|Biotic couplings on shallow water soft bottoms: examples from the northern Baltic Sea|
Bonsdorff, E.; Blomqvist, E.M. (1993). Biotic couplings on shallow water soft bottoms: examples from the northern Baltic Sea. Oceanogr. Mar. Biol. Ann. Rev. 31: 153-176
In: Oceanography and Marine Biology: An Annual Review. Aberdeen University Press/Allen & Unwin: London. ISSN 0078-3218, more
Benthos; Biotic factors; Shelf dynamics; ANE, Northern Baltic [Marine Regions]; Marine; Brackish water
|Authors|| || Top |
- Bonsdorff, E., more
- Blomqvist, E.M.
Biotic couplings in brackish shallow water systems have been studied extensively in the northern Baltic Sea. The non-tidal Baltic is characterised by steep horizontal and vertical, local and basin-wide environmental gradients (salinity, temperature, oxygen, exposure, sediment quality, archipelago systems) ranging from almost limnic, sheltered inner bays to brackish 'marine' conditions in the exposed open coastal zone. The species number of zoobenthos and fish is generally low, and most species live at the border of their physiological tolerance. Despite the physiological pressure on the organisms, biotic interactions (intra- and interspecific; within- and between trophic levels and functional groups) are significant in establishing the community organisation recorded in any local habitat at any given moment. Due to the salinity-stress, few epibenthic invertebrate predators occur in the Baltic, and benthivorous fish are important in the regulation of the infauna of the shallow (0-5 m) archipelago waters. Fish, however, mainly utilise these habitats in the summer season, whereas zoobenthos have a less marked seasonal variability in terms of biomass and species composition. As the number of key species is low, the ecosystem is highly vulnerable to unexpected catastrophic events, or man-made stress, such as eutrophication, but simultaneously the recovery potential of the biota is high.