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Pond Maintenance Principles Aquatic Plants and Algae Water Quality Fisheries Miscellaneous Problems Structural Maintenance Aquatic Plants and Algae Aquatic Plant and Algae Control Physical/Mechanical Control Biological Control Chemical Control Physical/Mechanical Control
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Pond Maintenance Principles • Aquatic Plants and Algae • Water Quality • Fisheries • Miscellaneous Problems • Structural Maintenance
Aquatic Plant and Algae Control • Physical/Mechanical Control • Biological Control • Chemical Control
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
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
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
For use in PA waters, a chemical must be: • EPA registered as a pesticide • PA Dept. Agriculture listed • Labeled for aquatic use
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
Chemical Control – Identify Your Problem • Algae • Submerged Aquatic Plants • Emergent Plants • Floating Plants
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
Floating-leaf Pondweed Curly-leaf Pondweed Large-leaf Pondweed Thin-leaf Pondweed
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
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
Watermeal Duckweed
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
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
READ AND FOLLOW THE PRODUCT LABEL !!!!
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
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
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
Median Coliform Bacteria in Ponds (Hill et al. 1962)
How Common are the Problems? (Hill et al. 1962) unless treated with copper herbicides
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
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)
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)
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
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
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
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
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)
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
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
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
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
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