Science Assessment Artifact 3

Florida State College at Jacksonville

BSC1005: Life in its Biological Environment

Science Assessment – Artifact 3: Amphipod Reburrowing Time in Response to Sediment Pollution

Introduction

Water bodies all over the world are suffering from poor water quality. Estuaries, areas where river and ocean water mix, can be contaminated by run-off of pollutants from both urban and agricultural areas. Benthic organisms live on, in or near the bottom of a body of water. Clams, oysters and crabs are familiar examples of benthic organisms. . Benthic communities are vital to the ecosystem at large. They supply food and habitat to primary and secondary producers, and are veritable restaurants for pelagic fish. Their resident filter feeders such as oysters, tubeworms and sponges help improve water quality. But benthic communities are also one of the aquatic areas most vulnerable to human-induced problems, especially eutrophication and contamination.

Because most benthic organisms can move only limited distances if at all, they cannot escape as industrial contaminants accumulate in the sediment, or when eutrophication causes their habitat to become anoxic (devoid of oxygen). Instead, many organisms die or suffer impaired growth, reproduction or foraging and escape abilities. As a result of their sensitivity, benthic organisms often make good biological indicators of poor environmental conditions. Scientists can assess the quality of an aquatic habitat by monitoring the abundance of an indicator species. Amphipods are one organism that is used to study environmental conditions. An amphipod is a small crustacean found in all types of aquatic environments and even on land.

The Chesapeake Bay is the nation's largest estuary. One indicator species being used to study the environmental condition of the Chesapeake Bay is the amphipod Leptocheirus plumulosus. L. plumulosus burrows in the sediment to avoid predation. It is highly sensitive to various pollutants, yet is easy to grow in the lab making it a good species for pollution experiments. This activity focuses on an experiment examining the burrowing response of L. plumulosus to polluted sediments.

Data

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.

Questions

1. What is the problem or question to be solved?

2. What is the hypothesis that was tested?

3. What are the variables that were used?

4. Based on your answer to the previous questions, how was the hypothesis tested?

5. Which set of amphipods had the fastest average reburrowing time? Which had the slowest? Explain.

6. Did the type of sediment the amphipod originated from have an effect on reburrowing times (e.g., compare times for "clean to clean" and "clean to Baltimore")? Why do you think that is?

7. Based on the experimental result, what biases or error sources exist in the process?

Adapted from: Amphipods: More than Mud. Written by: Lisa Ayers Lawrence, Virginia Sea Grant, Virginia Institute of Marine Science Credits: Chesapeake Ecotox Research Program, Linda Schaffner, Bruce Vogt. Retrieved 10/11/14 from http://www2.vims.edu/bridge/DATA.cfm?Bridge_Location=archive0202.html

_1353569437.xls

Chart1

Clean to Clean

Clean to Baltimore

Baltimore to Clean

Baltimore to Baltimore

Sediment Type

Average Reburrowing Time (sec)

3.3

68.1

24

109.6

Sheet1

	Reburrowing Time (sec)
	Clean to Clean	Clean to Baltimore	Baltimore to Clean	Baltimore to Baltimore			Clean to Clean	Clean to Baltimore	Baltimore to Clean	Baltimore to Baltimore
	7	53	10	66			3.3	68.1	24	109.6
	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
	3.3	68.1	24	109.6

Sheet1

Sediment Type

Average Reburrowing Time (sec)

Sheet2

Sheet3