Impact of sea ice on the marine iron cycle and phytoplankton productivity

Abstract

Abstract. Iron is a key nutrient for phytoplankton growth in the surface ocean. At high latitudes, the iron cycle is closely related to the dynamics of sea ice. In recent decades, Arctic sea ice cover has been declining rapidly and Antarctic sea ice has exhibited large regional trends. A significant reduction of sea ice in both hemispheres is projected in future climate scenarios. In order to adequately study the effect of sea ice on the polar iron cycle, sea ice bearing iron was incorporated in the Community Earth System Model (CESM). Sea ice acts as a reservoir for iron during winter and releases the trace metal to the surface ocean in spring and summer. Simulated iron concentrations in sea ice generally agree with observations in regions where iron concentrations are relatively low. The maximum iron concentrations simulated in Arctic and Antarctic sea ice are much lower than observed, which is likely due to underestimation of iron inputs to sea ice or missing mechanisms. The largest iron source to sea ice is suspended sediments, contributing fluxes of iron of 2.2 × 10 8 mol Fe month −1 in the Arctic and 4

Major impacts of climate change on deep-sea benthic ecosystems

“…Thus, the immediate direct impacts on seafloor communities will be relatively short-lived, but the wider effects may be longer lasting. Finally, melting of icebergs and glacial ice may lead to freshening of surface waters leading to enhanced stratification of the upper water column and the release of essential nutrients and trace metals such as iron (Wang et al, 2014). Together with decreased sea-ice cover these factors may act to increase primary production and POC flux.…”

Is the meiofauna a good indicator for climate change and anthropogenic impacts?

“…Among heavy metals, some, such as iron, are essential for biological processes (Wang et al 2014). However, at higher concentrations, specific elements, including copper, zinc or lead, can be toxic (Baize 1997).…”

Introduction to the special issue on the Life in Antarctica: Boundaries and Gradients in a Changing Environment (XIth SCAR Biology Symposium)

“…The southward displacement of the polar front may also alter the Earth's climate, modify community composition of plankton (Flores et al 2012;Wang et al 2014) and benthos (Thatje et al 2005a) and facilitate the intrusion of non-local species from more northern regions, which is also taking place due to the growing tourism in the islands off the Antarctic Peninsula (Frenot et al 2005).…”