Stress response in temperate and polar benthos: populations to molecules.

• Main Author: Abele, Doris
• Format: Conference Object
• Language: unknown
• Published: 2006
• Subjects: Antarc*; Antarctic; Antarctic Peninsula; Iceberg*; South Shetland Islands
• Online Access: https://epic.awi.de/id/eprint/16235/; https://hdl.handle.net/10013/epic.26217

Stress response in temperate and polar benthos: from populations to moleculesDoris Abele, Alfred-Wegner Institute for Polar and Marine Reserach, Bremerhaven, Germany ([e-mail])The Antarctic Peninsula is an area of rapid recent climate change. Mean air temperature has risen by 2.5°centigrade over the last 5 decades, and glaciers are melting mainly along the Western coasts and on the adjacent islands. This results in increased sediment transport to coastal areas, freshening of coastal surface waters and high incidence of iceberg scours in shallow environments. Additionally, animals at shallow depths receive high doses of detrimental UVB radiation during ozone hole conditions in the southern spring.Antarctic animals are adapted to very constant and predictable cold water conditions. They generally have low metabolic rates and especially sedentary species also have low scope for activity, resulting in slower growth and development (Peck et al. 2004), but longer life expectancy compared to temperate animals with a similar lifestyle (Philipp et al. 2005). Stress sensitivity is increased by specific features at the tissue and cell level like loss of the inducible heat shock response in ice fish (Hofmann et al. 2000). Also the extremely high tissue iron levels found in molluscs around the volcanic South Shetland islands may render these animals more sensitive to stress (Gonzalez unpublished), because the fraction of free tissue iron acts as Fenton catalyst producing reactive oxygen species, which may interfere with cellular signalling.In stress research, two possible scenarios should be distinguished: Subcritical stress (slow changes of temperature or tolerable exposure to heavy metals like iron) will raise costs for tissue maintenance and repair. This will limit the aerobic scope, meaning the amount of energy an animal can use to perform activity and to grow (Peck et al 2004). Populations under constant stress will therefore have different age to size relations than unstressed populations. Contrary, ...