Chlorophyll-a content and ash-free dry mass of quantitative samples of the biofilm on benthic substrate from three chalkstream sites in the Wessex chalk area (Nine Mile River, River Till and River Wylye). Chlorophyll a content and biomass were determined from up to 10 replicate samples at each site on each sampling occasion. The data are presented as means with standard deviation. Data were collected on seven occasions on the Wylye and Nine Mile River and on five occasions on the Till, between October 2012 and October 2013. Data were collected to construct quantified food webs detailing the flux of mass and nutrients between nodes of the food web. This dataset was created as part of work package 3.2 of the Wessex Biodiversity & Ecosystem Service Sustainability (BESS) project.
Publication date: 2017-06-26
Samples were collected on 7 separate occasions from Nine Mile River and the River Wyle. However samples were only collected on five occasions from the River Till. We did not sample this river during the salmonid breeding season Dec-Mar so as not to disturb redds. Also two replicate chlorophyll-a samples were not processed from Nine Mile River in March 2013.
Standard laboratory procedures for determining chlorophyll-a and ash-free dry mass (AFDM) content were strictly followed but there was no formal quality assurance procedure, such as repeat analysis of replicate aliquots from the same replicate scrap. Final values were checked for marked outliers (none were found) before calculations were undertaken.