When the weather turns really hot for an extended period, or cold enough so the average water temps drop below 40 degrees, we start to hear this question a lot, especially from folks who stocked their pond during the preceding spring.
Rest assured, just because you can't see your fish doesn't mean they are dead. But don't take my word for it; let me explain why you aren't seeing them.
Fish are cold-blooded, which means their environment regulates their body temperature. When the water temperature in your pond decreases, so does the fish's body temperature.
Additionally, water temperature is positively correlated to the fish's metabolism; when water temperatures decrease, so does their metabolism. They become less active, requiring far less caloric intake to survive throughout the winter. So, they just aren't moving around much.
Not only are the fish sluggish, but they are also hanging out where it's warmest.
If your pond is ten or more feet deep, that probably means they are at the deepest point, taking advantage of geothermal heat. If it warms up a bit, and there's a place where the sun can heat the water a couple of degrees, you may see some activity there.
Mostly, the fish will suspend or hold tight to cover that can radiate heat, such as any habitat that extends above the surface, dock floats, rock banks, standing timber/stumps, or laydowns. They will also seek areas close to a well or spring that expels warmer water.
If you hope to see your fish during the winter months, these are the best places to look.
Since fish are cold-blooded, they seek comfortable environments.
In the summertime, and especially in Texas, when it gets hot, the fish, again, go deep.
The fish do that because the deeper water is cooler and can support a higher oxygen concentration (mg/L), creating a less stressful environment for them.
It is also known to support a greater zooplankton density during the day, which is a primary food source for many prey species.
You can learn more about the seasonal migration of fish through the water column in "Pond King’s Fish Habitat Basics."
Dedicated pond and lake owners know it takes more than having water with fish in it to have a thriving aquatic ecosystem. A key aspect of pond management is assessing your fish population.
Fish assessments are highly recommended to get an idea how your fishery is doing. Good pond management requires making good decisions at the right times to yield successful results.
To make informed decisions about what your fishery needs, at the very least, you need to know:
While visual observation is the easiest method for evaluating the fish population in your pond or lake, it is also the least reliable for several reasons.
There are several other methods of observation that we featured in "Monitor the Forage Population in Your Fishery."
While that post focuses on forage fish, you can use the same techniques to assess all fish species in your lake.
Of all the different methods, the most accurate is an electrofishing survey.
During an electrofishing survey, the fish are stunned using low electrical current levels.
Then, Pond King biologists work quickly to measure and count the fish, taking small samples from all across your pond or lake. The biologists record and then analyze the data to prepare comprehensive, custom reports to evaluate the health of the lake, and help you reach your fishery goals.
Fish are most active in shallow water during the spring months when the water temperature is around 60 degrees. The fish will be visible as they are getting ready to spawn and are in the shallows for an extended period.
Beware: even though you can visually observe the fish at this time, it is not a reliable way to assess the population.
The next time you are down at the pond, and you don't see any activity in the water, don't worry! Unless you see carcasses along your shoreline; your fish are there.
They're probably just too deep for you to see them.
If you have any questions or want to learn more about electrofishing surveys, call or contact our fisheries biologists We'll be glad to help you out!
See y'all down at the pond!