This is a GREAT time of the year to stock your lake, pond or stormwater device (BMP) with fish. The days are getting shorter and the nights are getting cooler. The water temperature is slowly dropping. That creates a little known biological phenomenon that makes this a great time to purchase, handle, transport and release your fish to be stocked. If you are stocking a new pond, you have a low cost option not available any other time of the year. If you are adding supplemental fish to an existing population, you should know about how many of which kind of fish you need. (See information on our web site if you have questions.)
Few people are aware of the significance of a biological principle affecting why fall is a good time to stock fish. Fish are “cold blooded” animals, meaning their body temperature is the same as the water in which they live. Therefore, the metabolism of a fish is directly related to the water temperature. Lots of people know that. But, most people do not know that for every 10 degree Centigrade (roughly 15 degrees Faranheit) drop in water temperature, a fish’s metabolism is reduced by one half. Most of the ponds we work on have already dropped 15 degrees F. in the past 3 month. That means the fish need half as much dissolved oxygen, half as much food and move half as fast in general. The same thing happens in reverse when the water is warming.
The practical application of that concept is that the fish are less stressed and easier to handle and transport when the water is cool. They aren’t as excitable either. Furthermore, cool water can hold more dissolved oxygen than warm water. More oxygen in the water and less demand for the oxygen by the cool fish reduces their stress.
If you are stocking a new pond, you may want to stock just your small inexpensive bream (bluegill, shellcracker, etc.) in the fall to grow over the winter and be spawning before predator fish such as bass are stocked in the spring. We can stock all of the species at one time since we have various sizes of each of the species. But, the smaller fish are less expensive and small forage fish stocked in the fall and small predator fish stocked in the spring is our least expensive option.
Fish need less food and move more slowly as the water cools. Therefore, there is likely somewhat less predation when the water is cooling. More of the fish you stock may survive without being eaten. We particularly like to stock sterile grass carp during late fall if there are many large bass in the lake. There is no reason to feed the expensive sterile carp that came all the way from Arkansas to the bass if we can help it.
We keep the water chilled in our fish holding system using a filtered and recirculated water supply. During cool weather less time is required to temper or acclimate the fish. It is important to adjust the water temperature by adding water from the pond before we release the fish from our transport tanks or you release the fish from the plastic bags inflated with oxygen. You can save time, have happier and more healthy fish and may be able to save money.
Go ahead and stock your fish this fall. Your fish will thank you!
Foster Lake & Pond Management provides the full range of lake, pond and stormwater BMP services and products. These include: construction, repairs, maintenance, certified inspections, fish stocking, fisheries management, lake mapping, vegetation management, docks, fountains and aeration.
We have provided aquatic and stormwater solutions to our North Carolina customers for 30 years.