An index to assess and monitor the progression of wasting disease in eelgrass Zostera marina

An index based on rapid visual determination of the relative amount of necrotic tissue on eelgrass shoots infected with wasting disease is described. The utility of the index for assessing and monitoring disease levels in natural and experimental populations of eelgrass is illustrated with examples from the field and a mesocosm experiment. Using the Wasting Index, monitoring of the disease along with environmental variables provided correlational data that aided understanding of the disease progression and linked disease severity with salinity. Once salinity increased above a threshold, disease spread rapidly and was inversely correlated with leave are

An index to assess and monitor the progression of wasting disease in eelgrass Zostera marina

An index based on rapid visual determination of the relative amount of necrotic tissue on eelgrass shoots infected with wasting disease is described. The utility of the index for assessing and monitoring disease levels in natural and experimental populations of eelgrass is illustrated with examples from the field and a mesocosm experiment. Using the Wasting Index, monitoring of the disease along with environmental variables provided correlational data that aided understanding of the disease progression and linked disease severity with salinity. Once salinity increased above a threshold, disease spread rapidly and was inversely correlated with leave are

Mesocosm experiments quantify the effects of eutrophication on eelgrass, Zostera marina

Outdoor mesocosm experiments were used to examine the response of eelgrass communities to excess nutrient loading and reduced light that simulated coastal eutrophication. A series of replicated manipulations conducted between 1988 and 1990 demonstrated the effects of reduced available light and increased loading of nitrogen plus phosphorus on habitats dominated by eelgrass Zostera marina L. Shade and nutrients each significantly affected eelgrass growth, morphology, density, and biomass. We found no significant interactions between the effects of shade and the effects of nutrients on any plant characteristics except leaf length. The growth rate of individual eelgrass shoots was linearly related to light, increasing throughout the range of available light. Biomass and daily biomass increase, or areal growth, were also linearly related to light, but specific growth showed no response to light. Shoot density increased with the log of light. Excess nutrient loading was shown to significantly reduce eelgrass growth and bed structure through stimulation of various forms of algae that effectively competed with eelgrass for light. The absence of significant interactions between the effects of shade and nutrients on eelgrass density, growth, and biomass suggests that the negative effect of algae on eelgrass occurs primarily through the reduction of light (i.e. shading). The outcome of nutrient enrichment was a shift in plant dominance from eelgrass to three algal forms: phytoplankton, epiphytic algae, and macroalgae. We quantified the effects of eutrophication and demonstrated that increased nutrient loading results in less light for eelgrass and that eelgrass growth linearly decreases with reduced light

Eelgrass in Estuarine Research Reserves Along the East Coast, USA

Eelgrass, Zostera marina L., is a submerged marine vascular plant that provides the basic structure of an extensive and important estuarine and coastal ecosystem. Currently, eelgrass populations around the world are declining dramatically due primarily to two causes: human pollution and a disease. The extensive loss of eelgrass threatens major alterations to the coastal environment and to the waterfowl and fish that depend on these plant communities. However, the eelgrass declines represent natural experiments that provide and opportunity to investigate a disease\u27s impact on an ecosystem, the characteristics of pollution-related declines, and finally, how declines from both causes can be diminished or mitigated

Quantum Mechanical Realization of a Popescu-Rohrlich Box

We consider quantum ensembles which are determined by pre- and post-selection. Unlike the case of only pre-selected ensembles, we show that in this case the probabilities for measurement outcomes at intermediate times satisfy causality only rarely; such ensembles can in general be used to signal between causally disconnected regions. We show that under restrictive conditions, there are certain non-trivial bi-partite ensembles which do satisfy causality. These ensembles give rise to a violation of the CHSH inequality, which exceeds the maximal quantum violation given by Tsirelson's bound, $B_{\rm CHSH}\le 2\sqrt2$, and obtains the Popescu-Rohrlich bound for the maximal violation, $B_{\rm CHSH}\le 4$. This may be regarded as an a posteriori realization of super-correlations, which have recently been termed Popescu-Rohrlich boxes.Comment: 5 page

Impacts of Marine Docks on Eelgrass in New England: A Spreadsheet-Based Model for Managers and Planners

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