Body size and dispersal mode as key traits determining metacommunity structure of aquatic organisms

Relationships between traits of organisms and the structure of their metacommunities have so far mainly been explored with meta-analyses. We compared metacommunities of a wide variety of aquatic organism groups (12 groups, ranging from bacteria to fish) in the same set of 99 ponds to minimise biases inherent to meta-analyses. In the category of passive dispersers, large-bodied groups showed stronger spatial patterning than small-bodied groups suggesting an increasing impact of dispersal limitation with increasing body size. Metacommunities of organisms with the ability to fly (i.e. insect groups) showed a weaker imprint of dispersal limitation than passive dispersers with similar body size. In contrast, dispersal movements of vertebrate groups (fish and amphibians) seemed to be mainly confined to local connectivity patterns. Our results reveal that body size and dispersal mode are important drivers of metacommunity structure and these traits should therefore be considered when developing a predictive framework for metacommunity dynamics

Late Glacial and Holocene Palaeolake History of the Última Esperanza Region of Southern Patagonia

We undertook multi-proxy analyses on two sediment cores from Lago Pato, a small lake basin at 51°S topographically separated from Lago del Toro in Torres del Paine (TdP), to provide insights into glacier dynamics and lake-level change in the TdP and Última Esperanza region over the last ∼30,000 cal a BP (30 ka). Lago Pato is situated in a region overridden by the Southern Patagonian Ice Field during the Last Glacial and in a transitional climatic zone of Southern Patagonia sensitive to seasonal- to millennial-scale changes in the Southern Hemisphere Westerly Winds (SWW). Results show that a deep ice-dammed and enlarged palaeolake encompassed Lago del Toro and Lago Pato c. 30–20 ka after the ice had retreated from local-Last Glacial Maximum (l-LGM) limits at c. 48–34 ka and during the build-up to the global-Last Glacial Maximum (g-LGM), c. 26–19 ka. Gaps in both sediment records between c. 20–13.4 ka and c. 20–10 ka suggest hiatuses in sediment accumulation during the g-LGM and Antarctic Cold Reversal (ACR) readvances and/or removal by lake lowering or flushing during the Late Glacial–early Holocene. The palaeolake level dropped from >100 m a.s.l. to ∼40–50 m a.s.l. towards the end of the ACR c. 13.4–13.0 ka, creating a shallower glaciolacustrine environment dammed by an ice tongue in the Estancia Puerto Consuelo–Última Esperanza fjord. Further lowering of the enlarged palaeolake level occurred when the ice thinned to <40 m a.s.l., eventually isolating Lago Pato from Lago del Toro and glaciogenic sediment input at c. 11.7 ka. After isolation, the ecology and water levels in Lago Pato became sensitive to regional climate shifts. The shallow, stable, and highly anoxic environment that developed after c. 11.7 ka is associated with weaker (or poleward shifted) SWW at 51°S and was replaced at c. 10 ka by an increasingly productive shallow-littoral lake with a variable lake-level and periodic shifts in anoxic-oxic bottom water conditions and ratios of benthic-planktonic diatoms. A more open Nothofagus forest, established at c. 8.6–7.5 ka, and more arid conditions c. 7.5–5.7 cal ka BP are linked to another phase of weaker (or poleward shifted) SWW at 51°S. More persistently wet conditions from c. 5.7 ka, with extensive closed Nothofagus forests and planktonic diatoms dominant, are associated with stronger (or equatorward shifted) SWW over 51°S. The abrupt return of benthic-to-tychoplanktonic diatoms after c. 3 ka reflects enhanced SWW at 51°S. Increasingly stable lacustrine and littoral wetland conditions established in the last ∼500 years reflect weaker SWW and lasted until recent decades

Kan Vlaanderen het tij nog keren voor de Europese paling? Effecten van tien jaar Europese bescherming op het voortbestaan van de Paling in Vlaanderen

Despite the many restoration measures launched to prevent the Eelfrom further decline, glass eel recruitment and yellow eel density remain troublesome. Eel life is challenging in Flemish waters, where migration routes are blocked by barriers, where unnatural banks and toxic substances hamper growth and reproductive capacity and where pumping stations abruptly end many Eels’ lives. In spite of high levels of pollutants in its meat, Eels still end up on anglers plates (ca. 30 tons/year). Urgent actions are needed to increase the amount of easily accessible high-quality watercourses with more natural flow dynamics. As long as the tides are not turned, a more vigorous European policy on the restriction of the Eel fishery (including elvers) seems indispensable

Diversity and habitat specificity of free-living protozoa in commercial poultry houses.

&lt;p&gt;Despite stringent biosecurity measures, infections by bacterial food pathogens such as Campylobacter are a recurrent problem in industrial poultry houses. As the main transmission route remains unclear, persistence of these infections has been linked to bacterial survival and possibly multiplication within protozoan vectors. To date, however, virtually no information is available on the diversity and occurrence of free-living protozoa in these environments. Using a combination of microscopic analyses of enrichment cultures and molecular methods (denaturing gradient gel electrophoresis [DGGE]) on natural samples, we show that, despite strict hygiene management, free-living protozoa are common and widespread throughout a 6-week rearing period in both water and dry samples from commercial poultry houses. Protozoan communities were highly diverse (over 90 morphotaxa and 22 unique phylotypes from sequenced bands) and included several facultative pathogens and known bacterial vectors. Water samples were consistently more diverse than dry ones and harbored different communities, mainly dominated by flagellates. The morphology-based and molecular methods yielded markedly different results: amoebic and, to a lesser degree, ciliate diversity was seriously underestimated in the DGGE analyses, while some flagellate groups were not found in the microscopic analyses. Some recommendations for improving biosecurity measures in commercial poultry houses are suggested.&lt;/p&gt;</p

Queering the family? A multi-layered analysis of relations of inequality in transnational adoption

This paper explores the tensions between the (equal) parental right claims in adopting countries and the global inequalities in class, race and geographical location that shape transnational adoption. It uses the story told by a Belgian couple who disguised their lesbian relationship from the authorities involved to explore the narratives of child, family and nation that undergird transnational adoption. The paper discusses the potential and limits of the creation of non-traditional families for producing greater equity and significant reinterpretations of kinship and the family script. Moreover, taking into account different layers of both oppression and privilege, it discusses the ethical implications of the (queer) liberal ideologies of parental rights and Western moral superiority that prevail in transnational adoption. It argues for a shift away from the desire to create non-biological and/or non-heterosexual forms of private nuclear kinship through transnational adoption to a more profound and critical re-thinking of the (transnational) care of children, with space and acceptance for profoundly different constellations of care