The following data are a subset from an experiment by Dr. Linda Schaffner and Bruce Vogt at the Virginia Institute of Marine Science. All amphipods were collected from Queen's Creek, a tributary of the Chesapeake Bay in Virginia. The goal of the experiment was to determine whether or not sediment contamination has an effect on the reburrowing time of amphipods.

Four groups of 10 amphipods were placed in different sediment types and their reburrowing times were measured in seconds. The experimental procedure was as follows.

• All 40 amphipods were cultured in contaminant-free Queens Creek sediment.
• 20 of the amphipods were transferred to another tank of clean sediment. The other 20 amphipods were transferred to contaminated Baltimore sediment. All amphipods were cultured in these sediments for 18 days.
• TREATMENT: Groups of 10 amphipods were placed in different sediment types and their reburrowing times were measured in seconds.
  • From the 20 amphipods that were cultured in clean sediment, 10 were placed in clean sediment, the other 10 were placed in contaminated Baltimore sediment.
  • From the 20 amphipods that were cultured in contaminated Baltimore sediment, 10 were placed in clean sediment and the other 10 were placed in contaminated sediment.
• Reburrowing time in seconds was measured for each amphipod.

For example, the first amphipod in the first column was transferred from clean sediment to another container of clean sediment, and took 7 seconds to reburrow. (Click here for a more detailed explanation of the experimental method.)

Reburrowing Time (sec)
Clean to Clean	Clean to Baltimore	Baltimore to Clean	Baltimore to Baltimore
7	53	10	66
2	25	7	7
4	80	28	29
4	22	2	180
5	15	79	300
2	107	4	83
3	10	3	43
2	150	3	46
1	210	4	90
3	9	100	252

Data from Schaffner and Vogt's Chesapeake Ecotox Research Project (CERP): Quantifying Ecological Risks of Contaminated Sediments on Living Resources in Supporting Decisions on Habitat Restoration Strategies in the Chesapeake Bay, in prep. Please do not cite. Funded by National Oceanographic and Atmospheric Administration.