Physical and biological changes in the Arctic Ocean
By Professor Dr. Harald Loeng|
Institute of Marine Research, P.O. Box 1870 Nordnes, Bergen, 5817, Norway. E-mail: email@example.com
Physical factors that make arctic marine ecosystems unique are a very high proportion of shallow continental shelves, dramatic seasonal change, low temperature, extensive permanent and seasonal ice-cover, and a large supply of freshwater from rivers and melting ice. Because of these conditions, many of which are challenging for marine biota, arctic marine ecosystems have a large number of specialists, many of which are not found elsewhere. These organisms have, through time, been able to adapt to the environment, but they are still challenged by extreme inter-annual variations.
The possible pathways by which climate variability may affect ecological processes are many and vary across a broad range of temporal and spatial scales. Climate variability affects fish both directly through physiology, including metabolic and reproductive processes, as well as through affecting their biological environment (predators, prey, species interactions) and abiotic environment (habitat type and structure). Furthermore, ecological responses to climatic variation may be immediate or lagged, linear or nonlinear, and may result from interactions between climate and other sources of variability.
The presentation will focus on physical and biological characteristics of Arctic Ocean and adjacent seas, and how ecosystems interact. There is ample evidence of the effects of climate variability on the marine ecosystems, e.g. the response of the abundance and distribution of fish species associated with long-term temperature changes. These occur as direct physiological responses as well as indirectly through effects on the prey, predators or competitors. However, many aspects of the interaction between the atmosphere and the ocean, and between climate and the marine ecosystem require a better understanding before the high levels of uncertainty associated with present predicted responses to climate change can be significantly reduced. This understanding can only be achieved through monitoring and research. The latter should include comparisons between and among other subarctic and arctic regions.
|Willem Barentsz Poolinstituut|
Bundeling van kennis, onderzoek en onderwijs over de Noord- en de Zuidpool
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