The dataset details surface sediment colloidal carbohydrate concentrations across six intertidal sites in the winter and summer of 2013. Colloidal carbohydrate concentrations in surface sediments (top 2mm) provide a quantitative measure of the extracellular polymeric substances (EPS) secreted by organisms that form the microphytobenthos (MPB) community. Three of the sites were in Morecambe Bay, North West England and three of the sites were in Essex, South East England, each of these sites consisted of a saltmarsh area and adjacent mudflat area, twenty two sampling quadrats were placed on each area. Five replicate sediment samples were taken at each quadrat and were analysed using the Dubois Phenol-Sulphuric Assay which involves spectrophotometer analysis of absorptions to determine colloidal carbohydrate concentrations. Values for colloidal carbohydrate concentrations are expressed as glucose equivalents in micrograms per gram of sediment.
This data was collected as part of Coastal Biodiversity and Ecosystem Service Sustainability (CBESS): NE/J015644/1. The project was funded with support from the Biodiversity and Ecosystem Service Sustainability (BESS) programme. BESS is a six-year programme (2011-2017) funded by the UK Natural Environment Research Council (NERC) and the Biotechnology and Biological Sciences Research Council (BBSRC) as part of the UK's Living with Environmental Change (LWEC) programme.
Publication date: 2016-04-25
Sediment colloidal carbohydrate concentration was determined through the collection of contact cores. Contact cores use liquid nitrogen to freeze the top 2mm of the sediment surface, excess unfrozen sediment is removed and the sample core is stored below -80 degree centigrade. The sample is weighed to determine wet weight and freeze dried to remove all water. Colloidal carbohydrate concentration is determined using the Dubois Phenol-Sulphuric assay. A sediment sub-sample (50-500mg, depending on site) is taken from dried contact core sediment and known volume of distilled water is added. Sample is vortexed and centrifuged then a set volume of supernatant is removed. Concentrated sulphuric acid and 5 percent phenol are added to the supernatant sample ensuring the ratio of sample: phenol: acid is kept at 1:1:5 by volume. Allow 35mins for colour to develop. Decant the samples into cuvettes and read the absorbance at 486.5nm on Thermo Biomate 5 spectrophotometer. Use figures from regression analysis of glucose standards to calculate colloidal carbohydrate concentration expressed as glucose equivalents in micrograms per gram (µg g-1). Note: zeroes indicate colloidal carbohydrate concentration below detectable level. Twenty two 1 x 1 m quadrats were randomly allocated to each mudflat and saltmarsh site using R (R Development Core Team, 2014) to specify four different spatial scales (A = 1 quadrat only, B = 3 quadrats at 1 m to 10 m apart, C = 6 quadrats at 10 m to 100 m apart, D = 12 quadrats at 100 m to 1000 m or site maximum).