Search results
Results from the WOW.Com Content Network
Red circles show the location and size of many dead zones (in 2008). Black dots show dead zones of unknown size. The size and number of marine dead zones—areas where the deep water is so low in dissolved oxygen that sea creatures cannot survive (except for some specialized bacteria)—have grown in the past half-century.
This page was last edited on 26 February 2006, at 01:27 (UTC).; Text is available under the Creative Commons Attribution-ShareAlike 4.0 License; additional terms may apply.
Red circles show the location and size of many dead zones (in 2008). Black dots show dead zones of unknown size. The size and number of marine dead zones—areas where the deep water is so low in dissolved oxygen that sea creatures cannot survive (except for some specialized bacteria)—have grown in the past half-century. [19]
Dead zones are hypoxic, meaning the water has very low levels of dissolved oxygen. This kills off marine life or forces it to leave the area, removing life from the area and giving it the name dead zone. Hypoxic zones or dead zones can occur naturally, but nutrient pollution from human activity has turned this natural process into an ...
In 2018, scientists confirmed the Gulf of Oman contains one of the world's largest marine dead zones, where the ocean contains little or no oxygen and marine wildlife cannot exist. The dead zone encompasses nearly the entire 165,000-square-kilometre (63,700 sq mi) Gulf of Oman and equivalent to the size of Florida, United States of America.
A study collecting over 850 published experiments "reporting oxygen thresholds and/or lethal times for a total of 206 species spanning the full taxonomic range of benthic metazoans." [ 18 ] Individual species will have different adaptive responses to anoxic conditions based on their biological makeup and the condition of their habitat.
The dead zone at the outlet of the Mississippi River is a consequence of nitrates from fertilizer being carried off agricultural fields and funnelled down the river system to the Gulf of Mexico. Runoff also plays a part in the carbon cycle , again through the transport of eroded rock and soil.
The oxygen minimum zone (OMZ), sometimes referred to as the shadow zone, is the zone in which oxygen saturation in seawater in the ocean is at its lowest. This zone occurs at depths of about 200 to 1,500 m (700–4,900 ft), depending on local circumstances.