Climate change facilitated the early colonization of the Azores Archipelago during medieval times.

Humans have made such dramatic and permanent changes to Earth's landscapes that much of it is now substantially and irreversibly altered from its preanthropogenic state. Remote islands, until recently isolated from humans, offer insights into how these landscapes evolved in response to human-induced perturbations. However, little is known about when and how remote systems were colonized because archaeological data and historical records are scarce and incomplete. Here, we use a multiproxy approach to reconstruct the initial colonization and subsequent environmental impacts on the Azores Archipelago. Our reconstructions provide unambiguous evidence for widespread human disturbance of this archipelago starting between 700-60+50 and 850-60+60 Common Era (CE), ca. 700 y earlier than historical records suggest the onset of Portuguese settlement of the islands. Settlement proceeded in three phases, during which human pressure on the terrestrial and aquatic ecosystems grew steadily (i.e., through livestock introductions, logging, and fire), resulting in irreversible changes. Our climate models suggest that the initial colonization at the end of the early Middle Ages (500 to 900 CE) occurred in conjunction with anomalous northeasterly winds and warmer Northern Hemisphere temperatures. These climate conditions likely inhibited exploration from southern Europe and facilitated human settlers from the northeast Atlantic. These results are consistent with recent archaeological and genetic data suggesting that the Norse were most likely the earliest settlers on the islands.

Effect of Previous Frozen Storage, Canning Process and Packing Medium on the Fatty Acid Composition of Canned Mackerel.

This study addressed the fatty acid (FA) composition of canned Atlantic mackerel (Scomber scombrus). In it, the effect of prior frozen storage (6 months at −18 °C), different packing media (water, brine, and sunflower, refined and extra virgin olive oils), and canning procedure was investigated. As a result, the canning procedure led to a decrease (p < 0.05) in saturated FA (STFA) levels, an increase (p < 0.05) in polyunsaturated FA (PUFA) and total ω3 FA values, and higher PUFA/STFA and ω3/ω6 ratio values. Concerning the packing medium effect, the great presence of C18:2ω6 in sunflower oil led to high PUFA and PUFA/STFA values and low ω3/ω6 ratios when compared to other packing media. However, the high presence of C18:1ω9 in both olive oils tested did not lead to remarkable increases (p > 0.05) of this FA presence. Additionally, the presence of total ω3 FAs, C20:5ω3 and C22:6ω3 did not provide differences in canned fish muscle as a result of using different packing media. In all canned samples, ω3/ω6 values were included in the 8.2−10.8 range. Prior frozen storage did not have a substantial effect (p > 0.05) on the FA group (STFA, monounsaturated FA, PUFA, total ω3 FA) and FA ratio (PUFA/STFA and ω3/ω6) values.

Naturally and Anthropogenically Induced Lingulodinium polyedra Dinoflagellate Red Tides in the Galician Rias (NW Iberian Peninsula).

Despite the fact that the first red tide reported on the coasts of the Iberian Peninsula was due to Lingulodinium polyedra, knowledge about their frequency and, particularly, about the environmental conditions contributing to bloom initiation is still scarce. For this reason, L. polyedra bloom episodes were observed and studied in three Galician rias during the summer season based on the 1993-2008 record database period; additionally, samples were collected in summer 2008. Proliferations of L. polyedra occurred in the rias of Ares and Barqueiro in June and August, respectively, while in the Ria of Coruña, they persisted from the end of June to early September. Red tides developed when the surface temperature reached 17 °C, with "seasonal thermal window" conditions, and when salinities were ≥30, i.e., an "optimal salinity window"; when these parameters were lower than these thresholds, cyst germination decreased. A cyst transport mechanism from sediments to the surface must also exist; this mechanism was found to be natural (tidal currents) in the ria of Barqueiro or anthropogenic (dredging) in the rias of Ares and Coruña. Surface temperatures during summer were usually favorable for cyst germination (85 to 100%) during the 1993-2008 period; however, water temperatures below 10 m depth only rarely reached the 17 °C threshold (2 to 18%). During this 16-year period, dredging activities could explain 71% (Coruña) and 44% (Ares) of the recorded bloom events. When a bloom episode developed in early summer, favorable conditions did not lead to a new red tide, probably due to the lag period required by cysts for germination. Moreover, blooms did not develop when high densities of diatoms (>1,000,000 cells·L-1) remained in the water column as a result of summer upwelling pulses occurring in specific years. The temperature-sediment disturbance pattern found in this study provides a useful tool for the prevention of eventual risks resulting from red tides of this dinoflagellate.

Oceanographical Context of the First Bloom of the Silicoflagellate Octactis speculum (Ehrenberg) Recorded to Cause Salmon Mortality in a Galician Ria: Was This Bloom a Rare Event in the Iberian Coast?

Harmful algal blooms are one of the leading causes of mortality in salmon aquaculture, with significant economic consequences. From 15 to 31 October 1996, a bloom of the skeletonized form of Octactis speculum (Ehrenberg) F.H. Chang, J.M. Grieve & J.E. Sutherland was detected in the small Merexo inlet (1.7 km2 area), located on the southern shore of the Ria of Muxía (Galicia, NW Spain). The O. speculum population inside the inlet (data period: 1992-1996) seldom exceeded 4·103 cell·L-1. However, its concentration reached 2·105 cell·L-1 during the bloom, coinciding with a decrease in light penetration from 5 to 2 m deep, as measured using a Secchi disk. Although similar concentrations were reported during late October 1992, this was the first time that a bloom was associated with caged salmon (Salmo salar, Linnaeus 1758) mortality in the Galician coastal waters. This mortality was not associated with anoxia in the water column, but with fish gill irritations and mucus segregation due to gill clogging. Excess nitrate and silicate, the latter being essential for skeleton formation, were measured in the inlet during the bloom, with phosphate acting as the limiting nutrient (high negative correlation). Blooms of O. speculum occurred in autumn-winter, when water was retained within the inlet under meteorological conditions of southwest winds (which prompted downwelling conditions) and clear skies. A review of the oceanographic database of the Galician rias showed that massive O. speculum proliferations are also commonplace in other rias with similar environmental conditions, such as the Ria of Ares-Betanzos, and can therefore constitute a threat for the development of salmon aquaculture on this coast.

Effect of Previous Frozen Storage and Coating Medium on the Essential Macroelement and Trace Element Content of Canned Mackerel.

The effect of previous frozen storage (-18 °C for 6 months) and different coating media (aqueous: water and brine; oily: sunflower, refined olive, and extra-virgin olive oils) on the essential macroelement and trace element content of canned Atlantic mackerel (Scomber scombrus) was studied. Previous frozen storage led to an increased (p < 0.05) content of canned samples of K (oil-coated samples) and Ca (all coating conditions) and to a decreased (p < 0.05) content of P (aqueous-coating samples) and S (water- and oil-coated samples). For trace elements, a content increase (p < 0.05) in Cu and Se (brine-canned samples) and Mn (water- and refined-olive-oil-coated samples) was detected in canned fish muscle with frozen storage. Concerning the coating effect, aqueous-coating samples showed lower (p < 0.05) Mg, P, S, K, and Ca contents than their corresponding oil-coated samples. For trace elements, lower average contents were found for Co, Cu, Mn, Se, and Fe in aqueous-coating fish muscle when compared to their counterparts coated in oily media. Content changes in the different elements in canned fish muscle are discussed based on interactions with other tissue constituents and modifications that such constituents undergo during processing (i.e., protein denaturation, liquor losses from the muscle, lipid changes).

Unprecedented recent regional increase in organic carbon and lithogenic fluxes in high altitude Pyrenean lakes.

We have conducted a monitoring survey and paleolimnological study of a W-E transect of six high altitude lakes (1870-2630 m asl) in the western and central Pyrenees (Spain) to evaluate the regional response to current global change in high altitude Mediterranean mountains. The reconstructed Total Organic Carbon (TOCflux) and lithogenic (Lflux) fluxes during the last 1200 years show the expected variability as lakes differ in altitude, geological and climate settings, limnological properties and human impact history. However, all show unique patterns after 1850 CE, particularly during the Great Acceleration (after 1950 CE). Recent Lflux increase could be related to higher erodibility by rainfall and run-off during the longer snow-free season in the Pyrenees. In all sites, higher TOCflux and geochemical (lower δ13COM, lower C/N) and biological (diatom assemblages) signatures since 1950 CE suggest an increase in algal productivity, likely favored by warmer temperatures and higher nutrient deposition. These recent, unprecedented Lflux and TOCflux increases, in spite of their diverse history and limnological properties of the lakes, demonstrate the regional impact of the Great Acceleration not only in the ecological dynamics of alpine lakes but also in the hydrological cycle in high altitude mountain watersheds.

The vanishing and the establishment of a new ecosystem on an oceanic island - Anthropogenic impacts with no return ticket.

A multiproxy approach was applied to a sediment core retrieved from the deep crater Lake Funda, located in the middle of the North Atlantic Ocean on Flores Island, Azores archipelago (Portugal). The purpose of this study was to determine how this ecosystem responded to natural and anthropogenic forces over the last millennium. We distinguished three main phases in lake evolution using multiproxy reconstructions and documentary sources. (A) Climate and lake catchment processes, as well as internal ones, were the main drivers of ecosystem variability before 1335 CE, when human disturbances were absent in the Lake Funda catchment. (B) The second phase is marked by unprecedented changes in all studied proxies between 1335 and 1560 CE, including abrupt changes in the composition and diversity of diatom and chironomid assemblages. Synergistic effects from high climate variability and the onset of human disturbances in the catchment (e.g., introduction of livestock) during the Medieval Climate Anomaly-Little Ice Age transition, led to an increase in lake trophic state from mesotrophic to eutrophic conditions. (C) In the last phase (1560 CE to the present), the eutrophic conditions in Lake Funda were maintained through a positive feedback loop between lake productivity and in-lake phosphorous recycling. Variability within the lake ecosystem was mainly associated with climate variability and internal lake dynamics (e.g., phosphorus remobilization). Our results show that a paleoecological approach is crucial to understanding lake ecological states in the present-day in order to develop locally adapted management and restoration strategies. A long-term perspective enables us to understand the harmful consequences of ongoing climate change and human disturbances on lake ecosystems.

Nutritional and Healthy Value of Chemical Constituents Obtained from Patagonian Squid (Doryteuthis gahi) By-Products Captured at Different Seasons.

This study focuses on the extraction of nutritional and healthy constituents of whole by-products resulting from the commercialisation of Patagonian squid (Doriteuthis gahi). By-products corresponding to squid individuals captured at different seasons were comparatively analysed for proximate composition, lipid classes content, fatty acid (FA) profile, and macroelement and trace element composition. As a result, moisture, lipid, protein, and ash values were included in the ranges 829.0-842.8, 17.5-21.8, 106.0-123.7, and 9.3-13.3 g·kg-1 by-products, respectively. Phospholipids showed to be the most abundant lipid class (359.2-463.5 g·kg-1 lipids), while triacylglycerols were only present in a 9.5-13.1 g·kg-1 lipids range. Valuable levels were detected for α-tocopherol (539.6-973.3 mg·kg-1 lipids), polyunsaturated fatty acids (PUFA; 50.5-52.6 g·100 g-1 FA), ω3 PUFA (47.0-48.6 g·100 g-1 FA), PUFA/saturated FA ratio (1.4-1.6), and ω3/ω6 ratio (12.1-13.4). Among macroelements, S, P, and Na showed to be more abundant than K, Mg, and Ca. Profitable levels of Co, Cu, Fe, Mn, Se, and Zn were detected in all kinds of individuals. In spite of content variations found as a result of the capture season of Patagonian squid individuals, whole by-products of this cephalopod species can be considered as a profitable source to provide the food and pharmaceutical industries with useful value-added constituents.

Macroelements and Trace Elements Content in Brine-Canned Mackerel (Scomber colias) Subjected to High-Pressure Processing and Frozen Storage.

This study analysed the effect of prior high-pressure processing (HPP; 200-600 MPa, 2 min), freezing (-30 °C, 48 h), and frozen storage (-18 °C, 6 months) on the macroelement and trace element content in brine-canned mackerel (Scomber colias). Most elements (Na, Ca, Ba, Mn, Fe, Cu, Cd, Sn, As, S, and Se) showed an increased (p < 0.05) presence in mackerel muscle canned after freezing. A content increase (p < 0.05) was also observed for Na and Sn if prior frozen storage was also applied; on the contrary, Ca, Ba, Mn, Fe, Cd, S, and Se showed a content decrease (p < 0.05) as a result of such storage. Freezing, frozen storage, and canning led to lower values (p < 0.05) in canned fish for K, Mg, Pb, and P. Prior HPP led to relevant content decreases (p < 0.05) for K, Mg, Ca, Ba, Mn, Fe, Pb, and P contents in fish canned after the freezing step; HPP provoked additional decreases (p < 0.05) in Ca, Ba, and Mn levels in samples corresponding to 6-month frozen storage. On the contrary, prior HPP led to marked increases (p < 0.05) for Cd, S, and Se contents in all canned samples. Content changes are explained on the basis of modifications of other constituents and liquor losses from muscle.

A combined approach to establishing the timing and magnitude of anthropogenic nutrient alteration in a mediterranean coastal lake- watershed system.

Human activities have profoundly altered the global nutrient cycle through Land Use and Cover Changes (LUCCs) since the industrial revolution and especially during the Great Acceleration (1950 CE). Yet, the impact of such activities on terrestrial and aquatic ecosystems above their ecological baselines are not well known, especially when considering the response of these systems to the intensity of LUCCs on nutrient cycles. Here, we used a multiproxy approach (sedimentological, geochemical and isotopic analyses, historical records, climate data, and satellite images) to evaluate the role that LUCCs have on Nitrogen (N) cycling in a coastal mediterranean watershed system of central Chile over the last two centuries. Despite long-term anthropogenic use (agriculture, cattle grazing) in the Matanzas watershed- lake system, these LUCC appear to have had little impact on nutrient and organic matter transfer since the Spanish Colonial period. In contrast, the largest changes in N dynamics occurred in the mid-1970s, driven by the replacement of native forests and grasslands by government-subsidized tree plantations of introduced Monterey pine (Pinus radiata) and eucalyptus (Eucalyptus globulus). These LUCC had major impacts on the transfer of organic matter (which increased by 9.4%) and nutrients (as revealed by an increase in total N) to Laguna Matanzas. Our study shows that the presence of anthropogenic land use/cover changes do not necessarily alter nutrient supply and N availability per se but rather it is the magnitude and intensity of such changes that produce major impact on these processes in these mediterranean watersheds.

Copper speciation in continental inputs to the Vigo Ria: sewage discharges versus river fluxes.

Continental inputs of copper via rivers and sewage into the Vigo Ria were evaluated. The main fluvial input is not contaminated and the most degraded discharges occur on the southern margin of the middle ria. Continental inputs of copper and ligands to the ria are dominated by sewage treatment plants (136 mol Cu day(-1), 124 mol L day(-1)) supported by rivers (15 mol Cu day(-1), 21 mol L day(-1)). The dissolved fraction is the main channel of discharge for rivers (66%) with particulate matter being predominant in sewage (63%). Dissolved copper is organically complexed both in rivers (99.8%) and sewage (99.9%). This minor difference may be attributed to the fact that the stability of sewage complexes is greater than those in rivers. Moreover, ligand concentrations are higher in sewage than in rivers. Thus, the natural continental inputs of copper and ligands into the ria are magnified by anthropogenic inputs (5-15 and 3-5 times higher for copper and ligands, respectively).

Thorium accumulation in the sedimentary environment of the Vigo Ria (NW Iberian Peninsula).

Thorium levels and their association with Fe, Sc, Ca, and Particulate Organic Carbon (POC) were researched in sediments of the Vigo Ria in order to assess the influence of radioactive gneisses from the neighbouring continental Galiñeiro Complex. Sediment of 50 surface samples and 1 core was analysed by ICP-MS and the results were validated with certificate reference material from marine sediment. It was found that Th accumulates in the middle Ria zone (9-15 mg kg(-1)) as a result of the terrestrial source. The thorium concentration in the Ria (average: 9.4+/-5.1 mg kg(-1)) is not anthropogenically impacted in accordance with its own regional background level (11.4+/-3.5 mg kg(-1)), which is two times higher than the content in earth's crust. Throughout the relationship Th/Fe, Th may be associated with the iron cycle in the Ria, probably through iron oxy-hydroxide scavenging.

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-1 and 18 to 210mg·kg-1, respectively, and exhibited significant correlations with sediment grain-size, Al, Fe, Mg and Mn, suggesting a preferential association to fine-grained material (e.g. aluminosilicates but also Al hydroxides and Fe oxyhydroxides). The PAAS (Post-Archean Australian Shale) normalized patterns display three distinct YREE fractionation pattern groups along the Tagus estuary: a first group, characterized by medium to coarse-grained material, a depleted and almost flat PAAS-normalized pattern, with a positive anomaly of Eu, representing one of the lithogenic components; a second group, characterized mainly by fine-grained sediment, with higher shale-normalized ratios and an enrichment of LREE relative to HREE, associated with waste water treatment plant (WWTP) outfalls, located in the northern margin; and, a third group, of fine-grained material, marked by a significant enrichment of Y, a depletion of Ce and an enrichment of HREE over LREE, located near an inactive chemical-industrial complex (e.g. pyrite roast plant, chemical and phosphorous fertilizer industries), in the southern margin. The data allow the quantification of the YREE contents and its spatial distribution in the surface sediments of the Tagus estuary, identifying the main potential sources and confirming the use of rare earth elements as tracers of anthropogenic activities in highly hydrodynamic estuaries.

Possible impact of environmental policies in the recovery of a Ramsar wetland from trace metal contamination.

The Umia-Grove Intertidal Complex is located within the Ria of Arousa (NW Iberian Peninsula). Out of its significance for wintering shorebirds it has been included in the Ramsar List of Wetlands of International Importance as well as in international protection networks such as the European Natura 2000 and Important Bird and Biodiversity Areas-BirdLife International. In a sediment analysis conducted in the year 1999, the wetland was found to have been contaminated by potentially toxic trace metals, to wit: Cr, Cu, Ni, and Pb. Sediment samples retrieved in 2014 to make an updated assessment of the condition of the ecosystem showed evidence of the presence of selected trace elements, namely, Cd, Co, Cr, Cu, Ni, Pb, and Zn, within or slightly above the background ranges of local, regional, and general references. In the 15-year time frame between the two samplings there has been noticeable change in the relationship between nature and society as a consequence of the entry into force of a number of regulations aimed at avoiding the emission of contaminants; among others, the ban of Pb in gasoline, the deployment of wastewater treatment plants according to the European Water Framework Directive, and the limitation of the use of Cu pesticides. With the ensuing drop of human pressure, the self-purifying capacity of the ecosystem has effectively contributed to the wetland's recovery. Nevertheless, the application of a normalized enrichment factor to the more recent set of samples suggests the presence of relict low contamination by Cd, Cu, and Ni in localized areas. The compared analysis of the wetland condition in the two years is a sign of the success of the policies and regulations for environmental protection, but further work and more effectiveness are necessary in order to preserve threatened ecosystems of such importance as the Umia-Grove wetland.

Total and labile metals in surface sediments of the tropical river-estuary system of Marabasco (Pacific coast of Mexico): Influence of an iron mine.

Marabasco is a tropical river-estuary system comprising the Marabasco river and the Barra de Navidad Lagoon. The river is impacted by the Peña Colorada iron mine, which produces 3.5 million tons of pellets per year. Thirteen surface sediment samples were collected in May 2005 (dry season) in order to establish background levels of Al, Cd, Co, Cu, Fe, Ni, Pb, and Zn in the system and to ascertain the potential mobility of metals in the sediments. Analyses were carried out in the fraction finer than 63 microm, and labile metals extracted according the BCR procedure. Certified reference materials were used for validation of methods. Total concentrations of Cd, Co, Cu, Ni, Pb, and Zn were in the range of 0.05-0.34, 6-95, 0.7-31, 9-26, 2-18, and 53-179 mgkg(-1), respectively; Al and Fe ranges of 24-127, and 26-69 mgg(-1) correspondingly. Cadmium was found to be significantly labile in the sediments (20-100%), followed by Co (0-35%), Ni (3-16%) and Zn (0-25%), whereas the labile fraction for Cu, Fe and Pb was almost negligible (<4%). According with the total metal concentrations, background levels and normalised enrichment factors (NEF) of the metals studied, the impact of the Peña Colorada iron mine on the Marabasco system is lower than expected when compared with other similar World systems influenced by mining activities.

The relative effects of upwelling and river flow on the phytoplankton diversity patterns in the ria of A Coruña (NW Spain).

Phytoplankton species assemblages in estuaries are connected to those in rivers and marine environments by local hydrodynamics leading to a continuous flow of taxa. This study revealed differential effects of upwelling and river flow on phytoplankton communities observed in 2011 along a salinity gradient from a river reservoir connected to the sea through a ria-marine bay system in A Coruña (NW Spain, 43° 16-21' N, 8° 16-22' W). With 130 phytoplankton taxa identified, the assemblages were dominated in general by diatoms, particularly abundant in the bay and in the estuary, but also by chlorophycea and cyanobacteria in the reservoir. Considering the entire seasonal cycle, the local assemblages were mainly characterized by changes in cryptophytes and diatoms, small dinoflagellates and some freshwater chlorophycea. Salinity, nitrate, and organic matter variables, were the main environmental factors related to the changes in the phytoplankton communities through the system, while phosphate and nitrite were also important for local communities in the estuary and the bay, respectively. The corresponding local phytoplankton assemblages showed moderate levels of connectivity. The estuarine community shared a variable number of taxa with the adjacent zones, depending on the relative strength of upwelling (major influence from the bay) and river flow (major influence of the reservoir) but had on average 35% of unique taxa. Consequently, local and zonal diversity patterns varied seasonally and were not simply related to the salinity gradient driven by the river flow.

Contributions of trace elements to the sea by small uncontaminated rivers: Effects of a water reservoir and a wastewater treatment plant.

Trace element contributions from small rivers to estuaries is an issue barely addressed in the literature. In this work, freshwater flowing into the Ria of Cedeira (NW Iberian Peninsula) was studied during a hydrological year through the input from three rivers, one considered uncontaminated (the Das-Mestas River), a second affected by urban treated wastewater discharges (the Condomiñas River), and the third containing a water reservoir for urban supply (the Forcadas River). With the objective of assessing the possible influence of human pressure, the annual yields for selected trace elements (Al, Fe, As, Cd, Co, Cr, Cu, Mn, Mo, Ni and Pb) were estimated and compared by normalizing by basin surface. Both dissolved and particulate transported elements were considered. After the data treatment and analysis it can be highlighted that: (i) the Das Mestas River is suitable to be included between the short European pristine baseline of small rivers, at least regarding the transported trace elements; (ii) natural enrichments were identified associated to the lithology of the basin in the Das-Mestas River (i.e. As) and in the Condomiñas River (i.e. Co, Cr and Ni); this fact highlights the importance of considering the local background for a proper assessment; (iii) the impoundment in the Forcadas River is related with a general decrease, even depletion, of the particulate and dissolved transported trace elements, except Mn; (iv) the discharge of sewage to the Condomiñas River is increasing the inputs to the ria of some trace elements in the particulate phase (i.e. Al, Cu and Pb). Both observed human-induced changes can be regarded as typical disturbances of trace element contributions from small rivers to estuaries.

Land inputs of trace metals, major elements, particulate organic carbon and suspended solids to an industrial coastal bay of the NE Atlantic.

Rivers, streams and municipal and industrial effluents flowing into the Ferrol Ria (NW Spain) were analyzed for dissolved and particulate trace elements (Cd, Cu, Pb, Zn), particulate major elements (Al, Fe, Si), particulate organic carbon and nitrogen (POC and PON), and total suspended solids. Trace metal clean techniques were applied. Mean annual fluxes of these components were calculated. Dissolved trace metal concentrations in the major freshwater inputs were found to be within typical values for uncontaminated rivers: Cd: 0.020-0.035 nM; Cu: 11.7-19.2 nM; Pb: 0.40-0.71 nM and Zn: 18-54 nM. Two sources of suspended particulate matter (SPM) were observed: (i). a detrital SPM, which becomes more important at high river discharges, with metal concentrations tending to lithogenic values; (ii). an organic- and metal-rich SPM, which becomes dominant at low discharges. Municipal and industrial effluents in the northern shore, despite of constitute a minor freshwater contribution to the bay, were responsible for more than 50% of total inputs of Cu, Cd, Pb, Zn, POC and PON. The fluxes of trace metals obtained for the Ferrol Ria are in the range of other inhabited world semi-enclosed embayments.

Land inputs, behaviour and contamination levels of copper in a ria estuary (NW Spain).

Copper concentrations were measured in the sediments and dissolved phase of the water column in the Lérez Estuary (Pontevedra Ria, Galicia), NW Spain, and in the freshwater-sewage inputs to the estuary. Dissolved copper fluxes in the estuary were quantified. Results show that the freshwater end-member in the Lérez Estuary has minimal copper contamination ([Cu](Dissolved)=7+/-4 nM, Sediment Enrichment Factor=1) and the source of dissolved copper inputs is localized in the saline end-member ([Cu](Dissolved)=20-55 nM, Sediment Enrichment Factor=6-7). A non-conservative behaviour of dissolved copper showing a net addition during estuarine mixing was observed. The budgetary calculations and the copper sediment distribution suggest that the major copper input to the estuary-ria system is located at the Marín-Placeres transect, playing an important role in the net addition of copper within the estuarine mixing. The importance of upwelling in the renewal of the Galician coastal waters and dilution of continental inputs is discussed.