Motivation: The BioTIME database contains raw data on species identities and abundances in ecological assemblages through time. These data enable users to calculate temporal trends in biodiversity within and amongst assemblages using a broad range of metrics. BioTIME is being developed as a community‐led open‐source database of biodiversity time series. Our goal is to accelerate and facilitate quantitative analysis of temporal patterns of biodiversity in the Anthropocene.Main types of variables included: The database contains 8,777,413 species abundance records, from assemblages consistently sampled for a minimum of 2 years, which need not necessarily be consecutive. In addition, the database contains metadata relating to sampling methodology and contextual information about each record.Spatial location and grain: BioTIME is a global database of 547,161 unique sampling locations spanning the marine, freshwater and terrestrial realms. Grain size varies across datasets from 0.0000000158 km²(158 cm²) to 100 km²(1,000,000,000,000 cm²).Time period and grain: BioTIME records span from 1874 to 2016. The minimal temporal grain across all datasets in BioTIME is a year.Major taxa and level of measurement: BioTIME includes data from 44,440 species across the plant and animal kingdoms, ranging from plants, plankton and terrestrial invertebrates to small and large vertebrates.Software format: .csv and .SQL.

The surface stability of intertidal cohesive sediments maintained in a laboratory tidal ecosystem was examined in relation to the migratory behavior of epipelic diatoms. Stability was measured by a new portable device—a cohesive strength meter. Diatom#x2010;inhabited sediments increased significantly in surface stability over 7.3#x2010;h tidal exposure as compared with consolidated and unconsolidated control sediments. Low#x2010;temperature scanning electron microscopy showed an extensive extracellular matrix throughout the surface of diatom#x2010;inhabited sediments. This matrix was considered to consist mainly of mucopolysaccharides produced by diatoms as part of their locomotive mechanism. A matrix of very fine strands (possibly of bacterial origin) was found on the consolidated control sediment but had little effect on stability. Surface stability imparted by the mucilage produced by epipelic diatoms decayed after the return of the tide, but when dense populations of diatoms were present (10⁶ diatoms cm⁻²) some residual stability remained after a full tidal inundation.

Measurements of microbial extracellular polymeric substances (EPS) of natural field populations are required to understand the processes of biogenic stabilization and the microbial ecology of intertidal sediments. EPS in sediments can be measured by the phenol‐sulfuric acid assay to measure carbohydrate concentration in sediment samples. We conducted comparative studies of storage and extraction methods for carbohydrate fractions on intertidal estuarine sediments. Measurements of both total and colloidal (material remaining in suspension after aqueous extraction and centrifugation) carbohydrate concentrations were highly dependent on storage conditions, sample size, extraction media, and time. Precipitation (in 70% ethanol) of EPS from saline (25‰) extractions of colloidal carbohydrate (colloidal S) from four different sediment microbial assemblages showed that 20% of colloidal carbohydrate present in extracts consisted of EPS. Concentrations of colloidal S were highly correlated with diatom biomass as determined by chlorophyll a concentrations. Extractions that used 100 mM Na₂EDTA as the extracting medium (colloidal EDTA) increased the concentrations of colloidal carbohydrate obtained and, in sediments dominated by bacteria and cyanobacteria, increased the percentage of EPS in the material to 38%. Uronic acids comprised 20% of the total amount of carbohydrate measured in both total sediment and colloidal‐S extracts but increased to 65% in colloidal‐EDTA extracts, suggesting that colloidal‐EDTA extractions remove bacterial capsular EPS and EPS more closely associated with sediment particles.

Benthic diatom communities have been documented many times to exhibit a predictable pattern of migration entrained to diurnal and tidal cycles forming transient biofilms in the estuarine intertidal. The highly visible nature of these biofilms means that many anecdotal descriptions of this behaviour exist, yet much still remains to be elucidated about these behaviours and what drives them. There has been a resurgence in work examining the migratory patterns of benthic diatoms because of the important roles they play in the overall functioning of the ecosystem (e.g. primary production). It is the aim of this paper to provide a comprehensive overview of the migratory literature to date. The paper will review the methodology that was historically used to examine patterns in diatom migration as well as introduce new technologies (e.g. remote sensing). The patterns and cues for migration are discussed, highlighting the fact that whilst a “classic” pattern of migration is often found (migration of cells to the sediment surface as the tide leaves the site followed by a downwards migration in anticipation of the incoming tide), these cannot be considered to be consistent, with many site and taxon specific idiosyncrasies. Furthermore, it has been suggested that cells also migrate within the biofilm, cycling their position at the sediment surface therefore maximising their overall fitness, and this hypothesis is discussed. The vertical migration strategy of the benthic diatoms is critical to their pivotal role in the structure and functioning of estuarine intertidal mudflats and the costs and benefits of a microphytobenthic existence are discussed in this context.