Biodiversity and ecology of deep-sea copepods in polar seas - speciation processes and ecological niches in the homogeneous environment of the pelagic realm
Zusammenfassung der Projektergebnisse
The biodiversity of pelagic deep-sea ecosystems has received growing scientific interest in the last decade, especially in the framework of international initiatives such as Census of Marine Zooplankton. While a growing number of deep-sea Zooplankton has been identified and genetically characterised, little information is available on the mechanisms minimizing inter-specific competition and thus allowing closely related species to co-occur in the deepsea pelagic realm, where physical barriers and isolation mechanisms are almost absent. Moreover, speciation and radiation processes in the almost homogeneous environment of the deep sea are far from understood. Focussing on the two dominant, species-rich copepod families Euchaetidae and Aetideidae and based on a combination of field studies, molecular genetic analyses and trophic biomarker assessments in both polar regions, the project strived to characterize ecological niches of co-occurring species, with regard to vertical distribution, dietary composition and reproductive behaviour. Vertical partitioning of the water column between closely related species and the separation of trophic niches among cooccurring species interact in reducing inter-specific competition and sustain a high biodiversity in the three-dimensional environment of the pelagic deep sea. Another relevant result of the project is the importance of herbivorous calanid copepods as prey for camivorous copepods throughout the water column. Trophic biomarkers of calanid copepods as prey were detected in high concentrations even in bathypelagic Paraeuchaeta barbata from both polar regions. The seasonal vertical migrations of calanids provide a trophic shortcut from the surface layer to the deep sea and provide a stable food supply for carnivorous deep-sea inhabitants throughout a large fraction of the annual cycle. Prey availability in the deep-sea may even be enhanced during winter, when epipelagic production is at its minimum resulting in an "inverse seasonality" for deep-sea inhabitants.
Projektbezogene Publikationen (Auswahl)
- (2009) Ecological niches of Arctic deep-sea copepods: Vertical partitioning, dietary preferences and different trophic levels minimize inter-specific competition. Deep Sea Research Part I, Vol. 56, Issue 5: 741-756
Laakmann, S., Kochzius, M., Auel, H.
- (2009) Vertical distribution and dietary preferences of deep-sea copepods (Euchaetidae and Aetideldae; Calanoida) in the vicinity of the Antarctic Polar Front. Polar Biology, Vol. 32, Number 5: 679-689
Laakmann, S., Stumpp, M., Auel, H.
