BENZO[a]PYRENE AND ZINC SOLUBILIZATION BY DIGESTIVE FLUIDS OF BENTHIC INVERTEBRATES—A CROSS-PHYLETIC STUDY

Abstract

Contaminant bioavailability via digestive exposure was examined for 18 species of marine benthic invertebrates, using incubation of digestive fluids with sediments that were spiked with either radiolabeled benzo-[a]-pyrene (BaP) or zinc. Interphyletic trends in contaminant solubilization were compared with measures of digestive biochemistry, including enzyme activities, surfactancy, pH, and fluid phase organic carbon, amino acids, and lipids. Contaminant solubilization ranged from values equal to that of a seawater control to as much as an order of magnitude higher but were lower than those obtained with commonly used chemical extractants. Digestive fluids from echinoderms and a cnidarian tended to be relatively weak, those from polychaetes and echiurans were relatively strong, and those from taxa such as sipunculans and mollusks were intermediate. These trends correlated strongly with concentrations or activities of digestive biochemicals but not with pH. These correlations are consistent with previous work on mechanisms of digestive solubilization of polycyclic aromatic hydrocarbons (PAH) and metals, though strong covariance among digestive parameters does not allow this approach to be used for identification of specific mechanism(s).

Digestive bioavailability to a deposit feeder (Arenicola marina) of polycyclic aromatic hydrocarbons associated with anthropogenic particles

“…Ingestion of contaminated sediment is a major route of exposure to hydrophobic organic contaminants for deposit feeders [20,22,27,28]. Benthic organisms can accumulate contaminants through interstitial water and dietary exposures.…”

From Incorporation to Toxicity

“…Other examples of extraction methods are provided in the review by Hunter et al (2011). Biological extractants such as digestive fluids of endobenthic invertebrates (polychaetes, sipunculans) and fish have been also used for the extraction of trace elements, polyaromatic hydrocarbons (PAHs), or PCBs (Mayer et al, 1996(Mayer et al, , 2001Weston and Maruya, 2002;Goto and Wallace, 2009;Baumann et al, 2012;Wang et al, 2012). Artificial gut fluids consisting of chemical extractants able to recreate conditions relatively similar to those encountered in guts of invertebrates or fish were also used, such as acid solutions at physiological pH levels for metal extraction (Amiard et al, 1995Ettajani et al, 1996;Peña-Icart et al, 2014) or sodium dodecyl sulfate for PAHs (Ahrens et al, 2005).…”

Particulate Organic Detritus and Detritus Feeders in Coastal Food Webs

“…Deposit-feeding detritivores can be distinguished from her bivores (or other live-cell feeders) by high enzyme activities (especially protease) and high surfactancies (Mayer et al, 1997(Mayer et al, , 2001Ahrens et al, 2001aAhrens et al, , 2001b. They subsist on food that is poor, dilute, and remarkably variable in digestibility and nutri tional quality (Lopez and Levinton, 1987).…”