MacroBen

Often marine biological data are the result of projects with a limited temporal and spatial cover. By combining the small datasets obtain by such individual projects, massive databases can be created that make large scale analyses possible. Such datasets are especially important when one considers the recent observation of major shifts of marine species due to global change. Within the [www.marbef.org MarBEF] working group Global Patterns of Marine Biodiversity across Ecosystems (Theme 1), an integrated database (MacroBen) on soft-bottom macrobenthos was compiled.

Constituent datasets

Each dataset was archived and described in detail at the data centre of the Flanders Marine Institute (VLIZ). Describing these datasets in a standardised way made it possible to create a searchable metadata inventory. This helps scientists to discover desired data and also enables them to share their data with other scientist. All metadata descriptions are publicly available. Archiving the datasets prevents them from being lost by ensuring the long-term integrity of the data. Most of the child databases (28 of the 44) can be found here the other 18 here .

Integrating the datasets

The MacroBen database integrates datasets on softbottom macrobenthic fauna from all European seas. A total of 44 datasets was collected, harmonised and integrated into a relational Access database. The integrated database includes both quantitative and qualitative data on organisms and several abiotic parameters ranging from the northeast Atlantic and the North Sea, Norwegian Sea and Arctic Ocean, the Baltic Sea and the Mediterranean and Black seas. During harmonisation of the different datasets problems occurred because not all datasets used the same taxonomy, didn't mention which datum they used (to indicate the sampling position) or used different sampling methods.

The data management of MacroBen is based on a series of Access databases: 1 Access database for each constituent dataset, and 1 to contain the integrated data. The latter also contains tools and a simple user interface to work with the data. This system made it possible to manage the data from individual datasets separately, and go through an iterative process of data cleaning and harmonisation.

The database

The MacroBen database contains data from 1937 to 2005 from different research and monitoring programmes and includes 22 897 sampled stations and 465 354 distribution records (Table 1). Depth is available for 416 312 distribution records (86%). There are 7481 taxa, of which 7203 were valid. The database contains 40 766 abiotic readings from 75 different parameters from both the sediment and water; 46 datasets provided by 24 European institutes were collected and integrated into the MacroBen database. The samples range geographically from 32° 2’ 48’’N to 81° 27’N and from 42° 55’ 1’’W to 58° 56’ 35’’E (Fig. 3). The North Sea and northeast Atlantic region has the highest sampling density. Datasets from the Belgian part of the North Sea and the southern part of the Dutch continental shelf account for 37% of the total biotic records, while <0.05% of the total records in MacroBen are from the Skagerrak and Baltic Sea region. It is essential to allow for these strongly unequal sampling densities across the different geographical regions in evaluating the ecological basis for any observed patterns.

DATA POLICY

All data stored in the MacroBen database are subject to the declaration of mutual understanding for data sharing within MarBEF Theme 1. The policy implies that the participating institutes, organisations and/or the collector of the dataset remain owners of their contributed dataset, and in control of the conditions under which datasets can be used by a third party. Metadata as an essential tool for data discovery, is publicly available for all datasets, and includes the conditions of use. A description of the process that led to the policy, as well as a more complete description of the policy itself, is given in the introduction to this Theme Section. (Somerfield et al. 2008).