Overview of data
WeBS Core Count Data
As part of the WeBS Core Count scheme around 2000 wetlands are counted on a monthly basis. For any of these sites, where available, data can be provided at different spatial scales. Post-1993, larger sites have often been divided into smaller count areas or sectors and wherever possible data are stored at this finer level. Site level data, such as for an estuary as a whole, will include summed data of all of the constituent sectors of that particular site and will take into account any variation in coverage. Although sector level data can be summed to provide site totals, these may provide misleading results if completeness of coverage is not taken into account. When data are required for a number of sectors, but these do not constitute an entire site then summed data for these consolidated sectors can be provided in a ‘custom consolidation’. These data will take into account any variation of coverage of each of the sectors.
WeBS Low Count Data
The WeBS Low Tide Count scheme covers most of the major estuaries in the UK with a view to providing information on species distributions within the estuary. Sites are counted approximately once every six years rather than annually. Data for a single site over a single winter are provided to external users in a standardised manner, in order to ensure a degree of consistency of interpretation of the data. It is important to note that, unfortunately, it is not always the case that a complete dataset is obtained – certain count sections may be missed in any one month or, in some cases, the whole site may not be counted on one of the four months specified. The sometimes incomplete nature of the data is accounted for in the summarised tabulations, and in the table of site coverage.