How do dead zones in the ocean affects ocean life?

1 Answer
Feb 2, 2016

Answer:

Dead zones are areas with very low oxygen concentration, which makes it very difficult for marine life to survive.

Explanation:

Also known as hypoxic zones, dead zones are areas with very low oxygen concentration, which makes it difficult for marine life to survive. Smaller reproductive organs have been observed in some species of fish inhabiting areas of low dissolved oxygen content.

Dead zones can occur naturally but many are due to human activities. An increase in nutrients in the ocean from fertilizers and sewage causes plants to grow more than they normally would. In turn, we see an increase in phytoplankton (algae blooms) which use up oxygen from the surrounding water. When the phytoplankton dies, it falls to the ocean floor and even more oxygen is used as it decomposes.

http://www.csmonitor.com/From-the-news-wires/2010/0628/Dead-zone-in-Gulf-of-Mexico-will-be-the-size-of-New-Jersey

Algae bloom so large it can be seen from space:
http://www.cbc.ca/news/technology/toxic-algae-blooms-what-you-should-know-about-the-mysterious-phenomena-1.3117687

Thus, dead zones are aptly named because the low oxygen concentration negatively effects many species and the area is usually devoid of life.