MP13 Aquatic Ecotoxicology
Monday, 14 November 2005: 8:00 AM - 6:30 PM in Exhibit Hall

(ZIE-1117-827034) A simple and efficient water-renewal system for large volume sediment toxicity testing.

Ziegler, G¹, Fisher, D¹, ¹ University of Maryland Wye Research and Education Center, Queenstown, Maryland, USA

ABSTRACT- Sediment toxicity tests are a valuable screening tool for potentially toxic sediments and an important component of the sediment quality triad approach used to assess benthic habitats. When used as a screening tool sediment tests are often simultaneously conducted on a large number of sites at a specific time of the year. Guidelines for conducting whole-sediment toxicity tests require the exchange of overlying water in test vessels to maintain acceptable water quality. The siphoning and renewal of overlying water is a tedious task taking several minutes per beaker compounded by 5 replicate beakers per site. Previously described renewal systems were evaluated and considered too expensive and complicated or were unable to deliver the required volumes. Here we describe a water renewal system based on plexiglass modules that accurately deliver water (500 ml ± 5%) at a controlled flow rate (1.8 ml per second ± 10%). Each module contains 10 chambers, enough for 2 tests, with the option to add more modules for additional tests. Modules are simple and inexpensive (approx. $70.00 / module) while also being flexible with an adjustable flow rate delivered through vinyl tubing. These units have been used in 28-day chronic sediment tests with Leptocheirus plumulosus .

Key words: Sediment toxicity, Water renewal system