Understanding the Spawn on the White River Tailwaters
As far as we know, trout are not native to the area we call the Ozarks, but they have been introduced to tailwaters and spring fed streams. They have become important to our fishery programs and angler enjoyment. Some of these trout reproduce, and, particularly with regards to brown trout, this wild trout reproduction has resulted in world record fish in Arkansas.
As my understanding of the nature and importance of the spawn to healthy fisheries has increased over the years, I've become even more convinced anglers should learn to leave spawning trout be and find other willing fish for their pursuit during the spawn. In this day, it is a matter of lack of understanding, I think mostly, that anglers continue to fish for spawning trout, especially on redds, although many anglers do it without compunction. In my experience, many, upon hearing convincing reasons, often come to agree that it is best to not fish the spawn. I hope this helps those who love trout and want to see more wild fish.
What is the spawn?
The spawn is when trout abandon their usual natural defenses and move into shallow water in order to reproduce. The process is simple. A male and female trout settle on a redd, then arch their bodies and deposit eggs and milt simultaneously. The female immediately covers the eggs with loose gravels. The process is repeated by digging new redds upstream from the first until the female is spent, which may take part of a day to a week. Redds may be identified by the lighter color of the gravels as they are cleaned of algae by this process. There may be one redd in an area or many.
Females move downstream soon after spawning. Considerable weight loss is encountered, from a third in females to up to a half in males. The amount of eggs a female can produce are roughly 1,000 eggs per pound of fish. A very small percentage of those eggs become fertile, hatch, and make it to the yearling stage. On brown trout in Arkansas tailwaters, it can be as low as a 0-3% success rate. In particularly good spawning years, the success rate may be significantly higher due to prime water conditions and water temperature.
When do different species spawn?
Browns and brooks in fall; cutthroats and rainbows in the spring.
Hatchery fish spawning times can be altered and usually are by water temperature. Once trout are reintroduced to the wild, spawning times often revert back to "normal" times with the change in water temperature. Wild spawning rainbows usually spawn early in the year in Arkansas tailwaters. However, I have witnessed rainbows actively spawning in the fall numerous times in the tailwaters. Rainbow trout spawning success seems to be best in low water years, and Arkansas Game and Fish Commission biologists have documented some rainbow trout reproduction in a few areas. Biologists say the average peak spawn for brown trout on Bull Shoals and Norfork tailwaters is October 31st. Brown trout reproduction is well documented in all of the tailwaters of the White, and it is these spawning trout that offer the best chance of success for a wild trout program in Arkansas. In 2012, Bonneville cutthroat were also introduced as eggs to the Norfork and White River tailwaters. The future of these trout in the Arkansas tailwater fishing program will depend on spawning success.
How can I tell if fish are spawning?
If the trout are in the shallows where concentrations of big fish would not normally be and it is during the usual spawning time, they are there to spawn. A display of spawning behavior mentioned above also indicates spawning fish. They may be actively spawning or resting, but they are there to reproduce.
How do people fish the spawn?
Keep in mind that trout lower their natural defenses during this time, so they are particularly vulnerable to methods which normally would not work. Some anglers spot light fish on the redds at night. Some fish over and over to big fish in the shallows during the day. The reality is that many of these fish are snagged and not caught by the fish eating the fly. An angler can get very adept, knowingly or unknowingly, at sinking the leader so the leader passes through the fish's mouth and draws the fly to snag the fish from outside of the far side of the jaw or the inside of the near side. This is also a stressful time for the fish with major weight loss and all the trout's energies being funneled into reproduction. Adding to that stress by catching it at this time can lead to an aborted spawn or even delayed mortality.
Should I fish the spawn?
You should let your conscience be your guide, but fishing the spawn is not sport fishing and has traditionally been shunned by sport anglers. Walton said it was against nature and cited Deuteronomy 22.6 as an argument.
Why should I as an angler care?
If you have an interest in seeing large, river bread trophy fish in the future, you should allow the trophy sized fish the opportunity to naturally reproduce. They have the best gene pool and conditioning around—not the hatchery fish.
Trout Spawning Facts:
- The word "redd" is Scottish for the nest made by a fish, especially of a salmon. There is a verb that refers to the act of clearing away, removing, setting in order which may explain the connection, but the precise origin of word is unknown.
- The majority of female brown trout are sexually mature by age three.
- Females "cut" a redd by turning sideways and flipping their tails to move out gravel from an area. Paired males and females release their "gametes" at the same time. The female covers over the redd by the same tail movement and both adults abandon the redd. Redds are larger and longer in faster water.
- Water temperature, flows, and dissolved oxygen content determine survivability and hatching of trout eggs. Higher temperatures result in earlier hatch times. For brown trout, little trout or "fry" may begin to emerge from the redds as early as the first of February.
- Angler wading over redds may negatively affect survival of trout eggs and sac fry. Fry are particularly susceptible to being destroyed by wading anglers as they near emergence and their sacs soften.
- Wild trout are difficult to rear in hatcheries, and record sized fish likely come from wild fish plantings that have subsequently naturally reproduced in the river. Successful reproduction is vital to maintaining wild trout populations and producing trophy fish.
- White River tailwater reproductive brown trout success rate may vary annually from 0-67 percent. [Source: "Factors Influencing Brown Trout Reproductive Success in Ozark Tailwater Rivers," by Danielle R. Pender, University of Arkansas Thesis, 1998.]
- Minimum flow will increase spawning habitat and survivability of trout eggs and fry.
Constructive comments welcome.