Glacial melting and marine ecosystems
As the name implies, global warming will affect the whole world, yet polar regions may experience the strongest effect. Those effects remain to be fully understood. The EU-funded IMCONET (Interdisciplinary modelling of climate change in coastal western Antarctica – network for staff exchange and training) project examined the effect of climate change in the West Antarctic Peninsula (WAP). The team integrated over 25 years of data from shallow-water sites into ecosystem models, intended to relate changes in the marine community to abiotic changes. Researchers also compared current local Antarctic processes to recent and late Holocene deglaciation patterns. A new glacier inventory detailed changes in the glacier extent on the WAP. Studies of ice dynamics revealed that glacier extension strongly depends on geometry. WAP glaciers that had lost mass during the period 1992-1996 regained the mass between 2010 and 2014. Such changes were consistent with project data showing colder temperatures and increased precipitation since 2001. Researchers used new models to estimate the amount of glacier melt for Potter Cove and the extent to which melting affects the ecosystem. The team analysed new Holocene sediment cores, which showed relative sea-level changes during the era. Researchers also used the core data, in particular biomarkers from penguin guano, to reconstruct previous volcanic activity, climate change, sea-ice distribution and relative sea-level changes. The study focused on a major gentoo penguin colony. Results indicated that the youngest parts of the inner cores contained sediment from a glacial moraine that formed during the little ice age (1300-1850). The inner core showed an absence of many susceptible marine species due to the influence of glacial melt. Investigators concluded that glacial run-off blocks light in the coastal environment, altering the conditions for primary producers. Few species can cope with glacial melting conditions of high sediment and low light. As a result, glacial melting decimated coastal Antarctic ecosystems. The work produced a fundamental new understanding of how climate change is likely to affect Antarctic marine communities. Antarctic islands, having smaller ice caps, are more sensitive to climate change, and serve as early warnings of the effects of regional climate change.
Keywords
Glacial melting, marine ecosystems, Antarctic, IMCONET, climate change, sea-level changes
