The response of cultured meiofaunal and benthic foraminiferal communities to lead exposure: Results from mesocosm experiments

Abstract

Lead (Pb) is regarded as a highly toxic element that poses a serious threat to biota. A mesocosm experiment was performed to assess the influence of Pb on meiofaunal (metazoans within 45-500 μm) and benthic foraminiferal (protozoan) communities. To this end, sediments bearing such communities were incubated in mesocosms, exposed to different levels of Pb in seawater, and monitored for up to 8 wk. Concentrations of Pb <1 ppm in water did not promote a significant increase of this metal in sediments. Relatively high concentrations of Pb seemed to affect meiofaunal and benthic foraminiferal communities by reducing their richness or diversity, and the abundance of the most sensitive taxa. The mesocosm approach can be considered an effective method to document the responses of meiofaunal and benthic foraminiferal communities to various kinds and concentrations of pollutants over time. This approach allows the evaluation of dose-response relationships, validates the outcomes of field studies, and possibly confirms the sediment quality guidelines and thresholds. Environ Toxicol Chem 2018;37:2439-2447. © 2018 SETAC.

Sources and Metal Pollution of Sediments from a Coastal Area of the Central Western Adriatic Sea (Southern Marche Region, Italy)

“…Generally, natural metal concentrations in sediments are not detrimental to inhabiting organisms [30]. For metabolism, organisms essentially require some key micronutrients (i.e., iron, copper, zinc, manganese, cobalt) [31] but at high metals concentration can pose a toxicological threat to marine organisms [8,32,33]. Sediment features such as mineralogy, sediment texture, metal properties, pH, organic matter, oxidation-reduction potential, and adsorption and desorption processes are important controlling factors for the accumulation and availability of heavy metals in the sediment [34][35][36][37][38][39][40][41][42].…”

Shell Growth of Large Benthic Foraminifera under Heavy Metals Pollution: Implications for Geochemical Monitoring of Coastal Environments

“…This study was promoted by the recent efforts of using benthic foraminiferal shells' geochemistry as reliable and accessible living data loggers for HMs in seawater. Several laboratory experiments and field studies were set to find the HMs' threshold concentrations and their effect on the foraminifera growth rates and population response [20][21][22][23][24][25][26][27][28], pseudopodia activity [22,24,29], symbionts response [30], cytological and morphological alterations [20,25,[28][29][30][31][32][33][34][35][36] (i.e., their vitality), as well as the partition coefficients of HMs between the foraminifera shell and the ambient seawater [4,21,37,38]. Previous studies have examined the physiological response of different benthic foraminifera species to very extreme conditions of 10-500 µg L −1 (120 days) [31] and 3-11 µg L −1 Cu (82 days) [21], and 0-20 mg L −1 Cd (30 days) [22] that are orders of magnitude higher than its 'typical' ambient concentrations.…”

Benthic Foraminiferal Response to Sedimentary Processes in a Prodeltaic Environment: The Gulf of Patti Case Study (Southeastern Tyrrhenian Sea)

“…However, under specific conditions (i.e., anoxic environments), the accuracy of this method may be affected by the presence of undecayed protoplasm, which can persist for weeks or months after death [57,[59][60][61]. While the staining criteria are confidently applied to the superficial samples, ambiguities may arise in the case of deeper intervals [62], commonly consisting of a slight overestimation of the living assemblages [63].…”