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Repositorio da Universidade dos Açores (8.559 recursos)

O Repositório Institucional da Universidade dos Açores desenvolvido no âmbito do projecto RCAAP.

DB - Artigos em Revistas Internacionais / Articles in International Journals

Mostrando recursos 1 - 20 de 39

  1. Modeling adult emergence and fecundity of factitious hosts under different food sources supports massive egg production management

    Tavares, João; Silva, Luís; Oliveira, Luísa
    COPYRIGHT: © Cambridge University Press 2017

  2. Modeling adult emergence and fecundity of factitious hosts under different food sources supports massive egg production management

    Tavares, João; Silva, Luís; Oliveira, Luísa
    COPYRIGHT: © Cambridge University Press 2017

  3. Potential of Trichogramma achaeae (Hymenoptera : Trichogrammatidae) in Biological Control of Tuta absoluta (Lepidoptera: Gelechiidae) in Azorean Greenhouse Tomato Crops

    Oliveira, Luísa; Durão, Ana C.; Fontes, João; Roja, Inês S.; Tavares, João
    Tuta absoluta (Meyrick) (Lepidoptera: Gelechiidae) is an important pest of tomato crops. It is native to South America and has rapidly extended its range into Mediterranean countries. The parasitoid Trichogramma achaeae Nagaraja and Nagarkatti (Hymenoptera: Trichogrammatidae) has been recommended as a possible biological control agent of this invasive pest. The pest and parasitoid were accidentally introduced into the Azores Islands and became well-established owing to the climate conditions of the region. During an undertaken survey to determine the presence of natural parasitism, 2.5% of the T. absoluta eggs were found to be parasitized by Tr. achaeae, and no other egg...

  4. Spatial segregation of calving and nursing Risso’s dolphins (Grampus griseus) in the Azores, and its conservation implications

    Hartman, Karin L.; Fernandez, Marc; Azevedo, José M. N.
    Calving can be a critical period for cetaceans. Areas providing security for vulnerable calves, and high food availability for lactating females can be critical habitats requiring specific conservation measures. Here, we test the hypothesis that calving and nursing habitat could be defined for Risso’s dolphins (Grampus griseus). We investigated the spatial and temporal preferences of this species around Pico Island, Azores, using data gathered from land-based surveys and dedicated at-sea observations between 2004 and 2007. We divided observed pods into three groups: (1) those with newborn and young calves, (2) those with older calves or juveniles and (3) those consisting...

  5. Temperate facultative cleaner wrasses selectively remove ectoparasites from their client-fish in the Azores

    Narvaez, Pauline; Furtado, Miguel; Neto, Ana I.; Moniz, Isadora; Azevedo, José M. N.; Soares, Marta S. C.
    Cleaner fishes are key contributors to the health of fish communities. However, much of the information in the literature refers to tropical systems, while fewer studies have examined the activity of cleaner fish inhabiting temperate ecosystems. Facultative cleaner fish are assumed to clean only during their juvenile phase, and have a broader diet than obligatory cleaner fish. Here, we focused on 2 facultative cleaner fish species, Coris julis and Thalassoma pavo, that live along the temperate coasts of the Azorean island of São Miguel. We found that these species focused their cleaning activities on relatively few species of clients, which...

  6. Sex differences in residency patterns of Risso's dolphins (Grampus griseus) in the Azores : causes and management implications

    Hartman, Karin L.; Fernandez, Marc; Wittich, Anja; Azevedo, José M. N.
    Knowledge of the residency patterns of marine mammals is an important element for management and conservation strategies. Here we investigate a population of Grampus griseus off Pico Island, Azores. Our data set covers the period 2004–2007, based on at-sea observations of 1,250 individually identified animals, 303 of known or assumed sex. Using photo identification and GPS locations we calculated mean monthly sighting rates and lagged identification rates to analyze temporal patterns, and estimated kernel density to study the home range. Our results show site fidelity and relatively restricted home ranges, which corroborate the existence of a resident population on the...

  7. Nature-based solutions : new influence for environmental management and research in Europe

    Eggermont, Hilde; Balian, Estelle; Azevedo, José M. N.; Beumer, Victor; Brodin, Tomas; Claudet, Joachim; Fady, Bruno; Grube, Martin; Keune, Hans; Lamarque, Penelope; Reuter, Katrin; Smith, Matt; van Ham, Chantal; Weisser, Wolfgang W.; Le Roux, Xavier
    Greening roofs or walls to cool down city areas during summer, to capture storm water, to abate pollution, and to increase human well-being while enhancing biodiversity: nature-based solutions (NBS) refer to the sustainable management and use of nature for tackling societal challenges. Building on and comple- menting traditional biodiversity conservation and management strategies, NBS integrate science, policy, and practice and create biodiversity benefits in terms of diverse, well-managed ecosystems.

  8. Differences in the structure and functioning of two communities : frondose and turf-forming macroalgal dominated habitats

    Martins, Gustavo M.; Hipólito, Cláudia; Parreira, Filipe; Prestes, Afonso L.; Dionísio, Maria Ana; Azevedo, José M. N.; Neto, Ana I.
    In many coastal regions, vegetated habitats (e.g. kelps forests, seagrass beds) play a key role in the structure and functioning of shallow subtidal reef ecosystems, by modifying local environmental conditions and by providing food and habitat for a wide range of organisms. In some regions of the world, however, such idiosyncratic ecosystems are largely absent and are often replaced by less notable ecosystem formers. In the present study, we empirically compared the structure and functioning of two distinct shallow-water habitats present in the Azores: one dominated by smaller frondose brown macroalgae (Dictyotaceae and Halopteris) and one dominated by low-lying turfs....

  9. Factors limiting the establishment of canopy-forming algae on artificial structures

    Cacabelos, Eva; Martins, Gustavo M.; Thompson, Richard C.; Prestes, Afonso L.; Azevedo, José M. N.; Neto, Ana I.
    Macroalgal canopies are important ecosystem engineers, contributing to coastal productivity and supporting a rich assemblage of associated flora and fauna. However, they are often absent from infrastructures such as coastal defences and there has been a worldwide decline in their distribution in urbanised coastal areas. The macroalga Fucus spiralis is the only high-shore canopy forming species present in the Azores. It is widely distributed in the archipelago but is never found on coastal infrastructures. Here we evaluate factors that may potentially limit its establishment on artificial structures. A number of observational and manipulative experiments were used to test the hypotheses...

  10. Crabs tell the difference : relating trace metal content with land use and landscape attributes

    Álvaro, Nuno V.; Neto, Ana I.; Couto, Ruben P.; Azevedo, José M. N.; Rodrigues, Armindo
    Heavy metal concentration in a given locality depends upon its natural characteristics and level of anthropogenic pressure. Volcanic sites have a different heavy metal footprint from agriculture soils and both differ from urban centres. Different animal species absorb heavy metals differently according to their feeding behaviour and physiology. Depending on the capability to accumulate heavy metals, some species can be used in biomonitoring programs for the identification of disturbed areas. Crabs are included in these species and known to accumulate heavy metals. The present study investigates the potential of Pachygrapsus marmoratus (Fabricius, 1787), a small crab abundant in the Azores...

  11. First report of ciguatoxins in two starfish species : Ophidiaster ophidianus and Marthasterias glacialis

    Silva, Marisa; Rodriguez, Inés; Barreiro, Aldo; Kaufmann, Manfred; Neto, Ana I.; Hassouani, Meryem; Sabour, Brahim; Alfonso, Amparo; Botana, Luis; Vasconcelos, Vitor
    Ciguatera fish poisoning (CFP) is a syndrome caused by the ingestion of fish contaminated with Ciguatoxins (CTXs). These phycotoxins are produced mainly by dinoflagellates that belong to the genus Gambierdiscus that are transformed in more toxic forms in predatory fish guts, and are more present in the Indo-Pacific and Caribbean areas. It is estimated that CFP causes per year more than 10,000 intoxications worldwide. With the rise of water temperature and anthropogenic intervention, it is important to study the prevalence of CFP in more temperate waters. Through inter- and subtidal sampling, 22 species of organisms were collected, in Madeira and...

  12. A new multiplexed microsatellite tool for metapopulation studies in the overexploited endemic limpet Patella aspera (Röding, 1798)

    Faria, João; Rivas, Manuel; Martins, Gustavo M.; Hawkins, Stephen J.; Ribeiro, Pedro; Pita, Alfonso; Neto, Ana I.; Presa, Pablo
    Patellid limpets are ecologically important keystone grazers having a long history of overexploitation in the Macaronesian Archipelagos (NE Atlantic islands), where some species, such as Patella aspera, are under serious risk.[1, 2] Patella aspera is a protandric sequential hermaphrodite species with external fertilization, in which individuals start off as males but may undergo a sex reversal with age.[3] Hence, exploitation tends to focus on the larger females in the population as larger limpets (predominantly females) are selectively removed. Despite conservation legislation in Canaries, Madeira and Azores, limpets are under severe pressure and few individuals survive long enough to become females,...

  13. Long-term modifications of coastal defences enhance marine biodiversity

    Martins, Gustavo M.; Jenkins, Stuart R.; Neto, Ana I.; Hawkins, Stephen J.; Thompson, Richard C.
    Realization that hard coastal infrastructures support lower biodiversity than natural habitats has prompted a wealth of research seeking to identify design enhancements offering ecological benefits. Some studies showed that artificial structures could be modified to increase levels of diversity. Most studies, however, only considered the short-term ecological effects of such modifications, even though reliance on results from short-term studies may lead to serious misjudgements in conservation. In this study, a sevenyear experiment examined how the addition of small pits to otherwise featureless seawalls may enhance the stocks of a highly-exploited limpet. Modified areas of the seawall supported enhanced stocks of...

  14. Rhodolith forming coralline algae in the Upper Miocene of Santa Maria Island (Azores, NE Atlantic) : a critical evaluation

    Rebelo, Ana C.; Rasser, Michael; Riosmena-Rodríguez, Rafael; Neto, Ana I.; Ávila, Sérgio P.
    The Late Miocene Malbusca outcrop is located in the southeastern coast of Santa Maria Island (Azores, NE Atlantic), interspersed in volcanic formations. At ~20 meters above present sea level, a prominent discontinuous layer of rhodoliths seizes with an extension of ~250 meters. This paper presents the first taxonomic record of fossil rhodolith forming coralline algae for the Miocene of the Azores. The preserved taxonomic features used were the following: (1) arrangement of basal filaments, (2) epithallial cells (when observable), (3) presence of cell fusions, (4) conceptacle type, (5) number of cells layers which conceptacle chamber floors are situated below the...

  15. Early patterns of recovery from disturbance in intertidal algal assemblages: consistency across regions within a marine province

    Martins, Gustavo M.; Jenkins, Stuart R.; Ramírez, Rubén; Tuya, Fernando; Neto, Ana I.; Arenas, Francisco
    The importance of disturbance and the subsequent rate and pattern of recovery has been long recognised as an important driver of community structure. Community recovery is affected by processes operating at local and regional scales yet the examination of community level responses to a standardised disturbance at regional scales (i.e. among regions under different environmental conditions) has seldom been attempted. Here, we mechanically disturbed rocky intertidal lower shore algal dominated assemblages at three locations within each of three different regions within the Lusitanian biogeographical province (Azores, northern Portugal and the Canary Islands). All organisms were cleared from experimental plots and...

  16. The genus Corallina (Corallinaceae, Corallinales, Rhodophyta) in the Azores (NE Atlantic): character expression and taxonomic evaluation

    Couto, Ruben P.; Rosas-Alquicira, Edgar; Rodrigues, Armindo; Neto, Ana I.
    Morphological and anatomical characters used for segregating species within the genus Corallina (Corallinaceae, Rhodophyta) have been compiled and evaluated in 120 specimens collected in the Azores. The morphological, anatomical and statistical evaluation of the thirty four segregating characters for the genus Corallina performed in the present study revealed no species segregation, either showing no differences across the whole lot of specimens or being highly variable within sets of plants. This suggests that all studied material belongs to one species, so far Ellisolandia elongata (formely Corallina elongata), thus reinforcing old proposed synonyms. A morphological and anatomical account is provided for this...

  17. Invasion success and development of benthic assemblages: effect of timing, duration of submersion and substrate type

    Pinto, Fátima V.; Torrontegi, Olalla; Prestes, Afonso L.; Álvaro, Nuno V.; Neto, Ana I.; Martins, Gustavo M.
    Copyright © 2013 Elsevier Ltd. All rights reserved.

  18. Preliminary observations on the benthic marine algae of the Gorringe seabank (northeast Atlantic Ocean)

    Tittley, Ian; Álvaro, Nuno Miguel Vaz; Neto, Ana I.
    Copyright © Springer-Verlag Berlin Heidelberg and AWI 2014.

  19. Edible Azorean macroalgae as source of rich nutrients with impact on human health

    Paiva, Lisete S.; Lima, Elisabete; Patarra, Rita F.; Neto, Ana I.; Baptista, José
    Copyright © 2014 Elsevier Ltd. All rights reserved.

  20. Shells of Patella aspera as 'islands' for epibionts

    Martins, Gustavo M.; Faria, João; Furtado, Miguel; Neto, Ana I.
    Copyright © Marine Biological Association of the United Kingdom, 2014.

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