Zooplankton drive diurnal changes in oxygen concentration at Tisler cold-water coral reef
Tisler Reef is a Norwegian cold-water coral reef in the Northeastern Skagerrak, which lies at an average depth of 120 m, is constructed principally of the scleractinian coral Lophelia pertusa and hosts a dynamic and diverse ecosystem. The availability of oxygen within Tisler Reef, recorded between 2006 and 2008, showed a decline during the summer months, caused by both the isolation of the reef from the atmosphere under conditions of seasonal stratification, and the enhanced respiration in the water column during the seasonal zooplankton proliferations. Concentrations of dissolved oxygen were replenished from high-current flows advecting water from off the reef. Low current flow conditions (< 0.05 m s−1) coincided with a short-term reduction in oxygen, the extent of which varied seasonally and were observed to be greatest during July and August, coinciding with the summer Calanus proliferation in the Skagerrak. Normalized acoustic backscatter amplitude during the summer months showed a strong signal of zooplankton diurnal vertical migration, coinciding with the lowest oxygen concentrations at the reef observed during, and lagging slightly after, the deep phase of the zooplankton vertical migration. This effect was most obvious during low-flow conditions; highlighting the importance of zooplankton and associated activity as a consumer of oxygen at the reef.
KeywordsCold-water coral Oxygen Zooplankton Replenishment Respiration
The authors wish to thank the staff of the Sven Lovén Centre for Marine Sciences, Tjärnö, Univeristy of Göteborg. This research has received funding from the European Community’s Seventh Framework Programme (FP7/2007-2013) under the HERMIONE project, grant agreement No 226354, and by the HERMES project, EC contract GOCE-CT-2005-511234). This research was supported under Australian Research Council’s Special Research Initiative for Antarctic Gateway Partnership (Project ID SR140300001).
Compliance with ethical standard
Conflict of interest
On behalf of all authors, the corresponding author states that there is no conflict of interest.
- Dahlgren TG, Wiklund H, Kallstrom B, Lundälv T, Smith CR, Glover AG (2006) A shallow-water whale-fall experiment in the north Atlantic. Cah Biol Mar 47:385–389Google Scholar
- Deines K (1999) Backscatter estimation using broadband acoustic Doppler Current Profilers. Proceedings of the Ieee Sixth Working Conference on Current Measurement 249–253Google Scholar
- Etnoyer P, Morgan LE (2005) Habitat-forming deep-sea corals in the Northeast Pacific Ocean. In: Freiwald A, Roberts JM (eds) Cold-Water Corals and Ecosystems. Springer, BerlinGoogle Scholar
- Freiwald A, Fosså J, Grehan A, Koslow T (2004) Cold-water coral reefs. UNEPWCMCGoogle Scholar
- Kaartvedt S (2010) Chapter Nine - Diel Vertical migration behaviour of the Northern Krill (Meganyctiphanes norvegica Sars). In: Tarling G.A. (eds) Advances in Marine Biology. Academic Press, pp 255–275Google Scholar
- Linnaeus C (1758) Systema naturae : Appendices zoologicae. Edition XII. Hagae Comitis : W. Junk, 1935Google Scholar
- Wilson CB (1932) Copepods of the Woods Hole region, Massachusetts. U.S. Nat. Hist. Mus. 158:635–676Google Scholar
- Wisshak M, Freiwald A, Lundalv T, Gektidis M (2005) The physical niche of the bathyal Lophelia pertusa in a non-bathyal setting: environmental controls and palaeoecological implications. Erlangan Earth Conf 979–1001Google Scholar