Pond Maintenance Principles

1. Pond Maintenance Principles • Aquatic Plants and Algae • Water Quality • Fisheries • Miscellaneous Problems • Structural Maintenance

2. Aquatic Plants and Algae

3. Aquatic Plant and Algae Control • Physical/Mechanical Control • Biological Control • Chemical Control

4. Physical/Mechanical Control • frequently overlooked! • cutting, raking, mowing, digging, pulling • most effective for small quantities near shore • usually need to repeat several times per year • need to harvest plants and algae if possible • mechanical harvesters for larger lakes ($$) • drawdown • best during freezing temperatures • aeration • most effective on algae

5. Draw Down

6. Aeration

7. Biological Control • triploid grass carp (white amur) • prefer submerged aquatic plants • pondweeds, naiads, elodea, coontail, muskgrass • little control of algae and other plants • thrive in warm water (68°F+) • can reach 25 pounds or more • may cause discoloration of water by waste • sterile fish must be stocked • permit required (1 to 15 per acre) • koi, carp not recommended

8. Grass Carp

9. Chemical Control • widely used (and abused!!) • must carefully calculate pond area or volume • identify target plant/algae • select appropriate herbicide • obtain state permit • read and follow label carefully! • treat < 50% of pond area or spot treat • start in shallowest part of pond • may cause fish kills in sensitive species

10. Chemical Control

11. For use in PA waters, a chemical must be: • EPA registered as a pesticide • PA Dept. Agriculture listed • Labeled for aquatic use

12. Permit to Apply a Herbicide • joint PAFBC and DEP permit • name and location of water body • use of water • species of fish present • total and treated area of water • average depth of water body • name of plant (or fish) to be controlled • commercial and manufacture’s name of chemical • dosage of chemical to be applied (label) • number of treatments to be made in year • output of water body • required for private or public waters • effective for current calendar year

13. Chemical Control – Identify Your Problem • Algae • Submerged Aquatic Plants • Emergent Plants • Floating Plants

14. Filamentous Algae

15. Chara

16. Algae Control • Copper Compounds • very effective at 0.25 to 0.5 ppm • disrupts cell membrane • more toxic in soft and acidic water • may kill sensitive fish (trout, catfish, carp) • Dyes • block sunlight (blue/yellow dyes) • preventative • safe for fish but “artificial” appearance

17. Floating-leaf Pondweed Curly-leaf Pondweed Large-leaf Pondweed Thin-leaf Pondweed

18. Coontail-top / watermilfoil - bottom

19. Elodea

20. Bladderwort

21. Submerged Plant Control • Hydrothol 191 (monopotassium endothall) • Aquathol-K (dipotassium endothall) • contact stops photosynthesis, can’t eat fish-3 days • Weedtrine-D (diquat dibromide) • Reward (diquat dibromide) • absorbed and stops photosynthesis, degrades fast • Sonar SRP (fluridone) • absorbed by leaves and roots, inhibits carotene • Komeen (elemental copper) • inhibits cell growth

22. Cattails

23. Phragmites

24. Purple Loosestrife

25. Emergent Plant Control • Rodeo (glyphosate) • moves through plant from contact to roots • eventually causes death of plant • Weedtrine (2,4-D) • plant cells divide rapidly exhausting food source • roots lose ability to take up nutrients • death from several disturbances of plant

26. Spatterdock

27. Water Lily

28. Watermeal Duckweed

29. Floating Plant Control • Rodeo (glyphosate) • moves through plant from contact to roots • eventually causes death of plant • AquaKleen/Aquacide/Navigate (2,4-D) • plant cells divide rapidly exhausting food source • roots lose ability to take up nutrients • death from several disturbances of plant • Sonar A.S. (fluridone) • absorbed by leaves and roots, inhibits carotene

30. Chemical Control - Summary • Algae • copper compounds or dyes • Submerged Aquatic Plants • endothall, diquat, fluridone, copper? • Emergent Plants • glyphosate, 2,4-D • Floating Plants • glyphosate, 2,4-D, fluridone

31. READ AND FOLLOW THE PRODUCT LABEL !!!!

32. Trade Name vs. Active Ingredient • 2,4-D • AquaKleen, Aquacide, Navigate, Weedtrine II • Glyphosate • Rodeo • Fluridone • Sonar, Sonar AS • Elemental Copper • Cutrine Plus, Earthtec, K-Tea, Lescocide-Plus • Diquat • Reward, Weedtrine

33. Pond Water Quality

34. Pond Water Quality • controlled by: • source of water (spring, stream, surface runoff) • geology, soils • land-use and other nearby activities ** • water quality requirements depend on pond use • human or animal drinking water • swimming • fishing • aesthetics

35. Ponds for Drinking Water • not a common source of drinking water in PA • all ponds will require treatment for drinking • coliform bacteria occur in all ponds • from soil, septic system, animal waste, wildlife • some bacteria may cause gastrointestinal illnesses • disinfection is necessary

36. Median Coliform Bacteria in Ponds (Hill et al. 1962)

37. How Common are the Problems? (Hill et al. 1962) unless treated with copper herbicides

38. Ponds for Drinking Water • protozoans • giardia, cryptosporidium • nitrate • from fertilizers, manure, septic systems • drinking water standard = 10 mg/L as NO3-N • pesticides • highest during or shortly after application due to drift or surface runoff • blue green algae • treat with algacide but follow label directions

39. Aesthetic Drinking Water Problems • odor and taste • usually due to decay of organic material • muddy water • find source, chemical additions, or filtration • metals (iron, manganese) • pH • recommend 6.5 to 8.5 (low more common than high) • low pH may cause corrosive water • hardness • calcium and magnesium (especially high pH ponds)

40. Ponds for Animal Watering • similar problems but less stringent standards • nitrate-N should be less than 100 mg/L • fecal coliform bacteria • <10 per 100 ml for adults, absent for calves • blue-green algae - toxins • pH should be 5.1 to 9.0 for dairy cows • watch use of aquatic herbicides (copper) • iron and manganese - taste problem • sulfate < 250 mg/L (mining)

41. Pond Water Quality for Fish • temperature • all fish have temperature preferences and lethal thresholds • Difficult to control - match fish to temperature regime • used to determine fish spawning times • dissolved oxygen • normal = 10-15 mg/L • warmwater fish like D.O. > 3 mg/L • coldwater fish like D.O. > 5 mg/L • depletion caused by decay of organic matter • most common cause of fish kills in ponds

42. Pond Water Quality for Fish • pH • can be treated with occasional chemical additions • warmwater fish (pH 6 to 9), coldwater (pH 5 to 9) • low pH may cause stunted growth of fish • aquatic herbicides • can be toxic to fish (especially young fish) • obtain a permit and read the label carefully • herbicide runoff • some very toxic to fish • especially high following first rain after application

43. Pond Water Quality for Swimming • coliform bacteria • 2000 total coliform bacteria per 100 ml of water • 200 fecal coliform bacteria per 100 ml • odor • turbidity • swimmers itch • free swimming parasite • controlled with copper sulfate

44. Water Quality for Aquatic Herbicides • hardness • affects dose of some chemicals • temperature • some labels recommend temperature • 60 to 75 F • can be used to predict fish spawning

45. Pond Water Quality for Aesthetics • odor • occurs in about 5% of ponds usually during summer • increases with depth water taken from • usually from anaerobic decay of plants, algae • muddy water • most common problem, especially in new ponds • other causes - muskrats, crayfish, fish, livestock, waterfowl, zooplankton and wind action • control - remove the source? • If control is not possible, chemicals may work (ground limestone, hydrated lime, gypsum, alum)

46. Water Testing Options • use DEP certified labs • drinking (human or animal) • coliform bacteria, pH, nitrate, hardness, pesticides? • swimming • fecal and total coliform bacteria • fishing • temperature, dissolved oxygen, pH, pesticides? • aquatic herbicides • hardness, temperature

47. What Can You Do? • strictly limit activities on pond watershed • maintain vegetated buffer strip around pond • limit fertilizer, manure and pesticide use near pond • properly site and maintain septic systems • use diversion ditches and land grading to divert contaminated surface water • use aquatic herbicides with care • aeration may be helpful in some cases • water treatment works in some cases • get water tested

48. Water Quality - Summary • Use of water critical! • Temperature • affects spawning and provides clue of when newly hatched fish are present • vital for trout • important for use of chemicals (60°F - 75°F) • Dissolved Oxygen • critical for fish survival • normal = 10-15 mg/L, fish require 3 to 5 mg/L • low DO - fish gulp at surface, snails/crayfish leave water

49. Water Quality - Summary • pH • less important than DO • optimum = 6.5 to 8.5, fish survive in 5 to 9 • low pH linked to stunted growth of fish • Nutrients • cause plant and algae growth • Hardness • influences effectiveness of herbicides • Agricultural Chemicals • drift or runoff of especially insecticides a problem • proper timing of spraying and buffer strips help

50. Nutrient Management • N and P cause increased plant and algae growth • Sources • runoff from barnyards, cropland, feedlots • sewage systems • managed turf (golf courses, developments) • Control (BMP’s) - impact will not be immediate! • redirect runoff • reduce fertilizer use • buffer strips (tall grass or forests) • maintain on-lot septic systems