m Zon es: ot Al l Bad

Oxygen is an essential component for most life not only on land but in the ocean as well.Oxygen is not spread evenly throughout the ocean as some may assume.There are factors that can affect oxygen in bodies of water such as too much organic material which causes oxygen depletion.Areas in the ocean with low amounts of oxygen are called Oxygen Minimum Zones.Areas without oxygen are called Oxygen Depleted Zones.

Oxygen Minimum Zones (OMZ) are not inherently bad. They are an essential component of the nitrogen and carbon cycle in the ocean.

OMZs experience a rain of organic material (algae, animal remains,nutrients, runoff material,etc.).Bacteria and archaea use oxygen to consume the organic matter. Deep sea oxygen levels are dependent on the oxygen acquired at the surface and the oxygen used by archaea.

A scenario that is being studied is how climate change might affect Oxygen Minimum Zones.Modeling has not been clear on this until recently.A team from Princeton led by Laure Resplandy,a biogeochemical oceanographer and an assistant professor of geosciences at the High Meadows Environmental Institute at Princeton,thinks that they can predict the OMZ expansion in the East Pacific Ocean.They stated,?this is significant for two reasons:for one,as oxygen levels go down, vital economic species like tuna and crabs won? t be able to feed,swim or reproduce unless they relocate to ocean regions with more oxygen.This has major implications for ecosystems near the ocean?s coasts and the industries that depend on them,from fishing to tourism.Second,OMZs are a significant source of nitrous oxide,a major greenhouse gas.?

Earlier climate models displayed inconsistent trends, both positive and negative, with Resplandy noting,?for 15 years,we?ve been circling around the same conundrum: with global warming,the ocean is losing oxygen,so we expect oxygen minimum zones to expand,but our climate models showed inconsistent trends.?Resplandy thinks that the current climate models displaying and predicting the size of OMZs are much more accurate.Changing to more layered thought processes regarding OMZs is what Resplandy believes helped, coupled with new modeling systems.

The current prediction is that OMZs will grow.By 2050 they could be as much as .6%of the world's ocean volume.The OMZs growth would affect commercial species like tuna.

OMZs have a core where the oxygen is at its lowest.The surrounding layer around the core is predicted to expand, with the core contracting.

OMZs create nitrous oxide so the contraction of the OMZ does mean less nitrous oxide will be released into the atmosphere.According to paleo-oceanographers,possible events similar to this phenomenon occurred during warm periods 15-50 million years ago.As of right now,the data show that the OMZ cores are shrinking despite global warming.