Ecological quality assessment of estuarine macrobenthic communities using an integrative approach.

Macrobenthic communities play a crucial role in the functioning of estuarine ecosystems and serve as bioindicators of environmental quality. This study assessed the ecological quality of an estuarine system using the AMBI and M-AMBI indices. The following parameters were considered: (i) environmental factors (total organic matter, organic carbon, grain size, calcium carbonate), (ii) sediment trace metals (Pb, Zn, Cu, Cr, Co, Ni, Hg, Li, As), (iii) species composition (morphological and molecular identification), and (iv) anthropogenic activities.

Spatial distribution and temporal trends of butyltin compounds (TBT, DBT & MBT) in short sediment cores of the SW Portuguese Shelf (western Iberian Margin, NE Atlantic).

Spatial patterns and temporal trends of the butyltin compounds tributyltin (TBT), dibutyltin (DBT), and monobutyltin (MBT) were investigated in a set of sediment samples collected along the SW Portuguese continental shelf. This region did not reach the Good Environmental Status (GES) in accordance with the Marine Strategy Framework Directive (MSFD) during a first evaluation carried out in 2012. Overall, MBT and DBT were the predominant organotin species detected, but high concentrations of TBT were found in and around disposal sites for dredge sludge derived from the dredging in navigation channels, harbours, and shipyard facilities of the Tagus and Sado estuaries.

Elemental composition of whole body soft tissues in bivalves from the Bijagós Archipelago, Guinea-Bissau.

Marine bivalves are bioindicators of coastal environmental pollution, integrating monitoring programs worldwide. Nonetheless, the choice of particular species as an indicator requires validation, achieved by understanding the differences in element concentrations among and within species. The present study compares the chemical composition of whole body soft tissues of four common bivalve species from the Bijagós Archipelago, a pristine region of West Africa.

Rare earth and trace elements in deep-sea sponges of the North Atlantic.

The available data on trace elements (TE) of deep-sea organisms is scarce and nonexistent for rare earth elements (REE). Hence, this study characterizes REE and TE in five porifera genera (Jaspis, Geodia, Hamacantha, Leiodermatium, Poliopogon) collected in deep-sea areas (between 481 and 2656 m) of the North Atlantic. Aluminium was the most common TE while lead was the less abundant.

Influence of diagenetic processes and terrestrial/anthropogenic sources in the REE contents of the Cascais submarine canyon (Iberian western coast).

Temporal variations of rare earth elements (REE) and their fractionation patterns, major elements, Pb and Hg were determined in two multicores collected at 445 and 2100 m water depth (mwd) in the Cascais submarine canyon (CSC). The PAAS-normalized REE patterns suggest mixing of Tagus estuarine and marine sediments, marked by MREE (Nd-Dy series) enrichment and by positive Eu-anomaly, with marine sediments. The positive Eu/Eu* implies incorporation of detrital feldspar minerals derived from the estuary.

Sources and distribution of yttrium and rare earth elements in surface sediments from Tagus estuary, Portugal.

The distribution and sources of yttrium and rare-earth elements (YREE) in surface sediments were studied on 78 samples collected in the Tagus estuary (SW Portugal, SW Europe). Yttrium and total REE contents ranged from 2.4 to 32mg·kg and 18 to 210mg·kg, respectively, and exhibited significant correlations with sediment grain-size, Al, Fe, Mg and Mn, suggesting a preferential association to fine-grained material (e.

Insights of Pb isotopic signature into the historical evolution and sources of Pb contamination in a sediment core of the southwestern Iberian Atlantic shelf.

Stable Pb isotopic ratios and concentrations of Al, Cu and Pb were measured in a 5m long sediment core (VC2B) retrieved at 96m water depth in the southwestern Iberian Atlantic shelf. Five phases during the last 9.5kyrs were identified, two of them (Roman Period and modern mining) marked by a decrease of Pb/Pb ratios reflecting additional inputs of Pb derived from mining activities.

Footprint of roman and modern mining activities in a sediment core from the southwestern Iberian Atlantic shelf.

A 5-m long sediment core (VC2B), retrieved in the Southwestern Iberian Atlantic shelf, at 96m water depth, was used to assess major changes in climate and human activities during the last 9.7kyrs. Analytical measurements included sedimentological (mean grain size, and the contents of sand, silt and clay), geochemical (major, minor, trace and rare earth elements; REEs) and chronological ((210)Pb and (14)C) parameters.

Reconstruction of organochlorine compound inputs in the Tagus Prodelta.

Twenty century time-resolved variability of riverine deposits of polychlorobiphenyls (PCBs), DDTs, hexachlorocyclohexanes (HCHs) and hexachlorobenzene (HCB) was studied in three (210)Pb dated sediment cores collected in a depositional shelf area adjacent to the Tagus estuary (the Tagus Prodelta). The geographic and temporal distribution patterns were consistent with discharge of these organochlorine compounds (OCs) in the area associated with the Tagus mouth. Their concentrations were not correlated with the sedimentary total organic carbon.

Comparing spatial and temporal changes in metal trends (Cr, Ni, Pb and Zn) on the Portuguese shelf since the 1970s.

Comparison between an archive dataset, collected during the 1970s (1974-1977), and samples taken during the PALEO1 cruise (2002) enabled evaluation of large-scale and long-term spatiotemporal changes in Al, Cr, Ni, Pb and Zn contents in bulk surface sediments in four areas of the Portuguese shelf. The so-called gradient method (GM) with normalisation to Al, a proxy for terrigenous clay content, was applied. The studied areas are distributed from north to south along the western margin, with the northernmost located off shore the Ave and Douro rivers, a central one located off shore the Lis River and a southern one located off shore the Mira River.

Temporal evolution of lead isotope ratios in sediments of the Central Portuguese Margin: a fingerprint of human activities.

Stable Pb isotope ratios ((206)Pb/(207)Pb, (208)Pb/(206)Pb), (210)Pb, Pb, Al, Ca, Fe, Mn and Si concentrations were measured in 7 sediment cores from the west coast of the Iberian Peninsula to assess the Pb contamination throughout the last 200 years. Independently of their locations, all cores are characterized by increasing Pb/Al rends not related to grain-size changes. Conversely, decreasing trends of (206)Pb/(207)Pb were found towards the present.

Evaluation of the contamination of platinum in estuarine and coastal sediments (Tagus Estuary and Prodelta, Portugal).

Platinum contamination in estuarine and coastal sediments has been evaluated in three cores collected from the Tagus Estuary and Prodelta shelf sediments. Elevated concentrations, up to 25-fold enrichment compared to background values, were found in the upper layers of the estuarine sediments. The degree of Pt enrichment in the estuarine sediments varied depending on the proximity to vehicular traffic sources, with a maximum concentration of 9.