Moluscos bivalves em Portugal: composição química e metais contaminantes

Dissertação para obtenção do Grau de Mestre em Tecnologia e Segurança Alimentar

Alterazione di risposte fisiologiche in invertebrati marini esposti nella Baia di Cadice (Spagna) come indici della qualità dell'ambiente

La forte crescita nella pescicoltura ha portato ad una significativa pressione ambientale di origine antropica nei sistemi costieri. Il bivalve locale Scrobicularia plana è stato usato come bioindicatore per valutare la qualità ambientale di un ecosistema affetto da scarichi di acque residuali di una piscifattoria nel braccio di mare Rio San Pedro (Spagna sud-occidentale). I bivalvi sono stati raccolti nei sedimenti intertidali nell'ottobre del 2010 da cinque siti del braccio di mare, seguendo un gradiente di inquinamento decrescente dall'effluente al sito di controllo. Per valutare l'esposizione e l'effetto di contaminanti legati alle acque residuali delle piscifattorie è stata selezionata una batteria di biomarker. Sono state misurate nei tessuti delle ghiandole digestive dei bivalvi: l'attività di enzimi del sistema di detossificazione della Fase I (etossiresorufina-O-deetilasi, EROD e dibenzilfluoresceina, DBF) l'attività di un enzima del sistema di detossificazione di Fase II (glutatione S-transferasi, GST), l'attività di enzimi antiossidanti (glutatione perossidasi, GPX e glutatione reduttasi, GR) e parametri di stress ossidativo (perossidazione lipidica, LPO, e danno al DNA). In parallelo sono state misurate in situ, nelle aree di studio, temperatura, pH, salinità e ossigeno disciolto nelle acque superficiali; nelle acque interstiziali sono stati misurati gli stessi parametri con l'aggiunta del potenziale redox. Sono state trovate differenze significative (p<0,05) tra siti di impatto e sito di controllo per quanto riguarda l'attività di EROD e GR, LPO e danno al DNA; è stato osservato un chiaro gradiente di stress riconducibile alla contaminazione, con alte attività di questi biomarker nell'area di scarico delle acque residuali della pescicoltura e livelli più bassi nel sito di controllo. È stata trovata inoltre una correlazione negativa significativa (p<0,01) tra la distanza alla fonte di inquinamento e l’induzione dei biomarker. Sono state analizzate le componenti abiotiche, inserendole inoltre in una mappa georeferenziata a supporto. Ossigeno disciolto, pH, salinità e potenziale redox mostrano valori bassi vicino alla fonte di inquinamento, aumentando man mano che ci si allontana da esso. I dati ottenuti indicano nel loro insieme che lo scarico di acque residuali dalle attività di pescicoltura nel braccio di mare del Rio San Pedro può indurre stress ossidativo negli organismi esposti che può portare ad un'alterazione dello stato di salute degli organismi.

Benthos fauna in the North Sea from 2 surveys in 1986 and 1987

During two surveys in the North Sea, in summer 1986 and in winter 1987, larger epibenthos was collected with a 2 m beam trawl. The distributions of the species were checked for average linkage by means of the JACCARD-index cluster analysis. In summer two main clusters can be recognized. These are situated to the north and to the south of the Dogger Bank. In winter two main clusters may be recognized as well, but these clusters divide the North Sea into a western and an eastern part. We conclude, that these differences of epibenthos characteristics are correlated with seasonal changes in water body distributions.

Widespread contamination of coastal sediments in the Transmanche Channel with anti-androgenic compounds

This study analysed the levels of androgen receptor antagonist activity in extracts of coastal sediments sampled from estuaries in southern UK and northern France. Anti-androgenic (AA) activity varied between <0.2 and 224.3±38.4μg flutamide equivalents/g dry weight of sediment and was significantly correlated with the total organic carbon and silt content of samples. AA activity was detected in tissues extracts of clams, Scrobicularia plana, sampled from a contaminated estuary, some of which was due to uptake of a series of 4 or 5 ring polycyclic aromatic hydrocarbons (PAHs). Initial studies also indicated that fractionated extracts of male, but not female, clams also contained androgen receptor agonist activity due to the presence of dihydrotestosterone in tissues. This study reveals widespread contamination of coastal sediments of the Transmanche region with anti-androgenic compounds and these contaminants should be investigated for their potential to disrupt sexual differentiation in aquatic organisms.

Widespread contamination of coastal sediments in the Transmanche Channel with anti-androgenic compounds

This study analysed the levels of androgen receptor antagonist activity in extracts of coastal sediments sampled from estuaries in southern UK and northern France. Anti-androgenic (AA) activity varied between <0.2 and 224.3±38.4μg flutamide equivalents/g dry weight of sediment and was significantly correlated with the total organic carbon and silt content of samples. AA activity was detected in tissues extracts of clams, Scrobicularia plana, sampled from a contaminated estuary, some of which was due to uptake of a series of 4 or 5 ring polycyclic aromatic hydrocarbons (PAHs). Initial studies also indicated that fractionated extracts of male, but not female, clams also contained androgen receptor agonist activity due to the presence of dihydrotestosterone in tissues. This study reveals widespread contamination of coastal sediments of the Transmanche region with anti-androgenic compounds and these contaminants should be investigated for their potential to disrupt sexual differentiation in aquatic organisms.

Neuroprotective effects of oral lamotrigine administration on rabbit retinas after pars plana vitrectomy and silicone oil injection

Purpose: To investigate potential retinal neuroprotective effects of oral lamotrigine in rabbits after pars plana vitrectomy (PPV) and intravitreal silicone oil injection (SOI). Methods: Twelve New Zealand rabbits (weight, 2.0-2.5 kg) underwent PPV with SOI on the right eye. For 30 days postoperatively, 6 rabbits received a daily oral dose of lamotrigine (25 mg/kg), and 6 rabbits received a daily oral dose of water. The animals were killed 30 days after surgery. All retinas were processed histologically, immunostained using glial fibrillary acidic protein (GFAP), and analyzed by fluorescence microscopy. Retina sections from all groups were analyzed by TUNEL for the presence of apoptosis and stained with hematoxylin-eosin for morphologic analysis and retina cell density measurements in each layer using a Zeiss Axiophot microscope and KS 400 software. Results: Retinas from water-operated eyes showed a significant decrease in cell density associated with cell death compared with retinas from water-control eyes; cell density was reduced by 56% in the outer nuclear layer (ONL), 49% in the inner nuclear layer (INL), and 64% in the ganglion cell layer (GCL). Lamotrigine-operated retinas showed a reduction in cell death when compared with water-operated retinas; cell death was reduced by 52% in the ONL, 25% in the INL, and 56% in the GCL. Water-operated retinas showed TUNEL-positive cells and GFAP immunofluorescence throughout Muller cell processes; lamotrigine-operated retinas showed no TUNEL-positive cells and decreased GFAP staining when compared with water-operated retinas. Conclusions: PPV with SOI was associated with apoptosis of retinal cells and activation of glial cells in rabbit eyes. Oral lamotrigine administration provided protection against these effects.

3D GIS modelling using ESRI's CityEngine: a case study from the University Jaume I in Castellon de la Plana Spain

Dissertation submitted in partial fulfillment of the requirements for the Degree of Master of Science in Geospatial Technologies.