25 research outputs found
Coral community dynamics and disturbances : a modelling approach for Caribbean coral reefs
The capacity of reefs to recover after disturbance is fundamental to prediction of
their stability. This is particularly relevant now, following the global decline of reefs
during the last decades. A discrete, spatially explicit model (probabilistic cellular
automaton) was developed to simulate a Caribbean coral community. Community
complexity was generated from behaviour of fundamental units of corals, the polyps.
Regarding background disturbance, area disturbed and patch size were investigated;
both were equally important in driving coral community structure and diversity. A
powerlaw model was developed to predict natural disturbances, and implemented in
later testing of system dynamics. Corals were assigned differential susceptibilities to
background disturbances. Results assessed against field data showed that most
modelled species had realistic colony size frequency distributions (though 20% had
insufficient comparison data).
Following model development, recovery from single impacts (simulated warming
events) was tested. Model responses indicate importance of local setting to
community resilience. Individual susceptibility of species was mediated by life
history strategy investment.
Application of a warming sequence of predicted anomalies for this century was then
introduced. Community composition changed betwee1 0-40 years from
predominantly persistent, large, slow growing species to small, fecund, fast growing
species. After 40 years a phase shift occurred in which algae dominated the
community. It is concluded that the future may herald declines in the main Caribbean
reef-building species, in ways that match several previous but largely untested
speculations. This model indicates that there will be serious implications to reefs,
including their numerous commercially important species.
The model includes all known major life history attributes of the corals, based on real
data. Structural properties of the model were tested for stability and computational
efficiency.
Disturbances of
several types were investigated; natural background disturbance, and
warming events, both as single and repeated incidents to assess recovery dynamics in
the light of ongoing, intensifying climate-mediated global changes
Visions for the North Sea: The Societal Dilemma Behind Specifying Good Environmental Status.
We augment discussions about the Good Environmental Status of the North Sea by developing two extreme visions and assessing their societal benefits. One vision (‘Then’) assumes restoration of benthic functioning; we contend that trawling had already degraded the southern North Sea a century ago. Available information is used to speculate about benthic functioning in a relatively undisturbed southern North Sea. The second vision (‘Now’) draws on recent benthic functioning. The supply of five ecosystem services, supported by benthic functioning, is discussed. ‘Then’ offers confidence in the sustainable supply of diverse services but restoration of past function is uncertain and likely to be paired with costs, notably trawling restraints. ‘Now’ delivers known and valued services but sustained delivery is threatened by, for example, climate change. We do not advocate either vision. Our purpose is to stimulate debate about what society wants, and might receive, from the future southern North Sea
Early loss of Crebbp confers malignant stem cell properties on lymphoid progenitors.
Loss-of-function mutations of cyclic-AMP response element binding protein, binding protein (CREBBP) are prevalent in lymphoid malignancies. However, the tumour suppressor functions of CREBBP remain unclear. We demonstrate that loss of Crebbp in murine haematopoietic stem and progenitor cells (HSPCs) leads to increased development of B-cell lymphomas. This is preceded by accumulation of hyperproliferative lymphoid progenitors with a defective DNA damage response (DDR) due to a failure to acetylate p53. We identify a premalignant lymphoma stem cell population with decreased H3K27ac, which undergoes transcriptional and genetic evolution due to the altered DDR, resulting in lymphomagenesis. Importantly, when Crebbp is lost later in lymphopoiesis, cellular abnormalities are lost and tumour generation is attenuated. We also document that CREBBP mutations may occur in HSPCs from patients with CREBBP-mutated lymphoma. These data suggest that earlier loss of Crebbp is advantageous for lymphoid transformation and inform the cellular origins and subsequent evolution of lymphoid malignancies
Coral community dynamics and disturbance A modelling approach for Caribbean coral reefs
Available from British Library Document Supply Centre- DSC:DXN058212 / BLDSC - British Library Document Supply CentreSIGLEGBUnited Kingdo
Identification of indicator species to represent the full range of benthic life history strategies for Lyme Bay and the consideration of the wider application for monitoring of Marine Protected Areas
The work presented in this report is part of a larger project funded by Defra which focuses on assessing the various changes that may ensue as a result of protection of a 60nm area of Lyme Bay to mobile fishing gear, both in ecological and economic terms. The ecological monitoring includes monitoring of representative indicator species of the reef to examine recoverability and to “assess the long-term effects of fishery area closures on long lived and sessile benthic species”. The current report outlines the selection of such indicator species for Lyme Bay and the wider application of this and alternative methods to monitoring MPAs
Protecting nationally important marine biodiversity in Wales report to Wales Environment Link /
Wales has both national and international commitments to protect its marine environment and biodiversity including commitments to designing a network of marine protected areas (MPAs) (e.g. under the OSPAR Convention and the World Summit on Sustainable Development 2002). At EU level, the Habitats Directive requires that a "coherent European ecological network of special areas of conservation shall be set up under the title Natura 2000". This requirement encompasses both the terrestrial and marine environments
Isles of Scilly seagrass mapping
The objectives of this study are to utilise aerial survey and GIS methods, along with historic information, contextual information, and ground truthing to produce an up to date, accurate, GIS based map showing the current extent of seagrass (Zostera marina) in the Isles of Scilly. The results will enable changes in the extent of the seagrass to be monitored and so inform the site managers as to any changes that may need to be made to the future management of the SAC
Do marine protected areas deliver flows of ecosystem services to support human welfare?
This paper examines the potential relationships between the ecosystem services provided by the coastal and marine environment and the designation of marine protected areas. The hypothesis is that relationships exist between the provision of ecosystem services and the features protected by marine protected areas. It is considered that protection will maintain these features in good ecological condition and in some cases will restore ecological functioning with positive effects on the delivery of ecosystem services, as pressures upon the protected features are reduced. As the number of marine protected area designations grows, system-wide effects to communities from improvements in delivery of a range of ecosystem services may be realised. This paper provides a comparative analysis of the jurisdictional marine protected area policies proposed by the English, Welsh and Scottish Governments. It presents structured assessment matrices developed from the literature and expert opinion, of ecosystem service provision by marine protected habitats and species and applies the findings to a range of existing UK marine protected areas to demonstrate its relevance. The approach and case study findings are discussed within the wider context of marine ecosystem services and marine protected area management
Mapping marine benthic biodiversity in Wales
The UK is committed through international agreements and European obligations to the
establishment of an ecologically coherent network of Marine Protected Areas (MPAs) to
conserve marine ecosystems and biodiversity. The Welsh Assembly Government has committed
to using the new Marine Conservation Zone (MCZ) designation provided in the Marine and
Coastal Access Act to create sites afforded a high level of protection. In addition the Marine and
Coastal Access Act allows for the establishment of a system of Marine Spatial Planning in Welsh
waters. The identification of areas of high biodiversity could be helpful for planning both
Marine Protected Areas and for Marine Spatial Planning