Researchers identified areas with low dissolved oxygen (DO) levels resulting in unhealthy benthic communities shown here in red, orange, and yellow.

A new report is available summarizing the findings of an NCCOS-funded survey of sediments and overlying waters of the northwest Gulf of Mexico continental shelf, conducted in August 2011. The study found no evidence of biological impacts linked to poor sediment quality. Low values of species richness and diversity of sediment-dwelling benthic organisms were associated with poor water quality, characterized by low dissolved oxygen, or 'hypoxia', and high nitrogen levels. These results suggest that sediments in the surveyed area of the northwest Gulf of Mexico seem to be in good condition with respect to contaminants and total organic carbon. Indications of stress in benthic communities appear to be related primarily to the well-documented hypoxic 'Dead Zone' on the inner Louisiana continental shelf.

For more information, contact Len.Balthis@noaa.gov