Ohio Pond Management Assessing Fish Populations An owner of a new or renovated pond can generally follow the steps in a management plan right from the start if the pond has been properly stocked. However, in established ponds, assessment of the fish population may be necessary. A pond’s fish population can be assessed with a combination of shoreline seining & by keeping angler diary records. These methods provide an idea of the kinds and sizes of fishes present in the pond. Seining. Determining the status of a pond’s fish population is easy with a seine. Seining is used to determine the spawning success of largemouth bass and bluegills, so capturing large fish with the seine is not important. The seine should be as least 12 feet long with 1/4-inch mesh. During late June or July, pull the seine along the shoreline in at least three different areas of the pond to capture small fish hatched earlier in the year. The presence or absence, and abundance of fish collected with the seine tell a lot about the status of the pond’s fish population. Ideally, a seine sample should contain many small bluegills that range from one half to two inches long and fewer numbers of young largemouth bass. This would indicate the presence of both species, and that both are successfully spawning. The absence or very low numbers of either young largemouth bass or small bluegills in the seine usually indicates that the pond’s fish population needs help. The kinds, sizes, and numbers of fishes caught by anglers will usually tell Net & Seine Supplies: Nichols Net and Twine Co., Rt 3, Bend Road, East St. Louis, IL 62201 (telephone: 618-876-7700) Nylon Net Co., Box 592, Memphis, TN 38101 (telephone: 201-783-9800) Sterling Net & Twine Company, 18 Label St., Montclair, NJ 07042 (telephone: 201-783-9800) the rest of the story. Angler Diaries. Angler diaries are another source of information that can be used to assess the quality of pond fishing and the status of the fish population. It can be very important to take a few moments to write down the kind, number, and approximate lengths of fishes caught, and indicate whether they were released or harvested. These notes are the best way to document the quality of the fishing and the numbers of fish harvested from the pond. Anglers can help a great deal by recording this information periodically, or even for each trip, on index cards or in a notebook. Other notes that may be of interest include date, hours fished, or weather conditions. Download a sample angler diary (PDF). Diaries not only provide a written historical record of the pond’s fishery, but can be entertaining and informative to read as the years go by. The information contained in the angler diary can be used to help develop a management plan to achieve the quality of fishing that the owner desires. See table demonstrating how to use angler diary information to develop the desired type of fishing based upon the five primary management options.