1. If fish are to be stocked, Ohio ponds should be at least feet deep.
A. 6
B. 8
C. 10
D. 12
2. To discourage growth of aquatic vegetation:
A. Use gravel or sand on pond banks
B. Maintain large areas of pond water less than 3 feet depth
C. Build pond banks with a 3:1 slope
D. All of the above
3. Snow on the ice covering a pond may cause a fish kill because the living pond weeds use up all the oxygen.
A. True
B. False
4. Run-off is a major contributor to a pond's nutrient enrichment and aquatic weed growth. Sources of run-off may include:
A. Fertilized fields or lawns
B. Septic fields or storm sewers
C. Feedlots or pastures
D. All of the above
5. Phosphorus is the most important nutrient affecting the growth of phytoplankton, filamentous algae and free floating flowering plants.
A. True
B. False
1. Correct Answer: B, OPM
Explanation: Ohio ponds should be at least 8 feet deep if fish are to be stocked, and banks should be built with 3:1 slopes. A properly built pond, when full, will have a minimum of water less than 3 feet deep to discourage growth of aquatic vegetation.
2. Correct Answer: C, OPM
Explanation: See answer for question 1.
3. Correct Answer: B, OPM
Explanation: Snow blanketing the ice prevents light penetration, and plants can no longer produce oxygen. When this situation exists and the decomposition of dead vegetation uses some of the available dissolved oxygen, there may be insufficient oxygen for fish and they may suffocate. Removal of snow from at least one-tenth of the pond surface will greatly reduce the likelihood of this happening.
4. Correct Answer: D, ILL
Explanation: Runoff is a major contributor to nutrient enrichment, so it is not unusual to see the most prolific weed growths occurring in shallow shoreline areas where the runoff is first received. Specific nutrient contributors from urban watersheds include sewage effluent, storm sewer drainage, and septic field seepage. A major agricultural source is runoff from fertilized fields, feedlots, and nearby pastures.
5. Correct Answer: A
Explanation: The nutrients that most often regulate aquatic plant growth are carbon, nitrogen, and phosphorus. Of the three, phosphorus is generally agreed to be the most important. Because the nitrogen and carbon content of most natural fresh waters exceeds that of phosphorus ten times or more, phosphorus is most likely to be the first nutrient to limit plant growth. Therefore, the addition of small amounts of phosphorus to phosphorusdepleted waters produces extremely large increases in the volume of living plant material (biomass).