Effects of Bottom Water Hypoxia on the Benthic Communities of the SoutheasternLouisiana Continental Shelf. University Research Initiative

摘要

The overall objective of the study was to determine the effects of hypoxic bottomwater on the benthic community structure of two distinct areas on the southeastern Louisiana continental shelf. The South Timbalier block area in 20 m water depth is affected by severe oxygen deficiency for extended periods during mid-summer. The West Delta block area, in 20 m water depth but 74 km closer to the Mississippi River delta, is intermittently subjected to reduced dissolved oxygen levels, but not as severe as the South Timbalier area nor for prolonged periods. The hypoxia-affected fauna was dominated primarily by polychaetes of smaller individuals, with overall less biomass, especially during the peak of severe hypoxia. Longer-lived, larger, higher biomass organisms were virtually absent from the hypoxia-affected study sites.