Including ecology in biodiversity data management systems requires classifications ofhabitat terms that provide standard definitions and indicate their relationships. In addition to databases,a wide range of intergovernmental, conservation and fishery organizations require classificationsof habitats and ecosystems to enable comparisons between areas and organize information inmaps and reports. However, all of the terms used to describe habitats are concepts whose definitionis context-dependent. This paper reviews the key concepts and ecological perspectives involved inclassifying marine ‘habitats’ and ‘biotopes’ (habitat plus its associated species) so as to advise howthey may be used in data management systems. Classifications of biotopes provide practical measuresof biodiversity at the ecosystem level. As an example the habitat of a benthic invertebrate isvery different in spatial scale to that of a parasite, plankton, tuna or whale. Habitats can be geophysicaland/or biogenic, and may operate at different spatial scales. For example, aggregations of deepseacoral colonies <1 m in diameter may form km-scale reefs which contain other habitats (e.g. sediments,sponges). An ecosystem can be physiographically defined as a lagoon, seamount, estuary,abyssal plain or entire ocean. Different sampling methods will define different regions, such as satelliteimages of ocean colour, acoustic maps of the seabed, in situ sampling of water or sediment coresand maps derived from analyses of species distributions that may define biogeographic regions.Because they are sampled (and thus defined) by different methods and can operate at different spatialscales, separate classifications are recommended for (1) nekton, plankton and benthos and (2)regions (defined to suit political, geographic or management areas), seascapes (defined by topographyor water mass), biotopes and guilds (e.g. based on body size, diet or sampling method). Furthermore,it is recommended to record the measurable features used to describe biotopes (e.g. depth,dominant species, substratum) and to avoid imposing a classification hierarchy where the conceptsand methods of defining them are different. Indeed, one can let users create the most parsimoniousclassification for their purposes. |
