Denitrification of the Oceans Increases Due to Warming
A lack of dissolved nitrogen in the oceans’ surface limits growth and productivity. This is a practice that is often mirrored in reef aquaria where free nutrients are not desirable. In a recent study published in Nature Geoscience, a team measured the effects over time of warming waters on ocean productivity. It was discovered that increasing temperatures, which cause a decrease in oxygen carrying capacity, increased denitrification or the shift from dissolved inorganic nitrogen compounds (ammonia, nitrite, nitrate, urea) to gaseous nitrogen (N2).
While the effects on the ocean overall were significant reductions in oxygen concentrations, in our home systems there is no oxygen limitation and insignificant amounts of denitrification in the water column. However, it highlights the need to have low oxygen environments, like those provided in sufficiently deep sandbeds and internal pore spaces of live rock to help us maintain low inorganic nitrogen levels in our tanks.
For more information, see the summary on ENN (http://www.enn.com/ecosystems/article/46053) or the publication. (http://www.nature.com/ngeo/journal/vaop/ncurrent/full/ngeo1832.html)