NW Portuguese Coast Research Articles

Microplastic contamination in marine mussels from the Atlantic coast of North Portugal and human risk of microplastic intake through mussel consumption

Microplastic (MP) pollution has become a global concern due to its potential impacts on the environment, ecosystem services and human health. The goals of the present study were to document the MP contamination in wild specimens of Mytilus galloprovincialis sampled along the Atlantic coast of the North region of Portugal continental (NW Portuguese coast), and to estimate the human risk of MP intake (HRI) through the consumption of local mussels as seafood. Mussels were collected at four sampling sites along the NW Portuguese coast (40 mussels per site), and the whole soft body of each mussel was analysed for MP content. HRI estimates were based on the mean of MP items per wet weight of mussel analysed tissue (MP/g) and consumption habits. A total of 132 MP items were recovered from mussels. MP had diverse sizes (98–2690 μm) and colours. The most common shapes were fibres (39%) and pellets (36%). Five polymers were identified in the MP: polyethylene (50%), polystyrene (15%), poly(ethylene vinyl acetate) (14%), polyamide (12%) and polypropylene (9%). From the 160 analysed mussels, 55% had MP. The mean and standard error of the mean of mussel contamination ranged from 0.206 ± 0.067 and 0.709 ± 0.095 MP/g. Compared to estimates based on MP contamination in mussels from other areas and varied consumption habits, the HRI through the consumption of mussels from the NW Portuguese coast is relatively low.

Bioremediation of Petroleum Hydrocarbons in Seawater: Prospects of Using Lyophilized Native Hydrocarbon-Degrading Bacteria.

This work aimed to develop a bioremediation product of lyophilized native bacteria to respond to marine oil spills. Three oil-degrading bacterial strains (two strains of Rhodococcus erythropolis and one Pseudomonas sp.), isolated from the NW Portuguese coast, were selected for lyophilization after biomass growth optimization (tested with alternative carbon sources). Results indicated that the bacterial strains remained viable after the lyophilization process, without losing their biodegradation potential. The biomass/petroleum ratio was optimized, and the bioremediation efficiency of the lyophilized bacterial consortium was tested in microcosms with natural seawater and petroleum. An acceleration of the natural oil degradation process was observed, with an increased abundance of oil-degraders after 24 h, an emulsion of the oil/water layer after 7 days, and an increased removal of total petroleum hydrocarbons (47%) after 15 days. This study provides an insight into the formulation and optimization of lyophilized bacterial agents for application in autochthonous oil bioremediation.

Validation and Evaluation of Selected Organic Pollutants in Shrimp and Seawater Samples from the NW Portuguese Coast.

The development of coastal regions has contributed to the intensification of environmental contamination, which can accumulate in aquatic biota, such as shrimps. These crustaceans, besides being delicious and being a good source of nutrients, can also accumulate environmental pollutants. Amongst others, these include organochlorine pesticides (OCPs), organophosphorus pesticides (OPPs), brominated flame retardants (BFRs), polychlorinated biphenyls (PCBs) and synthetic musks (SMs). These pollutants, classified as endocrine disruptors, are related to adverse effects in humans and since one of the major routes of exposition is ingestion, this is a cause for concern regarding their presence in food. The aim of the present study was to quantify the presence of environmental pollutants in shrimp samples and in the water from their habitat along the northwest Portuguese coast. In seawater samples, only two OCPs (lindane and DDD) and one BFR (BTBPE) were detected, and in shrimp samples, one OCP (DDD) and three SMs (HHCB, AHTN and ketone) were found. Bioaccumulation and the risk assessment of dietary exposure of SMs in shrimp samples were investigated. It was observed that all shrimp samples analyzed significantly presented bioaccumulation of the three SMs found. Concentrations of SMs detected in shrimp samples do not present a health risk for the adult Portuguese population.

Persistent and emerging pollutants assessment on aquaculture oysters (Crassostrea gigas) from NW Portuguese coast (Ria De Aveiro)

The study aim was to determine a range of relevant persistent and emerging pollutants in oysters produced in an aquaculture facility located in an important production area, to assure their safety for human consumption. Pollutants, including 16 PAHs, 3 butyltins (BTs), 29 flame retardants (FRs, including organophosphate and halogenated FRs), 35 pesticides (including 9 pyrethroid insecticides) and 13 personal care products (PCPs, including musks and UV filters), were determined in oysters' tissues collected during one year in four seasonal sampling surveys. The seasonal environmental pollution on the production site was evaluated by water and sediment analysis. Furthermore, oysters' nutritional quality was also assessed and related with the consumption of healthy seafood, showing that oysters are a rich source of protein with low fat content and with a high quality index all year around. Results showed that most analysed pollutants were not detected either in oyster tissues or in environmental matrixes (water and sediments). The few pollutants detected in oyster tissues, including both regulated and non-legislated pollutants, such as a few PAHs (fluorene, phenanthrene, anthracene, fluoranthene, pyrene and indenopyrene), FRs (TPPO, TDCPP, DCP, BDE-47, BDE-209 and Dec 602) and PCPs (galaxolide, galaxolidone, homosalate and octocrylene), were present at low levels (in the ng/g dw range) and did not represent a significant health risk to humans. The observed seasonal variations related to human activities (e.g. tourism in summer) highlights the need for environmental protection and sustainable resource exploration for safe seafood production.

Climate, tectonics and beach erosion: the case of Espinho (NW Portuguese coast)

Sea level is a very changeable surface. Furthermore, the land may also be moving, in a slower rate,generating relative sea level changes. The causes of relative sea level changes are variable, but the onesthat cause more intense variations are related to climate.During Little Ice Age (LIA) Northern Hemisphere's summer temperatures fell significantly below theAD 1961–1990 range. This climate situation was responsible for a greater discharge of rivers, whichcould lead to a greater transportation of sediments to the coastline. During these cold periods, sea levelwas lower than in present time. All this could imply a coastline progradation, with the successiveabandon of older beach ridges, reinforcing the sandy supply for dune building. The coastal situationshould be, in some sense, the opposite of the situations that we face today.In present warm period, rivers carry less sediment than during LIA. Moreover, the recent sea level risecontributes to a coastal migration inlands and the erosion of previous beaches and dunes.Our investigation on ancient marine levels and Holocene cemented dunes suggests that the area nearEsmoriz (20 km south of Porto, NW Portuguese coast) is probably subsiding. This possible subsidence,together with recent sea level rise, induced by the end of LIA, could explain the severe coastal erosionthat is taking place at Espinho area (15 km south of Porto) since the middle of the XIX century.This example shows clearly the complexity of relative sea-level changes. Because of this complexity,sea level curves are not similar worldwide, as they depend on the interference of multiple time-scalesphenomena.

Indigenous microbial communities along the NW Portuguese Coast: Potential for hydrocarbons degradation and relation with sediment contamination

Hydrocarbon degradation (HD) potential by autochthonous microorganisms in the coastal sediments of the NW area of Portugal (coastal sandy beaches and estuaries of the rivers Minho and Douro) was evaluated, investigating if water and sediment contamination/characteristics influence it. Sediments were characterized for microbial abundance (by DAPI), HD microorganisms' abundance (by MPN), microbial community structure (by ARISA), hydrocarbons (by FTIR and SPME-GC–MS), hazardous and noxious substances (SPME-GC–MS) and metals (by AAS). To our knowledge, this is the first time all these pollutants, including the selected HNS, were measured simultaneously in sediments of the selected coastal area. Higher contaminants concentrations were, generally, registered in Douro samples. A clear differentiation of the microbial community structure between beaches and estuaries was observed, as well as, between Douro and Minho river estuaries. BIO-ENV analysis indicated both sediment characteristics (e.g. OM content) and contaminants presence/concentrations (e.g. tetrachloroethylene presence) affected the structure of the microbial community along the studied areas. In all the selected sites, the characterized autochthonous microbial communities showed potential for hydrocarbons degradation, with HD microorganisms being found in all collected sediments. These microorganisms can be a valuable asset to recover contaminated areas, but sediment characteristics and contaminants presence/levels need to be taken into account as they can affect their bioremediation potential and the success of their application as biotechnological tool.

Natural protection of the coast: mapping coastal protection service provided by nearshore marine habitats

Event Abstract Back to Event Natural protection of the coast: mapping coastal protection service provided by nearshore marine habitats Sandra Ramos1, Jacinto Cunha1, Ana Bio1*, Eva Amorim1 and Michael Elliott2 1 Centro Interdisciplinar de Pesquisa Marine e Ambiental (CIIMAR), Portugal 2 Institute of Estuarine and Coastal Studies, University of Hull, United Kingdom Given the global climatic changes, coastal zones are more vulnerable to sea level rise and climate extreme events. Nearshore marine habitats, such as sand dunes and salt marshes, have the ability to naturally provide protection to floods, storm waves and erosion, which has been considered as an important ecosystem service. The NW of Portugal is part of the Iberian Peninsula ecoregion, receiving the influence of three oceanic water masses. Its coast features rocky and sandy beaches and several estuaries, some of them under environmental protection. This area is highly urbanized, hosting the second major city of Portugal (Porto) and supporting several human activities, with tourism exponentially growing over the last decade. The coastal zones are prime real estate areas and new tourism economic opportunities are growing fast, stressing the need to manage human activities without compromising ecosystem health and the maintenance of ecosystem services, namely coastal protection. Integrated in the MarRISK project, different modelling tools will be combined to assess coastal protection provided by the natural habitats, like sand dunes and salt-marshes of NW Portugal. Using different habitat features, as bathymetry, topography and waves data obtained within the MarRISK project, with vegetation and land-cover profiles, the protection service provided by sand dunes and salt-marshes will be assessed. Output maps will represent the amount of avoided erosion or inundation along the NW-Portuguese coast, in the presence/absence of the nearshore marine habitats. These maps will be important to help decision-makers understand the importance of protecting these natural habitats. Acknowledgements This research was supported by the Strategic Funding UID/Multi/04423/2013 through national funds provided by FCT – Foundation for Science and Technology and European Regional Development Fund (ERDF), and by the European Union MarRISK project: Adaptación costera ante el Cambio Climático: conocer los riesgos y aumentar la resiliencia (0262_MarRISK_1_E), through EP INTERREG V A España-Portugal (POCTEP) program. Sandra Ramos was supported by a FCT scholarship (SFRH/BPD/102721/2014). Keywords: ecosystem services, Climate Change, Dunes, Coastal ecosystems, coastal management Conference: IMMR'18 | International Meeting on Marine Research 2018, Peniche, Portugal, 5 Jul - 6 Jul, 2018. Presentation Type: Poster Presentation Topic: Biodiversity, Conservation and Coastal Management Citation: Ramos S, Cunha J, Bio A, Amorim E and Elliott M (2019). Natural protection of the coast: mapping coastal protection service provided by nearshore marine habitats. Front. Mar. Sci. Conference Abstract: IMMR'18 | International Meeting on Marine Research 2018. doi: 10.3389/conf.FMARS.2018.06.00012 Copyright: The abstracts in this collection have not been subject to any Frontiers peer review or checks, and are not endorsed by Frontiers. They are made available through the Frontiers publishing platform as a service to conference organizers and presenters. The copyright in the individual abstracts is owned by the author of each abstract or his/her employer unless otherwise stated. Each abstract, as well as the collection of abstracts, are published under a Creative Commons CC-BY 4.0 (attribution) licence (https://creativecommons.org/licenses/by/4.0/) and may thus be reproduced, translated, adapted and be the subject of derivative works provided the authors and Frontiers are attributed. For Frontiers’ terms and conditions please see https://www.frontiersin.org/legal/terms-and-conditions. Received: 28 Apr 2018; Published Online: 07 Jan 2019. * Correspondence: PhD. Ana Bio, Centro Interdisciplinar de Pesquisa Marine e Ambiental (CIIMAR), Matosinhos, Portugal, anabio@ciimar.up.pt Login Required This action requires you to be registered with Frontiers and logged in. To register or login click here. Abstract Info Abstract The Authors in Frontiers Sandra Ramos Jacinto Cunha Ana Bio Eva Amorim Michael Elliott Google Sandra Ramos Jacinto Cunha Ana Bio Eva Amorim Michael Elliott Google Scholar Sandra Ramos Jacinto Cunha Ana Bio Eva Amorim Michael Elliott PubMed Sandra Ramos Jacinto Cunha Ana Bio Eva Amorim Michael Elliott Related Article in Frontiers Google Scholar PubMed Abstract Close Back to top Javascript is disabled. Please enable Javascript in your browser settings in order to see all the content on this page.

Bioaccumulation of persistent and emerging pollutants in wild sea urchin Paracentrotus lividus

Marine pollution has been increasing as a consequence of anthropogenic activities. The preservation of marine ecosystems, as well as the safety of harvested seafood, are nowadays a global concern. Here, we report for the first time the contamination levels of a large set of 99 emerging and persistent organic contaminants (butyltins (BTs), polycyclic aromatic hydrocarbons (PAHs), pesticides including pyrethroids, pharmaceuticals and personal care products (PCPs) and flame retardants) in roe/gonads of sea urchin Paracentrotus lividus. Sea urchins are a highly prized worldwide delicacy, and the harvesting of this seafood has increased over the last decades, particularly in South West Atlantic coast, where this organism is harvested mainly for exportation. Sampling was performed in three harvesting sites of the NW Portuguese coast subjected to distinct anthropogenic pressures: Carreço, Praia Norte and Vila Chã, with sea urchins being collected in the north and south areas of each site.Butyltins and pharmaceuticals were not found at measurable levels. Several PAHs, four pyrethroids insecticides, four PCPs and eleven flame retardants were found in roe/gonads of sea urchins, though in general at low levels. Differences among harvesting sites and between areas within each site were found, the lowest levels of contaminants being registered in Carreço. The accumulation of contaminants in sea urchins’ roe/gonads seemed to reflect the low anthropogenic pressure felt in the sampling sites. Nevertheless, taking into account the low accumulated levels of chemicals, results indicate that sea urchins collected in South West Atlantic coast are safe for human consumption.

Distribution ranges of the acorn barnacle Perforatus (=Balanus) perforatus (Bruguière, 1789) in the NE Atlantic are influenced by reproductive parameters

The acorn barnacle Perforatus perforatus has a defined breeding temperature range and reproductive season that varies geographically. This study aims to investigate the influence of reproductive parameters of P. perforatus in species distribution ranges in the NE Atlantic. The hypothesis tested is that the breeding season of P. perforatus off NW Portugal begins earlier and is longer than at the northern distribution limit of this species, and that fecundity is higher in terms of number of broods per individual per breeding season. The span of the breeding season and fecundity indices were assessed based on the presence and maturation of ovigerous lamellae and correlated with temperature. Results showed that the breeding season in the NW Portuguese coast lasts over 10 months (February–November) and the number of broods was determined to be 9.2 ind/year. Temperature seems to be a primary factor determining the breeding season, but other factors, such as food availably, light and photoperiod, are also of great importance. However, the higher quantity of embryos produced in NW Portugal is not reflected in a higher abundance of settled adults in rocky shores. Contrarily, the species is particularly abundant in artificial substrata offshore.

Modeling the occurrence of shellfish poisoning outbreaks caused by Gymnodinium catenatum (Dinophyceae) through electromagnetic signal triggering

Accumulation of paralytic shellfish poisoning toxins (PSTs) in bivalves attributed to Gymnodinium catenatum blooms at the NW Portuguese coast was previously associated with periods of low solar activity (measured by the radio flux [R]), or low geomagnetic A(a) index. It was also observed that reduction of R preceded the occurrence of toxin accumulation, while A(a) index increase could be related to its absence during periods of low activity. For modeling toxin accumulation, the monthly decrease in R was studied along the decade 2003-2012. A match that helped explaining the highly toxic years of 2007 and 2008 was obtained by plotting the formula: ΔR = (R(n-1) - R(n))/(R(n) - 65)2, where 65 represented the lowest radio activity known to date. The complex denominator was required to take into account the sunspot cycle. A 1-2 month lag was observed between maximal relative decline and maximal PSTs accumulation. PSTs in bivalves from the Portuguese south coast were related with natural electromagnetic cycles for the first time, and were not statistically associated with low R. A statistically significant association with low A(a) index also was not achieved, due to the low number of occurrences, although the 25-75 percentile was restricted to low Aa indexes in a similar way to that found for the NW coast. PSTs accumulation outside solar minima could be triggered by a steep decline in the A(a) index (ΔA), but no lag was observed in this case. While ΔR amplitude helped explaining the highly toxic years of 2007 and 2008 at the NW coast, the amplitude of ΔA was not related to the severity of the accumulation. Other kind of local electromagnetic signaling was investigated resorting to the occurrence of seismologic phenomena, because these events can trigger electric activities. No statistical association was found between seism number or magnitude and PSTs at the south coast, located near the boundary between the African and Eurasian plates, and marked by moderate seismicity.

Estimating the contribution of N-sulfocarbamoyl paralytic shellfish toxin analogs GTX6 and C3 + 4 to the toxicity of mussels (Mytilus galloprovincialis) over a bloom of Gymnodinium catenatum

Gymnodinium catenatum, a dinoflagellate species with a global distribution, is known to produce paralytic shellfish poisoning (PSP) toxins. The profile of toxins of G. catenatum is commonly dominated by sulfocarbamoyl analogs including the C3+4 and GTX6, which to date has no commercial certified reference materials necessary for their quantification via chemical methods, such as liquid chromatography. The aim of this study was to assess the presence of C3+4 and GTX6 and their contribution to shellfish toxicity. C3+4 and GTX6 were indirectly quantified via pre-column oxidation liquid chromatography with fluorescence detection after hydrolysis conversion into their carbamate analogs. Analyses were carried out in mussel samples collected over a bloom of G. catenatum (>63×103cellsl−1) in Aveiro lagoon, NW Portuguese coast. Concentration levels of sulfocarbamoyl toxin analogs were two orders of magnitude higher than decarbamoyl toxins, which were in turn one order of magnitude higher than carbamoyl toxins. Among the sulfocarbamoyl toxins, C1+2 were clearly the dominant compounds, followed by C3+4 and GTX6. The least abundant sulfocarbamoyl toxin was GTX5. The most important compounds in terms of contribution for sample toxicity were C1+2, which justified 26% of the PSP toxicity. The lesser abundant dcSTX constitutes the second most important compound with similar % of toxicity to C1+2, C3+4 and GTX6 were responsible for approximately 11% and 13%, respectively. The median of the sum of C3+4 and GTX6 was 27%. These levels reached a maximum of 60% as was determined for the sample collected closest to the G. catenatum bloom. This study highlights the importance of these low potency PSP toxin analogs to shellfish toxicity. Hydrolysis conversion of C3+4 and GTX6 is recommended for determination of PSP toxicity when LC detection methods are used for PSP testing in samples exposed to G. catenatum.

Studies on the morphology and growth of statoliths in Caenogastropoda

Gravireception in gastropods occurs by the displacement of statoparticles (multiple statoconia or a single statolith) inside statocysts, resulting from changes in the animal's position. An easy method for extraction and processing of statoliths is given and their morphology and microstructure described in 12 species of caenogastropods collected on the NW Portuguese coast, belonging to eight different families. In addition, statolith growth was studied in two species, Nucella lapillus and Nassarius reticulatus. The relation between statolith diameter (StD) and shell height (SH) follows logistic curves [in N. lapillus SH = 34.98/(1 + 190.817−49.082 StD), P < 0.001; and in N. reticulatus SH = 31.03/(1 + 116.709−36.577 StD), P < 0.001]. All statoliths observed are hard and translucent, with several concentric layers delimited by well-marked growth rings. Recently, some studies have shown that these rings are annual and can be used to determine the age of some gastropods and we show that this applies in a wider range of caenogastropods. Statolith rings were clearer in species collected offshore (Aporrhais pespelecani, Ranella olearium, Charonia lampas and N. reticulatus), because additional disturbance rings were more often present in statoliths from inshore species (Crepidula fornicata, Littorina littorea, Peringia ulvae, Trivia monacha, N. reticulatus, Nassarius incrassatus, N. lapillus, Ocenebra erinaceus and Ocinebrina aciculata). Statoliths thus have potential for sclerochronology and may provide an important record of the physical and chemical characteristics of the marine environment throughout ontogeny.

Metal accumulation and oxidative stress biomarkers in octopus (Octopus vulgaris) from Northwest Atlantic

Metals are ubiquitous in the environment and accumulate in aquatic organisms and are known for their ability to enhance the production of reactive oxygen species (ROS). In aquatic species, oxidative stress mechanisms have been studied by measuring antioxidant enzyme activities and oxidative damages in tissues. The aim of this study was to apply and validate a set of oxidative stress biomarkers and correlate responses with metal contents in tissues of common octopus (Octopus vulgaris). Antioxidant enzyme activity (catalase — CAT, superoxide dismutase — SOD and glutathione S-transferases — GST), oxidative damages (lipid peroxidation — LPO and protein carbonyl content — PCO) and metal content (Cu, Zn, Pb, Cd and As) in the digestive gland and arm of octopus, collected in the NW Portuguese coast in different periods, were assessed after capture and after 14days in captivity. CAT and SOD activities were highly responsive to fluctuations in metal concentrations and able to reduce oxidative damage, LPO and PCO in the digestive gland. CAT activity was also positively correlated with SOD and GST activities, which emphasizes that the three enzymes respond in a coordinated way to metal induced oxidative stress. Our results validate the use of oxidative stress biomarkers to assess metal pollution effects in this ecological and commercial relevant species. Moreover, octopus seems to have the ability to control oxidative damage by triggering an antioxidant enzyme coordinated response in the digestive gland.

Cholinesterase and glutathione S-transferase activities of three mollusc species from the NW Portuguese coast in relation to the ‘Prestige’ oil spill

In November 2002, the tanker ‘Prestige’ released about 19,000 tonnes of a heavy fuel oil (no. 6) before sinking with about 58,000 tonnes of its cargo, 135 miles from Cabo Finisterra (Spain). A considerable part of the released fuel oil reached the Galician coast, causing a heavy black tide and an ecological disaster. Although the black tide did not reach the NW coast of Portugal, it is possible that some of the fuel oil or its components also arrived to this area directly through the sea water and/or indirectly through the food chain. Therefore, the aim of this study was to investigate possible changes in two widely used biomarkers, the activity of the enzymes cholinesterases (ChE) and glutathione S-transferases (GST), of three molluscs ( Mytilus galloprovincialis, Nucella lapillus and Monodonta lineata) from wild populations of the NW Portuguese coast in relation to the ‘Prestige’ oil spill. Molluscs were collected seasonally before (autumn 2002) and after (winter 2002/2003), spring and summer 2003) the oil spill at several sites along the Portuguese NW coast. Enzymatic activities determined before the accident were compared with those determined at different times after the oil spill taking into consideration abiotic factors. Information from different parameters was integrated by Redundancy Analysis and Principal Response Curves (PRC). Results show that GST and ChE activities were influenced by abiotic factors. Despite this influence, the results of PRC analysis also suggest that some of the fuel oil reached the NW Portuguese coast changing the patterns of ChE and GST activities of local populations of rocky shore species. Furthermore, the present study highlights the need of long-term monitoring with wild populations to assess both historical and punctual effects of pollution in the marine environment.

Erosion risk levels at the NW Portuguese coast: The Douro mouth - Cape Mondego stretch

The entire northwestern coast of Portugal is undergoing severe erosion and there are several areas at high risk of erosion. Commonly considered as a problem—because it jeopardizes human development along the coast—erosion is indeed a natural process of sediment redistribution. This paper presents a brief analysis of erosion driving forces and the subsequent state of vulnerability that coastal segments between the mouth of the River Douro and Cape Mondego are facing. The paper also discusses erosion risk levels, low or high, and the subsequent questions whether there are populations, economical assets or natural habitats at risk and/or areas prone to coastal flooding. Main challenges and future trends along the study area are identified in the light of understanding the underlying causes of conflicts and what realistically can be achieved given the morphodynamics and hydrodynamic processes, human development established along this coastal segment and the existing policies.

Erosion risk levels at the NW Portuguese coast: the Douro mouth—Cape Mondego stretch

Erosion risk levels at the NW Portuguese coast: the Douro mouth—Cape Mondego stretch

Are coastal resources of NW Portugal fingerprinting hydrocarbons released from the Prestige accident?

Seventy-one samples of mussels, sardine, hake, blue whiting and pouting from the NW Portuguese coast, collected between 18 November 2002 and 6 January 2003, were analyzed for total hydrocarbons, individual n-alkanes and major isoprenoids, pristane and phytane. Hydrocarbons (expressed on chrysene equivalents) registered in whole soft tissues of mussels were below 0.5 µg g–1, with a few exceptions (maximum 1.6 µg g–1). Relatively low levels and sporadic enhanced values were also found in fish fillet samples. In spite of this, analyses of individual n-alkanes and major isoprenoids showed that 10–61% of the samples (according to the species) exhibited these compounds in the proportions of the Prestige fuel signature. Similar diagnostic ratios in biological samples and Prestige fuel and n-alkane composition corroborate the fingerprint hypothesis in coastal resources from NW Portugal.