The impact of environmental change on the Antarctic silverfish Pleuragramma antarcticum - Identifying physiological and ecological limits
Final Report Abstract
This project originally aimed to investigate the vulnerability of the Antarctic silverfish, Pleuragramma antarcticum, to environmental alterations due to climate change. The design of the project included different physiological and feeding experiments. Due to the lack of live P. antarcticum a variety of alternative experiments and analyses were carried out. The feeding experiments included: (i) experiments on feeding preferences and assimilation efficiency depending on prey composition in Notothenia coriiceps, and (ii) experiments on the effect of prey size on detection capability and feeding efficiency in N. coriiceps and N. rossii. The experiments clearly showed that there is a preference for particular food items, and that detection and feeding efficiency strongly depend on prey size in both species. A physiological experiment was carried out with N. coriiceps, investigating the effect of increasing water temperature on fish performance (inferred from oxygen consumption). During the expedition ANT XXVII-3 distribution and abundance of P. antarcticum in relation to oceanographic features was investigated using a hydroacoustic approach combined with fishery. As we failed in keeping P. antarcticum from net catches alive, different kind of tissue and whole animal samples were taken for later analyses. The data from this expedition indicated strong regional differences in P. antarcticum condition; these differences were also reflected in stomach fullness. General diet compositions differed between sampling locations, but did not explain the differences in in fish condition. To further unravel the regional differences, we applied anatomical MR imaging in combination with localized 1H-MR spectroscopy on the preserved whole-animal samples taken in these different locations. Besides of morphological images, fat/water content and lipid composition were determined. The results showed regional differences in lipid content in correlation to the latitudinal origin and nutritional state. The results from these analyses provide deep insight into the role of lipids in P. antarcticum, and moreover, the information obtained from this approach offers the potential of a variety of MR studies on formalin-fixed specimens or tissue for biological and medical research. Although there were many failures in this project and the originally planned experiments could not be performed, the overall output of the project in terms of publications (already published and currently in preparation), new data and newly developed approaches, is really satisfying and represents an important contribution to the scientific community.
Publications
- (2011). The role of body size in complex food webs: A cold case. Advances in Ecological Research 45: 181-223
Jacob U., Thierry A., Brose U., Arntz W.E., Berg S., Brey T., Fetzer I., Jonsson T., Mintenbeck K., Möllmann C., Petchey O., Riede S., Dunne J.A.
- (2012). Impact of climate change on fish in complex Antarctic ecosystems. Advances in Ecological Research 46: 351-426
Mintenbeck, K., Barrera-Oro, E.R., Brey, T., Jacob, U., Knust, R., Mark, F.C., Moreira, E., Strobel, A., Arntz, W.E.
- (2012). Metabolic shifts in the Antarctic fish Notothenia rossii in response to rising temperature and PCO2. Frontiers in Zoology 9: 28
Strobel, A., Bennecke, S., Leo, E., Mintenbeck, K., Pörtner, H.-O., Mark, F.C.
(See online at https://doi.org/10.1186/1742-9994-9-28) - (2012). The Expedition ANTARKTIS XXVII/3 (CAMBIO) of RV "Polarstern" in 2011. Reports on Polar and Marine Research 644, 200pp.
Knust, R., Mintenbeck, K. eds.
