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Ecological and environmental factors affecting alkenone distributions in seawater and sediments

The use of alkenones to estimate past sea surface temperatures has gained wide acceptance, but there are still some issues that need to be resolved before alkenone proxies can be used confidently in all environmental settings. A particular concern is defining what seawater temperature is recorded by the alkenone distributions preserved in sediments. Does it, for example, reflect a seasonal average or a snapshot of bloom conditions or some other combination of environmental effects? This paper reviews some of the environmental and ecological factors that might affect alkenone distributions and, in particular, the influence of depth and seasonality on alkenone production in the water column.