Lower water column

{
  "id": "MLC-T-ENV-016156",
  "term": "Lower water column",
  "field": "Environment",
  "term_source": "Lower Water Column",
  "definition": "The area below the pycnocline (or, if absent, below mid-depth in the water column), the lower portion of the water column is often dimly or negligibly illuminated (particularly in estuaries) and can be heterotrophic. These deeper waters have limited contact with the atmosphere, may be reduced in oxygen content, and can have a high degree of interaction with bottom sediments. This layer receives organic and mineral material from upper waters and is frequently the site of anoxia. In estuaries, the salt wedge and counter current flow occur in this layer.",
  "subject": "Natural environments",
  "references": [
    "Federal Geographic Data Committee Coastal and Marine Ecological Classification Standard, June 2012 FGDC-STD-018-2012"
  ],
  "url": "https://mlchart.com/terminology/environment/lower-water-column/"
}