Fisheries, Wildlife, and Ecology

Aquatic invasive species can spread quickly and harm your pond ecosystem. In this section, find educational resources on pond management and invasive water species, including European water chestnut, algae blooms, and Eurasian watermilfoil. Gain access to Penn State Extension’s field guide to common aquatic plants of Pennsylvania.

Invasive Species in Your Pond

Aquatic invasive species are non-native plants, animals, and pathogens often brought to water bodies such as ponds and water gardens by artificial means. Their aggressive nature can have a profound effect on pond ecosystems and cause various economic, environmental, and health issues.

Invasive species thrive in a wide range of conditions and typically compete with native species for food, space, and water. What’s more, they reproduce and become established quickly and can lead to a tremendous biodiversity loss.

Common invasive water species in Pennsylvania include hydrilla, goldfish, and Eurasian watermilfoil. Discover more about aquatic species with Penn State Extension’s free Preventing the Spread of Aquatic Invaders webinar.

Fish and Wildlife Management

Animals can be moved via bait or pets, as well as by attaching to debris such as mud and vegetation. Preventing the introduction and establishment of non-native aquatic animals and nuisance wildlife is crucial for long-term pond and fishery sustainability. In addition, fisheries should carefully check water parameters such as temperature and dissolved oxygen before deciding which fish species to stock in the pond.

Occasionally, fish kills from excessive water temperature or lack of dissolved oxygen occur. Find more information on this and other causes of fish kills in ponds with Penn State Extension. Additionally, explore wildlife control resources on topics such as snapping turtles and their role in the pond health, as well as protecting dragonflies and damselflies. Tips on determining the proportional stock density using the Fish Population Exercise is available, as well.

Invasive Aquatic Plants

Invasive plants are often introduced to new bodies of water via boat engines, trailers, and other improperly cleaned equipment.

When choosing pond plants, consider using species native to the region. If using exotic species, sound aquatic plant management, and disposal practices are essential. Note: avoid using invasive plants unless they are well outside their hardiness zone.

If excessive plant and algae growth are present, consider physical and biological control methods first. Effective physical control strategies to consider are physical plant harvesting, mechanized harvesting, and aeration. Biological methods include non-native plant-eating fish such as grass carp, various pond additives, and barley straw for algae control.

Chemical control, such as applying pesticides and herbicides, should be investigated after careful consideration of applicable physical and biological strategies.

Pond Pesticide Application

When using chemical control methods, or herbicides, to remove nuisance aquatic plants, several steps must be followed to ensure a safe and effective application. These steps include identifying the problematic plant, selecting a herbicide, and following the label instructions.

It is important to know that a permit is required for any aquatic herbicide application in Pennsylvania. The permits are reviewed and issued by the PA Department of Environmental Protection. The permit application requires information such as pond uses, types of fish present, total water body area, and name of the chemical to be applied. Additional pond maintenance permits may be required from other government agencies, as well.

In this section, you will find information on aquatic invasive species in ponds and strategies used to control them. Practical advice can be obtained through the Aquatic Pesticide Management online course, as well as the Professional Pest Managers workshop.