Brown trout realize it’s spawning time

As the unrelenting rains of late spring and summer have finally waned, many of rivers and streams in the region are finally dropping to more normal levels. We can only hope this situation continues and that it will allow us to enjoy at least a few weeks of fall fishing opportunities.

Another consideration is fall is spawning time for trout, and abnormally high water levels have the potential to adversely affect that important process. Hundreds of streams in Pennsylvania are stocked with trout to provide fishing opportunities for a few weeks each spring, but many streams throughout the state also produce sufficient natural reproduction of trout to support self-sustaining year-round fisheries. Waters capable of producing ample populations of wild trout are truly special and highly valuable resources.

Both brook and brown trout are fall spawners. Brook trout, of course, are the only species of trout native to Pennsylvania. Brown trout were imported from Europe, and rainbows were transplanted here from the Pacific coast of North America. In their native range, rainbows are spring spawners, and even though they have been stocked extensively throughout the eastern United States, rainbows successfully reproduce in very few streams. In our area, I have observed rainbows involved in spawning behavior during both spring and fall on Spring Creek in Centre County and Spruce Creek in Huntingdon County.

Wild brook trout in Pennsylvania now exist mainly in our smaller headwater streams, and these fish end to spawn in late September and early October. Brown trout typically spawn a little later, usually during late October and November. Brown trout are highly adaptable, so any unpolluted waterway that stays cold enough to support trout year-round will probably harbor some wild brown trout.

The female trout selects the actual spawning site, which must meet some specific requirements. Most spawning take place in relatively shallow water, typically a foot or less, with some amount of current flow. A bottom composition with plenty of smooth gravel in the right size is most important — pea-sized for smaller fish up to the size of a golf ball for bigger trout. After the female finds a suitable spawning site, it will begin to excavate a shallow nest known as a “redd.” To do this, the fish rolls on its side and quickly beats its tail up and down to dislodge the gravel and create a shallow depression in which to deposit its eggs. Between the time the female arrives at the spawning site and when she begins to excavate the redd, one or more males will show up to court her. In the case of multiple suitors, each will attempt to chase off the other until one of the males has asserted its dominance and claims its mate.

Once the redd is prepared, the female positions herself over the nest with the male close beside her. In synchronization, she releases eggs while the male sprays them with sperm, and the fertilized eggs settle into the depression. Any eggs that miss the mark will be swept away by the current and quickly eaten by trout or other fish. The number of eggs a female produces depends on the sized of the individual fish. Wild brook trout are likely to be somewhere between 6 to 14 inches and will produce 100 to more than 1,000 eggs. A small brown trout can produce about 600 eggs, while a larger fish could yield 3,000 or more eggs.

After depositing its eggs, the female again uses its tail to cover them with a thin layer of gravel for protection. That is the final bit of parental care either parent provides. The male departs soon after the spawning act and will mate with other receptive females if possible. The female will stay at the nest site for a day or so, mostly for rest and recovery from the stress of spawning, before returning to its home pool.

The incubation period for trout eggs is directly related to water temperature and therefore varies widely in the wild. At optimal temperatures of 50 degrees, trout eggs can hatch in as soon as three weeks; in the average temperatures found in our Pennsylvania streams during late fall and early winter, most trout typically hatch in January and February.

Despite the large numbers of eggs a single female trout might produce, only a small percentage of each new generation of trout will survive to become large enough to interest an angler. And fewer still will make it to trophy size. That’s why most dedicated trout fishermen practice catch and release when it comes to wild trout. They are truly special fish.

Get ready for Nov. 1

If you plan to be on the water this fall, remember that all boaters are required to wear a life jacket from Nov. 1 through April 30 while underway or at anchor on boats less than 16 feet in length or on any canoe or kayak.

The requirement applies to all Pennsylvania waters. Of course, wearing a life jacket while boating on any size craft during cold weather is a good idea that could easily save your life. Surviving the crippling shock of being plunged unexpectedly into frigid water increase dramatically for victims wearing a life jacket.

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