Repositório Institucional da Universidade de Aveiro
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D3.2. Specifications & requirements for sites infrastructure
No full textThis document describes work that has been accomplished
in Deliverable 3.2. in
WP3
of the
LITES project (Grant agreement no. 238916). The LITES project was started in December 2009,
and
after prolongation its
duration is 60
months
(including 10 months suspension period)
.
This Deliverable is part of Task 3.1. “On
-
site qualification of pilots”.
The objective of this task is
to collect local topographical data for each Pilot Site, current yearly energy consumption, and other
technical data, in order to write specifications for the preparation of infrastructure of pilot sites before
installing the
luminaries.
Write specification and requirement for pilot sites’ infrastructure preparation
(noting
that infrastructure preparation is under responsibility of the pilot sites and off
-
project
budget)
Tidal transport and dispersal of marine toxic microalgae in a shallow, temperate coastal lagoon
No full textA numerical model was used to predict toxic microalgal transport and dispersion in Ria de Aveiro in Portugal. A previously developed Lagrangean particle tracking model coupled to a calibrated two-dimensional hydrodynamic model of Ria de Aveiro was used. Microalgae were regarded as passive particles and the methodology used allowed the determination of their trajectories, as induced by the tidal currents predicted by the hydrodynamic model. The model assumes Ria de Aveiro as vertically homogeneous and does not take into account the vertical distribution patterns of microalgae. Simulations were carried out during extreme spring and neap tides, with microalgal released at the mouth of the lagoon at the local flood. The maximum and minimum areas affected during the occurrence of toxic microalgal blooms were estimated to evaluate the suitability of the distribution of the sampling stations included in the local monitoring program. It was found that the tidal currents greatly determine the microalgal horizontal distribution and dispersal in the lagoon. The results confirmed that the locations of water and bivalve shellfish sampling stations, postulated by INIAP/IPIMAR, in the context of the local harmful algal bloom (HAB) program, were appropriate, although some possible refinements were identified
Ectoenzymatic activity and glucose heterotrophic metabolism in a shallow estuary (Ria de Aveiro, Portugal): influence of bed sediments and salt marshes
No full textBacterioplankton abundance and activity were studied in the estuarine system of Ria de Aveiro (Portugal) to test if tidal resuspension of
sediments and transport of particles from the salt marshes may act as factors of variability of bacterial communities. The total and attached cell
abundance, ectoenzymatic activity and the heterotrophic metabolism of glucose, as well as seston, chlorophyll
a
and particulate organic carbon
(POC) were monitored during four 10-h periods along the tidal cycle at four sampling sites across a transect. The variation of particulate
materials (seston, POC and chlorophyll
a
) along the transect was not significantly correlated with either distance to the margin or distance to
the sediment surface. Nevertheless, proximity to the salt marsh or to the bottom sediment surface favoured glucose incorporation and
aminopeptidase activity. A multiple stepwise linear regression analysis using temperature, salinity, seston, POC, chlorophyll
a
, distance to
sediment surface and distance to the margin as independent variables explained 66.5% of the variability of the fraction of particle-attached
bacteria and only a very small proportion (12–43%) of the observed variability of total bacterial abundance, ectoenzymatic activity and glucose
utilization. The spatial patterns of variation of the concentration of particulate material (seston, POC and chlorophyll
a
) do not clearly indicate
the occurrence of sediment resuspension and runoff from the margins. This, together with the poor contribution of these parameters to the
transversal and tidal variability of bacterial activity, dismisses the importance of inputs of suspended material across the sediment/water
interface and from neighbouring salt marshes in the control of bacterial density and activity
The estuarine quality paradox, environmental homeostasis and the difficulty of detecting anthropogenic stress in naturally stressed areas
No full textEstuaries have long been regarded as environmentally naturally stressed areas because of the high degree of variability in their physico-chemical characteristics, for example oxygen, temperature and salinity in the water column and bed sediment dynamics. However, their biota is well-adapted to cope with that stress and so the areas may be regarded as resilient because of that inherent variability; their ability to absorb stress without adverse effects is regarded here as Environmental Homeostasis. Hence these areas may only be regarded as stressful for marine or freshwater-adapted organisms and that for estuarine organisms this environmental stress is regarded as a subsidy whereby they successfully capitalise on the stressful conditions. In addition, using examples of the estuarine fauna and flora, this article indicates that the characteristics of natural stress in estuaries are similar to those for anthropogenic stress. An over-reliance on ecosystem structural features, such as diversity, in quality indicators therefore makes the detection of the anthropogenic stress more difficult. This difficulty is termed the Estuarine Quality Paradox. Because of these difficulties, the article argues that functional characteristics either as well as or rather than structural ones should be used in detecting environmental perturbations in estuaries
Industrialization of advanced optical technologies for environmental monitoring
No full textIn this work, an innovative fully integrated monitoring infrastructure based on optical fibre sensors was developed and implemented. In the framework of the research project named PROTEU [Tecnologias Avançadas para a Monitorização de Sistemas Estuarinos e Costeiros (PDCTM/P/MAR/15275/1999)], an 11 km optical fibre cable with Bragg sensors each 500 m was installed from the lagoon mouth to Vouga river, along the bed of the Espinheiro channel, allowing the real-time measurement of water temperature at each sensor location. The results of this project are currently feeding several studies concerning Ria de Aveiro and the surrounding area and are crucial for a continuous assessment and management of the environmental conditions. Meanwhile, a fibre optic sensing system for simultaneous measurement of temperature and salinity based on fibre Bragg grating (FBG) technology was also developed. In the following sections, a complete description of the fabrication process, as well as theoretical and experimental results regarding this particular sensing system, are addressed. Earlier in situ local measurements, as well as the latest remote monitoring and data processing scheme, are described. The developed technology is now being exploited by FiberSensing, an INESC Porto spin-off company devoted to the development of optical fibre Bragg grating-based sensor systems for advanced monitoring applications. The main markets of the company are the ones of structural health monitoring in civil and geotechnical engineering, energy production and distribution, and environment
Mercury contamination in sandy soils surrounding an industrial emission source (Estarreja, Portugal)
No full textThis study reports the degree and the extent of mercury contamination in sandy soils surrounding a chloralkali plant at Estarreja, Portugal. Total mercury concentration in the soils studied is at a maximum in the upper 5 cm, ranging from 117 to 49,233 μg kg−1. The profile distribution pattern for total mercury together with the results of a sequential extraction suggest that the element is strongly retained by the soil components. An upper limit of acceptable levels of mercury for this area is proposed based both on statistics and regulatory guidelines from other countries. Taking that limit, geostatistical methods were used to delimit a zone of heavy contamination. Atmospheric fall-out seems to be the main source of contamination of the soils studied
The feeding strategy of the dunlin (Calidris alpina L.) in artificial and non-artificial habitats at Ria de Aveiro, Portugal
No full textUsually waders (Aves, Charadrii) feed in the inter-tidal zone over the low tide period and roost over high tide. But
occasionally when their energetic needs increase, due to adverse weather conditions or to a need to store fat to fuel
migration, the birds also feed during high tide, sometimes in agricultural land. At the Ria de Aveiro, about 44%
(corresponding to 4500 birds) of the wintering dunlin (Calidris alpina) use artificial salt pan habitats throughout
the winter whilst the others utilize natural intertidal habitats, mainly mudflats. The dunlin that feed intertidally in
natural areas, such as the Canal de Mira, do not feed over high tide. In contrast, the birds that use the salt pan area
feed both during low tide, in abandoned salt pans whose walls are breached and thus allow access to the tide, and
high tide, in active salt pans, and keep on doing so throughout the winter. The energetic needs of both groups of
birds are thought to be similar. However, the benthos of the abandoned salt pans seem to be different, and poorer
in energetic terms, from those of the natural mudflats. It is argued that dunlin wintering in the salt pan area must
compensate for this by feeding over high tide in active salt pans. Rather than just being a means of obtaining
more energy at certain times of high energy demand, it would seem that feeding in active salt pans over high tide
should be considered as a normal component of the feeding strategy of these birds, a strategy that is different from
those wintering in the natural mudflats. These findings highlight the importance of the salt exploitation industry to
waders and also show that artificial habitats can support large numbers of wintering waders
Mercury accumulation patterns and biochemical endpoints in wild fish (Liza aurata): A multi-organ approach
No full textThe integration of bioaccumulation and effect biomarkers in fish has been proposed for risk evaluation of aquatic contaminants. However, this approach is still uncommon, namely in the context of mercury contamination. Furthermore, a multi-organ evaluation allows an overall account of the organisms' condition. Having in mind the organs' role on metal toxicokinetics and toxicodynamics, gills, liver and kidney of golden grey mullet (Liza aurata) were selected and mercury accumulation, antioxidant responses and peroxidative damage were assessed. Two critical locations in terms of mercury occurrence were selected from an impacted area of the Ria de Aveiro, Portugal (L1, L2), and compared with a reference area. Although kidney was the organ with the highest mercury load, only gills and liver were able to distinguish mercury accumulation between reference (R) and contaminated stations. Each organ demonstrated different mercury burdens, whereas antioxidant responses followed similar patterns. Liver and kidney showed an adaptive capacity to the intermediate degree of contamination/accumulation (L1) depicted in a catalase activity increase. In contrast, none of the antioxidants was induced under higher contamination/accumulation (L2) in any organ, with the exception of renal GST. The lack of lipid peroxidation increase observed in the three organs denunciates the existence of an efficient antioxidant system. However, the evidences of limitations on antioxidants performance at L2 cannot be overlooked as an indication of mercury-induced toxicity. Having in mind the responses of the three organs, CAT revealed to be the most suitable parameter for identifying mercury exposure in the field. Overall, organ-specific mercury burdens were unable to distinguish the intermediate degree of contamination, while antioxidant responses revealed limitations on signalizing the worst scenario, reinforcing the need to their combined use
Monitoring pollution of coastal lagoon using Liza aurata kidney oxidative stress and genetic endpoints: an integrated biomarker approach
No full textDespite the importance of fish kidney in several
functions (immune, metabolism and excretion of xenobiotics) its use in coastal water biomonitoring focusing on
protection and damage is scarce. Five critical sites in Ria
de Aveiro (Portugal; Barra—BAR, Gafanha—GAF, Rio
Novo do Principe—RIO; Laranjo—LAR and Vagos—
VAG) were assessed in comparison to a reference site
(Torreira—TOR), focusing on
Liza aurata
kidney antioxidant defences versus damage responses. Non protein thiols
were higher at RIO (near a former bleached kraft pulp mill
effluent) and total glutathione at RIO, LAR (mercury
contaminated) and VAG (polycyclic aromatic hydrocarbons contaminated). Catalase and glutathione
S-transferase
activities were higher at RIO and LAR whereas no differences were found in glutathione peroxidase activity.
However, glutathione reductase was higher at BAR (subject to naval traffic), GAF (harbour water area), RIO and
LAR. No peroxidative damage was observed despite the
decreased DNA integrity at RIO and VAG. The integrated
biomarker response index ranked impacted sites as:
LAR>RIO>BAR>GAF>VAG>TOR
Seasonal Liza aurata tissue-specific DNA integrity in a multi-contaminated coastal lagoon (Ria de Aveiro, Portugal)
No full textIn this study, the DNA integrity of golden grey mullet (
Liza aurata
) collected in differently contaminated
sites of a coastal lagoon, Ria de Aveiro (Portugal), was assessed, over the period of 1 year, using the DNA
alkaline unwinding assay, in four different tissues (gill, kidney, liver and blood) and compared to a refer-
ence site. The four tissues displayed different DNA integrity basal levels, clearly affected by seasonal fac-
tors. Gill and kidney were, respectively, the most and least sensitive tissues. All sites demonstrated the
capacity to interfere with DNA integrity. The sites displaying the highest and lowest DNA damage capa-
bility were, respectively, Barra (subject to naval traffic) and Vagos (contaminated with polycyclic aro-
matic hydrocarbons). In terms of seasonal variability, autumn seems to be the more critical season
(more DNA damage) unlike summer when no DNA damage was found in any tissue. Data recommend
the continued monitoring of this aquatic system