Effect of high CO2 and ocean acidification on photosynthesis and response to oxidative stress in seagrasses

Climate change scenarios comprise significant modifications of the marine realm, notably ocean acidification and temperature increase, both direct consequences of the rising atmospheric CO2 concentration. These changes are likely to impact marine organisms and ecosystems, namely the valuable seagrass-dominated coastal habitats. The main objective of this thesis was to evaluate the photosynthetic and antioxidant responses of seagrasses to climate change, considering CO2, temperature and light as key drivers of these processes. The methodologies used to determine global antioxidant capacity and antioxidant enzymatic activity in seagrasses were optimized for the species Cymodocea nodosa and Posidonia oceanica, revealing identical defence mechanisms to those found in terrestrial plants. The detailed analysis and identification of photosynthetic pigments in Halophila ovalis, H.stipulacea, Zostera noltii, Z marina, Z. capricorni, Cymodocea nodosa and Posidonia oceanica, sampled across different climatic zones and depths, also revealed a similarity with terrestrial plants, both in carotenoid composition and in the pigment-based photoprotection mechanisms. Cymodocea nodosa plants from Ria Formosa were submitted to the combined effect of potentially stressful light and temperature ranges and showed considerable physiological tolerance, due to the combination of changes in the antioxidant system, activation of the VAZ cycle and accumulation of leaf soluble sugars, thus preventing the onset of oxidative stress. Cymodocea nodosa plants living in a naturally acidified environment near submarine volcanic vents in Vulcano Island (Italy) showed to be under oxidative stress despite the enhancement of the antioxidant capacity, phenolics concentration and carotenoids. Posidonia oceanica leaves loaded with epiphytes showed a significant increase in oxidative stress, despite the increase of antioxidant responses and the allocation of energetic resources to these protection mechanisms. Globally, the results show that seagrasses are physiologically able to deal with potentially stressful conditions from different origins, being plastic enough to avoid stress in many situations and to actively promote ulterior defence and repair mechanisms when under effective oxidative stress.

Assemblage structure and secondary production of mesozooplankton in shallow water volcanic CO2 vents of the Azores

Dissertação de mestrado, Biologia Marinha, Faculdade de Ciências e Tecnologia, Universidade do Algarve, 2015

Contribuição dos métodos geofísicos para o modelo evolutivo da região de Santo André desde o último máximo glaciário

Tese de doutoramento, Geologia (Geologia Económica e do Ambiente), Universidade de Lisboa, Faculdade de Ciências, 2014

Changes in the Pollen Seasons of the Early Flowering Trees Alnus spp. and Corylus spp. in Worcester United Kingdom 1996-2005

Previous work on Betula spp. (birch) in the UK and at five sites in Europe has shown that pollen seasons for this taxon have tended to become earlier by about 5–10 days per decade in most regions investigated over the last 30 years. This pattern has been linked to the trend to warmer winters and springs in recent years. However, little work has been done to investigate the changes in the pollen seasons for the early flowering trees. Several of these, such as Alnus spp. and Corylus spp., have allergens, which cross-react with those of Betula spp., and so have a priming effect on allergic people. This paper investigates pollen seasons for Alnus spp. and Corylus spp. for the years 1996–2005 at Worcester, in the West Midlands, United Kingdom. Pollen data for daily average counts were collected using a Burkard volumetric trap sited on the exposed roof of a three-storey building. The climate is western maritime. Meteorological data for daily temperatures (maximum and minimum) and rainfall were obtained from the local monitoring sites. The local area up to approximately 10 km surrounding the site is mostly level terrain with some undulating hills and valleys. The local vegetation is mixed farmland and deciduous woodland. The pollen seasons for the two taxa investigated are typically late December or early January to late March. Various ways of defining the start and end of the pollen seasons were considered for these taxa, but the most useful was the 1% method whereby the season is deemed to have started when 1% of the total catch is achieved and to have ended when 99% is reached. The cumulative catches (in grains/m3) for Alnus spp. varied from 698 (2001) to 3,467 (2004). For Corylus spp., they varied from 65 (2001) to 4,933 (2004). The start dates for Alnus spp. showed 39 days difference in the 10 years (earliest 2000 day 21, latest 1996 day 60). The end dates differed by 26 days and the length of season differed by 15 days. The last 4 years in the set had notably higher cumulative counts than the first 2, but there was no trend towards earlier starts. For Corylus spp. start days also differed by 39 days (earliest 1999 day 5, latest 1996 day 44). The end date differed by 35 days and length of season by 26 days. Cumulative counts and lengths of season showed a distinct pattern of alternative high (long) and low (short) years. There is some evidence of a synchronous pattern for Alnus spp.. These patterns show some significant correlations with temperature and rainfall through the autumn, winter and early spring, and some relationships with growth degree 4s and chill units, but the series is too short to discern trends. The analysis has provided insight to the variation in the seasons for these early flowering trees and will form a basis for future work on building predictive models for these taxa.

Plume-lithosphere interaction at Santiago Island (Cape Verde) : implications for ocean island magma genesis models

Tese de doutoramento, Geologia (Geoquímica), Universidade de Lisboa, Faculdade de Ciências, 2014

Mass-wasting episodes in the geological evolution of the Azores islands : timing, recurrence, mechanisms and consequence

Tese de doutoramento (co-tutela), Geologia (Geodinâmica Interna), Faculdade de Ciências da Universidade de Lisboa, Faculté des Sciences D’Orsay-Université Paris-Sud, 2014

Geological structure and acoustic properties of sediments in Effingham Inlet

Thesis written for Oceanography 445

Accuracy assessment of depth estimates from variation in pre- and post-processing of multi-beam SONAR surveys in a fjord environment

Senior thesis written for Oceanography 445

Automatic recognition of seafloor features in sub-bottom profiles using eigenimages

Senior thesis written for Oceanography 445

The effects of sill-circulation on zooplankton patchiness

Senior thesis written for Oceanography 445

Host-symbiont interactions in the deep-sea vent mussel Bathymodiolus azoricus : a molecular approach

Tese de Doutoramento, Ciências do Mar, especialidade de Biologia Marinha, 19 de Dezembro de 2015, Universidade dos Açores.

Estratigrafia e interpretação paleogeográfica do Cenozóico continental do norte de Portugal

Palaeogeographic and tectono-sedimentary interpretation of northern Portugal, in which previous studies (geomorphology, lithostratigraphy, mineralogy, sedimentology, palaeontology, etc.) were considered, is here proposed. Cenozoic shows different features according to its morphotectonic setting in the eestern region (Trás-os-Montes) or near to the Atlantic coast (western region, Minho and Douro Litoral areas). Although in the eastern region the sedimentary record is considered late Neogene, in some places Paleogene (?) was identified. This oldest record, represented by alluvial deposits, was preserved from complete erosion because of its position inside Bragança-Vilariça-Manteigas fault zone grabens. Later sedimentary episodes (upper Tortonian-Zanclean ?), represented by two allostratigraphical units, were interpreted as proximal fluvial braided systems of an endorheic hydrographic network, draining to the Spanish Duero Basin (eastwards); nowadays, they still remained in tectonic depressions and incised-valleys. Later on, eastern sedimentation becomes scarcer because Atlantic fluvial systems (e.g. the pre-Douro), successively, captured previous endorheic drainages. The proximal reaches of the allostratigraphic unit considered Placencian is recorded in Mirandela (western Trás-os-Montes) but the following fluvial episode (Gelasian-early Pleistocene ?) was already documented in east Trás-os-Montes, preserved in high platforms and in tectonic depressions. Placencian and Quaternary sedimentary records in the western coastal zone, mainly represented by terraces, are located in the Minho, Lima, Alverães, Cávado and Ave large fluvial valleys and in the Oporto littoral platform. In conclusion, northern Portugal Tertiary sedimentary episodes were mainly controlled by tectonics, but later on (Placencian-Quaternary) also by eustasy.

Depleted arc volcanism in the Alboran Sea and shoshonitic volcanism in Morocco: geochemical and isotopic constraints on Neogene tectonic processes

Samples of volcanic rocks from Alboran Island, the Alboran Sea floor and from the Gourougou volcanic centre in northern Morocco have been analyzed for major and trace elements and Sr-Nd isotopes to test current theories on the tectonic geodynamic evolution of the Alboran Sea. The Alboran Island samples are low-K tholeiitic basaltic andesites whose depleted contents of HFS elements (similar to0.5xN-MORB), especially Nb (similar to0.2xN-MORB), show marked geochemical parallels with volcanics from immature intra-oceanic arcs and back-arc basins. Several of the submarine samples have similar compositions, one showing low-Ca boninite affinity. Nd-143/Nd-144 ratios fall in the same range as many island-arc and back-arc basin samples, whereas Sr-87/Sr-86 ratios (on leached samples) are somewhat more radiogenic. Our data point to active subduction taking place beneath the Alboran region in Miocene times, and imply the presence of an associated back-arc spreading centre. Our sea floor suite includes a few more evolved dacite and rhyolite samples with (Sr-87/Sr-86)(0) up to 0.717 that probably represent varying degrees of crustal melting. The shoshonite and high-K basaltic andesite lavas from Gourougou have comparable normalized incompatible-element enrichment diagrams and Ce/Y ratios to shoshonitic volcanics from oceanic island arcs, though they have less pronounced Nb deficits. They are much less LIL- and LREE-enriched than continental arc analogues and post-collisional shoshonites from Tibet. The magmas probably originated by melting in subcontinental lithospheric mantle that had experienced negligible subduction input. Sr-Nd isotope compositions point to significant crustal contamination which appears to account for the small Nb anomalies. The unmistakable supra-subduction zone (SSZ) signature shown by our Alboran basalts and basaltic andesite samples refutes geodynamic models that attribute all Neogene volcanism in the Alboran domain to decompression melting of upwelling asthenosphere arising from convective thinning of over-thickened lithosphere. Our data support recent models in which subsidence is caused by westward rollback of an eastward-dipping subduction zone beneath the westemmost Mediterranean. Moreover, severance of the lithosphere at the edges of the rolling-back slab provides opportunities for locally melting lithospheric mantle, providing a possible explanation for the shoshonitic volcanism seen in northern Morocco and more sporadically in SE Spain. (C) 2004 Elsevier B.V. All rights reserved.

Oceanic intraplate volcanoes exposed: Example from seamounts accreted in Panama

Two Paleogene ocean islands are exposed in the Azuero Peninsula, west Panama, within sequences accreted in the early-Middle Eocene. A multidisciplinary approach involving litho-logic mapping, paleontological age determinations, and petrological study allows reconstruction of the stratigraphy and magmatic evolution of one of these intraplate oceanic volcanoes. From base to top, the volcano's structure comprises submarine basaltic lava flows locally interlayered with hemipelagic sediments, basaltic breccias, shallow-water limestones, and subaerial basaltic lava. Gabbros and basaltic dikes were emplaced along a rift zone of the island. Geochemical trends of basaltic lavas include decreased Mg# {[Mg/(Mg + Fe)] * 100} and, with time, increased incompatible element contents thought to be representative of many poorly documented intraplate volcanoes in the Pacific. Our results show that, in addition to deep drilling, the roots of oceanic islands can be explored through studies of accreted and subaerially exhumed oceanic sequences.

Recueil de lettres originales.

Contient : 1 Lettre de « CHARLES [III, duc DE SAVOIE]... à monseigneur le mareschal de Momoransy,... A Geneve, le XIe jour de janvier » ; 2 Lettre de « CHARLES [III, duc DE SAVOIE]... à monseigneur le grant maistre, mon nepveu... Escript à Thurin, le XXVIIe de decembre » ; 3 Lettre de « CHARLES [III, duc DE SAVOIE]... à mon nepveur monseigneur le grant mestre... Escript à Chambery, le XIIIIe de juing » ; 4 Lettre de « PHILIPPES DE SAVOYE,... à monseigneur le grand maestre, mon nepveu... De Paris, ce XXIIIIe de decembre » ; 5 Lettre de « PHILIPPES DE SAVOYE,... à monseigneur... le grant mestre, mon bon nepveu... De Paris, le penultime de juillet » ; 6 Lettre de RENE, « batar de Savoye... à mon bon frere monseigneur le mareschal de Montmorancy,... Escript à Paris, le dernier jour de juing » ; 7 Lettre de RENE, « batar de Savoye... à monseigneur le mareschal de Montmorency, mon bon frere... Escript à Sainct Germain en Laye, ce XXIIme jour de juillet » ; 8 Lettre de RENE, « batar de Savoye... à monseigneur le mareschal de Montmorency, mon bon frere... Escript à Bloys, ce XXIXe de novembre » ; 9 Lettre de RENE, « batar de Savoye... à monseigneur de La Rochepot, mon bon frere... De Lugan, ce XIIIme de may» ; 10 Lettre de RENE, « batar de Savoye... à monseigneur de La Rochepot, mon bon frere... Escript à Martigny en Valleys, le IIIIme jour de juing » ; 11 Lettre de RENE, « batar de Savoye... à monseigneur le mareschal de Montmorancy, mon bon frere... Escript à Sainct Germain en Laye, ce VIme jour d'octobre » ; 12 Lettre de RENE, « batar de Savoye... à monseigneur le mareschal de Montmorancy, mon bon frere... Escript à Bloys, le IIIe jour de feuvrier » ; 13 Lettre de RENE, « batar de Savoye... à monseigneur le mareschal de Montmorency, mon bon frere... De Sainct Germain, ce XVIme jour de fevrier » ; 14 Lettre de RENE, « batar de Savoye... à monseigneur le mareschal de Montmorency, mon bon frere... De Fontaynebleau, ce premier jour de aoust » ; 15 Lettre de RENE, « batar de Savoye... à monseigneur le mareschal de Montmorency, mon bon frere... De Paris, ce XXIXme jour de juillet » ; 16 Lettre de RENE, « batar de Savoye... à monseigneur le mareschal de Montmorency, mon bon frere... De Chartres, ce mardy au soir deuxme de juing » ; 17 Lettre de RENE, « batar de Savoye... à mon bon frere monseigneur le mareschal de Montmorency,... Escript à Sainct Germain en Laye, le XVme jour de juing » ; 18 Lettre de RENE, « batar de Savoye... Escript à Sainct Germain en Laye, ce XIIIe jour de fevrier » ; 19 Lettre de RENE, « batar de Savoye... à monseigneur le mareschal de Montmorency, mon bon frere... Escript à Sainct Germain en Laye, ce XXIIIme de fevrier, à XI heures du matin » ; 20 Lettre de RENE, « batar de Savoye... à monseigneur de La Rochepot, mareschal de France, mon bon frere... Escript à Lyon, le XIme jour d'aoust » ; 21 Lettre de RENE, « batar de Savoye... à monseigneur le mareschal de Montmorency, mon bon frere... Escript à Bloys, le deuxiesme de janvyer » ; 22 Lettre de RENE, « batar de Savoye... à monseigneur le mareschal de Montmorency, mon bon frere... A Saint Germain en Laye, le dernier jour d'avril » ; 23 Lettre de RENE, « batar de Savoye... à monseigneur le mareschal de Montmorency, mon bon frere... Escript à Sainct Germain en Laye, le XXIe jour de feuvrier » ; 24 Lettre de RENE, « batar de Savoye... à mon bon frere monseigneur le mareschal de Montmorency,... A Paris, le XVIIIe de juing » ; 25 Lettre de RENE, « batar de Savoye... à monseigneur le mareschal de Montmorency, mon bon frere... De Saint Germain en Laye, ce IIme jour de juillet » ; 26 Lettre de RENE, « batar de Savoye... à monseigneur le mareschal de Montmorency, mon bon frere... Escript à Bloys, le XVIIIme jour de decembre » ; 27 Lettre de RENE, « batar de Savoye... à monseigneur le mareschal de Montmorency, mon bon frere... De Milly, ce IIIIme jour d'aoust » ; 28 Lettre de RENE, « batar de Savoye... à monseigneur le mareschal de Montmorency, mon bon frere... De Sainct Germain en Laye, ce XXIIIme jour de juing » ; 29 Lettre de RENE, « batar de Savoye... à mon bon frere monseigneur le mareschal de Montmorency,... A Paris, ce XVIIIe de juing » ; 30 Lettre de RENE, « batar de Savoye... à monseigneur le mareschal de Montmorency, mon bon frere... Escript à Sainct Germain en Laye, ce XXIIIIme jour de septembre » ; 31 Lettre de RENE, « batar de Savoye... à monseigneur le mareschal de Montmorency, mon bon frere... Escript à Bloys, le XXIXe de decembre » ; 32 Lettre de RENE, « batar de Savoye... à monseigneur l'amant Frontz de Undervalden,... Escript à Compiegne, le IIIIe jour de decembre » ; 33 Lettre de RENE, « batar de Savoye... à monseigneur le mareschal de Montmorency, mon bon frere... De Sainct Germain en Laye, ce XIIme de fevrier » ; 34 Lettre de RENE, « batar de Savoye... à monseigneur le mareschal de Montmorency, mon bon frere... Escript à Bloys, le XXIIIe jour de janvyer » ; 35 Lettre de RENE, « batar de Savoye... à monseigneur le mareschal de Montmorency, mon bon frere... Escript à Bloys, le XIIe jour de janvyer » ; 36 Lettre de RENE, « batar de Savoye... Escript à Compiegne, le IIIIe jour de decembre » ; 37 Lettre de RENE, « batar de Savoye... à monseigneur le mareschal de Montmorency, mon bon frere... Escript à Bloys, ce jour de Pasques » ; 38 Lettre de RENE, « batar de Savoye... Escript à Compiegne, le IIIIe jour de decembre » ; 39 Lettre de RENE, « batar de Savoye... à monseigneur le mareschal de Montmorency, mon bon frere... De Bloys, ce XIIIIme jour de may » ; 40 Lettre de RENE, « batar de Savoye... Escript à Compiegne, le IIIIe jour de decembre »