Ponds

Pond Pest Management

Prior to digging or re-digging a pond, landowners need to contact their Soil Conservation District or Natural Resources Conservation Service Office to obtain the appropriate permits. In most counties, these offices can offer assistance in pond sitting and design.

Aquatic herbicides enable man­agers to quickly control problem weeds in commercial fish ponds. However, herbicides should be viewed as only one method that can be used for aquatic weed management. Other methods of aquatic weed control include (a) preventive methods such as proper pond site selection and construction, fertilization and draw-downs, (b) biological meth­ods such as the grass carp (Ctenopharyngodon idella), and (c) mechanical methods such as seining and raking. A combination of these methods into a compre­hensive plan will provide the most cost effective, environment­ally safe means of aquatic weed management. 

Many different aquatic plants can be found in, on and around fish culture ponds. These plants range from microscopic organisms known as plankton algae which drift suspended in the water, to larger plants rooted in the pond bottom. Certain types of aquatic plants are essential for fish production. However, aquatic plants that interfere with commercial fish production are considered to be weeds.

Cattail is probably the best known perennial aquatic plant in the world. There are four different 1 species of cattail in the North America, and all are commonly found in wet or hydric soils. Throughout the United States, they are commonly found in marshes, swamps and shallow waters. The plant can also be found in brackish water in coastal areas and can form dense colonies that can grow 10 to 12 feet.

Common reed is a tall, perennial grass which may grow as tall as 13 feet, and is sometimes equated to or confused with giant reed, Arundo donax, which has a larger lighter or tawny colored inflorescence (clustered flowers) than common reed. Both plants are found in swamps, marshes, and along the shorelines of ditches and canals in fresh or brackish waters. Common reed can establish itself in water several feet deep or on high ground where soil with the rhizomes (horizontal underground stems) were moved with fill.

Among the world's smallest flowering plants, duckweed is one of the more commonly seen free floaters. Three common genera of duckweed are found in Maryland waters: common or little duckweed (Lemna species), giant or greater duckweed (Spirodella species) and watermeal (Wolffia species).

America and is often confused with Brazilian elodea (Egeria densa), which was introduced from South 1 America. Both are found in similar habitats, and both were spread throughout their range by way of the aquarium trade. Elodea is a perennial and prefers quiet, still and fresh to slightly brackish waters. It is a prolific producer of oxygen and can grow into some of the thickest mats of aquatic vegetation in North America.

America, is a favorite of the aquarium industry, which may be how it extended its natural range. 1 The plant belongs to the waterlily family, although it is classified as a submersed and not floating plant.

The potamogetons are probably the most common and diverse group of aquatic vegetation found in Maryland. They are perennials and found in all types of freshwater of the Chesapeake Bay. Curlyleaf pondweed is actually an exotic plant believed to have been introduced from Europe in the 1800s, and gets its name from the obvious curls in the leaves. The plant generally prefers moderately moving fertile waters, and silty-day bottoms. It can be an indicator of pollution. In the winter, the plant turns bluegreen in color and the leaves become more flattened.