole body burdens in mummichogs, respectively (i.e., prey-driven bioreduction of metals), while bioaccumulation of Cu and Zn in mummichogs was similar among populations. The findings in this study suggest that metal intracellular partitioning within prey may be partially responsible for metal trophic availability to a predator in metal-polluted habitats, while there was also evidence that some predator-dependent processes may offset differential trophic availabilities from prey.

Metal intracellular partitioning as a detoxification mechanism for mummichogs (Fundulus heteroclitus) living in metal-polluted salt marshes

“…In the current study, the lack of difference in Pb whole body burden ($0.72 lg g À1 dry weight) in mummichogs among the populations (except for the Mill Creek population, 1.3 lg g À1 dry weight) appeared to reflect Pb whole body burdens ($0.71 lg g À1 dry weight) in prey (grass shrimp), rather than sediment-associated Pb concentrations (84-660 lg g À1 dry weight) (Goto and Wallace, 2009). However, there were substantial differences in Pb intracellular partitioning among the populations.…”

“…The results of the present study suggest that metal whole body burdens in mummichogs generally reflect those in prey, rather than sediment-associated metal concentrations, indicating the importance of food as metal exposure pathways in the field (Goto and Wallace, 2009). Furthermore, metal intracellular partitioning within mummichogs revealed some subtle differences in metal handling capacities among the populations, which may be associated with potential mechanisms to tolerate elevated concentrations of trace metals available in the environment.…”

“…1, Table 1: trace metal data from Goto and Wallace, 2009). Neck Creek is polluted with various chemicals due to its proximity to many oil refineries as well as abandoned industrial facilities.…”

“…In fact, only concentrations of Pb associated with MRG consistently increased with the whole body burdens, suggesting a potential indicator for physiological responses to Pb by mummichogs. Studies on aquatic invertebrates living in metal-polluted environments have reported that Pb is often preferentially (P60%) partitioned to insoluble fractions (e.g., Cain et al, 2000;Goto and Wallace, 2009). Metal-tolerant aquatic insects living in highly metal-polluted streams, for instance, sequester a substantial amount of Pb (more than 95% of the whole body burdens) into an insoluble cellular component (Cain et al, 2000).…”

Trace Metal Accumulation in Sediments and Benthic Macroinvertebrates before and after Maintenance of a Constructed Wetland

“…Once thawed, the samples were placed into pre-weighed, acid-washed vials and dried in an oven at 105 °C. After determination of dry weights, samples were suspended in 70% nitric acid (HNO3) and digested on a hot plate for 3 to 4 days per Goto and Wallace (2009). After digestion, samples were dried on a hot plate, resuspended in 5 mL of 2% HNO3, and passed through a 0.4-|j.m filter.…”