Daniel Burden
Value Added Agriculture Program Coordinator
Iowa State University Extension and Outreach
Ponds are incredibly special landscape features; homes to a myriad of water-loving creatures and a magnet for terrestrial wildlife. Additionally, ponds can be managed as agricultural water reservoirs or to treat run-off drainage, for rural agrotourism (“for-fee” fishing, rural-retreat, waterfowl hunting, retrieving-dog training), or simply as the jewel centerpiece of your rural acreage.
Acreage ponds are human-managed features. A “natural” environment, similar to a northern lake, where the fish, forage and water system is more or less “in balance,” as fisheries biologists would say, is difficult to establish in acreage ponds. More often than not, pond management is trying to hit an ever-moving target. That said, even natural lakes and ponds have most of the same issues as acreage ponds, and any water resource can ultimately be managed for its health and your enjoyment.
Fish populations continually change and never reach the state of equilibrium, or general stability, often referred to simply as “balance.” For fun fishing, most folks want a little more action in the system; so most biologists and pond owners strive for satisfactory relationships between the predator and prey populations and the overall health of the system. To do this, one manages the pond’s ability to support those relationships by managing the fish populations through selective harvest and possibly supplemental stocking (introduction or re-introduction), and controlling nutrient levels that can knock the entire system out of balance by severely changing water chemistry.
With a little patience, one can imagine what’s possible in a pond project; do a little research, get some advice, and then try a little experimentation. Owning a pond can be incredibly rewarding. The Iowa Department of Natural Resources notes that there are more than 110,000 privately owned ponds in Iowa.
This is a great project to bring in children and teens as helper “consultant/managers.” There are few “classrooms” that are as educational as aquatic systems. In your pond, there is a complex interplay between the sun, water, atmosphere, water chemistry, and a myriad of macro- and microscopic animal and plant life. Helping to guide a young person through all aspects of pond establishment and management instills deep and multi-faceted glimpses into the true complexity of our shared existence on Earth, and the rewarding challenges of environmental engineering.
When considering fish in a farm pond, there are a few important questions to consider:
According to Iowa DNR fisheries biologist, Darcy Cashatt, the most sustainable and maintenance-free species mix to introduce into a new pond (or manage in an existing pond) are largemouth bass and bluegill. Other species like channel catfish and hybrid sunfish can be nice additions, though will need to be restocked periodically to sustain their numbers. Crappie should only be stocked if the pond is clear and supports lots of largemouth bass. Talk to your local fisheries-extension biologist or stocking expert. Whichever you choose, based on the size, depth and natural food availability of your pond, this will give you an idea of the cost of stocking and reasonable removal rates for harvesting the fish. The size of the fish and stocking rates will be up to you; usually predatory fish are stocked with some consideration to size and age uniformity to eliminate within-species cannibalism.
What will be the forage base for fish? Cover and some natural forage base (fish, invertebrates, amphibians) go a long way to sustain and ensure the health of the system. For example, in the Midwest, most warm-water farm-pond multi-species recreational stockings are oriented toward large-mouth bass as the top predator; the fry of bluegills in the system become an important part of the forage base for the bass and large pan fish. Bluegills and black crappies, if too dense, will “stunt-off,” not grow to a decent size and choke the system with little fish. Usually this is remedied by supplemental stocking of some nice big and aggressive bass. Many pond owners manage the forage base by allowing fishing that encourages removal of bluegills and crappies, good for their population dynamics; but catch-and-release only for bass. This ensures a sustainable sport-fishing resource, allows some fish-for-food removal, and keeps big bass in the system for forage-species management.
What are the water-resource dynamics of your system? Do you need constant or summer aeration? What about controlling or channeling run-off and run-in water? Most constructed ponds have a dam and overflow system to hold water at a particular level, as well as facilitate draining the pond for improvement, maintenance or renovation. What about the run-in water? If it is laden with sediment and agricultural or other nutrients, you may want to consider one or more small “pre-filter” cattail ponds where the vegetation can help to filter the sediment and utilize the nutrient. If you have excessive nutrient levels, these can result in algae-choked water and blooms that reduce dissolved oxygen levels and create catastrophic fish kills. If you have a couple of small “filter” ponds, it is far easier to renovate these every five to ten years, than to drain and re-stock the main water body.
Adult largemouth bass are the most popular sport fish stocked in warm-water ponds. Voracious predators, they are stocked into ponds with a good forage base of fish and amphibians. Oftentimes, Bass are stocked in combination with lesser sport/forage species (bluegills, sunfish, or bluegill/sunfish hybrids).
The best example of a cold-water pond would be a cold artesian spring-fed trout pond with a constant level, stable banks and substantial flow-through recharge of the water. Cold–water ponds are most-suited to small-mouth bass and trout. Trout usually are not stocked with other fish, especially competing predators, other than perhaps minnows. Minnows can augment the aquatic-insect forage base and additionally boost growth rates. Trout in pond systems usually feed upon aquatic insects and other invertebrates, as well as supplemental fish feed. The stocked cohort usually does not have high survival into the third post-stocking year, so it is acceptable to immediately initiate some fish harvest with a plan to re-stock at four-year or so intervals. Longer-term survival is possible, for example, in a deep clear-water quarry site with natural spring-water percolation, great water chemistry with high dissolved oxygen content, and a good natural forage base; but outside the northern states, these systems tend to be rare.
People with ponds often have concerns about algae or aquatic plants choking out the pond. Usually they are not the actual problem, but a symptom of it. The problem is abundance of available nutrients from run-off lawn or farm-field fertilizer, grass clippings, leaves, pastured-animal waste, dead organic matter from dead aquatic plants. These most common sources of nutrients problems supply enormous amounts of dissolved nitrogen and phosphorous which, in turn, promote excessive algae and aquatic vascular plant growth, which, as they seasonally die and decay, create a vicious excess-nutrient cycle.
There are solutions that range from physical filter/sediment ponds to chemical treatments to the mechanical removal of weed beds. Aeration is expensive, but is worthwhile to prevent winter- and summer-fish-kill situations. The added oxygen helps with natural degradation of plant material in a way that helps to minimize excess carbon dioxide, phosphorous and nitrogen; making less of these compounds available for plant growth and keeping the water cleaner and the fish happier.
What is the best way to manage your pond? Spend time there with a fishing pole or ice-fishing rig. Use it to bring together family and friends, and above all, introduce children to the outdoors, outdoor ethics and ecology. The status of the pond’s fishery, determined by fishing success, is a great barometer for how well you have designed and implemented your management plan. With proper management, a correctly stocked pond generally results in a balanced fish population that provides good fishing for years to come. Just think of the memories that can be created for generations to come!
Resources
Recently a webinar series is presented by the north Central Region Aquaculture Center (NCRAC) funded by USDA/NIFA in partnership with the National Aquaculture Association includes many useful resources including a downloadable PDF of the presentation Recreational Fish Pond Management by University of Georgia Fisheries and Aquaculture Outreach Specialist, Dr. James “Jay” Shelton.
Intro Guide to Pond Management, Iowa State University Extension and Outreach
Aquatic Plant Management, Iowa State University Extension and Outreach
Fish Stocking Guide for Iowa Ponds, Iowa State University Extension and Outreach
Pond Stocking and Management, Iowa Department of Natural Resources
Pond Management Resources Penn State University Extension
Managing Ponds and Lakes for Aquaculture and Fisheries in Missouri: Pond Construction and Management Considerations. University of Missouri Extension; G9474.
Pond Management Handbook: A Guide to Managing Ponds and Attracting Wildlife Ohio Department of Natural Resources, Division of Wildlife.
Pond Fish Management Cornell University