62 resultados para northwest Mediterranean

em QUB Research Portal - Research Directory and Institutional Repository for Queen's University Belfast


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The cosmopolitan genus Ceramium (Ceramiaceae, Rhodophyta) is a large and systematically complex group. The taxonomy of this genus remains in a chaotic state due to the high degree of morphological variation. Culture studies, suggesting a strong influence of environment on phenotype, and the use of molecular tools have recently questioned the validity of morphological features used in species recognition. Here we compare three Ceramium taxa from Venice lagoon with samples from northwest Europe using the plastid ribulose-1,5-bisphosphate carboxylase/oxygenase gene (rbcL) and the rbcL-rbcS intergenic spacer combined with morphological observations. A strongly banded species, previously identified as member of a poorly understood and misnamed group, the Ceramium diaphanum complex sensu Feldmann-Mazoyer, is probably conspecific with British samples of Ceramium diaphanum sensu Harvey, for which no valid name has been identified up to now. We show that Ceramium polyceras (Kutzing) Zanardini is a valid name for this species. A fully corticated Ceramium species morphologically resembling C. secundatum differs at the species level from Atlantic C. secundatum; a valid name for this entity is Ceramium derbesii Solier ex Kutzing, described from Mediterranean France. A third species characterized by cortical spines, previously listed as Ceramium ciliation var. robustum (J. Agardh) Mazoyer, is shown to be Ceramium nudiusculum (Kutzing) Rabenhorst, originally described from Venice.

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The spread of nonindigenous species into new habitats is having a drastic effect on natural ecosystems and represents an increasing threat to global biodiversity. In the marine environment, where data on the movement of invasive species is scarce, the spread of alien seaweeds represents a particular problem. We have employed a combination of plastid microsatellite markers and DNA sequence data from three regions of the plastid genome to trace the invasive history of the green alga Codium fragile ssp. tomentosoides. Extremely low levels of genetic variation were detected, with only four haplotypes present in the species’ native range in Japan and only two of these found in introduced populations. These invasive populations displayed a high level of geographical structuring of haplotypes, with one haplotype localized in the Mediterranean and the other found in Northwest Atlantic, northern European and South Pacific populations. Consequently, we postulate that there have been at least two separate introductions of C. fragile ssp. tomentosoides from its native range in the North Pacific.

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This article examines Greek-Turkish crisis behaviour in the Eastern Mediterranean over the past two decades. Crises are first defined and classified, after which a number of common misperceptions are then addressed in light of recent experience. Three broad categories of foreign policy crises are analyzed: 1) those involving ethnically related minorities across the border; 2) those with 'alien' minorities within borders; and 3) those with third countries involving territories and resources. The article examines whether crises are simply elite-driven or partly endorsed and motivated by mass publics in both countries, and whether Greek-Turkish crisis behaviour reflects enduring ethnic rivalries, 'genuine' security interests, or domestic political needs and norms. The article draws upon the Greek-Turkish experience of the past two decades to illuminate contemporary dilemmas and issues which policymakers face in this region.

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1. A comparison was made of the daily energy expenditure (DEE), resting metabolic rate (RMR) and water turnover (WTO) of two populations of Common Spiny Mice Acomys cahirinus from north- and south-facing slopes (NFS and SFS) of the same valley, which represented 'Mediterranean' and 'desert' habitats, respectively.

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Mediterranean islands exemplify well the interactions between tourism, heritage and culture on islands. After an introduction that considers their heritage and the pressures which might be applied by tourism because of insular characteristics such as scale, the paper considers the Spanish island of Mallorca as a case study. First its history and consequent heritage is identified and then various stages in its tourism development, which might be recognized in Butler’s model, are treated with particular reference to two very different foreigner commentators on the island, George Sand and Robert Trimnell. The mass market tourism exemplified by Trimnell has brought a reaction and in recent decades Mallorca has given much more consideration to its environment and heritage, illustrated here through the example of the district of Calvià and its Local Agenda 21 policies. This has seen a considerable impact on the island’s tourism and marketing initiatives, as well as upon its natural environment.