Spatial variability of Arctic sea ice algae

• Main Author: Lange, Benjamin
• Format: Thesis
• Language: unknown
• Published: University of Hamburg 2016
• Subjects: Arctic; Arctic Ocean; Climate change; ice algae; Phytoplankton; Sea ice
• Online Access: https://epic.awi.de/id/eprint/52367/; https://epic.awi.de/id/eprint/52367/1/Lange_PhD-Thesis_submission.pdf; https://hdl.handle.net/10013/epic.bd3d39f6-a18d-436c-ba4a-cd3e764605e2

The most pronounced effects of global climate change have been experienced in the Arctic region. In particular, Arctic sea ice decline and volume loss have emphasized the impeding threat of continued climate change, and have been center stage in the public eye for over a decade. Many of the observed changes in the Arctic are related to the physical system because these parameters, such as sea ice extent and thickness, are more easily observed from space and airborne platforms. The linkage between ecosystem function and its physical environment is clear from all well investigated systems. This undoubtedly means that the observed changes to the physical system have had an equally dramatic impact on the Arctic ecosystem. Our understanding of the Arctic marine ecosystem, however, is severely limited due to the methodological and logistical constraints of monitoring ecological properties. This has caused significant seasonal and geographical knowledge gaps, particularly in the high (> 80ºN) and central Arctic Ocean. Over the past decades a disproportional emphasis has been put on the importance of primary production (PP) and the availability of food in the water column. Observations have indicated an overall increase in Arctic-wide net primary production (NPP) as a result of a thinning and declining sea ice cover, and increasing duration of the phytoplankton growth season. This increased biomass may suggest a corresponding increase in the biomass of consumers and higher trophic levels. This premise, however, neglects the rather important role that the sea ice environment and sea ice algae play in the Arctic food web. The timing, duration and spatial availability of ice algae are drastically different compared to pelagic phytoplankton. Therefore, it is only by first gaining a better understanding of the base of the Arctic food web that we can start to understand the rest of the food web. Throughout this thesis, we aimed to assess how sea ice algae biomass availability and habitat will be affected by continued ...