PM09 Sediment Quality Assessment Cases
Exhibit Hall
8:00 AM - Monday
(PM134) Impact of Organism Size on the Synthetic-Based Drilling Fluid Sediment Toxicity Bioassay using Leptocheirus plumulosus.
Nguyen, K1, Candler, J1, Rabke, S1, 1 M-I SWACO, Houston, Texas, USA
ABSTRACT- Many factors have been determined to play crucial roles in the synthetic-based drilling fluid (SBF) sediment toxicity bioassays. These factors include the sediment composition used in the test, the reference drilling fluid batch and animal health and size. This study was designed to investigate how screen size retention of Leptocheirus plumulosus affects the variability of drilling fluid LC50 test results with the aim of developing parameters that increase the consistency of test results between laboratories. The key parameters studied include comparing animal size (840-micron versus 710-micron retaining screen size) and weight-to-length ratio of L. plumulosus. The study was designed to test these size-weight trends in a controlled fashion in order to reduce overall variability of the 4-day sediment toxicity test required for offshore drilling discharge compliance.
Key words: animal size, sediment, Leptocheirus plumulosus, benthic toxicity testing