Pedro A. Reis

Metal levels in sediments from the Minho estuary salt marsh: a metal clean area?

Total-recoverable metals (Al, Cr, Cu, Fe, Mn, Ni, Pb and Zn) in sediments from Minho estuary salt marsh were determined to evaluate possible increase in anthropogenic contamination by metals and to evaluate the possibility of this area to be considered a pristine area in terms of metals, which can be used as a reference site for other metal-contaminated national and international estuaries/salt marshes. This study revealed that the spatial distribution of metals in the salt marsh sediments was not homogeneous and that two sampling sites (sites 5 and 7) had indications of anthropogenic contamination. However, metal levels in these salt marsh sediments were lower than those observed in the wetlands of the main Portuguese estuaries. Comparison with Portuguese and international reference values used in the evaluation of the ecological quality of sediments, indicated that the sediments can be classified as “clean sediment” and that metal levels were lower or similar (only for Cu and Ni) to the values of ERL, which are the values that define the concentrations ranges that are rarely associated to adverse biologic effects in organisms. In addition, metal levels in the sediments were in chemical forms that were not easily available to organisms, indicating that these sediments probably will not have negative influences in the organisms living in the salt marsh, although no life-form ecological safety tests have been carried out. Therefore, the Minho estuary salt marsh area can probably be considered a pristine area in terms of metals and can be used as a reference for other metal-contaminated estuaries/salt marshes.

Fucus spiralis as monitoring tool of metal contamination in the northwest coast of Portugal under the European Water Framework Directives.

Metals (Cd, Cr, Cu, Fe, Mn and Zn) in coastal seawaters and soft tissues of macroalga Fucus spiralis from the northwest coast of Portugal were determined to assess spatial variations of metal bioavailabilities and bioaccumulation factors to compare different ecological quality classifications. Both coastal seawaters and soft tissues of F. spiralis showed significant spatial variations in their metal concentrations along the coast. The macroalgae F. spiralis accumulated more efficiently Cd, Mn and Zn and showed low bioaccumulation factors to Cr, Cu and Fe. Regarding the metal guidelines of the Norwegian Pollution Control Authority, the entire northwest (NW) coast of Portugal in April 2013 should be classified as ‘class I—unpolluted’ for all metals, except in Ave for Cu (‘class II—moderately polluted’) and Cavado for Cd and Cu (‘class II—moderately polluted’), revealing the low metal bioavailabilities of these seawaters. As there were always significant positive correlations between all metals in seawaters and F. spiralis, this macroalga species was considered a suitable monitoring tool of metal contamination in the NW coast of Portugal and a useful aquatic organism to be included in the European Environmental Specimen Banks in order to establish a real-time environmental monitoring network under the European Water Framework Directives.

A fast and simple methodology for determination of yttrium as an inert marker in digestibility studies

The need to develop a fast, simple and low cost methodology for the determination of yttrium in fish diets and faeces using a microwave digestion system and atomic absorption spectrometry with flame atomization analysis was the main aim of this study. The final methodology consisted in the digestion of approximately 300mg of dry fish diet or 100mg of dry fish faeces in teflon vessels using Parr reactor bombs, at high pressure, in a domestic microwave system with nitric acid solution. After digestion, 330μl of a 120mg potassium nitrate/ml solution was added to each solution. Yttrium was determined using a calibration with aqueous standards. Analytical difficulties and problems encountered during the optimizations were overcome and the application of the final methodology to the fish diets and faeces samples was carried out with suitable results.

Effects of subtle pollution at different levels of biological organisation on species-rich assemblages

We investigated effects of subtle nutrient enrichment and metal pollution on different levels of biological organization (i.e. whole assemblage, population and individual) of species-rich assemblages. We used rockpools as model system, applying a multi-factorial sampling design to test hypotheses on differences between disturbed and reference locations. Results indicated that disturbed and reference locations supported similar assemblages, as well as individual fitness-related life-traits were ineffective to discriminate between the two conditions. In contrast, assemblages responded to pollution through a reduction of the abundance of sensitive species and a proliferation of tolerant species, although these alterations were detectable only once the influence of dominant taxa was down-weighed by data transformation. Present findings suggest that, contrarily to individual level variables, assemblage structure after data transformation and patterns of distribution and abundance of differently sensitive taxa would be a powerful tool to detect effects of subtle pollution on species-rich assemblages.

Pollicipes pollicipes as a Biomonitor of PAHs Contamination in Seawaters of the Northwest Coast of Portugal

ABSTRACT Simple, fast, and economic solid phase microextration–gas chromatography–mass spectrometry (SPME–GC–MS) methods were validated for the determination of 8 United States Environmental Protection Agency priority polycyclic aromatic hydrocarbons (PAHs: naphthalene, acenaphthylene, acenaphthene, fluorene, phenanthrene, anthracene, fluoranthene and pyrene) in coastal seawaters and soft tissues of goose barnacles Pollicipes pollicipes. Under the optimized conditions, the limits of detection ranged from 0.012 to 1.069 ng L−1 and 0.002 to 0.061 µg kg−1 (dry weight basis) for seawaters and soft tissues, respectively. Precision varied between 3.9% and 20.0% for seawaters and between 8.4% and 19.1% for soft tissues, which are acceptable repeatabilities for environmental analyses. Finally, the accuracy of the optimized conditions also showed suitable recoveries, varying between 81.5% and 105.5% in spiked seawater samples and between 88.0% and 103.4% in the standard reference material for organics in mussel tissues (NIST SRM 2977). These methods were applied to a monitoring program performed along the northwest coast of Portugal during four seasons in 2011 in order to assess the levels of these compounds present in coastal waters and in the tissues of goose barnacles, one food resource of high commercial value. The results showed that although the concentrations of PAHs in seawaters and P. pollicipes varied significantly along the coast and between seasons (p < 0.05), in general the concentrations in seawater can be classified as “Class II – Good/Natural Background Concentrations” during the four seasons of 2011. As for the concentrations of PAHs in P. pollicipes, they were positively correlated (p < 0.05) with their concentrations in seawater, indicating that P. pollicipes may be an adequate biomonitor species of PAHs availabilities along the coast of Portugal throughout the year.

The spatial and seasonal variation of trace metals in coastal seawater and soft tissue of Chthamalus montagui around the northwest coast of Portugal

Metal concentrations (Cd, Cr, Cu, Fe, Mn and Zn) were determined in seawaters and soft tissues of Chthamalus montagui from the northwest coast of Portugal during the four seasons of 2011. The main objectives of this work were to assess seasonal and spatial variations of metals in order to detect hot spots of contamination, to establish correlations between metals in coastal seawaters and C. montagui and to calculate metal bioaccumulation factors (BAFs) in each season. Metal concentrations in coastal seawaters ranged within Cd: 1.2–35 ng L−1; Cr: 15–87 ng L−1; Mn: 77–1763 ng L−1; Cu: 126–1819 ng L−1; Fe: 430–4048 ng L−1 and Zn: 2889–16867 ng L−1 and in C. montagui ranged for Cd: 0.39–1.98 mg kg−1; Cr: 0.45–3.13 mg kg−1; Cu: 0.93–5.70 mg kg−1; Mn: 2.2–20.4 mg kg−1; Fe: 135–707 mg kg−1 and Zn: 119–782 mg kg−1. Significant spatial and seasonal variations were found between: (i) metal concentrations in seawaters and C. montagui tissues; (ii) the distribution of metal concentrations in C. montagui tissues were Fe > Zn > Mn > Cu > Cr > Cd and (iii) C. montagui showed higher bioaccumulation factors for Fe and Cd than for Cu, Mn and Zn in all seasons. Regarding the metal concentrations accumulated in C. montagui tissues during each season of 2011, the ecological quality classifications of the NW coast of Portugal varied from “Class I–Unpolluted” to “Class III–Remarkably Polluted”.

Barnacle species as biomonitors of metal contamination in the northwest coast of Portugal: Ecological quality classification approach

ABSTRACT This work discusses the simultaneous use of barnacles C. montagui and P. pollicipes as biomonitors of metal (Cd, Cr, Cu, Fe, Mn, and Zn) contamination in the northwest (NW) coast of Portugal during the four seasons of 2011. The metal concentrations in soft tissues of both barnacles species, metal bioaccumulation factors (BAFs), and ecological quality classifications of coastal waters are presented. The most and the least metal-contaminated locations were, respectively, location 5 (“Cabo do Mundo”) and location 10 (“Moledo”). The most and the least metal-contaminated seasons of 2011 were, respectively, autumn and winter. Temporal comparisons with previous works of 2009–2011 showed that C. montagui bioaccumulated Cd, Cr, and Fe at higher rates and P. pollicipes accumulated more Zn besides Cd and Fe. In addition, global mean BAFs showed that the best season to collect both barnacle species for metal contamination assessment/monitoring purposes in future works would be spring and that P. pollicipes would be the best barnacle species to monitor metals. In terms of ecological quality classification, all NW coast of Portugal should be classified as “Class III – Remarkably Polluted” due the high concentrations of Zn found in barnacles species during the four seasons of 2011. This work suggested that both barnacle species are suitable species to be included in the Portuguese Environmental Specimen Banks under European Marine Strategy Framework Directive 2008/56/EC.