Holocene development and anthropogenic disturbance of a shallow lake system in Central Ireland recorded by diatoms

Three cores from two connected lakes in Central Ireland (Lough Kinale and Derragh Lough) were investigated using diatom analysis to establish the Holocene development of the lacustrine system, any local variations within the lakes and any anthropogenic influences. The study area was situated in a lowland location and the lakes were shallow, unstratified and interconnected. Litho-and bio-stratigraphical analyses of the lake cores and deposits beneath a mire separating the two lakes showed the changing spatial configuration of the lake system in the early Holocene and the separation of the initial lake into three basins (cf. lacustrine cells) and finally into two interlinked lakes. The evolution of the lake system is conceptualised as the development of distinct lacustrine cells, and its sediments have recorded changes in the physical (geography, depth and sedimentation) and chemical (water chemistry) properties of the lakes inferred through diatom analyses. The longest sequence, from the early Holocene, records fluctuating lake levels and these are correlated with geomorphological mapping and surveying of palaeoshorelines. The diatom assemblages of the upper 2 m of the three cores, covering approximately the last 2000–3000 radiocarbon years show considerable difference in trophic status and life-form categories. This is related to the location of the cores in the lake and also the distance from human settlement with particular reference to proximity to crannog (artificial island) construction and use. The most central core from the deepest part of Lough Kinale has the least representation of the human settlement and agricultural activity in the catchment and on the fringes of the lake, whereas the core taken from the edge of a crannog is able to identify when construction and use of the crannog occurred. The local nature of the palaeoecological response to human activity due to incomplete water mixing has the advantage of allowing the lake sediment cores to be used to determine spatially discrete settlement patterns

An engineered virus as a scaffold for three-dimensional self-assembly on the nanoscale

Exquisite control over positioning nanoscale components on a protein scaffold allows bottom-up self-assembly of nanodevices. Using cowpea mosaic virus, modified to express cysteine residues on the capsid exterior, gold nanoparticles were attached to the viral scaffold to produce specific interparticle distances (see picture). The nanoparticles were then interconnected using thiol-terminated conjugated organic molecules that act as "molecular wires", resulting in a 3D spherical conductive network, which is only 30 nm in diameter

Deliverable D5.2-5: Report on effects of global change on reference conditions and ecological status of lakes

WISER aims to support the implementation of the Water Framework Directive (WFD) by developing tools for the assessment of the ecological status of European surface waters. With many European lakes unlikely to achieve ‘good’ ecological status without restorative measures, the assessment systems used in the WFD are required to consider recovery in order to judge restoration success. Most previous projects dealing with assessment systems have focused on the effects of deterioration. WISER also deals with recovery. The report summarizes the progress made within the WISER project in the following areas: Reviewing the current understanding of the impacts of climate change on lakes and how this can be utilised to develop and improve our understanding of lake restoration. Investigating the pathways of degradation in lakes where eutrophication has been the primary stressor and examining how these pathways react during lake recovery following remedial action. Two further studies are presented which use lake sediment records and long-term monitoring data sets to assess the relative importance of climate versus eutrophication. The role of cladocerans in tracking long-term changes in shallow lakes is explored; a study which highlights the sensitivity of this biological group and presents it as a strong candidate as the single best indicator for assessing trophic change in lakes. Finally Baysian network models are presented as an effective tool for unravelling the complex interaction between the impacts of lake restoration and climate change on the ecological status of lakes. In addition to providing an assessment of the various tools available for tracking environmental change in lakes, this report highlights the complexities of ecosystem recovery under changing global conditions. A reduction of environmental stressors (e.g. eutrophication) will undoubtedly result in ecosystem improvement, but it is unlikely to simply be the reversal of deterioration and some examples show that recovery may lead to conditions very different from the original undisturbed stage. These studies contribute towards the scientific basis for underpinning the management of freshwaters in order that it is strengthened and targeted appropriately The main achievement of societal relevance is the increased understand of how strategies for the sustainable management of freshwaters, for example, as required by the WFD, may need to be modified to take account of global, especially climate change